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743 lines
22 KiB
743 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* linux/fs/jbd2/revoke.c |
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* |
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* Written by Stephen C. Tweedie <[email protected]>, 2000 |
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* |
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* Copyright 2000 Red Hat corp --- All Rights Reserved |
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* |
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* Journal revoke routines for the generic filesystem journaling code; |
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* part of the ext2fs journaling system. |
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* |
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* Revoke is the mechanism used to prevent old log records for deleted |
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* metadata from being replayed on top of newer data using the same |
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* blocks. The revoke mechanism is used in two separate places: |
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* |
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* + Commit: during commit we write the entire list of the current |
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* transaction's revoked blocks to the journal |
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* |
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* + Recovery: during recovery we record the transaction ID of all |
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* revoked blocks. If there are multiple revoke records in the log |
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* for a single block, only the last one counts, and if there is a log |
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* entry for a block beyond the last revoke, then that log entry still |
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* gets replayed. |
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* |
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* We can get interactions between revokes and new log data within a |
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* single transaction: |
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* |
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* Block is revoked and then journaled: |
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* The desired end result is the journaling of the new block, so we |
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* cancel the revoke before the transaction commits. |
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* |
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* Block is journaled and then revoked: |
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* The revoke must take precedence over the write of the block, so we |
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* need either to cancel the journal entry or to write the revoke |
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* later in the log than the log block. In this case, we choose the |
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* latter: journaling a block cancels any revoke record for that block |
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* in the current transaction, so any revoke for that block in the |
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* transaction must have happened after the block was journaled and so |
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* the revoke must take precedence. |
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* |
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* Block is revoked and then written as data: |
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* The data write is allowed to succeed, but the revoke is _not_ |
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* cancelled. We still need to prevent old log records from |
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* overwriting the new data. We don't even need to clear the revoke |
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* bit here. |
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* |
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* We cache revoke status of a buffer in the current transaction in b_states |
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* bits. As the name says, revokevalid flag indicates that the cached revoke |
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* status of a buffer is valid and we can rely on the cached status. |
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* |
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* Revoke information on buffers is a tri-state value: |
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* |
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* RevokeValid clear: no cached revoke status, need to look it up |
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* RevokeValid set, Revoked clear: |
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* buffer has not been revoked, and cancel_revoke |
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* need do nothing. |
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* RevokeValid set, Revoked set: |
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* buffer has been revoked. |
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* |
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* Locking rules: |
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* We keep two hash tables of revoke records. One hashtable belongs to the |
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* running transaction (is pointed to by journal->j_revoke), the other one |
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* belongs to the committing transaction. Accesses to the second hash table |
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* happen only from the kjournald and no other thread touches this table. Also |
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* journal_switch_revoke_table() which switches which hashtable belongs to the |
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* running and which to the committing transaction is called only from |
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* kjournald. Therefore we need no locks when accessing the hashtable belonging |
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* to the committing transaction. |
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* |
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* All users operating on the hash table belonging to the running transaction |
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* have a handle to the transaction. Therefore they are safe from kjournald |
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* switching hash tables under them. For operations on the lists of entries in |
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* the hash table j_revoke_lock is used. |
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* |
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* Finally, also replay code uses the hash tables but at this moment no one else |
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* can touch them (filesystem isn't mounted yet) and hence no locking is |
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* needed. |
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*/ |
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|
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#ifndef __KERNEL__ |
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#include "jfs_user.h" |
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#else |
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#include <linux/time.h> |
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#include <linux/fs.h> |
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#include <linux/jbd2.h> |
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#include <linux/errno.h> |
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#include <linux/slab.h> |
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#include <linux/list.h> |
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#include <linux/init.h> |
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#include <linux/bio.h> |
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#include <linux/log2.h> |
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#include <linux/hash.h> |
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#endif |
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|
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static struct kmem_cache *jbd2_revoke_record_cache; |
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static struct kmem_cache *jbd2_revoke_table_cache; |
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|
