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3532 lines
92 KiB
3532 lines
92 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* This file is part of UBIFS. |
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* |
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* Copyright (C) 2006-2008 Nokia Corporation. |
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* |
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* Authors: Adrian Hunter |
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* Artem Bityutskiy (Битюцкий Артём) |
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*/ |
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|
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/* |
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* This file implements TNC (Tree Node Cache) which caches indexing nodes of |
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* the UBIFS B-tree. |
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* |
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* At the moment the locking rules of the TNC tree are quite simple and |
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* straightforward. We just have a mutex and lock it when we traverse the |
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* tree. If a znode is not in memory, we read it from flash while still having |
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* the mutex locked. |
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*/ |
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|
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#include <linux/crc32.h> |
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#include <linux/slab.h> |
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#include "ubifs.h" |
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|
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static int try_read_node(const struct ubifs_info *c, void *buf, int type, |
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struct ubifs_zbranch *zbr); |
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static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, |
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struct ubifs_zbranch *zbr, void *node); |
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|
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/* |
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* Returned codes of 'matches_name()' and 'fallible_matches_name()' functions. |
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* @NAME_LESS: name corresponding to the first argument is less than second |
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* @NAME_MATCHES: names match |
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* @NAME_GREATER: name corresponding to the second argument is greater than |
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* first |
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* @NOT_ON_MEDIA: node referred by zbranch does not exist on the media |
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* |
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* These constants were introduce to improve readability. |
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*/ |
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enum { |
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NAME_LESS = 0, |
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NAME_MATCHES = 1, |
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NAME_GREATER = 2, |
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NOT_ON_MEDIA = 3, |
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}; |
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|
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/** |
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* insert_old_idx - record an index node obsoleted since the last commit start. |
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* @c: UBIFS file-system description object |
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* @lnum: LEB number of obsoleted index node |
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* @offs: offset of obsoleted index node |
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* |
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* Returns %0 on success, and a negative error code on failure. |
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* |
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* For recovery, there must always be a complete intact version of the index on |
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* flash at all times. That is called the "old index". It is the index as at the |
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* time of the last successful commit. Many of the index nodes in the old index |
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* may be dirty, but they must not be erased until the next successful commit |
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* (at which point that index becomes the old index). |
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* |
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* That means that the garbage collection and the in-the-gaps method of |
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* committing must be able to determine if an index node is in the old index. |
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* Most of the old index nodes can be found by looking up the TNC using the |
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* 'lookup_znode()' function. However, some of the old index nodes may have |
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* been deleted from the current index or may have been changed so much that |
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* they cannot be easily found. In those cases, an entry is added to an RB-tree. |
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* That is what this function does. The RB-tree is ordered by LEB number and |
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* offset because they uniquely identify the old index node. |
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*/ |
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static int insert_old_idx(struct ubifs_info *c, int lnum, int offs) |
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{ |
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struct ubifs_old_idx *old_idx, *o; |
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struct rb_node **p, *parent = NULL; |
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|
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old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS); |
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if (unlikely(!old_idx)) |
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return -ENOMEM; |
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old_idx->lnum = lnum; |
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old_idx->offs = offs; |
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|
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p = &c->old_idx.rb_node; |
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while (*p) { |
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parent = *p; |
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o = rb_entry(parent, struct ubifs_old_idx, rb); |
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if (lnum < o->lnum) |
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p = &(*p)->rb_left; |
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else if (lnum > o->lnum) |
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p = &(*p)->rb_right; |
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else if (offs < o->offs) |
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p = &(*p)->rb_left; |
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else if (offs > o->offs) |
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p = &(*p)->rb_right; |
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else { |
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ubifs_err(c, "old idx added twice!"); |
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kfree(old_idx); |
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return 0; |
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} |
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} |
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rb_link_node(&old_idx->rb, parent, p); |
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rb_insert_color(&old_idx->rb, &c->old_idx); |
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return 0; |
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} |
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|
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/** |
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* insert_old_idx_znode - record a znode obsoleted since last commit start. |
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* @c: UBIFS file-system description object |
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* @znode: znode of obsoleted index node |
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* |
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* Returns %0 on success, and a negative error code on failure. |
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*/ |
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int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode) |
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{ |
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if (znode->parent) { |
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struct ubifs_zbranch *zbr; |
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|
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zbr = &znode->parent->zbranch[znode->iip]; |
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if (zbr->len) |
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return insert_old_idx(c, zbr->lnum, zbr->offs); |
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} else |
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if (c->zroot.len) |
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return insert_old_idx(c, c->zroot.lnum, |
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c->zroot.offs); |
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return 0; |
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} |
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|
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/** |
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* ins_clr_old_idx_znode - record a znode obsoleted since last commit start. |
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* @c: UBIFS file-system description object |
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* @znode: znode of obsoleted index node |
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* |
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* Returns %0 on success, and a negative error code on failure. |
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*/ |
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static int ins_clr_old_idx_znode(struct ubifs_info *c, |
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struct ubifs_znode *znode) |
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{ |
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int err; |
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|
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if (znode->parent) { |
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struct ubifs_zbranch *zbr; |
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|
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zbr = &znode->parent->zbranch[znode->iip]; |
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if (zbr->len) { |
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err = insert_old_idx(c, zbr->lnum, zbr->offs); |
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if (err) |
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return err; |
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zbr->lnum = 0; |
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zbr->offs = 0; |
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zbr->len = 0; |
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} |
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} else |
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if (c->zroot.len) { |
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err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs); |
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if (err) |
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return err; |
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c->zroot.lnum = 0; |
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c->zroot.offs = 0; |
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c->zroot.len = 0; |
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} |
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return 0; |
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} |
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|
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/** |
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* destroy_old_idx - destroy the old_idx RB-tree. |
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* @c: UBIFS file-system description object |
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* |
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* During start commit, the old_idx RB-tree is used to avoid overwriting index |
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* nodes that were in the index last commit but have since been deleted. This |
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* is necessary for recovery i.e. the old index must be kept intact until the |
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* new index is successfully written. The old-idx RB-tree is used for the |
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* in-the-gaps method of writing index nodes and is destroyed every commit. |
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*/ |
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void destroy_old_idx(struct ubifs_info *c) |
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{ |
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struct ubifs_old_idx *old_idx, *n; |
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|
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rbtree_postorder_for_each_entry_safe(old_idx, n, &c->old_idx, rb) |
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kfree(old_idx); |
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|
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c->old_idx = RB_ROOT; |
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} |
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|
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/** |
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* copy_znode - copy a dirty znode. |
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* @c: UBIFS file-system description object |
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* @znode: znode to copy |
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* |
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* A dirty znode being committed may not be changed, so it is copied. |
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*/ |
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static struct ubifs_znode *copy_znode(struct ubifs_info *c, |
