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1159 lines
33 KiB
1159 lines
33 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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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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* Copyright (C) 2006, 2007 University of Szeged, Hungary |
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* |
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* Authors: Artem Bityutskiy (Битюцкий Артём) |
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* Adrian Hunter |
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* Zoltan Sogor |
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*/ |
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|
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/* |
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* This file implements UBIFS I/O subsystem which provides various I/O-related |
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* helper functions (reading/writing/checking/validating nodes) and implements |
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* write-buffering support. Write buffers help to save space which otherwise |
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* would have been wasted for padding to the nearest minimal I/O unit boundary. |
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* Instead, data first goes to the write-buffer and is flushed when the |
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* buffer is full or when it is not used for some time (by timer). This is |
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* similar to the mechanism is used by JFFS2. |
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* |
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* UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum |
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* write size (@c->max_write_size). The latter is the maximum amount of bytes |
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* the underlying flash is able to program at a time, and writing in |
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* @c->max_write_size units should presumably be faster. Obviously, |
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* @c->min_io_size <= @c->max_write_size. Write-buffers are of |
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* @c->max_write_size bytes in size for maximum performance. However, when a |
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* write-buffer is flushed, only the portion of it (aligned to @c->min_io_size |
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* boundary) which contains data is written, not the whole write-buffer, |
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* because this is more space-efficient. |
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* |
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* This optimization adds few complications to the code. Indeed, on the one |
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* hand, we want to write in optimal @c->max_write_size bytes chunks, which |
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* also means aligning writes at the @c->max_write_size bytes offsets. On the |
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* other hand, we do not want to waste space when synchronizing the write |
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* buffer, so during synchronization we writes in smaller chunks. And this makes |
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* the next write offset to be not aligned to @c->max_write_size bytes. So the |
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* have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned |
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* to @c->max_write_size bytes again. We do this by temporarily shrinking |
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* write-buffer size (@wbuf->size). |
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* |
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* Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by |
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* mutexes defined inside these objects. Since sometimes upper-level code |
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* has to lock the write-buffer (e.g. journal space reservation code), many |
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* functions related to write-buffers have "nolock" suffix which means that the |
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* caller has to lock the write-buffer before calling this function. |
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* |
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* UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not |
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* aligned, UBIFS starts the next node from the aligned address, and the padded |
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* bytes may contain any rubbish. In other words, UBIFS does not put padding |
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* bytes in those small gaps. Common headers of nodes store real node lengths, |
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* not aligned lengths. Indexing nodes also store real lengths in branches. |
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* |
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* UBIFS uses padding when it pads to the next min. I/O unit. In this case it |
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* uses padding nodes or padding bytes, if the padding node does not fit. |
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* |
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* All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when |
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* they are read from the flash media. |
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*/ |
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|
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#ifndef __UBOOT__ |
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#include <linux/crc32.h> |
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#include <linux/slab.h> |
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#else |
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#include <linux/compat.h> |
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#include <linux/err.h> |
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#endif |
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#include "ubifs.h" |
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|
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/** |
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* ubifs_ro_mode - switch UBIFS to read read-only mode. |
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* @c: UBIFS file-system description object |
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* @err: error code which is the reason of switching to R/O mode |
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*/ |