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/* Each revoke record represents one single revoked block. During |
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journal replay, this involves recording the transaction ID of the |
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last transaction to revoke this block. */ |
|
|
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struct jbd2_revoke_record_s |
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{ |
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struct list_head hash; |
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tid_t sequence; /* Used for recovery only */ |
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unsigned long long blocknr; |
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}; |
|
|
|
|
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/* The revoke table is just a simple hash table of revoke records. */ |
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struct jbd2_revoke_table_s |
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{ |
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/* It is conceivable that we might want a larger hash table |
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* for recovery. Must be a power of two. */ |
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int hash_size; |
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int hash_shift; |
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struct list_head *hash_table; |
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}; |
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|
|
|
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#ifdef __KERNEL__ |
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static void write_one_revoke_record(transaction_t *, |
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struct list_head *, |
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struct buffer_head **, int *, |
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struct jbd2_revoke_record_s *); |
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static void flush_descriptor(journal_t *, struct buffer_head *, int); |
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#endif |
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|
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/* Utility functions to maintain the revoke table */ |
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|
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static inline int hash(journal_t *journal, unsigned long long block) |
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{ |
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return hash_64(block, journal->j_revoke->hash_shift); |
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} |
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|
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static int insert_revoke_hash(journal_t *journal, unsigned long long blocknr, |
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tid_t seq) |
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{ |
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struct list_head *hash_list; |
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struct jbd2_revoke_record_s *record; |
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gfp_t gfp_mask = GFP_NOFS; |
|
|
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if (journal_oom_retry) |
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gfp_mask |= __GFP_NOFAIL; |
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record = kmem_cache_alloc(jbd2_revoke_record_cache, gfp_mask); |
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if (!record) |
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return -ENOMEM; |
|
|
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record->sequence = seq; |
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record->blocknr = blocknr; |
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hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; |
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spin_lock(&journal->j_revoke_lock); |
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list_add(&record->hash, hash_list); |
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spin_unlock(&journal->j_revoke_lock); |
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return 0; |
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} |
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|
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/* Find a revoke record in the journal's hash table. */ |
|
|
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static struct jbd2_revoke_record_s *find_revoke_record(journal_t *journal, |
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unsigned long long blocknr) |
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{ |
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struct list_head *hash_list; |
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struct jbd2_revoke_record_s *record; |
|
|
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hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)]; |
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|
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spin_lock(&journal->j_revoke_lock); |
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record = (struct jbd2_revoke_record_s *) hash_list->next; |
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while (&(record->hash) != hash_list) { |
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if (record->blocknr == blocknr) { |
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spin_unlock(&journal->j_revoke_lock); |
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return record; |
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} |
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record = (struct jbd2_revoke_record_s *) record->hash.next; |
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} |
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spin_unlock(&journal->j_revoke_lock); |
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return NULL; |
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} |
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|
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void jbd2_journal_destroy_revoke_record_cache(void) |
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{ |
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kmem_cache_destroy(jbd2_revoke_record_cache); |
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jbd2_revoke_record_cache = NULL; |
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} |
|
|
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void jbd2_journal_destroy_revoke_table_cache(void) |
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{ |
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kmem_cache_destroy(jbd2_revoke_table_cache); |
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jbd2_revoke_table_cache = NULL; |
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} |
|
|
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int __init jbd2_journal_init_revoke_record_cache(void) |
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{ |
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J_ASSERT(!jbd2_revoke_record_cache); |
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jbd2_revoke_record_cache = KMEM_CACHE(jbd2_revoke_record_s, |
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SLAB_HWCACHE_ALIGN|SLAB_TEMPORARY); |
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|
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if (!jbd2_revoke_record_cache) { |
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pr_emerg("JBD2: failed to create revoke_record cache\n"); |
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return -ENOMEM; |
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} |
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return 0; |
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} |
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|
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int __init jbd2_journal_init_revoke_table_cache(void) |
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{ |
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J_ASSERT(!jbd2_revoke_table_cache); |
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jbd2_revoke_table_cache = KMEM_CACHE(jbd2_revoke_table_s, |
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SLAB_TEMPORARY); |
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if (!jbd2_revoke_table_cache) { |
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pr_emerg("JBD2: failed to create revoke_table cache\n"); |
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return -ENOMEM; |
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} |
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return 0; |
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} |