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struct ubifs_znode *znode) |
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{ |
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struct ubifs_znode *zn; |
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|
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zn = kmemdup(znode, c->max_znode_sz, GFP_NOFS); |
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if (unlikely(!zn)) |
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return ERR_PTR(-ENOMEM); |
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|
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zn->cnext = NULL; |
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__set_bit(DIRTY_ZNODE, &zn->flags); |
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__clear_bit(COW_ZNODE, &zn->flags); |
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|
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ubifs_assert(c, !ubifs_zn_obsolete(znode)); |
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__set_bit(OBSOLETE_ZNODE, &znode->flags); |
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|
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if (znode->level != 0) { |
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int i; |
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const int n = zn->child_cnt; |
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|
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/* The children now have new parent */ |
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for (i = 0; i < n; i++) { |
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struct ubifs_zbranch *zbr = &zn->zbranch[i]; |
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|
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if (zbr->znode) |
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zbr->znode->parent = zn; |
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} |
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} |
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|
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atomic_long_inc(&c->dirty_zn_cnt); |
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return zn; |
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} |
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|
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/** |
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* add_idx_dirt - add dirt due to a dirty znode. |
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* @c: UBIFS file-system description object |
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* @lnum: LEB number of index node |
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* @dirt: size of index node |
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* |
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* This function updates lprops dirty space and the new size of the index. |
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*/ |
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static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt) |
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{ |
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c->calc_idx_sz -= ALIGN(dirt, 8); |
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return ubifs_add_dirt(c, lnum, dirt); |
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} |
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|
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/** |
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* dirty_cow_znode - ensure a znode is not being committed. |
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* @c: UBIFS file-system description object |
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* @zbr: branch of znode to check |
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* |
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* Returns dirtied znode on success or negative error code on failure. |
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*/ |
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static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c, |
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struct ubifs_zbranch *zbr) |
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{ |
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struct ubifs_znode *znode = zbr->znode; |
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struct ubifs_znode *zn; |
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int err; |
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|
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if (!ubifs_zn_cow(znode)) { |
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/* znode is not being committed */ |
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if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) { |
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atomic_long_inc(&c->dirty_zn_cnt); |
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atomic_long_dec(&c->clean_zn_cnt); |
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atomic_long_dec(&ubifs_clean_zn_cnt); |
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err = add_idx_dirt(c, zbr->lnum, zbr->len); |
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if (unlikely(err)) |
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return ERR_PTR(err); |
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} |
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return znode; |
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} |
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zn = copy_znode(c, znode); |
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if (IS_ERR(zn)) |
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return zn; |
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if (zbr->len) { |
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err = insert_old_idx(c, zbr->lnum, zbr->offs); |
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if (unlikely(err)) |
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return ERR_PTR(err); |
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err = add_idx_dirt(c, zbr->lnum, zbr->len); |
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} else |
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err = 0; |
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zbr->znode = zn; |
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zbr->lnum = 0; |
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zbr->offs = 0; |
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zbr->len = 0; |
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if (unlikely(err)) |
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return ERR_PTR(err); |
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return zn; |
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} |
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|
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/** |
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* lnc_add - add a leaf node to the leaf node cache. |
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* @c: UBIFS file-system description object |
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* @zbr: zbranch of leaf node |
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* @node: leaf node |
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* |
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* Leaf nodes are non-index nodes directory entry nodes or data nodes. The |
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* purpose of the leaf node cache is to save re-reading the same leaf node over |
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* and over again. Most things are cached by VFS, however the file system must |
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* cache directory entries for readdir and for resolving hash collisions. The |
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* present implementation of the leaf node cache is extremely simple, and |
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* allows for error returns that are not used but that may be needed if a more |
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* complex implementation is created. |
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* |
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* Note, this function does not add the @node object to LNC directly, but |
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* allocates a copy of the object and adds the copy to LNC. The reason for this |
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* is that @node has been allocated outside of the TNC subsystem and will be |
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* used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC |
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* may be changed at any time, e.g. freed by the shrinker. |
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*/ |
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static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
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const void *node) |
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{ |
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int err; |
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void *lnc_node; |
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const struct ubifs_dent_node *dent = node; |
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|
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ubifs_assert(c, !zbr->leaf); |
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ubifs_assert(c, zbr->len != 0); |
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ubifs_assert(c, is_hash_key(c, &zbr->key)); |
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err = ubifs_validate_entry(c, dent); |
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if (err) { |
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dump_stack(); |
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ubifs_dump_node(c, dent, zbr->len); |
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return err; |
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} |
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lnc_node = kmemdup(node, zbr->len, GFP_NOFS); |
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if (!lnc_node) |
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/* We don't have to have the cache, so no error */ |
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return 0; |
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|
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zbr->leaf = lnc_node; |
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return 0; |
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} |
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|
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/** |
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* lnc_add_directly - add a leaf node to the leaf-node-cache. |
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* @c: UBIFS file-system description object |
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* @zbr: zbranch of leaf node |
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* @node: leaf node |
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* |
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* This function is similar to 'lnc_add()', but it does not create a copy of |
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* @node but inserts @node to TNC directly. |
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*/ |
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static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
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void *node) |
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{ |
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int err; |
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|
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ubifs_assert(c, !zbr->leaf); |
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ubifs_assert(c, zbr->len != 0); |
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|
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err = ubifs_validate_entry(c, node); |
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if (err) { |
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dump_stack(); |
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ubifs_dump_node(c, node, zbr->len); |
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return err; |
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} |
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zbr->leaf = node; |
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return 0; |
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} |
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|
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/** |
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* lnc_free - remove a leaf node from the leaf node cache. |
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* @zbr: zbranch of leaf node |
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*/ |
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static void lnc_free(struct ubifs_zbranch *zbr) |
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{ |
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if (!zbr->leaf) |
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return; |
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kfree(zbr->leaf); |
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zbr->leaf = NULL; |
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} |
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|
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/** |
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* tnc_read_hashed_node - read a "hashed" leaf node. |
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* @c: UBIFS file-system description object |
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* @zbr: key and position of the node |
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* @node: node is returned here |
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* |
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* This function reads a "hashed" node defined by @zbr from the leaf node cache |
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* (in it is there) or from the hash media, in which case the node is also |
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* added to LNC. Returns zero in case of success or a negative error |
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* code in case of failure. |
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*/ |
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static int tnc_read_hashed_node(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
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void *node) |
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{ |
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int err; |
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|
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ubifs_assert(c, is_hash_key(c, &zbr->key)); |
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|
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if (zbr->leaf) { |
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/* Read from the leaf node cache */ |
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ubifs_assert(c, zbr->len != 0); |