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void ubifs_ro_mode(struct ubifs_info *c, int err) |
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{ |
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if (!c->ro_error) { |
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c->ro_error = 1; |
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c->no_chk_data_crc = 0; |
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c->vfs_sb->s_flags |= MS_RDONLY; |
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ubifs_warn(c, "switched to read-only mode, error %d", err); |
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dump_stack(); |
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} |
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} |
|
|
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/* |
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* Below are simple wrappers over UBI I/O functions which include some |
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* additional checks and UBIFS debugging stuff. See corresponding UBI function |
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* for more information. |
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*/ |
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|
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int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, |
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int len, int even_ebadmsg) |
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{ |
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int err; |
|
|
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err = ubi_read(c->ubi, lnum, buf, offs, len); |
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/* |
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* In case of %-EBADMSG print the error message only if the |
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* @even_ebadmsg is true. |
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*/ |
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if (err && (err != -EBADMSG || even_ebadmsg)) { |
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ubifs_err(c, "reading %d bytes from LEB %d:%d failed, error %d", |
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len, lnum, offs, err); |
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dump_stack(); |
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} |
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return err; |
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} |
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|
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int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, |
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int len) |
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{ |
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int err; |
|
|
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ubifs_assert(!c->ro_media && !c->ro_mount); |
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if (c->ro_error) |
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return -EROFS; |
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if (!dbg_is_tst_rcvry(c)) |
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err = ubi_leb_write(c->ubi, lnum, buf, offs, len); |
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#ifndef __UBOOT__ |
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else |
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err = dbg_leb_write(c, lnum, buf, offs, len); |
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#endif |
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if (err) { |
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ubifs_err(c, "writing %d bytes to LEB %d:%d failed, error %d", |
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len, lnum, offs, err); |
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ubifs_ro_mode(c, err); |
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dump_stack(); |
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} |
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return err; |
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} |
|
|
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int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len) |
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{ |
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int err; |
|
|
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ubifs_assert(!c->ro_media && !c->ro_mount); |
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if (c->ro_error) |
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return -EROFS; |
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if (!dbg_is_tst_rcvry(c)) |
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err = ubi_leb_change(c->ubi, lnum, buf, len); |
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#ifndef __UBOOT__ |
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else |
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err = dbg_leb_change(c, lnum, buf, len); |
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#endif |
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if (err) { |
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ubifs_err(c, "changing %d bytes in LEB %d failed, error %d", |
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len, lnum, err); |
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ubifs_ro_mode(c, err); |
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dump_stack(); |
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} |
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return err; |
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} |
|
|
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int ubifs_leb_unmap(struct ubifs_info *c, int lnum) |
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{ |
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int err; |
|
|
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ubifs_assert(!c->ro_media && !c->ro_mount); |
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if (c->ro_error) |
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return -EROFS; |
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if (!dbg_is_tst_rcvry(c)) |
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err = ubi_leb_unmap(c->ubi, lnum); |
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#ifndef __UBOOT__ |
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else |
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err = dbg_leb_unmap(c, lnum); |
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#endif |
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if (err) { |
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ubifs_err(c, "unmap LEB %d failed, error %d", lnum, err); |
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ubifs_ro_mode(c, err); |
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dump_stack(); |
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} |
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return err; |