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memcpy(node, zbr->leaf, zbr->len); |
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return 0; |
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} |
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|
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if (c->replaying) { |
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err = fallible_read_node(c, &zbr->key, zbr, node); |
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/* |
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* When the node was not found, return -ENOENT, 0 otherwise. |
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* Negative return codes stay as-is. |
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*/ |
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if (err == 0) |
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err = -ENOENT; |
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else if (err == 1) |
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err = 0; |
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} else { |
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err = ubifs_tnc_read_node(c, zbr, node); |
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} |
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if (err) |
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return err; |
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|
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/* Add the node to the leaf node cache */ |
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err = lnc_add(c, zbr, node); |
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return err; |
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} |
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|
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/** |
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* try_read_node - read a node if it is a node. |
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* @c: UBIFS file-system description object |
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* @buf: buffer to read to |
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* @type: node type |
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* @zbr: the zbranch describing the node to read |
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* |
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* This function tries to read a node of known type and length, checks it and |
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* stores it in @buf. This function returns %1 if a node is present and %0 if |
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* a node is not present. A negative error code is returned for I/O errors. |
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* This function performs that same function as ubifs_read_node except that |
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* it does not require that there is actually a node present and instead |
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* the return code indicates if a node was read. |
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* |
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* Note, this function does not check CRC of data nodes if @c->no_chk_data_crc |
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* is true (it is controlled by corresponding mount option). However, if |
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* @c->mounting or @c->remounting_rw is true (we are mounting or re-mounting to |
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* R/W mode), @c->no_chk_data_crc is ignored and CRC is checked. This is |
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* because during mounting or re-mounting from R/O mode to R/W mode we may read |
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* journal nodes (when replying the journal or doing the recovery) and the |
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* journal nodes may potentially be corrupted, so checking is required. |
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*/ |
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static int try_read_node(const struct ubifs_info *c, void *buf, int type, |
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struct ubifs_zbranch *zbr) |
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{ |
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int len = zbr->len; |
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int lnum = zbr->lnum; |
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int offs = zbr->offs; |
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int err, node_len; |
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struct ubifs_ch *ch = buf; |
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uint32_t crc, node_crc; |
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|
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dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); |
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|
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err = ubifs_leb_read(c, lnum, buf, offs, len, 1); |
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if (err) { |
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ubifs_err(c, "cannot read node type %d from LEB %d:%d, error %d", |
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type, lnum, offs, err); |
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return err; |
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} |
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|
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if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) |
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return 0; |
|
|
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if (ch->node_type != type) |
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return 0; |
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|
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node_len = le32_to_cpu(ch->len); |
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if (node_len != len) |
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return 0; |
|
|
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if (type != UBIFS_DATA_NODE || !c->no_chk_data_crc || c->mounting || |
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c->remounting_rw) { |
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crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); |
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node_crc = le32_to_cpu(ch->crc); |
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if (crc != node_crc) |
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return 0; |
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} |
|
|
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err = ubifs_node_check_hash(c, buf, zbr->hash); |
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if (err) { |
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ubifs_bad_hash(c, buf, zbr->hash, lnum, offs); |
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return 0; |
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} |
|
|
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return 1; |
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} |
|
|
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/** |
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* fallible_read_node - try to read a leaf node. |
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* @c: UBIFS file-system description object |
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* @key: key of node to read |
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* @zbr: position of node |
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* @node: node returned |
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* |
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* This function tries to read a node and returns %1 if the node is read, %0 |
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* if the node is not present, and a negative error code in the case of error. |
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*/ |
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static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key, |
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struct ubifs_zbranch *zbr, void *node) |
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{ |
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int ret; |
|
|
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dbg_tnck(key, "LEB %d:%d, key ", zbr->lnum, zbr->offs); |
|
|
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ret = try_read_node(c, node, key_type(c, key), zbr); |
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if (ret == 1) { |
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union ubifs_key node_key; |
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struct ubifs_dent_node *dent = node; |
|
|
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/* All nodes have key in the same place */ |
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key_read(c, &dent->key, &node_key); |
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if (keys_cmp(c, key, &node_key) != 0) |
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ret = 0; |
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} |
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if (ret == 0 && c->replaying) |
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dbg_mntk(key, "dangling branch LEB %d:%d len %d, key ", |
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zbr->lnum, zbr->offs, zbr->len); |
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return ret; |
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} |
|
|
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/** |
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* matches_name - determine if a direntry or xattr entry matches a given name. |
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* @c: UBIFS file-system description object |
|
* @zbr: zbranch of dent |
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* @nm: name to match |
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* |
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* This function checks if xentry/direntry referred by zbranch @zbr matches name |
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* @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by |
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* @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case |
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* of failure, a negative error code is returned. |
|
*/ |
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static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr, |
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const struct fscrypt_name *nm) |
|
{ |
|
struct ubifs_dent_node *dent; |
|
int nlen, err; |
|
|
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/* If possible, match against the dent in the leaf node cache */ |
|
if (!zbr->leaf) { |
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dent = kmalloc(zbr->len, GFP_NOFS); |
|
if (!dent) |
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return -ENOMEM; |
|
|
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err = ubifs_tnc_read_node(c, zbr, dent); |
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if (err) |
|
goto out_free; |
|
|
|
/* Add the node to the leaf node cache */ |
|
err = lnc_add_directly(c, zbr, dent); |
|
if (err) |
|
goto out_free; |
|
} else |
|
dent = zbr->leaf; |
|
|
|
nlen = le16_to_cpu(dent->nlen); |
|
err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); |
|
if (err == 0) { |
|
if (nlen == fname_len(nm)) |
|
return NAME_MATCHES; |
|
else if (nlen < fname_len(nm)) |
|
return NAME_LESS; |
|
else |
|
return NAME_GREATER; |
|
} else if (err < 0) |
|
return NAME_LESS; |
|
else |
|
return NAME_GREATER; |
|
|
|
out_free: |
|
kfree(dent); |
|
return err; |
|
} |
|
|
|
/** |
|
* get_znode - get a TNC znode that may not be loaded yet. |
|
* @c: UBIFS file-system description object |
|
* @znode: parent znode |
|
* @n: znode branch slot number |
|
* |
|
* This function returns the znode or a negative error code. |
|
*/ |
|
static struct ubifs_znode *get_znode(struct ubifs_info *c, |
|
struct ubifs_znode *znode, int n) |
|
{ |
|
struct ubifs_zbranch *zbr; |
|
|
|
zbr = &znode->zbranch[n]; |
|
if (zbr->znode) |
|
znode = zbr->znode; |
|
else |
|
znode = ubifs_load_znode(c, zbr, znode, n); |
|
return znode; |
|
} |
|
|
|
/** |
|
* tnc_next - find next TNC entry. |
|
* @c: UBIFS file-system description object |
|
* @zn: znode is passed and returned here |
|
* @n: znode branch slot number is passed and returned here |
|
* |
|
* This function returns %0 if the next TNC entry is found, %-ENOENT if there is |
|
* no next entry, or a negative error code otherwise. |
|
*/ |
|
static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n) |
|
{ |
|
struct ubifs_znode *znode = *zn; |
|
int nn = *n; |
|
|
|
nn += 1; |
|
if (nn < znode->child_cnt) { |
|
*n = nn; |
|
return 0; |
|
} |
|
while (1) { |
|
struct ubifs_znode *zp; |
|
|
|
zp = znode->parent; |
|
if (!zp) |
|
return -ENOENT; |
|
nn = znode->iip + 1; |
|
znode = zp; |
|
if (nn < znode->child_cnt) { |
|
znode = get_znode(c, znode, nn); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
while (znode->level != 0) { |
|
znode = get_znode(c, znode, 0); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
nn = 0; |
|
break; |
|
} |
|
} |
|
*zn = znode; |
|
*n = nn; |
|
return 0; |
|
} |
|
|
|
/** |
|
* tnc_prev - find previous TNC entry. |
|
* @c: UBIFS file-system description object |
|
* @zn: znode is returned here |
|
* @n: znode branch slot number is passed and returned here |
|
* |
|
* This function returns %0 if the previous TNC entry is found, %-ENOENT if |
|
* there is no next entry, or a negative error code otherwise. |
|
*/ |
|
static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n) |
|
{ |
|
struct ubifs_znode *znode = *zn; |
|
int nn = *n; |
|
|
|
if (nn > 0) { |
|
*n = nn - 1; |
|
return 0; |
|
} |
|
while (1) { |
|
struct ubifs_znode *zp; |
|
|
|
zp = znode->parent; |
|
if (!zp) |
|
return -ENOENT; |
|
nn = znode->iip - 1; |
|
znode = zp; |
|
if (nn >= 0) { |
|
znode = get_znode(c, znode, nn); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
while (znode->level != 0) { |
|
nn = znode->child_cnt - 1; |
|
znode = get_znode(c, znode, nn); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
nn = znode->child_cnt - 1; |
|
break; |
|
} |
|
} |
|
*zn = znode; |
|
*n = nn; |
|
return 0; |
|
} |
|
|
|
/** |
|
* resolve_collision - resolve a collision. |
|
* @c: UBIFS file-system description object |
|
* @key: key of a directory or extended attribute entry |
|
* @zn: znode is returned here |
|
* @n: zbranch number is passed and returned here |
|
* @nm: name of the entry |
|
* |
|
* This function is called for "hashed" keys to make sure that the found key |
|
* really corresponds to the looked up node (directory or extended attribute |
|
* entry). It returns %1 and sets @zn and @n if the collision is resolved. |
|
* %0 is returned if @nm is not found and @zn and @n are set to the previous |
|
* entry, i.e. to the entry after which @nm could follow if it were in TNC. |
|
* This means that @n may be set to %-1 if the leftmost key in @zn is the |
|
* previous one. A negative error code is returned on failures. |
|
*/ |
|
static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key, |