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} |
|
|
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int ubifs_leb_map(struct ubifs_info *c, int lnum) |
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{ |
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int err; |
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|
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ubifs_assert(!c->ro_media && !c->ro_mount); |
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if (c->ro_error) |
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return -EROFS; |
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if (!dbg_is_tst_rcvry(c)) |
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err = ubi_leb_map(c->ubi, lnum); |
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#ifndef __UBOOT__ |
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else |
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err = dbg_leb_map(c, lnum); |
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#endif |
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if (err) { |
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ubifs_err(c, "mapping LEB %d failed, error %d", lnum, err); |
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ubifs_ro_mode(c, err); |
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dump_stack(); |
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} |
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return err; |
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} |
|
|
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int ubifs_is_mapped(const struct ubifs_info *c, int lnum) |
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{ |
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int err; |
|
|
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err = ubi_is_mapped(c->ubi, lnum); |
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if (err < 0) { |
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ubifs_err(c, "ubi_is_mapped failed for LEB %d, error %d", |
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lnum, err); |
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dump_stack(); |
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} |
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return err; |
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} |
|
|
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/** |
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* ubifs_check_node - check node. |
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* @c: UBIFS file-system description object |
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* @buf: node to check |
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* @lnum: logical eraseblock number |
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* @offs: offset within the logical eraseblock |
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* @quiet: print no messages |
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* @must_chk_crc: indicates whether to always check the CRC |
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* |
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* This function checks node magic number and CRC checksum. This function also |
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* validates node length to prevent UBIFS from becoming crazy when an attacker |
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* feeds it a file-system image with incorrect nodes. For example, too large |
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* node length in the common header could cause UBIFS to read memory outside of |
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* allocated buffer when checking the CRC checksum. |
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* |
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* This function may skip data nodes CRC checking if @c->no_chk_data_crc is |
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* true, which is controlled by corresponding UBIFS mount option. However, if |
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* @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is |
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* checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are |
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* mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC |
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* is checked. This is because during mounting or re-mounting from R/O mode to |
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* R/W mode we may read journal nodes (when replying the journal or doing the |
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* recovery) and the journal nodes may potentially be corrupted, so checking is |
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* required. |
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* |
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* This function returns zero in case of success and %-EUCLEAN in case of bad |
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* CRC or magic. |
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*/ |
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int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, |
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int offs, int quiet, int must_chk_crc) |
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{ |
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int err = -EINVAL, type, node_len; |
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uint32_t crc, node_crc, magic; |
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const struct ubifs_ch *ch = buf; |
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|
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ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
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ubifs_assert(!(offs & 7) && offs < c->leb_size); |
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|
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magic = le32_to_cpu(ch->magic); |
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if (magic != UBIFS_NODE_MAGIC) { |
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if (!quiet) |
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ubifs_err(c, "bad magic %#08x, expected %#08x", |
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magic, UBIFS_NODE_MAGIC); |
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err = -EUCLEAN; |
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goto out; |
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} |
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|
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type = ch->node_type; |
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if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { |
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if (!quiet) |
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ubifs_err(c, "bad node type %d", type); |
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goto out; |
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} |