|
struct ubifs_znode **zn, int *n, |
|
const struct fscrypt_name *nm) |
|
{ |
|
int err; |
|
|
|
err = matches_name(c, &(*zn)->zbranch[*n], nm); |
|
if (unlikely(err < 0)) |
|
return err; |
|
if (err == NAME_MATCHES) |
|
return 1; |
|
|
|
if (err == NAME_GREATER) { |
|
/* Look left */ |
|
while (1) { |
|
err = tnc_prev(c, zn, n); |
|
if (err == -ENOENT) { |
|
ubifs_assert(c, *n == 0); |
|
*n = -1; |
|
return 0; |
|
} |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { |
|
/* |
|
* We have found the branch after which we would |
|
* like to insert, but inserting in this znode |
|
* may still be wrong. Consider the following 3 |
|
* znodes, in the case where we are resolving a |
|
* collision with Key2. |
|
* |
|
* znode zp |
|
* ---------------------- |
|
* level 1 | Key0 | Key1 | |
|
* ----------------------- |
|
* | | |
|
* znode za | | znode zb |
|
* ------------ ------------ |
|
* level 0 | Key0 | | Key2 | |
|
* ------------ ------------ |
|
* |
|
* The lookup finds Key2 in znode zb. Lets say |
|
* there is no match and the name is greater so |
|
* we look left. When we find Key0, we end up |
|
* here. If we return now, we will insert into |
|
* znode za at slot n = 1. But that is invalid |
|
* according to the parent's keys. Key2 must |
|
* be inserted into znode zb. |
|
* |
|
* Note, this problem is not relevant for the |
|
* case when we go right, because |
|
* 'tnc_insert()' would correct the parent key. |
|
*/ |
|
if (*n == (*zn)->child_cnt - 1) { |
|
err = tnc_next(c, zn, n); |
|
if (err) { |
|
/* Should be impossible */ |
|
ubifs_assert(c, 0); |
|
if (err == -ENOENT) |
|
err = -EINVAL; |
|
return err; |
|
} |
|
ubifs_assert(c, *n == 0); |
|
*n = -1; |
|
} |
|
return 0; |
|
} |
|
err = matches_name(c, &(*zn)->zbranch[*n], nm); |
|
if (err < 0) |
|
return err; |
|
if (err == NAME_LESS) |
|
return 0; |
|
if (err == NAME_MATCHES) |
|
return 1; |
|
ubifs_assert(c, err == NAME_GREATER); |
|
} |
|
} else { |
|
int nn = *n; |
|
struct ubifs_znode *znode = *zn; |
|
|
|
/* Look right */ |
|
while (1) { |
|
err = tnc_next(c, &znode, &nn); |
|
if (err == -ENOENT) |
|
return 0; |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &znode->zbranch[nn].key, key)) |
|
return 0; |
|
err = matches_name(c, &znode->zbranch[nn], nm); |
|
if (err < 0) |
|
return err; |
|
if (err == NAME_GREATER) |
|
return 0; |
|
*zn = znode; |
|
*n = nn; |
|
if (err == NAME_MATCHES) |
|
return 1; |
|
ubifs_assert(c, err == NAME_LESS); |
|
} |
|
} |
|
} |
|
|
|
/** |
|
* fallible_matches_name - determine if a dent matches a given name. |
|
* @c: UBIFS file-system description object |
|
* @zbr: zbranch of dent |
|
* @nm: name to match |
|
* |
|
* This is a "fallible" version of 'matches_name()' function which does not |
|
* panic if the direntry/xentry referred by @zbr does not exist on the media. |
|
* |
|
* This function checks if xentry/direntry referred by zbranch @zbr matches name |
|
* @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr |
|
* is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA |
|
* if xentry/direntry referred by @zbr does not exist on the media. A negative |
|
* error code is returned in case of failure. |
|
*/ |
|
static int fallible_matches_name(struct ubifs_info *c, |
|
struct ubifs_zbranch *zbr, |
|
const struct fscrypt_name *nm) |
|
{ |
|
struct ubifs_dent_node *dent; |
|
int nlen, err; |
|
|
|
/* If possible, match against the dent in the leaf node cache */ |
|
if (!zbr->leaf) { |
|
dent = kmalloc(zbr->len, GFP_NOFS); |
|
if (!dent) |
|
return -ENOMEM; |
|
|
|
err = fallible_read_node(c, &zbr->key, zbr, dent); |
|
if (err < 0) |
|
goto out_free; |
|
if (err == 0) { |
|
/* The node was not present */ |
|
err = NOT_ON_MEDIA; |
|
goto out_free; |
|
} |
|
ubifs_assert(c, err == 1); |
|
|
|
err = lnc_add_directly(c, zbr, dent); |
|
if (err) |
|
goto out_free; |
|
} else |
|
dent = zbr->leaf; |
|
|
|
nlen = le16_to_cpu(dent->nlen); |
|
err = memcmp(dent->name, fname_name(nm), min_t(int, nlen, fname_len(nm))); |
|
if (err == 0) { |
|
if (nlen == fname_len(nm)) |
|
return NAME_MATCHES; |
|
else if (nlen < fname_len(nm)) |
|
return NAME_LESS; |
|
else |
|
return NAME_GREATER; |
|
} else if (err < 0) |
|
return NAME_LESS; |
|
else |
|
return NAME_GREATER; |
|
|
|
out_free: |
|
kfree(dent); |
|
return err; |
|
} |
|
|
|
/** |
|
* fallible_resolve_collision - resolve a collision even if nodes are missing. |
|
* @c: UBIFS file-system description object |
|
* @key: key |
|
* @zn: znode is returned here |
|
* @n: branch number is passed and returned here |
|
* @nm: name of directory entry |
|
* @adding: indicates caller is adding a key to the TNC |
|
* |
|
* This is a "fallible" version of the 'resolve_collision()' function which |
|
* does not panic if one of the nodes referred to by TNC does not exist on the |
|
* media. This may happen when replaying the journal if a deleted node was |
|
* Garbage-collected and the commit was not done. A branch that refers to a node |
|
* that is not present is called a dangling branch. The following are the return |
|
* codes for this function: |
|
* o if @nm was found, %1 is returned and @zn and @n are set to the found |
|
* branch; |
|
* o if we are @adding and @nm was not found, %0 is returned; |
|
* o if we are not @adding and @nm was not found, but a dangling branch was |
|
* found, then %1 is returned and @zn and @n are set to the dangling branch; |
|
* o a negative error code is returned in case of failure. |
|
*/ |
|
static int fallible_resolve_collision(struct ubifs_info *c, |
|
const union ubifs_key *key, |
|
struct ubifs_znode **zn, int *n, |
|
const struct fscrypt_name *nm, |
|
int adding) |
|
{ |
|
struct ubifs_znode *o_znode = NULL, *znode = *zn; |
|
int o_n, err, cmp, unsure = 0, nn = *n; |
|
|
|
cmp = fallible_matches_name(c, &znode->zbranch[nn], nm); |
|
if (unlikely(cmp < 0)) |
|
return cmp; |
|
if (cmp == NAME_MATCHES) |
|
return 1; |
|
if (cmp == NOT_ON_MEDIA) { |
|
o_znode = znode; |
|
o_n = nn; |
|
/* |
|
* We are unlucky and hit a dangling branch straight away. |
|
* Now we do not really know where to go to find the needed |
|
* branch - to the left or to the right. Well, let's try left. |
|
*/ |
|
unsure = 1; |
|
} else if (!adding) |
|
unsure = 1; /* Remove a dangling branch wherever it is */ |
|
|
|
if (cmp == NAME_GREATER || unsure) { |
|
/* Look left */ |
|
while (1) { |
|
err = tnc_prev(c, zn, n); |
|
if (err == -ENOENT) { |
|
ubifs_assert(c, *n == 0); |
|
*n = -1; |
|
break; |
|
} |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) { |
|
/* See comments in 'resolve_collision()' */ |
|
if (*n == (*zn)->child_cnt - 1) { |
|
err = tnc_next(c, zn, n); |
|
if (err) { |
|
/* Should be impossible */ |
|
ubifs_assert(c, 0); |
|
if (err == -ENOENT) |
|
err = -EINVAL; |
|
return err; |
|
} |
|
ubifs_assert(c, *n == 0); |
|
*n = -1; |
|
} |
|
break; |
|
} |
|
err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm); |
|
if (err < 0) |
|
return err; |
|
if (err == NAME_MATCHES) |
|
return 1; |
|
if (err == NOT_ON_MEDIA) { |
|
o_znode = *zn; |
|
o_n = *n; |
|
continue; |
|
} |
|
if (!adding) |
|
continue; |
|
if (err == NAME_LESS) |
|
break; |
|
else |
|
unsure = 0; |
|
} |
|
} |
|
|
|
if (cmp == NAME_LESS || unsure) { |
|
/* Look right */ |
|
*zn = znode; |
|
*n = nn; |
|
while (1) { |
|
err = tnc_next(c, &znode, &nn); |
|
if (err == -ENOENT) |
|
break; |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &znode->zbranch[nn].key, key)) |
|
break; |
|
err = fallible_matches_name(c, &znode->zbranch[nn], nm); |
|
if (err < 0) |
|
return err; |
|
if (err == NAME_GREATER) |
|
break; |
|
*zn = znode; |
|
*n = nn; |
|
if (err == NAME_MATCHES) |
|
return 1; |
|
if (err == NOT_ON_MEDIA) { |
|
o_znode = znode; |
|
o_n = nn; |
|
} |
|
} |
|
} |
|
|
|
/* Never match a dangling branch when adding */ |
|
if (adding || !o_znode) |
|
return 0; |
|
|
|
dbg_mntk(key, "dangling match LEB %d:%d len %d key ", |
|
o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs, |
|
o_znode->zbranch[o_n].len); |
|
*zn = o_znode; |
|
*n = o_n; |
|
return 1; |
|
} |
|
|
|
/** |
|
* matches_position - determine if a zbranch matches a given position. |
|
* @zbr: zbranch of dent |
|
* @lnum: LEB number of dent to match |
|
* @offs: offset of dent to match |
|
* |
|
* This function returns %1 if @lnum:@offs matches, and %0 otherwise. |
|
*/ |
|
static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs) |
|
{ |
|
if (zbr->lnum == lnum && zbr->offs == offs) |
|
return 1; |
|
else |
|
return 0; |
|
} |
|
|
|
/** |
|
* resolve_collision_directly - resolve a collision directly. |
|
* @c: UBIFS file-system description object |
|
* @key: key of directory entry |
|
* @zn: znode is passed and returned here |
|
* @n: zbranch number is passed and returned here |
|
* @lnum: LEB number of dent node to match |
|
* @offs: offset of dent node to match |
|
* |
|
* This function is used for "hashed" keys to make sure the found directory or |
|
* extended attribute entry node is what was looked for. It is used when the |
|
* flash address of the right node is known (@lnum:@offs) which makes it much |
|
* easier to resolve collisions (no need to read entries and match full |
|
* names). This function returns %1 and sets @zn and @n if the collision is |
|
* resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the |
|
* previous directory entry. Otherwise a negative error code is returned. |
|
*/ |
|
static int resolve_collision_directly(struct ubifs_info *c, |
|
const union ubifs_key *key, |
|
struct ubifs_znode **zn, int *n, |
|
int lnum, int offs) |
|
{ |
|
struct ubifs_znode *znode; |
|
int nn, err; |
|
|
|
znode = *zn; |
|
nn = *n; |
|
if (matches_position(&znode->zbranch[nn], lnum, offs)) |
|
return 1; |
|
|
|
/* Look left */ |
|
while (1) { |
|
err = tnc_prev(c, &znode, &nn); |
|
if (err == -ENOENT) |
|
break; |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &znode->zbranch[nn].key, key)) |
|
break; |
|
if (matches_position(&znode->zbranch[nn], lnum, offs)) { |
|
*zn = znode; |
|
*n = nn; |
|
return 1; |
|
} |
|
} |
|
|
|
/* Look right */ |
|
znode = *zn; |
|
nn = *n; |
|
while (1) { |
|
err = tnc_next(c, &znode, &nn); |
|
if (err == -ENOENT) |
|
return 0; |
|
if (err < 0) |
|
return err; |
|
if (keys_cmp(c, &znode->zbranch[nn].key, key)) |
|
return 0; |
|
*zn = znode; |
|
*n = nn; |
|
if (matches_position(&znode->zbranch[nn], lnum, offs)) |
|
return 1; |
|
} |
|
} |
|
|
|
/** |
|
* dirty_cow_bottom_up - dirty a znode and its ancestors. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode to dirty |
|
* |
|
* If we do not have a unique key that resides in a znode, then we cannot |
|
* dirty that znode from the top down (i.e. by using lookup_level0_dirty) |
|
* This function records the path back to the last dirty ancestor, and then |
|
* dirties the znodes on that path. |
|
*/ |
|
static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
struct ubifs_znode *zp; |
|
int *path = c->bottom_up_buf, p = 0; |
|
|
|
ubifs_assert(c, c->zroot.znode); |
|
ubifs_assert(c, znode); |
|
if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) { |
|
kfree(c->bottom_up_buf); |
|
c->bottom_up_buf = kmalloc_array(c->zroot.znode->level, |
|
sizeof(int), |
|
GFP_NOFS); |
|
if (!c->bottom_up_buf) |
|
return ERR_PTR(-ENOMEM); |
|
path = c->bottom_up_buf; |
|
} |
|
if (c->zroot.znode->level) { |
|
/* Go up until parent is dirty */ |
|
while (1) { |
|
int n; |
|
|
|
zp = znode->parent; |
|
if (!zp) |
|
break; |
|
n = znode->iip; |
|
ubifs_assert(c, p < c->zroot.znode->level); |
|
path[p++] = n; |
|
if (!zp->cnext && ubifs_zn_dirty(znode)) |
|
break; |
|
znode = zp; |
|
} |
|
} |
|
|
|
/* Come back down, dirtying as we go */ |
|
while (1) { |
|
struct ubifs_zbranch *zbr; |
|
|
|
zp = znode->parent; |
|
if (zp) { |
|
ubifs_assert(c, path[p - 1] >= 0); |
|
ubifs_assert(c, path[p - 1] < zp->child_cnt); |
|
zbr = &zp->zbranch[path[--p]]; |
|
znode = dirty_cow_znode(c, zbr); |
|
} else { |
|
ubifs_assert(c, znode == c->zroot.znode); |
|
znode = dirty_cow_znode(c, &c->zroot); |
|
} |
|
if (IS_ERR(znode) || !p) |
|
break; |
|
ubifs_assert(c, path[p - 1] >= 0); |
|
ubifs_assert(c, path[p - 1] < znode->child_cnt); |
|
znode = znode->zbranch[path[p - 1]].znode; |
|
} |
|
|
|
return znode; |
|
} |
|
|
|
/** |
|
* ubifs_lookup_level0 - search for zero-level znode. |
|
* @c: UBIFS file-system description object |
|
* @key: key to lookup |
|
* @zn: znode is returned here |
|
* @n: znode branch slot number is returned here |
|
* |
|
* This function looks up the TNC tree and search for zero-level znode which |
|
* refers key @key. The found zero-level znode is returned in @zn. There are 3 |
|
* cases: |
|
* o exact match, i.e. the found zero-level znode contains key @key, then %1 |
|
* is returned and slot number of the matched branch is stored in @n; |
|
* o not exact match, which means that zero-level znode does not contain |
|
* @key, then %0 is returned and slot number of the closest branch or %-1 |
|
* is stored in @n; In this case calling tnc_next() is mandatory. |
|
* o @key is so small that it is even less than the lowest key of the |
|
* leftmost zero-level node, then %0 is returned and %0 is stored in @n. |
|
* |
|
* Note, when the TNC tree is traversed, some znodes may be absent, then this |
|
* function reads corresponding indexing nodes and inserts them to TNC. In |
|
* case of failure, a negative error code is returned. |
|
*/ |
|
int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key, |
|
struct ubifs_znode **zn, int *n) |
|
{ |
|
int err, exact; |
|
struct ubifs_znode *znode; |
|
time64_t time = ktime_get_seconds(); |
|
|
|
dbg_tnck(key, "search key "); |
|
ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); |
|
|
|
znode = c->zroot.znode; |
|
if (unlikely(!znode)) { |
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
|
|
znode->time = time; |
|
|
|
while (1) { |
|
struct ubifs_zbranch *zbr; |
|
|
|
exact = ubifs_search_zbranch(c, znode, key, n); |
|
|
|
if (znode->level == 0) |
|
break; |
|
|
|
if (*n < 0) |
|
*n = 0; |
|
zbr = &znode->zbranch[*n]; |
|
|
|
if (zbr->znode) { |
|
znode->time = time; |
|
znode = zbr->znode; |
|
continue; |
|
} |
|
|
|
/* znode is not in TNC cache, load it from the media */ |
|
znode = ubifs_load_znode(c, zbr, znode, *n); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
|
|
*zn = znode; |
|
if (exact || !is_hash_key(c, key) || *n != -1) { |
|
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); |
|
return exact; |
|
} |
|
|
|
/* |
|
* Here is a tricky place. We have not found the key and this is a |
|
* "hashed" key, which may collide. The rest of the code deals with |
|
* situations like this: |
|
* |
|
* | 3 | 5 | |
|
* / \ |
|
* | 3 | 5 | | 6 | 7 | (x) |
|
* |
|
* Or more a complex example: |
|
* |
|
* | 1 | 5 | |
|
* / \ |
|
* | 1 | 3 | | 5 | 8 | |
|
* \ / |
|
* | 5 | 5 | | 6 | 7 | (x) |
|
* |
|
* In the examples, if we are looking for key "5", we may reach nodes |
|
* marked with "(x)". In this case what we have do is to look at the |
|
* left and see if there is "5" key there. If there is, we have to |
|
* return it. |
|
* |
|
* Note, this whole situation is possible because we allow to have |
|
* elements which are equivalent to the next key in the parent in the |
|
* children of current znode. For example, this happens if we split a |
|
* znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something |
|
* like this: |
|
* | 3 | 5 | |
|
* / \ |
|
* | 3 | 5 | | 5 | 6 | 7 | |
|
* ^ |
|
* And this becomes what is at the first "picture" after key "5" marked |
|
* with "^" is removed. What could be done is we could prohibit |
|
* splitting in the middle of the colliding sequence. Also, when |
|
* removing the leftmost key, we would have to correct the key of the |