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|
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node_len = le32_to_cpu(ch->len); |
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if (node_len + offs > c->leb_size) |
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goto out_len; |
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|
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if (c->ranges[type].max_len == 0) { |
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if (node_len != c->ranges[type].len) |
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goto out_len; |
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} else if (node_len < c->ranges[type].min_len || |
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node_len > c->ranges[type].max_len) |
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goto out_len; |
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|
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if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting && |
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!c->remounting_rw && c->no_chk_data_crc) |
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return 0; |
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|
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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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if (!quiet) |
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ubifs_err(c, "bad CRC: calculated %#08x, read %#08x", |
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crc, node_crc); |
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err = -EUCLEAN; |
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goto out; |
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} |
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|
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return 0; |
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|
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out_len: |
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if (!quiet) |
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ubifs_err(c, "bad node length %d", node_len); |
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out: |
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if (!quiet) { |
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ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); |
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ubifs_dump_node(c, buf); |
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dump_stack(); |
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} |
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return err; |
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} |
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|
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/** |
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* ubifs_pad - pad flash space. |
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* @c: UBIFS file-system description object |
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* @buf: buffer to put padding to |
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* @pad: how many bytes to pad |
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* |
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* The flash media obliges us to write only in chunks of %c->min_io_size and |
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* when we have to write less data we add padding node to the write-buffer and |
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* pad it to the next minimal I/O unit's boundary. Padding nodes help when the |
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* media is being scanned. If the amount of wasted space is not enough to fit a |
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* padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes |
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* pattern (%UBIFS_PADDING_BYTE). |
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* |
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* Padding nodes are also used to fill gaps when the "commit-in-gaps" method is |
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* used. |
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*/ |
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void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) |
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{ |
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uint32_t crc; |
|
|
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ubifs_assert(pad >= 0 && !(pad & 7)); |
|
|
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if (pad >= UBIFS_PAD_NODE_SZ) { |
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struct ubifs_ch *ch = buf; |
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struct ubifs_pad_node *pad_node = buf; |
|
|
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ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
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ch->node_type = UBIFS_PAD_NODE; |
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ch->group_type = UBIFS_NO_NODE_GROUP; |
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ch->padding[0] = ch->padding[1] = 0; |
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ch->sqnum = 0; |
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ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); |
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pad -= UBIFS_PAD_NODE_SZ; |
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pad_node->pad_len = cpu_to_le32(pad); |
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crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); |
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ch->crc = cpu_to_le32(crc); |
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memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); |
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} else if (pad > 0) |
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/* Too little space, padding node won't fit */ |
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memset(buf, UBIFS_PADDING_BYTE, pad); |
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} |
|
|
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/** |
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* next_sqnum - get next sequence number. |
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* @c: UBIFS file-system description object |
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*/ |
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static unsigned long long next_sqnum(struct ubifs_info *c) |
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{ |
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unsigned long long sqnum; |
|
|
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spin_lock(&c->cnt_lock); |
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sqnum = ++c->max_sqnum; |
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spin_unlock(&c->cnt_lock); |
|
|
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if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { |
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if (sqnum >= SQNUM_WATERMARK) { |
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ubifs_err(c, "sequence number overflow %llu, end of life", |
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sqnum); |
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ubifs_ro_mode(c, -EINVAL); |
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} |
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ubifs_warn(c, "running out of sequence numbers, end of life soon"); |
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} |
|
|
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return sqnum; |
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} |
|
|
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/** |
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* ubifs_prepare_node - prepare node to be written to flash. |
|
* @c: UBIFS file-system description object |
|
* @node: the node to pad |
|
* @len: node length |
|
* @pad: if the buffer has to be padded |
|
* |
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* This function prepares node at @node to be written to the media - it |
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* calculates node CRC, fills the common header, and adds proper padding up to |
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* the next minimum I/O unit if @pad is not zero. |
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*/ |
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void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) |
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{ |
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uint32_t crc; |
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struct ubifs_ch *ch = node; |
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unsigned long long sqnum = next_sqnum(c); |
|
|
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ubifs_assert(len >= UBIFS_CH_SZ); |
|
|
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ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
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ch->len = cpu_to_le32(len); |
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ch->group_type = UBIFS_NO_NODE_GROUP; |
|
ch->sqnum = cpu_to_le64(sqnum); |
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ch->padding[0] = ch->padding[1] = 0; |
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crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); |
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ch->crc = cpu_to_le32(crc); |
|
|
|
if (pad) { |
|
len = ALIGN(len, 8); |
|
pad = ALIGN(len, c->min_io_size) - len; |
|
ubifs_pad(c, node + len, pad); |
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} |
|
} |
|
|
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/** |
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* ubifs_prep_grp_node - prepare node of a group to be written to flash. |
|
* @c: UBIFS file-system description object |
|
* @node: the node to pad |
|
* @len: node length |
|
* @last: indicates the last node of the group |
|
* |
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* This function prepares node at @node to be written to the media - it |
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* calculates node CRC and fills the common header. |
|
*/ |
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void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) |
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{ |
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uint32_t crc; |
|
struct ubifs_ch *ch = node; |
|
unsigned long long sqnum = next_sqnum(c); |
|
|
|
ubifs_assert(len >= UBIFS_CH_SZ); |
|
|
|
ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); |
|
ch->len = cpu_to_le32(len); |
|
if (last) |
|
ch->group_type = UBIFS_LAST_OF_NODE_GROUP; |
|
else |
|
ch->group_type = UBIFS_IN_NODE_GROUP; |
|
ch->sqnum = cpu_to_le64(sqnum); |
|
ch->padding[0] = ch->padding[1] = 0; |
|
crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); |
|
ch->crc = cpu_to_le32(crc); |
|
} |
|
|
|
#ifndef __UBOOT__ |
|
/** |
|
* wbuf_timer_callback - write-buffer timer callback function. |
|
* @timer: timer data (write-buffer descriptor) |
|
* |
|
* This function is called when the write-buffer timer expires. |
|
*/ |
|
static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) |
|
{ |
|
struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); |
|
|
|
dbg_io("jhead %s", dbg_jhead(wbuf->jhead)); |
|
wbuf->need_sync = 1; |
|
wbuf->c->need_wbuf_sync = 1; |
|
ubifs_wake_up_bgt(wbuf->c); |
|
return HRTIMER_NORESTART; |
|
} |
|
|
|
/** |
|
* new_wbuf_timer - start new write-buffer timer. |
|
* @wbuf: write-buffer descriptor |
|
*/ |
|
static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) |
|
{ |
|
ubifs_assert(!hrtimer_active(&wbuf->timer)); |
|
|
|
if (wbuf->no_timer) |
|
return; |
|
dbg_io("set timer for jhead %s, %llu-%llu millisecs", |
|
dbg_jhead(wbuf->jhead), |
|
div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), |
|
div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, |
|
USEC_PER_SEC)); |
|
hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, |
|
HRTIMER_MODE_REL); |
|
} |
|
#endif |
|
|
|
/** |
|
* cancel_wbuf_timer - cancel write-buffer timer. |
|
* @wbuf: write-buffer descriptor |
|
*/ |
|
static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) |
|
{ |
|
if (wbuf->no_timer) |
|
return; |
|
wbuf->need_sync = 0; |
|
#ifndef __UBOOT__ |
|
hrtimer_cancel(&wbuf->timer); |
|
#endif |
|
} |
|
|
|
/** |
|
* ubifs_wbuf_sync_nolock - synchronize write-buffer. |
|
* @wbuf: write-buffer to synchronize |
|
* |
|
* This function synchronizes write-buffer @buf and returns zero in case of |
|
* success or a negative error code in case of failure. |
|
* |
|
* Note, although write-buffers are of @c->max_write_size, this function does |
|
* not necessarily writes all @c->max_write_size bytes to the flash. Instead, |
|
* if the write-buffer is only partially filled with data, only the used part |
|
* of the write-buffer (aligned on @c->min_io_size boundary) is synchronized. |
|
* This way we waste less space. |
|
*/ |
|
int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) |
|
{ |
|
struct ubifs_info *c = wbuf->c; |
|
int err, dirt, sync_len; |
|
|
|
cancel_wbuf_timer_nolock(wbuf); |
|
if (!wbuf->used || wbuf->lnum == -1) |
|
/* Write-buffer is empty or not seeked */ |
|
return 0; |
|
|
|
dbg_io("LEB %d:%d, %d bytes, jhead %s", |
|
wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); |
|
ubifs_assert(!(wbuf->avail & 7)); |
|
ubifs_assert(wbuf->offs + wbuf->size <= c->leb_size); |
|
ubifs_assert(wbuf->size >= c->min_io_size); |
|
ubifs_assert(wbuf->size <= c->max_write_size); |
|
ubifs_assert(wbuf->size % c->min_io_size == 0); |
|
ubifs_assert(!c->ro_media && !c->ro_mount); |
|
if (c->leb_size - wbuf->offs >= c->max_write_size) |
|
ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); |
|
|
|
if (c->ro_error) |
|
return -EROFS; |
|
|
|
/* |
|
* Do not write whole write buffer but write only the minimum necessary |