|
* parent node, which would introduce additional complications. Namely, |
|
* if we changed the leftmost key of the parent znode, the garbage |
|
* collector would be unable to find it (GC is doing this when GC'ing |
|
* indexing LEBs). Although we already have an additional RB-tree where |
|
* we save such changed znodes (see 'ins_clr_old_idx_znode()') until |
|
* after the commit. But anyway, this does not look easy to implement |
|
* so we did not try this. |
|
*/ |
|
err = tnc_prev(c, &znode, n); |
|
if (err == -ENOENT) { |
|
dbg_tnc("found 0, lvl %d, n -1", znode->level); |
|
*n = -1; |
|
return 0; |
|
} |
|
if (unlikely(err < 0)) |
|
return err; |
|
if (keys_cmp(c, key, &znode->zbranch[*n].key)) { |
|
dbg_tnc("found 0, lvl %d, n -1", znode->level); |
|
*n = -1; |
|
return 0; |
|
} |
|
|
|
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); |
|
*zn = znode; |
|
return 1; |
|
} |
|
|
|
/** |
|
* lookup_level0_dirty - search for zero-level znode dirtying. |
|
* @c: UBIFS file-system description object |
|
* @key: key to lookup |
|
* @zn: znode is returned here |
|
* @n: znode branch slot number is returned here |
|
* |
|
* This function looks up the TNC tree and search for zero-level znode which |
|
* refers key @key. The found zero-level znode is returned in @zn. There are 3 |
|
* cases: |
|
* o exact match, i.e. the found zero-level znode contains key @key, then %1 |
|
* is returned and slot number of the matched branch is stored in @n; |
|
* o not exact match, which means that zero-level znode does not contain @key |
|
* then %0 is returned and slot number of the closed branch is stored in |
|
* @n; |
|
* o @key is so small that it is even less than the lowest key of the |
|
* leftmost zero-level node, then %0 is returned and %-1 is stored in @n. |
|
* |
|
* Additionally all znodes in the path from the root to the located zero-level |
|
* znode are marked as dirty. |
|
* |
|
* Note, when the TNC tree is traversed, some znodes may be absent, then this |
|
* function reads corresponding indexing nodes and inserts them to TNC. In |
|
* case of failure, a negative error code is returned. |
|
*/ |
|
static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key, |
|
struct ubifs_znode **zn, int *n) |
|
{ |
|
int err, exact; |
|
struct ubifs_znode *znode; |
|
time64_t time = ktime_get_seconds(); |
|
|
|
dbg_tnck(key, "search and dirty key "); |
|
|
|
znode = c->zroot.znode; |
|
if (unlikely(!znode)) { |
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
|
|
znode = dirty_cow_znode(c, &c->zroot); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
|
|
znode->time = time; |
|
|
|
while (1) { |
|
struct ubifs_zbranch *zbr; |
|
|
|
exact = ubifs_search_zbranch(c, znode, key, n); |
|
|
|
if (znode->level == 0) |
|
break; |
|
|
|
if (*n < 0) |
|
*n = 0; |
|
zbr = &znode->zbranch[*n]; |
|
|
|
if (zbr->znode) { |
|
znode->time = time; |
|
znode = dirty_cow_znode(c, zbr); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
continue; |
|
} |
|
|
|
/* znode is not in TNC cache, load it from the media */ |
|
znode = ubifs_load_znode(c, zbr, znode, *n); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
znode = dirty_cow_znode(c, zbr); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
|
|
*zn = znode; |
|
if (exact || !is_hash_key(c, key) || *n != -1) { |
|
dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n); |
|
return exact; |
|
} |
|
|
|
/* |
|
* See huge comment at 'lookup_level0_dirty()' what is the rest of the |
|
* code. |
|
*/ |
|
err = tnc_prev(c, &znode, n); |
|
if (err == -ENOENT) { |
|
*n = -1; |
|
dbg_tnc("found 0, lvl %d, n -1", znode->level); |
|
return 0; |
|
} |
|
if (unlikely(err < 0)) |
|
return err; |
|
if (keys_cmp(c, key, &znode->zbranch[*n].key)) { |
|
*n = -1; |
|
dbg_tnc("found 0, lvl %d, n -1", znode->level); |
|
return 0; |
|
} |
|
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
} |
|
|
|
dbg_tnc("found 1, lvl %d, n %d", znode->level, *n); |
|
*zn = znode; |
|
return 1; |
|
} |
|
|
|
/** |
|
* maybe_leb_gced - determine if a LEB may have been garbage collected. |
|
* @c: UBIFS file-system description object |
|
* @lnum: LEB number |
|
* @gc_seq1: garbage collection sequence number |
|
* |
|
* This function determines if @lnum may have been garbage collected since |
|
* sequence number @gc_seq1. If it may have been then %1 is returned, otherwise |
|
* %0 is returned. |
|
*/ |
|
static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1) |
|
{ |
|
int gc_seq2, gced_lnum; |
|
|
|
gced_lnum = c->gced_lnum; |
|
smp_rmb(); |
|
gc_seq2 = c->gc_seq; |
|
/* Same seq means no GC */ |
|
if (gc_seq1 == gc_seq2) |
|
return 0; |
|
/* Different by more than 1 means we don't know */ |
|
if (gc_seq1 + 1 != gc_seq2) |
|
return 1; |
|
/* |
|
* We have seen the sequence number has increased by 1. Now we need to |
|
* be sure we read the right LEB number, so read it again. |
|
*/ |
|
smp_rmb(); |
|
if (gced_lnum != c->gced_lnum) |
|
return 1; |
|
/* Finally we can check lnum */ |
|
if (gced_lnum == lnum) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_locate - look up a file-system node and return it and its location. |
|
* @c: UBIFS file-system description object |
|
* @key: node key to lookup |
|
* @node: the node is returned here |
|
* @lnum: LEB number is returned here |
|
* @offs: offset is returned here |
|
* |
|
* This function looks up and reads node with key @key. The caller has to make |
|
* sure the @node buffer is large enough to fit the node. Returns zero in case |
|
* of success, %-ENOENT if the node was not found, and a negative error code in |
|
* case of failure. The node location can be returned in @lnum and @offs. |
|
*/ |
|
int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key, |
|
void *node, int *lnum, int *offs) |
|
{ |
|
int found, n, err, safely = 0, gc_seq1; |
|
struct ubifs_znode *znode; |
|
struct ubifs_zbranch zbr, *zt; |
|
|
|
again: |
|
mutex_lock(&c->tnc_mutex); |
|
found = ubifs_lookup_level0(c, key, &znode, &n); |
|
if (!found) { |
|
err = -ENOENT; |
|
goto out; |
|
} else if (found < 0) { |
|
err = found; |
|
goto out; |
|
} |
|
zt = &znode->zbranch[n]; |
|
if (lnum) { |
|
*lnum = zt->lnum; |
|
*offs = zt->offs; |
|
} |
|
if (is_hash_key(c, key)) { |
|
/* |
|
* In this case the leaf node cache gets used, so we pass the |
|
* address of the zbranch and keep the mutex locked |
|
*/ |
|
err = tnc_read_hashed_node(c, zt, node); |
|
goto out; |
|
} |
|
if (safely) { |
|
err = ubifs_tnc_read_node(c, zt, node); |
|
goto out; |
|
} |
|
/* Drop the TNC mutex prematurely and race with garbage collection */ |
|
zbr = znode->zbranch[n]; |
|
gc_seq1 = c->gc_seq; |
|
mutex_unlock(&c->tnc_mutex); |
|
|
|
if (ubifs_get_wbuf(c, zbr.lnum)) { |
|
/* We do not GC journal heads */ |
|
err = ubifs_tnc_read_node(c, &zbr, node); |
|
return err; |
|
} |
|
|
|
err = fallible_read_node(c, key, &zbr, node); |
|
if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) { |
|
/* |
|
* The node may have been GC'ed out from under us so try again |
|
* while keeping the TNC mutex locked. |
|
*/ |
|
safely = 1; |
|
goto again; |
|
} |
|
return 0; |
|
|
|
out: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_get_bu_keys - lookup keys for bulk-read. |
|
* @c: UBIFS file-system description object |
|
* @bu: bulk-read parameters and results |
|
* |
|
* Lookup consecutive data node keys for the same inode that reside |
|
* consecutively in the same LEB. This function returns zero in case of success |
|
* and a negative error code in case of failure. |
|
* |
|
* Note, if the bulk-read buffer length (@bu->buf_len) is known, this function |
|
* makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares |
|
* maximum possible amount of nodes for bulk-read. |
|
*/ |
|
int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu) |
|
{ |
|
int n, err = 0, lnum = -1, offs; |
|
int len; |
|
unsigned int block = key_block(c, &bu->key); |
|
struct ubifs_znode *znode; |
|
|
|
bu->cnt = 0; |
|
bu->blk_cnt = 0; |
|
bu->eof = 0; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
/* Find first key */ |
|
err = ubifs_lookup_level0(c, &bu->key, &znode, &n); |
|
if (err < 0) |
|
goto out; |
|
if (err) { |
|
/* Key found */ |
|
len = znode->zbranch[n].len; |
|
/* The buffer must be big enough for at least 1 node */ |
|
if (len > bu->buf_len) { |
|
err = -EINVAL; |
|
goto out; |
|
} |
|
/* Add this key */ |
|
bu->zbranch[bu->cnt++] = znode->zbranch[n]; |
|
bu->blk_cnt += 1; |
|
lnum = znode->zbranch[n].lnum; |
|
offs = ALIGN(znode->zbranch[n].offs + len, 8); |
|
} |
|
while (1) { |
|
struct ubifs_zbranch *zbr; |
|
union ubifs_key *key; |
|
unsigned int next_block; |
|
|
|
/* Find next key */ |
|
err = tnc_next(c, &znode, &n); |
|
if (err) |
|
goto out; |
|
zbr = &znode->zbranch[n]; |
|
key = &zbr->key; |
|
/* See if there is another data key for this file */ |
|
if (key_inum(c, key) != key_inum(c, &bu->key) || |
|
key_type(c, key) != UBIFS_DATA_KEY) { |
|
err = -ENOENT; |
|
goto out; |
|
} |
|
if (lnum < 0) { |
|
/* First key found */ |
|
lnum = zbr->lnum; |
|
offs = ALIGN(zbr->offs + zbr->len, 8); |
|
len = zbr->len; |
|
if (len > bu->buf_len) { |
|
err = -EINVAL; |
|
goto out; |
|
} |
|
} else { |
|
/* |
|
* The data nodes must be in consecutive positions in |
|
* the same LEB. |
|
*/ |
|
if (zbr->lnum != lnum || zbr->offs != offs) |
|
goto out; |
|
offs += ALIGN(zbr->len, 8); |
|
len = ALIGN(len, 8) + zbr->len; |
|
/* Must not exceed buffer length */ |
|
if (len > bu->buf_len) |
|
goto out; |
|
} |
|
/* Allow for holes */ |
|
next_block = key_block(c, key); |
|
bu->blk_cnt += (next_block - block - 1); |
|
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) |
|
goto out; |
|
block = next_block; |
|
/* Add this key */ |
|
bu->zbranch[bu->cnt++] = *zbr; |
|
bu->blk_cnt += 1; |
|
/* See if we have room for more */ |
|
if (bu->cnt >= UBIFS_MAX_BULK_READ) |
|
goto out; |
|
if (bu->blk_cnt >= UBIFS_MAX_BULK_READ) |
|
goto out; |
|
} |
|
out: |
|
if (err == -ENOENT) { |
|
bu->eof = 1; |
|
err = 0; |
|
} |
|
bu->gc_seq = c->gc_seq; |
|
mutex_unlock(&c->tnc_mutex); |
|
if (err) |
|
return err; |
|
/* |
|
* An enormous hole could cause bulk-read to encompass too many |
|
* page cache pages, so limit the number here. |
|
*/ |
|
if (bu->blk_cnt > UBIFS_MAX_BULK_READ) |
|
bu->blk_cnt = UBIFS_MAX_BULK_READ; |
|
/* |
|
* Ensure that bulk-read covers a whole number of page cache |
|
* pages. |
|
*/ |
|
if (UBIFS_BLOCKS_PER_PAGE == 1 || |
|
!(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1))) |
|
return 0; |
|
if (bu->eof) { |
|
/* At the end of file we can round up */ |
|
bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1; |
|
return 0; |
|
} |
|
/* Exclude data nodes that do not make up a whole page cache page */ |
|
block = key_block(c, &bu->key) + bu->blk_cnt; |
|
block &= ~(UBIFS_BLOCKS_PER_PAGE - 1); |
|
while (bu->cnt) { |
|
if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block) |
|
break; |
|
bu->cnt -= 1; |
|
} |
|
return 0; |
|
} |
|
|
|
/** |
|
* read_wbuf - bulk-read from a LEB with a wbuf. |
|
* @wbuf: wbuf that may overlap the read |
|
* @buf: buffer into which to read |
|
* @len: read length |
|
* @lnum: LEB number from which to read |
|
* @offs: offset from which to read |
|
* |
|
* This functions returns %0 on success or a negative error code on failure. |
|
*/ |
|
static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum, |
|
int offs) |
|
{ |
|
const struct ubifs_info *c = wbuf->c; |
|
int rlen, overlap; |
|
|
|
dbg_io("LEB %d:%d, length %d", lnum, offs, len); |
|
ubifs_assert(c, wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
|
ubifs_assert(c, !(offs & 7) && offs < c->leb_size); |
|
ubifs_assert(c, offs + len <= c->leb_size); |
|
|
|
spin_lock(&wbuf->lock); |
|
overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); |
|
if (!overlap) { |
|
/* We may safely unlock the write-buffer and read the data */ |
|
spin_unlock(&wbuf->lock); |
|
return ubifs_leb_read(c, lnum, buf, offs, len, 0); |
|
} |
|
|
|
/* Don't read under wbuf */ |
|
rlen = wbuf->offs - offs; |
|
if (rlen < 0) |
|
rlen = 0; |
|
|
|
/* Copy the rest from the write-buffer */ |
|
memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); |
|
spin_unlock(&wbuf->lock); |
|
|
|
if (rlen > 0) |
|
/* Read everything that goes before write-buffer */ |
|
return ubifs_leb_read(c, lnum, buf, offs, rlen, 0); |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* validate_data_node - validate data nodes for bulk-read. |
|
* @c: UBIFS file-system description object |
|
* @buf: buffer containing data node to validate |
|
* @zbr: zbranch of data node to validate |
|
* |
|
* This functions returns %0 on success or a negative error code on failure. |
|
*/ |
|
static int validate_data_node(struct ubifs_info *c, void *buf, |
|
struct ubifs_zbranch *zbr) |
|
{ |
|
union ubifs_key key1; |
|
struct ubifs_ch *ch = buf; |
|
int err, len; |
|
|
|
if (ch->node_type != UBIFS_DATA_NODE) { |
|
ubifs_err(c, "bad node type (%d but expected %d)", |
|
ch->node_type, UBIFS_DATA_NODE); |
|
goto out_err; |
|
} |
|
|
|
err = ubifs_check_node(c, buf, zbr->len, zbr->lnum, zbr->offs, 0, 0); |
|
if (err) { |
|
ubifs_err(c, "expected node type %d", UBIFS_DATA_NODE); |
|
goto out; |
|
} |
|
|
|
err = ubifs_node_check_hash(c, buf, zbr->hash); |
|
if (err) { |
|
ubifs_bad_hash(c, buf, zbr->hash, zbr->lnum, zbr->offs); |
|
return err; |
|
} |
|
|
|
len = le32_to_cpu(ch->len); |
|
if (len != zbr->len) { |
|
ubifs_err(c, "bad node length %d, expected %d", len, zbr->len); |
|
goto out_err; |
|
} |
|
|
|
/* Make sure the key of the read node is correct */ |
|
key_read(c, buf + UBIFS_KEY_OFFSET, &key1); |
|
if (!keys_eq(c, &zbr->key, &key1)) { |
|
ubifs_err(c, "bad key in node at LEB %d:%d", |
|
zbr->lnum, zbr->offs); |
|
dbg_tnck(&zbr->key, "looked for key "); |
|
dbg_tnck(&key1, "found node's key "); |
|
goto out_err; |
|
} |
|
|
|
return 0; |
|
|
|
out_err: |
|
err = -EINVAL; |
|
out: |
|
ubifs_err(c, "bad node at LEB %d:%d", zbr->lnum, zbr->offs); |
|
ubifs_dump_node(c, buf, zbr->len); |
|
dump_stack(); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_bulk_read - read a number of data nodes in one go. |
|
* @c: UBIFS file-system description object |
|
* @bu: bulk-read parameters and results |
|
* |
|
* This functions reads and validates the data nodes that were identified by the |
|
* 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success, |
|
* -EAGAIN to indicate a race with GC, or another negative error code on |
|
* failure. |
|
*/ |
|
int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu) |
|
{ |
|
int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i; |
|
struct ubifs_wbuf *wbuf; |
|
void *buf; |
|
|
|
len = bu->zbranch[bu->cnt - 1].offs; |
|
len += bu->zbranch[bu->cnt - 1].len - offs; |
|
if (len > bu->buf_len) { |
|
ubifs_err(c, "buffer too small %d vs %d", bu->buf_len, len); |
|
return -EINVAL; |
|
} |
|
|
|
/* Do the read */ |
|
wbuf = ubifs_get_wbuf(c, lnum); |
|
if (wbuf) |
|
err = read_wbuf(wbuf, bu->buf, len, lnum, offs); |
|
else |
|
err = ubifs_leb_read(c, lnum, bu->buf, offs, len, 0); |
|
|
|
/* Check for a race with GC */ |
|
if (maybe_leb_gced(c, lnum, bu->gc_seq)) |
|
return -EAGAIN; |
|
|
|
if (err && err != -EBADMSG) { |
|
ubifs_err(c, "failed to read from LEB %d:%d, error %d", |
|
lnum, offs, err); |
|
dump_stack(); |
|
dbg_tnck(&bu->key, "key "); |
|
return err; |
|
} |
|
|
|
/* Validate the nodes read */ |
|
buf = bu->buf; |
|
for (i = 0; i < bu->cnt; i++) { |
|
err = validate_data_node(c, buf, &bu->zbranch[i]); |
|
if (err) |
|
return err; |
|
buf = buf + ALIGN(bu->zbranch[i].len, 8); |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* do_lookup_nm- look up a "hashed" node. |
|