|
* amount of min. I/O units. |
|
*/ |
|
sync_len = ALIGN(wbuf->used, c->min_io_size); |
|
dirt = sync_len - wbuf->used; |
|
if (dirt) |
|
ubifs_pad(c, wbuf->buf + wbuf->used, dirt); |
|
err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len); |
|
if (err) |
|
return err; |
|
|
|
spin_lock(&wbuf->lock); |
|
wbuf->offs += sync_len; |
|
/* |
|
* Now @wbuf->offs is not necessarily aligned to @c->max_write_size. |
|
* But our goal is to optimize writes and make sure we write in |
|
* @c->max_write_size chunks and to @c->max_write_size-aligned offset. |
|
* Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make |
|
* sure that @wbuf->offs + @wbuf->size is aligned to |
|
* @c->max_write_size. This way we make sure that after next |
|
* write-buffer flush we are again at the optimal offset (aligned to |
|
* @c->max_write_size). |
|
*/ |
|
if (c->leb_size - wbuf->offs < c->max_write_size) |
|
wbuf->size = c->leb_size - wbuf->offs; |
|
else if (wbuf->offs & (c->max_write_size - 1)) |
|
wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; |
|
else |
|
wbuf->size = c->max_write_size; |
|
wbuf->avail = wbuf->size; |
|
wbuf->used = 0; |
|
wbuf->next_ino = 0; |
|
spin_unlock(&wbuf->lock); |
|
|
|
if (wbuf->sync_callback) |
|
err = wbuf->sync_callback(c, wbuf->lnum, |
|
c->leb_size - wbuf->offs, dirt); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_wbuf_seek_nolock - seek write-buffer. |
|
* @wbuf: write-buffer |
|
* @lnum: logical eraseblock number to seek to |
|
* @offs: logical eraseblock offset to seek to |
|
* |
|
* This function targets the write-buffer to logical eraseblock @lnum:@offs. |
|
* The write-buffer has to be empty. Returns zero in case of success and a |
|
* negative error code in case of failure. |
|
*/ |
|
int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs) |
|
{ |
|
const struct ubifs_info *c = wbuf->c; |
|
|
|
dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead)); |
|
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt); |
|
ubifs_assert(offs >= 0 && offs <= c->leb_size); |
|
ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7)); |
|
ubifs_assert(lnum != wbuf->lnum); |
|
ubifs_assert(wbuf->used == 0); |
|
|
|
spin_lock(&wbuf->lock); |
|
wbuf->lnum = lnum; |
|
wbuf->offs = offs; |
|
if (c->leb_size - wbuf->offs < c->max_write_size) |
|
wbuf->size = c->leb_size - wbuf->offs; |
|
else if (wbuf->offs & (c->max_write_size - 1)) |
|
wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; |
|
else |
|
wbuf->size = c->max_write_size; |
|
wbuf->avail = wbuf->size; |
|
wbuf->used = 0; |
|
spin_unlock(&wbuf->lock); |
|
|
|
return 0; |
|
} |
|
|
|
#ifndef __UBOOT__ |
|
/** |
|
* ubifs_bg_wbufs_sync - synchronize write-buffers. |
|
* @c: UBIFS file-system description object |
|
* |
|
* This function is called by background thread to synchronize write-buffers. |
|
* Returns zero in case of success and a negative error code in case of |
|
* failure. |
|
*/ |
|
int ubifs_bg_wbufs_sync(struct ubifs_info *c) |
|
{ |
|
int err, i; |
|
|
|
ubifs_assert(!c->ro_media && !c->ro_mount); |
|
if (!c->need_wbuf_sync) |
|
return 0; |
|
c->need_wbuf_sync = 0; |
|
|
|
if (c->ro_error) { |
|
err = -EROFS; |
|
goto out_timers; |
|
} |
|
|
|
dbg_io("synchronize"); |
|
for (i = 0; i < c->jhead_cnt; i++) { |
|
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
|
|
|
cond_resched(); |
|
|
|
/* |
|
* If the mutex is locked then wbuf is being changed, so |
|
* synchronization is not necessary. |
|
*/ |
|
if (mutex_is_locked(&wbuf->io_mutex)) |
|
continue; |
|
|
|
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
|
if (!wbuf->need_sync) { |
|
mutex_unlock(&wbuf->io_mutex); |
|
continue; |
|
} |
|
|
|
err = ubifs_wbuf_sync_nolock(wbuf); |
|
mutex_unlock(&wbuf->io_mutex); |
|
if (err) { |
|
ubifs_err(c, "cannot sync write-buffer, error %d", err); |
|
ubifs_ro_mode(c, err); |
|
goto out_timers; |
|
} |
|
} |
|
|
|
return 0; |
|
|
|
out_timers: |
|
/* Cancel all timers to prevent repeated errors */ |
|
for (i = 0; i < c->jhead_cnt; i++) { |
|
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
|
|
|
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
|
cancel_wbuf_timer_nolock(wbuf); |
|
mutex_unlock(&wbuf->io_mutex); |
|
} |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_wbuf_write_nolock - write data to flash via write-buffer. |
|
* @wbuf: write-buffer |
|
* @buf: node to write |
|
* @len: node length |
|
* |
|
* This function writes data to flash via write-buffer @wbuf. This means that |
|
* the last piece of the node won't reach the flash media immediately if it |
|
* does not take whole max. write unit (@c->max_write_size). Instead, the node |
|
* will sit in RAM until the write-buffer is synchronized (e.g., by timer, or |
|
* because more data are appended to the write-buffer). |
|
* |
|
* This function returns zero in case of success and a negative error code in |
|
* case of failure. If the node cannot be written because there is no more |
|
* space in this logical eraseblock, %-ENOSPC is returned. |
|
*/ |
|
int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) |
|
{ |
|
struct ubifs_info *c = wbuf->c; |
|
int err, written, n, aligned_len = ALIGN(len, 8); |
|
|
|
dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, |
|
dbg_ntype(((struct ubifs_ch *)buf)->node_type), |
|
dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); |
|
ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); |
|
ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); |
|
ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); |
|
ubifs_assert(wbuf->avail > 0 && wbuf->avail <= wbuf->size); |
|
ubifs_assert(wbuf->size >= c->min_io_size); |
|
ubifs_assert(wbuf->size <= c->max_write_size); |
|
ubifs_assert(wbuf->size % c->min_io_size == 0); |
|
ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); |
|
ubifs_assert(!c->ro_media && !c->ro_mount); |
|
ubifs_assert(!c->space_fixup); |
|
if (c->leb_size - wbuf->offs >= c->max_write_size) |
|
ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); |
|
|
|
if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { |
|
err = -ENOSPC; |
|
goto out; |
|
} |
|
|
|
cancel_wbuf_timer_nolock(wbuf); |
|
|
|
if (c->ro_error) |
|
return -EROFS; |
|
|
|
if (aligned_len <= wbuf->avail) { |
|
/* |
|
* The node is not very large and fits entirely within |
|
* write-buffer. |
|
*/ |
|
memcpy(wbuf->buf + wbuf->used, buf, len); |
|
|
|
if (aligned_len == wbuf->avail) { |
|
dbg_io("flush jhead %s wbuf to LEB %d:%d", |
|
dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); |
|
err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, |
|
wbuf->offs, wbuf->size); |
|
if (err) |
|
goto out; |
|
|
|
spin_lock(&wbuf->lock); |
|
wbuf->offs += wbuf->size; |
|
if (c->leb_size - wbuf->offs >= c->max_write_size) |
|
wbuf->size = c->max_write_size; |
|
else |
|
wbuf->size = c->leb_size - wbuf->offs; |
|
wbuf->avail = wbuf->size; |
|
wbuf->used = 0; |
|
wbuf->next_ino = 0; |
|
spin_unlock(&wbuf->lock); |
|
} else { |
|
spin_lock(&wbuf->lock); |
|
wbuf->avail -= aligned_len; |
|
wbuf->used += aligned_len; |
|
spin_unlock(&wbuf->lock); |
|
} |
|
|
|
goto exit; |
|
} |
|
|
|
written = 0; |
|
|
|
if (wbuf->used) { |
|
/* |
|
* The node is large enough and does not fit entirely within |
|
* current available space. We have to fill and flush |
|
* write-buffer and switch to the next max. write unit. |
|
*/ |
|
dbg_io("flush jhead %s wbuf to LEB %d:%d", |
|
dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); |
|
memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); |
|
err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, |
|
wbuf->size); |
|
if (err) |
|
goto out; |
|
|
|
wbuf->offs += wbuf->size; |
|
len -= wbuf->avail; |
|
aligned_len -= wbuf->avail; |
|
written += wbuf->avail; |
|
} else if (wbuf->offs & (c->max_write_size - 1)) { |
|
/* |
|
* The write-buffer offset is not aligned to |
|
* @c->max_write_size and @wbuf->size is less than |
|
* @c->max_write_size. Write @wbuf->size bytes to make sure the |
|
* following writes are done in optimal @c->max_write_size |
|
* chunks. |
|
*/ |
|
dbg_io("write %d bytes to LEB %d:%d", |
|
wbuf->size, wbuf->lnum, wbuf->offs); |
|
err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs, |
|
wbuf->size); |
|
if (err) |
|
goto out; |
|
|
|
wbuf->offs += wbuf->size; |
|
len -= wbuf->size; |
|
aligned_len -= wbuf->size; |
|
written += wbuf->size; |
|
} |
|
|
|
/* |
|
* The remaining data may take more whole max. write units, so write the |
|
* remains multiple to max. write unit size directly to the flash media. |
|
* We align node length to 8-byte boundary because we anyway flash wbuf |
|
* if the remaining space is less than 8 bytes. |
|
*/ |
|
n = aligned_len >> c->max_write_shift; |
|
if (n) { |
|
n <<= c->max_write_shift; |
|
dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, |
|
wbuf->offs); |
|
err = ubifs_leb_write(c, wbuf->lnum, buf + written, |
|
wbuf->offs, n); |
|
if (err) |
|
goto out; |
|
wbuf->offs += n; |
|
aligned_len -= n; |
|
len -= n; |
|
written += n; |
|
} |
|
|
|
spin_lock(&wbuf->lock); |
|
if (aligned_len) |
|
/* |
|
* And now we have what's left and what does not take whole |
|
* max. write unit, so write it to the write-buffer and we are |
|
* done. |
|
*/ |
|
memcpy(wbuf->buf, buf + written, len); |
|
|
|
if (c->leb_size - wbuf->offs >= c->max_write_size) |
|
wbuf->size = c->max_write_size; |
|
else |
|
wbuf->size = c->leb_size - wbuf->offs; |
|
wbuf->avail = wbuf->size - aligned_len; |
|
wbuf->used = aligned_len; |
|
wbuf->next_ino = 0; |
|
spin_unlock(&wbuf->lock); |
|
|
|
exit: |
|
if (wbuf->sync_callback) { |
|
int free = c->leb_size - wbuf->offs - wbuf->used; |
|
|
|
err = wbuf->sync_callback(c, wbuf->lnum, free, 0); |
|
if (err) |
|
goto out; |
|
} |
|
|
|
if (wbuf->used) |
|
new_wbuf_timer_nolock(wbuf); |
|
|
|
return 0; |
|
|
|
out: |
|
ubifs_err(c, "cannot write %d bytes to LEB %d:%d, error %d", |
|
len, wbuf->lnum, wbuf->offs, err); |
|
ubifs_dump_node(c, buf); |
|
dump_stack(); |
|
ubifs_dump_leb(c, wbuf->lnum); |
|
return err; |
|
} |
|
|
|
/** |
|
* ubifs_write_node - write node to the media. |
|
* @c: UBIFS file-system description object |
|
* @buf: the node to write |
|
* @len: node length |
|
* @lnum: logical eraseblock number |
|
* @offs: offset within the logical eraseblock |
|
* |
|
* This function automatically fills node magic number, assigns sequence |
|
* number, and calculates node CRC checksum. The length of the @buf buffer has |
|
* to be aligned to the minimal I/O unit size. This function automatically |
|
* appends padding node and padding bytes if needed. Returns zero in case of |
|
* success and a negative error code in case of failure. |
|
*/ |
|
int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, |
|
int offs) |
|
{ |
|
int err, buf_len = ALIGN(len, c->min_io_size); |
|
|
|
dbg_io("LEB %d:%d, %s, length %d (aligned %d)", |
|
lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, |
|
buf_len); |
|
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
|
ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size); |
|
ubifs_assert(!c->ro_media && !c->ro_mount); |
|
ubifs_assert(!c->space_fixup); |
|
|
|
if (c->ro_error) |
|
return -EROFS; |
|
|
|
ubifs_prepare_node(c, buf, len, 1); |
|
err = ubifs_leb_write(c, lnum, buf, offs, buf_len); |
|
if (err) |
|
ubifs_dump_node(c, buf); |
|
|
|
return err; |
|
} |
|
#endif |
|
|
|
/** |
|
* ubifs_read_node_wbuf - read node from the media or write-buffer. |
|
* @wbuf: wbuf to check for un-written data |
|
* @buf: buffer to read to |
|
* @type: node type |
|
* @len: node length |
|
* @lnum: logical eraseblock number |
|
* @offs: offset within the logical eraseblock |
|
* |
|
* This function reads a node of known type and length, checks it and stores |
|
* in @buf. If the node partially or fully sits in the write-buffer, this |
|
* function takes data from the buffer, otherwise it reads the flash media. |
|
* Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative |
|
* error code in case of failure. |
|
*/ |
|
int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, |
|
int lnum, int offs) |
|
{ |
|
const struct ubifs_info *c = wbuf->c; |
|
int err, rlen, overlap; |
|
struct ubifs_ch *ch = buf; |
|
|
|
dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, |
|
dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); |
|
ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
|
ubifs_assert(!(offs & 7) && offs < c->leb_size); |
|
ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); |
|
|
|
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_read_node(c, buf, type, len, lnum, offs); |
|
} |
|
|
|
/* 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 */ |
|
err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0); |
|
if (err && err != -EBADMSG) |
|
return err; |
|
} |
|
|
|
if (type != ch->node_type) { |
|
ubifs_err(c, "bad node type (%d but expected %d)", |
|
ch->node_type, type); |
|
goto out; |
|
} |
|
|
|
err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
|
if (err) { |
|
ubifs_err(c, "expected node type %d", type); |
|
return err; |
|
} |
|
|
|
rlen = le32_to_cpu(ch->len); |
|
if (rlen != len) { |
|
ubifs_err(c, "bad node length %d, expected %d", rlen, len); |
|
goto out; |
|
} |
|
|
|
return 0; |
|
|
|
out: |
|
ubifs_err(c, "bad node at LEB %d:%d", lnum, offs); |
|
ubifs_dump_node(c, buf); |
|
dump_stack(); |
|
return -EINVAL; |
|
} |
|
|
|
/** |
|
* ubifs_read_node - read node. |
|
* @c: UBIFS file-system description object |
|
* @buf: buffer to read to |
|
* @type: node type |
|
* @len: node length (not aligned) |
|
* @lnum: logical eraseblock number |
|
* @offs: offset within the logical eraseblock |
|
* |
|
* This function reads a node of known type and and length, checks it and |
|
* stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched |
|
* and a negative error code in case of failure. |
|
*/ |
|
int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, |
|
int lnum, int offs) |
|
{ |
|
int err, l; |
|
struct ubifs_ch *ch = buf; |
|
|
|
dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); |
|
ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); |
|
ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); |
|
ubifs_assert(!(offs & 7) && offs < c->leb_size); |
|
ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); |
|
|
|
err = ubifs_leb_read(c, lnum, buf, offs, len, 0); |