* @c: UBIFS file-system description object |
|
* @key: node key to lookup |
|
* @node: the node is returned here |
|
* @nm: node name |
|
* |
|
* This function looks up and reads a node which contains name hash in the key. |
|
* Since the hash may have collisions, there may be many nodes with the same |
|
* key, so we have to sequentially look to all of them until the needed one is |
|
* found. This function returns zero in case of success, %-ENOENT if the node |
|
* was not found, and a negative error code in case of failure. |
|
*/ |
|
static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, |
|
void *node, const struct fscrypt_name *nm) |
|
{ |
|
int found, n, err; |
|
struct ubifs_znode *znode; |
|
|
|
dbg_tnck(key, "key "); |
|
mutex_lock(&c->tnc_mutex); |
|
found = ubifs_lookup_level0(c, key, &znode, &n); |
|
if (!found) { |
|
err = -ENOENT; |
|
goto out_unlock; |
|
} else if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
|
|
ubifs_assert(c, n >= 0); |
|
|
|
err = resolve_collision(c, key, &znode, &n, nm); |
|
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); |
|
if (unlikely(err < 0)) |
|
goto out_unlock; |
|
if (err == 0) { |
|
err = -ENOENT; |
|
goto out_unlock; |
|
} |
|
|
|
err = tnc_read_hashed_node(c, &znode->zbranch[n], node); |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_lookup_nm - look up a "hashed" node. |
|
* @c: UBIFS file-system description object |
|
* @key: node key to lookup |
|
* @node: the node is returned here |
|
* @nm: node name |
|
* |
|
* This function looks up and reads a node which contains name hash in the key. |
|
* Since the hash may have collisions, there may be many nodes with the same |
|
* key, so we have to sequentially look to all of them until the needed one is |
|
* found. This function returns zero in case of success, %-ENOENT if the node |
|
* was not found, and a negative error code in case of failure. |
|
*/ |
|
int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key, |
|
void *node, const struct fscrypt_name *nm) |
|
{ |
|
int err, len; |
|
const struct ubifs_dent_node *dent = node; |
|
|
|
/* |
|
* We assume that in most of the cases there are no name collisions and |
|
* 'ubifs_tnc_lookup()' returns us the right direntry. |
|
*/ |
|
err = ubifs_tnc_lookup(c, key, node); |
|
if (err) |
|
return err; |
|
|
|
len = le16_to_cpu(dent->nlen); |
|
if (fname_len(nm) == len && !memcmp(dent->name, fname_name(nm), len)) |
|
return 0; |
|
|
|
/* |
|
* Unluckily, there are hash collisions and we have to iterate over |
|
* them look at each direntry with colliding name hash sequentially. |
|
*/ |
|
|
|
return do_lookup_nm(c, key, node, nm); |
|
} |
|
|
|
static int search_dh_cookie(struct ubifs_info *c, const union ubifs_key *key, |
|
struct ubifs_dent_node *dent, uint32_t cookie, |
|
struct ubifs_znode **zn, int *n, int exact) |
|
{ |
|
int err; |
|
struct ubifs_znode *znode = *zn; |
|
struct ubifs_zbranch *zbr; |
|
union ubifs_key *dkey; |
|
|
|
if (!exact) { |
|
err = tnc_next(c, &znode, n); |
|
if (err) |
|
return err; |
|
} |
|
|
|
for (;;) { |
|
zbr = &znode->zbranch[*n]; |
|
dkey = &zbr->key; |
|
|
|
if (key_inum(c, dkey) != key_inum(c, key) || |
|
key_type(c, dkey) != key_type(c, key)) { |
|
return -ENOENT; |
|
} |
|
|
|
err = tnc_read_hashed_node(c, zbr, dent); |
|
if (err) |
|
return err; |
|
|
|
if (key_hash(c, key) == key_hash(c, dkey) && |
|
le32_to_cpu(dent->cookie) == cookie) { |
|
*zn = znode; |
|
return 0; |
|
} |
|
|
|
err = tnc_next(c, &znode, n); |
|
if (err) |
|
return err; |
|
} |
|
} |
|
|
|
static int do_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, |
|
struct ubifs_dent_node *dent, uint32_t cookie) |
|
{ |
|
int n, err; |
|
struct ubifs_znode *znode; |
|
union ubifs_key start_key; |
|
|
|
ubifs_assert(c, is_hash_key(c, key)); |
|
|
|
lowest_dent_key(c, &start_key, key_inum(c, key)); |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
err = ubifs_lookup_level0(c, &start_key, &znode, &n); |
|
if (unlikely(err < 0)) |
|
goto out_unlock; |
|
|
|
err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_lookup_dh - look up a "double hashed" node. |
|
* @c: UBIFS file-system description object |
|
* @key: node key to lookup |
|
* @node: the node is returned here |
|
* @cookie: node cookie for collision resolution |
|
* |
|
* This function looks up and reads a node which contains name hash in the key. |
|
* Since the hash may have collisions, there may be many nodes with the same |
|
* key, so we have to sequentially look to all of them until the needed one |
|
* with the same cookie value is found. |
|
* This function returns zero in case of success, %-ENOENT if the node |
|
* was not found, and a negative error code in case of failure. |
|
*/ |
|
int ubifs_tnc_lookup_dh(struct ubifs_info *c, const union ubifs_key *key, |
|
void *node, uint32_t cookie) |
|
{ |
|
int err; |
|
const struct ubifs_dent_node *dent = node; |
|
|
|
if (!c->double_hash) |
|
return -EOPNOTSUPP; |
|
|
|
/* |
|
* We assume that in most of the cases there are no name collisions and |
|
* 'ubifs_tnc_lookup()' returns us the right direntry. |
|
*/ |
|
err = ubifs_tnc_lookup(c, key, node); |
|
if (err) |
|
return err; |
|
|
|
if (le32_to_cpu(dent->cookie) == cookie) |
|
return 0; |
|
|
|
/* |
|
* Unluckily, there are hash collisions and we have to iterate over |
|
* them look at each direntry with colliding name hash sequentially. |
|
*/ |
|
return do_lookup_dh(c, key, node, cookie); |
|
} |
|
|
|
/** |
|
* correct_parent_keys - correct parent znodes' keys. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode to correct parent znodes for |
|
* |
|
* This is a helper function for 'tnc_insert()'. When the key of the leftmost |
|
* zbranch changes, keys of parent znodes have to be corrected. This helper |
|
* function is called in such situations and corrects the keys if needed. |
|
*/ |
|
static void correct_parent_keys(const struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
union ubifs_key *key, *key1; |
|
|
|
ubifs_assert(c, znode->parent); |
|
ubifs_assert(c, znode->iip == 0); |
|
|
|
key = &znode->zbranch[0].key; |
|
key1 = &znode->parent->zbranch[0].key; |
|
|
|
while (keys_cmp(c, key, key1) < 0) { |
|
key_copy(c, key, key1); |
|
znode = znode->parent; |
|
znode->alt = 1; |
|
if (!znode->parent || znode->iip) |
|
break; |
|
key1 = &znode->parent->zbranch[0].key; |
|
} |
|
} |
|
|
|
/** |
|
* insert_zbranch - insert a zbranch into a znode. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode into which to insert |
|
* @zbr: zbranch to insert |
|
* @n: slot number to insert to |
|
* |
|
* This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in |
|
* znode's array of zbranches and keeps zbranches consolidated, so when a new |
|
* zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th |
|
* slot, zbranches starting from @n have to be moved right. |
|
*/ |
|
static void insert_zbranch(struct ubifs_info *c, struct ubifs_znode *znode, |
|
const struct ubifs_zbranch *zbr, int n) |
|
{ |
|
int i; |
|
|
|
ubifs_assert(c, ubifs_zn_dirty(znode)); |
|
|
|
if (znode->level) { |
|
for (i = znode->child_cnt; i > n; i--) { |
|
znode->zbranch[i] = znode->zbranch[i - 1]; |
|
if (znode->zbranch[i].znode) |
|
znode->zbranch[i].znode->iip = i; |
|
} |
|
if (zbr->znode) |
|
zbr->znode->iip = n; |
|
} else |
|
for (i = znode->child_cnt; i > n; i--) |
|
znode->zbranch[i] = znode->zbranch[i - 1]; |
|
|
|
znode->zbranch[n] = *zbr; |
|
znode->child_cnt += 1; |
|
|
|
/* |
|
* After inserting at slot zero, the lower bound of the key range of |
|
* this znode may have changed. If this znode is subsequently split |
|
* then the upper bound of the key range may change, and furthermore |
|
* it could change to be lower than the original lower bound. If that |
|
* happens, then it will no longer be possible to find this znode in the |
|
* TNC using the key from the index node on flash. That is bad because |
|
* if it is not found, we will assume it is obsolete and may overwrite |
|
* it. Then if there is an unclean unmount, we will start using the |
|
* old index which will be broken. |
|
* |
|
* So we first mark znodes that have insertions at slot zero, and then |
|
* if they are split we add their lnum/offs to the old_idx tree. |
|
*/ |
|
if (n == 0) |
|
znode->alt = 1; |
|
} |
|
|
|
/** |
|
* tnc_insert - insert a node into TNC. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode to insert into |
|
* @zbr: branch to insert |
|
* @n: slot number to insert new zbranch to |
|
* |
|
* This function inserts a new node described by @zbr into znode @znode. If |
|
* znode does not have a free slot for new zbranch, it is split. Parent znodes |
|
* are splat as well if needed. Returns zero in case of success or a negative |
|
* error code in case of failure. |
|
*/ |
|
static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode, |
|
struct ubifs_zbranch *zbr, int n) |
|
{ |
|
struct ubifs_znode *zn, *zi, *zp; |
|
int i, keep, move, appending = 0; |
|
union ubifs_key *key = &zbr->key, *key1; |
|
|
|
ubifs_assert(c, n >= 0 && n <= c->fanout); |
|
|
|
/* Implement naive insert for now */ |
|
again: |
|
zp = znode->parent; |
|
if (znode->child_cnt < c->fanout) { |
|
ubifs_assert(c, n != c->fanout); |
|
dbg_tnck(key, "inserted at %d level %d, key ", n, znode->level); |
|
|
|
insert_zbranch(c, znode, zbr, n); |
|
|
|
/* Ensure parent's key is correct */ |
|
if (n == 0 && zp && znode->iip == 0) |
|
correct_parent_keys(c, znode); |
|
|
|
return 0; |
|
} |
|
|
|
/* |
|
* Unfortunately, @znode does not have more empty slots and we have to |
|
* split it. |
|
*/ |
|
dbg_tnck(key, "splitting level %d, key ", znode->level); |
|
|
|
if (znode->alt) |
|
/* |
|
* We can no longer be sure of finding this znode by key, so we |
|
* record it in the old_idx tree. |
|
*/ |
|
ins_clr_old_idx_znode(c, znode); |
|
|
|
zn = kzalloc(c->max_znode_sz, GFP_NOFS); |
|
if (!zn) |
|
return -ENOMEM; |
|
zn->parent = zp; |
|
zn->level = znode->level; |
|
|
|
/* Decide where to split */ |
|
if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) { |
|
/* Try not to split consecutive data keys */ |
|
if (n == c->fanout) { |
|
key1 = &znode->zbranch[n - 1].key; |
|
if (key_inum(c, key1) == key_inum(c, key) && |
|
key_type(c, key1) == UBIFS_DATA_KEY) |
|
appending = 1; |
|
} else |
|
goto check_split; |
|
} else if (appending && n != c->fanout) { |
|
/* Try not to split consecutive data keys */ |
|
appending = 0; |
|
check_split: |
|
if (n >= (c->fanout + 1) / 2) { |
|
key1 = &znode->zbranch[0].key; |
|
if (key_inum(c, key1) == key_inum(c, key) && |
|
key_type(c, key1) == UBIFS_DATA_KEY) { |
|
key1 = &znode->zbranch[n].key; |
|
if (key_inum(c, key1) != key_inum(c, key) || |
|
key_type(c, key1) != UBIFS_DATA_KEY) { |
|
keep = n; |
|
move = c->fanout - keep; |
|
zi = znode; |
|
goto do_split; |
|
} |
|
} |
|
} |
|
} |
|
|
|
if (appending) { |
|
keep = c->fanout; |
|
move = 0; |
|
} else { |
|
keep = (c->fanout + 1) / 2; |
|
move = c->fanout - keep; |
|
} |
|
|
|
/* |
|
* Although we don't at present, we could look at the neighbors and see |
|
* if we can move some zbranches there. |
|
*/ |
|
|
|
if (n < keep) { |
|
/* Insert into existing znode */ |
|
zi = znode; |
|
move += 1; |
|
keep -= 1; |
|
} else { |
|
/* Insert into new znode */ |
|
zi = zn; |
|
n -= keep; |
|
/* Re-parent */ |
|
if (zn->level != 0) |
|
zbr->znode->parent = zn; |
|
} |
|
|
|
do_split: |
|
|
|
__set_bit(DIRTY_ZNODE, &zn->flags); |
|
atomic_long_inc(&c->dirty_zn_cnt); |
|
|
|
zn->child_cnt = move; |
|
znode->child_cnt = keep; |
|
|
|
dbg_tnc("moving %d, keeping %d", move, keep); |
|
|
|
/* Move zbranch */ |
|
for (i = 0; i < move; i++) { |
|
zn->zbranch[i] = znode->zbranch[keep + i]; |
|
/* Re-parent */ |
|
if (zn->level != 0) |
|
if (zn->zbranch[i].znode) { |
|
zn->zbranch[i].znode->parent = zn; |
|
zn->zbranch[i].znode->iip = i; |
|
} |
|
} |
|
|
|
/* Insert new key and branch */ |
|
dbg_tnck(key, "inserting at %d level %d, key ", n, zn->level); |
|
|
|
insert_zbranch(c, zi, zbr, n); |
|
|
|
/* Insert new znode (produced by spitting) into the parent */ |
|
if (zp) { |
|
if (n == 0 && zi == znode && znode->iip == 0) |
|
correct_parent_keys(c, znode); |
|
|
|
/* Locate insertion point */ |
|
n = znode->iip + 1; |
|
|
|
/* Tail recursion */ |
|
zbr->key = zn->zbranch[0].key; |
|
zbr->znode = zn; |
|
zbr->lnum = 0; |
|
zbr->offs = 0; |
|
zbr->len = 0; |
|
znode = zp; |
|
|
|
goto again; |
|
} |
|
|
|
/* We have to split root znode */ |
|
dbg_tnc("creating new zroot at level %d", znode->level + 1); |
|
|
|
zi = kzalloc(c->max_znode_sz, GFP_NOFS); |
|
if (!zi) |
|
return -ENOMEM; |
|
|
|
zi->child_cnt = 2; |
|
zi->level = znode->level + 1; |
|
|
|
__set_bit(DIRTY_ZNODE, &zi->flags); |
|
atomic_long_inc(&c->dirty_zn_cnt); |
|
|
|
zi->zbranch[0].key = znode->zbranch[0].key; |
|
zi->zbranch[0].znode = znode; |
|
zi->zbranch[0].lnum = c->zroot.lnum; |
|
zi->zbranch[0].offs = c->zroot.offs; |
|
zi->zbranch[0].len = c->zroot.len; |
|
zi->zbranch[1].key = zn->zbranch[0].key; |
|
zi->zbranch[1].znode = zn; |
|
|
|
c->zroot.lnum = 0; |
|
c->zroot.offs = 0; |
|
c->zroot.len = 0; |
|
c->zroot.znode = zi; |
|
|
|
zn->parent = zi; |
|
zn->iip = 1; |
|
znode->parent = zi; |
|
znode->iip = 0; |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_add - add a node to TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: key to add |
|
* @lnum: LEB number of node |
|
* @offs: node offset |
|
* @len: node length |
|
* @hash: The hash over the node |
|
* |
|
* This function adds a node with key @key to TNC. The node may be new or it may |
|
* obsolete some existing one. Returns %0 on success or negative error code on |
|
* failure. |
|
*/ |
|
int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum, |
|
int offs, int len, const u8 *hash) |
|
{ |
|
int found, n, err = 0; |
|
struct ubifs_znode *znode; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
dbg_tnck(key, "%d:%d, len %d, key ", lnum, offs, len); |
|
found = lookup_level0_dirty(c, key, &znode, &n); |
|
if (!found) { |
|
struct ubifs_zbranch zbr; |
|
|
|
zbr.znode = NULL; |
|
zbr.lnum = lnum; |
|
zbr.offs = offs; |
|
zbr.len = len; |
|
ubifs_copy_hash(c, hash, zbr.hash); |
|
key_copy(c, key, &zbr.key); |
|
err = tnc_insert(c, znode, &zbr, n + 1); |
|
} else if (found == 1) { |
|
struct ubifs_zbranch *zbr = &znode->zbranch[n]; |
|
|
|
lnc_free(zbr); |
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len); |
|
zbr->lnum = lnum; |
|
zbr->offs = offs; |
|
zbr->len = len; |
|
ubifs_copy_hash(c, hash, zbr->hash); |
|
} else |
|
err = found; |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
|
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_replace - replace a node in the TNC only if the old node is found. |
|
* @c: UBIFS file-system description object |
|
* @key: key to add |
|
* @old_lnum: LEB number of old node |
|
* @old_offs: old node offset |
|
* @lnum: LEB number of node |
|
* @offs: node offset |
|
* @len: node length |
|
* |
|
* This function replaces a node with key @key in the TNC only if the old node |
|
* is found. This function is called by garbage collection when node are moved. |
|
* Returns %0 on success or negative error code on failure. |
|
*/ |
|
int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key, |
|
int old_lnum, int old_offs, int lnum, int offs, int len) |
|
{ |
|
int found, n, err = 0; |
|
struct ubifs_znode *znode; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
dbg_tnck(key, "old LEB %d:%d, new LEB %d:%d, len %d, key ", old_lnum, |
|
old_offs, lnum, offs, len); |
|
found = lookup_level0_dirty(c, key, &znode, &n); |
|
if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
|
|
if (found == 1) { |
|
struct ubifs_zbranch *zbr = &znode->zbranch[n]; |
|
|
|
found = 0; |