|
if (err && err != -EBADMSG) |
|
return err; |
|
|
|
if (type != ch->node_type) { |
|
ubifs_errc(c, "bad node type (%d but expected %d)", |
|
ch->node_type, type); |
|
goto out; |
|
} |
|
|
|
err = ubifs_check_node(c, buf, lnum, offs, 0, 0); |
|
if (err) { |
|
ubifs_errc(c, "expected node type %d", type); |
|
return err; |
|
} |
|
|
|
l = le32_to_cpu(ch->len); |
|
if (l != len) { |
|
ubifs_errc(c, "bad node length %d, expected %d", l, len); |
|
goto out; |
|
} |
|
|
|
return 0; |
|
|
|
out: |
|
ubifs_errc(c, "bad node at LEB %d:%d, LEB mapping status %d", lnum, |
|
offs, ubi_is_mapped(c->ubi, lnum)); |
|
if (!c->probing) { |
|
ubifs_dump_node(c, buf); |
|
dump_stack(); |
|
} |
|
return -EINVAL; |
|
} |
|
|
|
/** |
|
* ubifs_wbuf_init - initialize write-buffer. |
|
* @c: UBIFS file-system description object |
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* @wbuf: write-buffer to initialize |
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* |
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* This function initializes write-buffer. Returns zero in case of success |
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* %-ENOMEM in case of failure. |
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*/ |
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int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) |
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{ |
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size_t size; |
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|
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wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL); |
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if (!wbuf->buf) |
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return -ENOMEM; |
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|
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size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); |
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wbuf->inodes = kmalloc(size, GFP_KERNEL); |
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if (!wbuf->inodes) { |
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kfree(wbuf->buf); |
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wbuf->buf = NULL; |
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return -ENOMEM; |
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} |
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|
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wbuf->used = 0; |
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wbuf->lnum = wbuf->offs = -1; |
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/* |
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* If the LEB starts at the max. write size aligned address, then |
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* write-buffer size has to be set to @c->max_write_size. Otherwise, |
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* set it to something smaller so that it ends at the closest max. |
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* write size boundary. |
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*/ |
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size = c->max_write_size - (c->leb_start % c->max_write_size); |
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wbuf->avail = wbuf->size = size; |
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wbuf->sync_callback = NULL; |
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mutex_init(&wbuf->io_mutex); |
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spin_lock_init(&wbuf->lock); |
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wbuf->c = c; |
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wbuf->next_ino = 0; |
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|
|
#ifndef __UBOOT__ |
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hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); |
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wbuf->timer.function = wbuf_timer_callback_nolock; |
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wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); |
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wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; |
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wbuf->delta *= 1000000000ULL; |
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ubifs_assert(wbuf->delta <= ULONG_MAX); |
|
#endif |
|
return 0; |
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} |
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|
|
/** |
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* ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. |
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* @wbuf: the write-buffer where to add |
|
* @inum: the inode number |
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* |
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* This function adds an inode number to the inode array of the write-buffer. |
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*/ |
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void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) |
|
{ |
|
if (!wbuf->buf) |
|
/* NOR flash or something similar */ |
|
return; |
|
|
|
spin_lock(&wbuf->lock); |
|
if (wbuf->used) |
|
wbuf->inodes[wbuf->next_ino++] = inum; |
|
spin_unlock(&wbuf->lock); |
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} |
|
|
|
/** |
|
* wbuf_has_ino - returns if the wbuf contains data from the inode. |
|
* @wbuf: the write-buffer |
|
* @inum: the inode number |
|
* |
|
* This function returns with %1 if the write-buffer contains some data from the |
|
* given inode otherwise it returns with %0. |
|
*/ |
|
static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) |
|
{ |
|
int i, ret = 0; |
|
|
|
spin_lock(&wbuf->lock); |
|
for (i = 0; i < wbuf->next_ino; i++) |
|
if (inum == wbuf->inodes[i]) { |
|
ret = 1; |
|
break; |
|
} |
|
spin_unlock(&wbuf->lock); |
|
|
|
return ret; |
|
} |
|
|
|
/** |
|
* ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. |
|
* @c: UBIFS file-system description object |
|
* @inode: inode to synchronize |
|
* |
|
* This function synchronizes write-buffers which contain nodes belonging to |
|
* @inode. Returns zero in case of success and a negative error code in case of |
|
* failure. |
|
*/ |
|
int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) |
|
{ |
|
int i, err = 0; |
|
|
|
for (i = 0; i < c->jhead_cnt; i++) { |
|
struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; |
|
|
|
if (i == GCHD) |
|
/* |
|
* GC head is special, do not look at it. Even if the |
|
* head contains something related to this inode, it is |
|
* a _copy_ of corresponding on-flash node which sits |
|
* somewhere else. |
|
*/ |
|
continue; |
|
|
|
if (!wbuf_has_ino(wbuf, inode->i_ino)) |
|
continue; |
|
|
|
mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); |
|
if (wbuf_has_ino(wbuf, inode->i_ino)) |
|
err = ubifs_wbuf_sync_nolock(wbuf); |
|
mutex_unlock(&wbuf->io_mutex); |
|
|
|
if (err) { |
|
ubifs_ro_mode(c, err); |
|
return err; |
|
} |
|
} |
|
return 0; |
|
}
|
|
|