|
if (zbr->lnum == old_lnum && zbr->offs == old_offs) { |
|
lnc_free(zbr); |
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len); |
|
if (err) |
|
goto out_unlock; |
|
zbr->lnum = lnum; |
|
zbr->offs = offs; |
|
zbr->len = len; |
|
found = 1; |
|
} else if (is_hash_key(c, key)) { |
|
found = resolve_collision_directly(c, key, &znode, &n, |
|
old_lnum, old_offs); |
|
dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d", |
|
found, znode, n, old_lnum, old_offs); |
|
if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
|
|
if (found) { |
|
/* Ensure the znode is dirtied */ |
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
} |
|
zbr = &znode->zbranch[n]; |
|
lnc_free(zbr); |
|
err = ubifs_add_dirt(c, zbr->lnum, |
|
zbr->len); |
|
if (err) |
|
goto out_unlock; |
|
zbr->lnum = lnum; |
|
zbr->offs = offs; |
|
zbr->len = len; |
|
} |
|
} |
|
} |
|
|
|
if (!found) |
|
err = ubifs_add_dirt(c, lnum, len); |
|
|
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_add_nm - add a "hashed" node to TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: key to add |
|
* @lnum: LEB number of node |
|
* @offs: node offset |
|
* @len: node length |
|
* @hash: The hash over the node |
|
* @nm: node name |
|
* |
|
* This is the same as 'ubifs_tnc_add()' but it should be used with keys which |
|
* may have collisions, like directory entry keys. |
|
*/ |
|
int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key, |
|
int lnum, int offs, int len, const u8 *hash, |
|
const struct fscrypt_name *nm) |
|
{ |
|
int found, n, err = 0; |
|
struct ubifs_znode *znode; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
dbg_tnck(key, "LEB %d:%d, key ", lnum, offs); |
|
found = lookup_level0_dirty(c, key, &znode, &n); |
|
if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
|
|
if (found == 1) { |
|
if (c->replaying) |
|
found = fallible_resolve_collision(c, key, &znode, &n, |
|
nm, 1); |
|
else |
|
found = resolve_collision(c, key, &znode, &n, nm); |
|
dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n); |
|
if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
|
|
/* Ensure the znode is dirtied */ |
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
if (found == 1) { |
|
struct ubifs_zbranch *zbr = &znode->zbranch[n]; |
|
|
|
lnc_free(zbr); |
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len); |
|
zbr->lnum = lnum; |
|
zbr->offs = offs; |
|
zbr->len = len; |
|
ubifs_copy_hash(c, hash, zbr->hash); |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
if (!found) { |
|
struct ubifs_zbranch zbr; |
|
|
|
zbr.znode = NULL; |
|
zbr.lnum = lnum; |
|
zbr.offs = offs; |
|
zbr.len = len; |
|
ubifs_copy_hash(c, hash, zbr.hash); |
|
key_copy(c, key, &zbr.key); |
|
err = tnc_insert(c, znode, &zbr, n + 1); |
|
if (err) |
|
goto out_unlock; |
|
if (c->replaying) { |
|
/* |
|
* We did not find it in the index so there may be a |
|
* dangling branch still in the index. So we remove it |
|
* by passing 'ubifs_tnc_remove_nm()' the same key but |
|
* an unmatchable name. |
|
*/ |
|
struct fscrypt_name noname = { .disk_name = { .name = "", .len = 1 } }; |
|
|
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
if (err) |
|
return err; |
|
return ubifs_tnc_remove_nm(c, key, &noname); |
|
} |
|
} |
|
|
|
out_unlock: |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* tnc_delete - delete a znode form TNC. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode to delete from |
|
* @n: zbranch slot number to delete |
|
* |
|
* This function deletes a leaf node from @n-th slot of @znode. Returns zero in |
|
* case of success and a negative error code in case of failure. |
|
*/ |
|
static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n) |
|
{ |
|
struct ubifs_zbranch *zbr; |
|
struct ubifs_znode *zp; |
|
int i, err; |
|
|
|
/* Delete without merge for now */ |
|
ubifs_assert(c, znode->level == 0); |
|
ubifs_assert(c, n >= 0 && n < c->fanout); |
|
dbg_tnck(&znode->zbranch[n].key, "deleting key "); |
|
|
|
zbr = &znode->zbranch[n]; |
|
lnc_free(zbr); |
|
|
|
err = ubifs_add_dirt(c, zbr->lnum, zbr->len); |
|
if (err) { |
|
ubifs_dump_znode(c, znode); |
|
return err; |
|
} |
|
|
|
/* We do not "gap" zbranch slots */ |
|
for (i = n; i < znode->child_cnt - 1; i++) |
|
znode->zbranch[i] = znode->zbranch[i + 1]; |
|
znode->child_cnt -= 1; |
|
|
|
if (znode->child_cnt > 0) |
|
return 0; |
|
|
|
/* |
|
* This was the last zbranch, we have to delete this znode from the |
|
* parent. |
|
*/ |
|
|
|
do { |
|
ubifs_assert(c, !ubifs_zn_obsolete(znode)); |
|
ubifs_assert(c, ubifs_zn_dirty(znode)); |
|
|
|
zp = znode->parent; |
|
n = znode->iip; |
|
|
|
atomic_long_dec(&c->dirty_zn_cnt); |
|
|
|
err = insert_old_idx_znode(c, znode); |
|
if (err) |
|
return err; |
|
|
|
if (znode->cnext) { |
|
__set_bit(OBSOLETE_ZNODE, &znode->flags); |
|
atomic_long_inc(&c->clean_zn_cnt); |
|
atomic_long_inc(&ubifs_clean_zn_cnt); |
|
} else |
|
kfree(znode); |
|
znode = zp; |
|
} while (znode->child_cnt == 1); /* while removing last child */ |
|
|
|
/* Remove from znode, entry n - 1 */ |
|
znode->child_cnt -= 1; |
|
ubifs_assert(c, znode->level != 0); |
|
for (i = n; i < znode->child_cnt; i++) { |
|
znode->zbranch[i] = znode->zbranch[i + 1]; |
|
if (znode->zbranch[i].znode) |
|
znode->zbranch[i].znode->iip = i; |
|
} |
|
|
|
/* |
|
* If this is the root and it has only 1 child then |
|
* collapse the tree. |
|
*/ |
|
if (!znode->parent) { |
|
while (znode->child_cnt == 1 && znode->level != 0) { |
|
zp = znode; |
|
zbr = &znode->zbranch[0]; |
|
znode = get_znode(c, znode, 0); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
znode = dirty_cow_znode(c, zbr); |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
znode->parent = NULL; |
|
znode->iip = 0; |
|
if (c->zroot.len) { |
|
err = insert_old_idx(c, c->zroot.lnum, |
|
c->zroot.offs); |
|
if (err) |
|
return err; |
|
} |
|
c->zroot.lnum = zbr->lnum; |
|
c->zroot.offs = zbr->offs; |
|
c->zroot.len = zbr->len; |
|
c->zroot.znode = znode; |
|
ubifs_assert(c, !ubifs_zn_obsolete(zp)); |
|
ubifs_assert(c, ubifs_zn_dirty(zp)); |
|
atomic_long_dec(&c->dirty_zn_cnt); |
|
|
|
if (zp->cnext) { |
|
__set_bit(OBSOLETE_ZNODE, &zp->flags); |
|
atomic_long_inc(&c->clean_zn_cnt); |
|
atomic_long_inc(&ubifs_clean_zn_cnt); |
|
} else |
|
kfree(zp); |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_remove - remove an index entry of a node. |
|
* @c: UBIFS file-system description object |
|
* @key: key of node |
|
* |
|
* Returns %0 on success or negative error code on failure. |
|
*/ |
|
int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key) |
|
{ |
|
int found, n, err = 0; |
|
struct ubifs_znode *znode; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
dbg_tnck(key, "key "); |
|
found = lookup_level0_dirty(c, key, &znode, &n); |
|
if (found < 0) { |
|
err = found; |
|
goto out_unlock; |
|
} |
|
if (found == 1) |
|
err = tnc_delete(c, znode, n); |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_remove_nm - remove an index entry for a "hashed" node. |
|
* @c: UBIFS file-system description object |
|
* @key: key of node |
|
* @nm: directory entry name |
|
* |
|
* Returns %0 on success or negative error code on failure. |
|
*/ |
|
int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key, |
|
const struct fscrypt_name *nm) |
|
{ |
|
int n, err; |
|
struct ubifs_znode *znode; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
dbg_tnck(key, "key "); |
|
err = lookup_level0_dirty(c, key, &znode, &n); |
|
if (err < 0) |
|
goto out_unlock; |
|
|
|
if (err) { |
|
if (c->replaying) |
|
err = fallible_resolve_collision(c, key, &znode, &n, |
|
nm, 0); |
|
else |
|
err = resolve_collision(c, key, &znode, &n, nm); |
|
dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n); |
|
if (err < 0) |
|
goto out_unlock; |
|
if (err) { |
|
/* Ensure the znode is dirtied */ |
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
} |
|
err = tnc_delete(c, znode, n); |
|
} |
|
} |
|
|
|
out_unlock: |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_remove_dh - remove an index entry for a "double hashed" node. |
|
* @c: UBIFS file-system description object |
|
* @key: key of node |
|
* @cookie: node cookie for collision resolution |
|
* |
|
* Returns %0 on success or negative error code on failure. |
|
*/ |
|
int ubifs_tnc_remove_dh(struct ubifs_info *c, const union ubifs_key *key, |
|
uint32_t cookie) |
|
{ |
|
int n, err; |
|
struct ubifs_znode *znode; |
|
struct ubifs_dent_node *dent; |
|
struct ubifs_zbranch *zbr; |
|
|
|
if (!c->double_hash) |
|
return -EOPNOTSUPP; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
err = lookup_level0_dirty(c, key, &znode, &n); |
|
if (err <= 0) |
|
goto out_unlock; |
|
|
|
zbr = &znode->zbranch[n]; |
|
dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS); |
|
if (!dent) { |
|
err = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
|
|
err = tnc_read_hashed_node(c, zbr, dent); |
|
if (err) |
|
goto out_free; |
|
|
|
/* If the cookie does not match, we're facing a hash collision. */ |
|
if (le32_to_cpu(dent->cookie) != cookie) { |
|
union ubifs_key start_key; |
|
|
|
lowest_dent_key(c, &start_key, key_inum(c, key)); |
|
|
|
err = ubifs_lookup_level0(c, &start_key, &znode, &n); |
|
if (unlikely(err < 0)) |
|
goto out_free; |
|
|
|
err = search_dh_cookie(c, key, dent, cookie, &znode, &n, err); |
|
if (err) |
|
goto out_free; |
|
} |
|
|
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_free; |
|
} |
|
} |
|
err = tnc_delete(c, znode, n); |
|
|
|
out_free: |
|
kfree(dent); |
|
out_unlock: |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* key_in_range - determine if a key falls within a range of keys. |
|
* @c: UBIFS file-system description object |
|
* @key: key to check |
|
* @from_key: lowest key in range |
|
* @to_key: highest key in range |
|
* |
|
* This function returns %1 if the key is in range and %0 otherwise. |
|
*/ |
|
static int key_in_range(struct ubifs_info *c, union ubifs_key *key, |
|
union ubifs_key *from_key, union ubifs_key *to_key) |
|
{ |
|
if (keys_cmp(c, key, from_key) < 0) |
|
return 0; |
|
if (keys_cmp(c, key, to_key) > 0) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_remove_range - remove index entries in range. |
|
* @c: UBIFS file-system description object |
|
* @from_key: lowest key to remove |
|
* @to_key: highest key to remove |
|
* |
|
* This function removes index entries starting at @from_key and ending at |
|
* @to_key. This function returns zero in case of success and a negative error |
|
* code in case of failure. |
|
*/ |
|
int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key, |
|
union ubifs_key *to_key) |
|
{ |
|
int i, n, k, err = 0; |
|
struct ubifs_znode *znode; |
|
union ubifs_key *key; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
while (1) { |
|
/* Find first level 0 znode that contains keys to remove */ |
|
err = ubifs_lookup_level0(c, from_key, &znode, &n); |
|
if (err < 0) |
|
goto out_unlock; |
|
|
|
if (err) |
|
key = from_key; |
|
else { |
|
err = tnc_next(c, &znode, &n); |
|
if (err == -ENOENT) { |
|
err = 0; |
|
goto out_unlock; |
|
} |
|
if (err < 0) |
|
goto out_unlock; |
|
key = &znode->zbranch[n].key; |
|
if (!key_in_range(c, key, from_key, to_key)) { |
|
err = 0; |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
/* Ensure the znode is dirtied */ |
|
if (znode->cnext || !ubifs_zn_dirty(znode)) { |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
/* Remove all keys in range except the first */ |
|
for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) { |
|
key = &znode->zbranch[i].key; |
|
if (!key_in_range(c, key, from_key, to_key)) |
|
break; |
|
lnc_free(&znode->zbranch[i]); |
|
err = ubifs_add_dirt(c, znode->zbranch[i].lnum, |
|
znode->zbranch[i].len); |
|
if (err) { |
|
ubifs_dump_znode(c, znode); |
|
goto out_unlock; |
|
} |
|
dbg_tnck(key, "removing key "); |
|
} |
|
if (k) { |
|
for (i = n + 1 + k; i < znode->child_cnt; i++) |
|
znode->zbranch[i - k] = znode->zbranch[i]; |
|
znode->child_cnt -= k; |
|
} |
|
|
|
/* Now delete the first */ |
|
err = tnc_delete(c, znode, n); |
|
if (err) |
|
goto out_unlock; |
|
} |
|
|
|
out_unlock: |
|
if (!err) |
|
err = dbg_check_tnc(c, 0); |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_remove_ino - remove an inode from TNC. |
|
* @c: UBIFS file-system description object |
|
* @inum: inode number to remove |
|
* |
|
* This function remove inode @inum and all the extended attributes associated |
|
* with the anode from TNC and returns zero in case of success or a negative |
|
* error code in case of failure. |
|
*/ |
|
int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum) |
|
{ |
|
union ubifs_key key1, key2; |
|
struct ubifs_dent_node *xent, *pxent = NULL; |
|
struct fscrypt_name nm = {0}; |
|
|
|
dbg_tnc("ino %lu", (unsigned long)inum); |
|
|
|
/* |
|
* Walk all extended attribute entries and remove them together with |
|
* corresponding extended attribute inodes. |
|
*/ |
|
lowest_xent_key(c, &key1, inum); |
|
while (1) { |
|
ino_t xattr_inum; |
|
int err; |
|
|
|
xent = ubifs_tnc_next_ent(c, &key1, &nm); |
|
if (IS_ERR(xent)) { |
|
err = PTR_ERR(xent); |
|
if (err == -ENOENT) |
|
break; |
|
kfree(pxent); |
|
return err; |
|
} |
|
|
|
xattr_inum = le64_to_cpu(xent->inum); |
|
dbg_tnc("xent '%s', ino %lu", xent->name, |
|
(unsigned long)xattr_inum); |
|
|
|
ubifs_evict_xattr_inode(c, xattr_inum); |
|
|
|
fname_name(&nm) = xent->name; |
|
fname_len(&nm) = le16_to_cpu(xent->nlen); |
|
err = ubifs_tnc_remove_nm(c, &key1, &nm); |
|
if (err) { |
|
kfree(pxent); |
|
kfree(xent); |
|
return err; |
|
} |
|
|
|
lowest_ino_key(c, &key1, xattr_inum); |
|
highest_ino_key(c, &key2, xattr_inum); |
|
err = ubifs_tnc_remove_range(c, &key1, &key2); |
|
if (err) { |
|
kfree(pxent); |
|
kfree(xent); |
|
return err; |
|
} |
|
|
|
kfree(pxent); |
|
pxent = xent; |
|
key_read(c, &xent->key, &key1); |
|
} |
|
|
|
kfree(pxent); |
|
lowest_ino_key(c, &key1, inum); |
|
highest_ino_key(c, &key2, inum); |
|
|
|
return ubifs_tnc_remove_range(c, &key1, &key2); |
|
} |
|
|
|
/** |
|
* ubifs_tnc_next_ent - walk directory or extended attribute entries. |
|
* @c: UBIFS file-system description object |
|
* @key: key of last entry |
|
* @nm: name of last entry found or %NULL |
|
* |
|
* This function finds and reads the next directory or extended attribute entry |
|
* after the given key (@key) if there is one. @nm is used to resolve |
|
* collisions. |
|
* |
|
* If the name of the current entry is not known and only the key is known, |
|
* @nm->name has to be %NULL. In this case the semantics of this function is a |
|
* little bit different and it returns the entry corresponding to this key, not |
|
* the next one. If the key was not found, the closest "right" entry is |
|
* returned. |
|
* |
|
* If the fist entry has to be found, @key has to contain the lowest possible |
|
* key value for this inode and @name has to be %NULL. |
|
* |
|
* This function returns the found directory or extended attribute entry node |
|
* in case of success, %-ENOENT is returned if no entry was found, and a |
|
* negative error code is returned in case of failure. |
|
*/ |
|
struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c, |
|
union ubifs_key *key, |
|
const struct fscrypt_name *nm) |
|
{ |
|
int n, err, type = key_type(c, key); |
|
struct ubifs_znode *znode; |
|
struct ubifs_dent_node *dent; |
|
struct ubifs_zbranch *zbr; |
|
union ubifs_key *dkey; |
|
|
|
dbg_tnck(key, "key "); |
|
ubifs_assert(c, is_hash_key(c, key)); |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
err = ubifs_lookup_level0(c, key, &znode, &n); |
|
if (unlikely(err < 0)) |
|
goto out_unlock; |
|
|
|
if (fname_len(nm) > 0) { |
|
if (err) { |
|
/* Handle collisions */ |
|
if (c->replaying) |
|
err = fallible_resolve_collision(c, key, &znode, &n, |
|
nm, 0); |
|
else |
|
err = resolve_collision(c, key, &znode, &n, nm); |
|
dbg_tnc("rc returned %d, znode %p, n %d", |
|
err, znode, n); |
|
if (unlikely(err < 0)) |
|
goto out_unlock; |
|
} |
|
|
|
/* Now find next entry */ |
|
err = tnc_next(c, &znode, &n); |
|
if (unlikely(err)) |
|
goto out_unlock; |
|
} else { |
|
/* |
|
* The full name of the entry was not given, in which case the |
|
* behavior of this function is a little different and it |
|
* returns current entry, not the next one. |
|
*/ |
|
if (!err) { |
|
/* |
|
* However, the given key does not exist in the TNC |
|
* tree and @znode/@n variables contain the closest |
|
* "preceding" element. Switch to the next one. |
|
*/ |
|
err = tnc_next(c, &znode, &n); |
|
if (err) |
|
goto out_unlock; |
|
} |
|
} |
|
|
|
zbr = &znode->zbranch[n]; |
|
dent = kmalloc(zbr->len, GFP_NOFS); |
|
if (unlikely(!dent)) { |
|
err = -ENOMEM; |
|
goto out_unlock; |
|
} |
|
|
|
/* |
|
* The above 'tnc_next()' call could lead us to the next inode, check |
|
* this. |
|
*/ |
|
dkey = &zbr->key; |
|
if (key_inum(c, dkey) != key_inum(c, key) || |
|
key_type(c, dkey) != type) { |
|
err = -ENOENT; |
|
goto out_free; |
|
} |
|
|
|
err = tnc_read_hashed_node(c, zbr, dent); |
|
if (unlikely(err)) |
|
goto out_free; |
|
|
|
mutex_unlock(&c->tnc_mutex); |
|
return dent; |
|
|
|
out_free: |
|
kfree(dent); |
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return ERR_PTR(err); |
|
} |
|
|
|
/** |
|
* tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit. |
|
* @c: UBIFS file-system description object |
|
* |
|
* Destroy left-over obsolete znodes from a failed commit. |
|
*/ |
|
static void tnc_destroy_cnext(struct ubifs_info *c) |
|
{ |
|
struct ubifs_znode *cnext; |
|
|
|
if (!c->cnext) |
|
return; |
|
ubifs_assert(c, c->cmt_state == COMMIT_BROKEN); |
|
cnext = c->cnext; |
|
do { |
|
struct ubifs_znode *znode = cnext; |
|
|
|
cnext = cnext->cnext; |
|
if (ubifs_zn_obsolete(znode)) |
|
kfree(znode); |
|
} while (cnext && cnext != c->cnext); |
|
} |
|
|
|
/** |
|
* ubifs_tnc_close - close TNC subsystem and free all related resources. |
|
* @c: UBIFS file-system description object |
|
*/ |
|
void ubifs_tnc_close(struct ubifs_info *c) |
|
{ |
|
tnc_destroy_cnext(c); |
|
if (c->zroot.znode) { |
|
long n, freed; |
|
|
|
n = atomic_long_read(&c->clean_zn_cnt); |
|
freed = ubifs_destroy_tnc_subtree(c, c->zroot.znode); |
|
ubifs_assert(c, freed == n); |
|
atomic_long_sub(n, &ubifs_clean_zn_cnt); |
|
} |
|
kfree(c->gap_lebs); |
|
kfree(c->ilebs); |
|
destroy_old_idx(c); |
|
} |
|
|
|
/** |
|
* left_znode - get the znode to the left. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode |
|
* |
|
* This function returns a pointer to the znode to the left of @znode or NULL if |
|
* there is not one. A negative error code is returned on failure. |
|
*/ |
|
static struct ubifs_znode *left_znode(struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
int level = znode->level; |
|
|
|
while (1) { |
|
int n = znode->iip - 1; |
|
|
|
/* Go up until we can go left */ |
|
znode = znode->parent; |
|
if (!znode) |
|
return NULL; |
|
if (n >= 0) { |
|
/* Now go down the rightmost branch to 'level' */ |
|
znode = get_znode(c, znode, n); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
while (znode->level != level) { |
|
n = znode->child_cnt - 1; |
|
znode = get_znode(c, znode, n); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
} |
|
break; |
|
} |
|
} |
|
return znode; |
|
} |
|
|
|
/** |
|
* right_znode - get the znode to the right. |
|
* @c: UBIFS file-system description object |
|
* @znode: znode |
|
* |
|
* This function returns a pointer to the znode to the right of @znode or NULL |
|
* if there is not one. A negative error code is returned on failure. |
|
*/ |
|
static struct ubifs_znode *right_znode(struct ubifs_info *c, |
|
struct ubifs_znode *znode) |
|
{ |
|
int level = znode->level; |
|
|
|
while (1) { |
|
int n = znode->iip + 1; |
|
|
|
/* Go up until we can go right */ |
|
znode = znode->parent; |
|
if (!znode) |
|
return NULL; |
|
if (n < znode->child_cnt) { |
|
/* Now go down the leftmost branch to 'level' */ |
|
znode = get_znode(c, znode, n); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
while (znode->level != level) { |
|
znode = get_znode(c, znode, 0); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
} |
|
break; |
|
} |
|
} |
|
return znode; |
|
} |
|
|
|
/** |
|
* lookup_znode - find a particular indexing node from TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: index node key to lookup |
|
* @level: index node level |
|
* @lnum: index node LEB number |
|
* @offs: index node offset |
|
* |
|
* This function searches an indexing node by its first key @key and its |
|
* address @lnum:@offs. It looks up the indexing tree by pulling all indexing |
|
* nodes it traverses to TNC. This function is called for indexing nodes which |
|
* were found on the media by scanning, for example when garbage-collecting or |
|
* when doing in-the-gaps commit. This means that the indexing node which is |
|
* looked for does not have to have exactly the same leftmost key @key, because |
|
* the leftmost key may have been changed, in which case TNC will contain a |
|
* dirty znode which still refers the same @lnum:@offs. This function is clever |
|
* enough to recognize such indexing nodes. |
|
* |
|
* Note, if a znode was deleted or changed too much, then this function will |
|
* not find it. For situations like this UBIFS has the old index RB-tree |
|
* (indexed by @lnum:@offs). |
|
* |
|
* This function returns a pointer to the znode found or %NULL if it is not |
|
* found. A negative error code is returned on failure. |
|
*/ |
|
static struct ubifs_znode *lookup_znode(struct ubifs_info *c, |
|
union ubifs_key *key, int level, |
|
int lnum, int offs) |
|
{ |
|
struct ubifs_znode *znode, *zn; |
|
int n, nn; |
|
|
|
ubifs_assert(c, key_type(c, key) < UBIFS_INVALID_KEY); |
|
|
|
/* |
|
* The arguments have probably been read off flash, so don't assume |
|
* they are valid. |
|
*/ |
|
if (level < 0) |
|
return ERR_PTR(-EINVAL); |
|
|
|
/* Get the root znode */ |
|
znode = c->zroot.znode; |
|
if (!znode) { |
|
znode = ubifs_load_znode(c, &c->zroot, NULL, 0); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
} |
|
/* Check if it is the one we are looking for */ |
|
if (c->zroot.lnum == lnum && c->zroot.offs == offs) |
|
return znode; |
|
/* Descend to the parent level i.e. (level + 1) */ |
|
if (level >= znode->level) |
|
return NULL; |
|
while (1) { |
|
ubifs_search_zbranch(c, znode, key, &n); |
|
if (n < 0) { |
|
/* |
|
* We reached a znode where the leftmost key is greater |
|
* than the key we are searching for. This is the same |
|
* situation as the one described in a huge comment at |
|
* the end of the 'ubifs_lookup_level0()' function. And |
|
* for exactly the same reasons we have to try to look |
|
* left before giving up. |
|
*/ |
|
znode = left_znode(c, znode); |
|
if (!znode) |
|
return NULL; |
|
if (IS_ERR(znode)) |
|
return znode; |
|
ubifs_search_zbranch(c, znode, key, &n); |
|
ubifs_assert(c, n >= 0); |
|
} |
|
if (znode->level == level + 1) |
|
break; |
|
znode = get_znode(c, znode, n); |
|
if (IS_ERR(znode)) |
|
return znode; |
|
} |
|
/* Check if the child is the one we are looking for */ |
|
if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs) |
|
return get_znode(c, znode, n); |
|
/* If the key is unique, there is nowhere else to look */ |
|
if (!is_hash_key(c, key)) |
|
return NULL; |
|
/* |
|
* The key is not unique and so may be also in the znodes to either |
|
* side. |
|
*/ |
|
zn = znode; |
|
nn = n; |
|
/* Look left */ |
|
while (1) { |
|
/* Move one branch to the left */ |
|
if (n) |
|
n -= 1; |
|
else { |
|
znode = left_znode(c, znode); |
|
if (!znode) |
|
break; |
|
if (IS_ERR(znode)) |
|
return znode; |
|
n = znode->child_cnt - 1; |
|
} |
|
/* Check it */ |
|
if (znode->zbranch[n].lnum == lnum && |
|
znode->zbranch[n].offs == offs) |
|
return get_znode(c, znode, n); |
|
/* Stop if the key is less than the one we are looking for */ |
|
if (keys_cmp(c, &znode->zbranch[n].key, key) < 0) |
|
break; |
|
} |
|
/* Back to the middle */ |
|
znode = zn; |
|
n = nn; |
|
/* Look right */ |
|
while (1) { |
|
/* Move one branch to the right */ |
|
if (++n >= znode->child_cnt) { |
|
znode = right_znode(c, znode); |
|
if (!znode) |
|
break; |
|
if (IS_ERR(znode)) |
|
return znode; |
|
n = 0; |
|
} |
|
/* Check it */ |
|
if (znode->zbranch[n].lnum == lnum && |
|
znode->zbranch[n].offs == offs) |
|
return get_znode(c, znode, n); |
|
/* Stop if the key is greater than the one we are looking for */ |
|
if (keys_cmp(c, &znode->zbranch[n].key, key) > 0) |
|
break; |
|
} |
|
return NULL; |
|
} |
|
|
|
/** |
|
* is_idx_node_in_tnc - determine if an index node is in the TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: key of index node |
|
* @level: index node level |
|
* @lnum: LEB number of index node |
|
* @offs: offset of index node |
|
* |
|
* This function returns %0 if the index node is not referred to in the TNC, %1 |
|
* if the index node is referred to in the TNC and the corresponding znode is |
|
* dirty, %2 if an index node is referred to in the TNC and the corresponding |
|
* znode is clean, and a negative error code in case of failure. |
|
* |
|
* Note, the @key argument has to be the key of the first child. Also note, |
|
* this function relies on the fact that 0:0 is never a valid LEB number and |
|
* offset for a main-area node. |
|
*/ |
|
int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level, |
|
int lnum, int offs) |
|
{ |
|
struct ubifs_znode *znode; |
|
|
|
znode = lookup_znode(c, key, level, lnum, offs); |
|
if (!znode) |
|
return 0; |
|
if (IS_ERR(znode)) |
|
return PTR_ERR(znode); |
|
|
|
return ubifs_zn_dirty(znode) ? 1 : 2; |
|
} |
|
|
|
/** |
|
* is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: node key |
|
* @lnum: node LEB number |
|
* @offs: node offset |
|
* |
|
* This function returns %1 if the node is referred to in the TNC, %0 if it is |
|
* not, and a negative error code in case of failure. |
|
* |
|
* Note, this function relies on the fact that 0:0 is never a valid LEB number |
|
* and offset for a main-area node. |
|
*/ |
|
static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, |
|
int lnum, int offs) |
|
{ |
|
struct ubifs_zbranch *zbr; |
|
struct ubifs_znode *znode, *zn; |
|
int n, found, err, nn; |
|
const int unique = !is_hash_key(c, key); |
|
|
|
found = ubifs_lookup_level0(c, key, &znode, &n); |
|
if (found < 0) |
|
return found; /* Error code */ |
|
if (!found) |
|
return 0; |
|
zbr = &znode->zbranch[n]; |
|
if (lnum == zbr->lnum && offs == zbr->offs) |
|
return 1; /* Found it */ |
|
if (unique) |
|
return 0; |
|
/* |
|
* Because the key is not unique, we have to look left |
|
* and right as well |
|
*/ |
|
zn = znode; |
|
nn = n; |
|
/* Look left */ |
|
while (1) { |
|
err = tnc_prev(c, &znode, &n); |
|
if (err == -ENOENT) |
|
break; |
|
if (err) |
|
return err; |
|
if (keys_cmp(c, key, &znode->zbranch[n].key)) |
|
break; |
|
zbr = &znode->zbranch[n]; |
|
if (lnum == zbr->lnum && offs == zbr->offs) |
|
return 1; /* Found it */ |
|
} |
|
/* Look right */ |
|
znode = zn; |
|
n = nn; |
|
while (1) { |
|
err = tnc_next(c, &znode, &n); |
|
if (err) { |
|
if (err == -ENOENT) |
|
return 0; |
|
return err; |
|
} |
|
if (keys_cmp(c, key, &znode->zbranch[n].key)) |
|
break; |
|
zbr = &znode->zbranch[n]; |
|
if (lnum == zbr->lnum && offs == zbr->offs) |
|
return 1; /* Found it */ |
|
} |
|
return 0; |
|
} |
|
|
|
/** |
|
* ubifs_tnc_has_node - determine whether a node is in the TNC. |
|
* @c: UBIFS file-system description object |
|
* @key: node key |
|
* @level: index node level (if it is an index node) |
|
* @lnum: node LEB number |
|
* @offs: node offset |
|
* @is_idx: non-zero if the node is an index node |
|
* |
|
* This function returns %1 if the node is in the TNC, %0 if it is not, and a |
|
* negative error code in case of failure. For index nodes, @key has to be the |
|
* key of the first child. An index node is considered to be in the TNC only if |
|
* the corresponding znode is clean or has not been loaded. |
|
*/ |
|
int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level, |
|
int lnum, int offs, int is_idx) |
|
{ |
|
int err; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
if (is_idx) { |
|
err = is_idx_node_in_tnc(c, key, level, lnum, offs); |
|
if (err < 0) |
|
goto out_unlock; |
|
if (err == 1) |
|
/* The index node was found but it was dirty */ |
|
err = 0; |
|
else if (err == 2) |
|
/* The index node was found and it was clean */ |
|
err = 1; |
|
else |
|
BUG_ON(err != 0); |
|
} else |
|
err = is_leaf_node_in_tnc(c, key, lnum, offs); |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_dirty_idx_node - dirty an index node. |
|
* @c: UBIFS file-system description object |
|
* @key: index node key |
|
* @level: index node level |
|
* @lnum: index node LEB number |
|
* @offs: index node offset |
|
* |
|
* This function loads and dirties an index node so that it can be garbage |
|
* collected. The @key argument has to be the key of the first child. This |
|
* function relies on the fact that 0:0 is never a valid LEB number and offset |
|
* for a main-area node. Returns %0 on success and a negative error code on |
|
* failure. |
|
*/ |
|
int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level, |
|
int lnum, int offs) |
|
{ |
|
struct ubifs_znode *znode; |
|
int err = 0; |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
znode = lookup_znode(c, key, level, lnum, offs); |
|
if (!znode) |
|
goto out_unlock; |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
znode = dirty_cow_bottom_up(c, znode); |
|
if (IS_ERR(znode)) { |
|
err = PTR_ERR(znode); |
|
goto out_unlock; |
|
} |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
} |
|
|
|
/** |
|
* dbg_check_inode_size - check if inode size is correct. |
|
* @c: UBIFS file-system description object |
|
* @inode: inode to check |
|
* @size: inode size |
|
* |
|
* This function makes sure that the inode size (@size) is correct and it does |
|
* not have any pages beyond @size. Returns zero if the inode is OK, %-EINVAL |
|
* if it has a data page beyond @size, and other negative error code in case of |
|
* other errors. |
|
*/ |
|
int dbg_check_inode_size(struct ubifs_info *c, const struct inode *inode, |
|
loff_t size) |
|
{ |
|
int err, n; |
|
union ubifs_key from_key, to_key, *key; |
|
struct ubifs_znode *znode; |
|
unsigned int block; |
|
|
|
if (!S_ISREG(inode->i_mode)) |
|
return 0; |
|
if (!dbg_is_chk_gen(c)) |
|
return 0; |
|
|
|
block = (size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT; |
|
data_key_init(c, &from_key, inode->i_ino, block); |
|
highest_data_key(c, &to_key, inode->i_ino); |
|
|
|
mutex_lock(&c->tnc_mutex); |
|
err = ubifs_lookup_level0(c, &from_key, &znode, &n); |
|
if (err < 0) |
|
goto out_unlock; |
|
|
|
if (err) { |
|
key = &from_key; |
|
goto out_dump; |
|
} |
|
|
|
err = tnc_next(c, &znode, &n); |
|
if (err == -ENOENT) { |
|
err = 0; |
|
goto out_unlock; |
|
} |
|
if (err < 0) |
|
goto out_unlock; |
|
|
|
ubifs_assert(c, err == 0); |
|
key = &znode->zbranch[n].key; |
|
if (!key_in_range(c, key, &from_key, &to_key)) |
|
goto out_unlock; |
|
|
|
out_dump: |
|
block = key_block(c, key); |
|
ubifs_err(c, "inode %lu has size %lld, but there are data at offset %lld", |
|
(unsigned long)inode->i_ino, size, |
|
((loff_t)block) << UBIFS_BLOCK_SHIFT); |
|
mutex_unlock(&c->tnc_mutex); |
|
ubifs_dump_inode(c, inode); |
|
dump_stack(); |
|
return -EINVAL; |
|
|
|
out_unlock: |
|
mutex_unlock(&c->tnc_mutex); |
|
return err; |
|
}
|
|
|