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|
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static struct jbd2_revoke_table_s *jbd2_journal_init_revoke_table(int hash_size) |
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{ |
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int shift = 0; |
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int tmp = hash_size; |
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struct jbd2_revoke_table_s *table; |
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|
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table = kmem_cache_alloc(jbd2_revoke_table_cache, GFP_KERNEL); |
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if (!table) |
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goto out; |
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|
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while((tmp >>= 1UL) != 0UL) |
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shift++; |
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|
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table->hash_size = hash_size; |
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table->hash_shift = shift; |
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table->hash_table = |
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kmalloc_array(hash_size, sizeof(struct list_head), GFP_KERNEL); |
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if (!table->hash_table) { |
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kmem_cache_free(jbd2_revoke_table_cache, table); |
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table = NULL; |
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goto out; |
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} |
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|
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for (tmp = 0; tmp < hash_size; tmp++) |
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INIT_LIST_HEAD(&table->hash_table[tmp]); |
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|
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out: |
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return table; |
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} |
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|
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static void jbd2_journal_destroy_revoke_table(struct jbd2_revoke_table_s *table) |
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{ |
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int i; |
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struct list_head *hash_list; |
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|
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for (i = 0; i < table->hash_size; i++) { |
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hash_list = &table->hash_table[i]; |
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J_ASSERT(list_empty(hash_list)); |
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} |
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|
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kfree(table->hash_table); |
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kmem_cache_free(jbd2_revoke_table_cache, table); |
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} |
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|
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/* Initialise the revoke table for a given journal to a given size. */ |
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int jbd2_journal_init_revoke(journal_t *journal, int hash_size) |
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{ |
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J_ASSERT(journal->j_revoke_table[0] == NULL); |
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J_ASSERT(is_power_of_2(hash_size)); |
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|
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journal->j_revoke_table[0] = jbd2_journal_init_revoke_table(hash_size); |
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if (!journal->j_revoke_table[0]) |
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goto fail0; |
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|
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journal->j_revoke_table[1] = jbd2_journal_init_revoke_table(hash_size); |
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if (!journal->j_revoke_table[1]) |
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goto fail1; |
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|
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journal->j_revoke = journal->j_revoke_table[1]; |
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|
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spin_lock_init(&journal->j_revoke_lock); |
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|
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return 0; |
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|
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fail1: |
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jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]); |
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journal->j_revoke_table[0] = NULL; |
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fail0: |
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return -ENOMEM; |
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} |
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|
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/* Destroy a journal's revoke table. The table must already be empty! */ |
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void jbd2_journal_destroy_revoke(journal_t *journal) |
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{ |
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journal->j_revoke = NULL; |
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if (journal->j_revoke_table[0]) |
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jbd2_journal_destroy_revoke_table(journal->j_revoke_table[0]); |
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if (journal->j_revoke_table[1]) |
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jbd2_journal_destroy_revoke_table(journal->j_revoke_table[1]); |
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} |
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|
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|
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#ifdef __KERNEL__ |
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|
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/* |
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* jbd2_journal_revoke: revoke a given buffer_head from the journal. This |
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* prevents the block from being replayed during recovery if we take a |
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* crash after this current transaction commits. Any subsequent |
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* metadata writes of the buffer in this transaction cancel the |
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* revoke. |
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* |
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* Note that this call may block --- it is up to the caller to make |
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* sure that there are no further calls to journal_write_metadata |
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* before the revoke is complete. In ext3, this implies calling the |
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* revoke before clearing the block bitmap when we are deleting |
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* metadata. |
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* |
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* Revoke performs a jbd2_journal_forget on any buffer_head passed in as a |
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* parameter, but does _not_ forget the buffer_head if the bh was only |
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* found implicitly. |
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* |
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* bh_in may not be a journalled buffer - it may have come off |
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* the hash tables without an attached journal_head. |
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* |
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* If bh_in is non-zero, jbd2_journal_revoke() will decrement its b_count |
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* by one. |
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*/ |
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|
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int jbd2_journal_revoke(handle_t *handle, unsigned long long blocknr, |
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struct buffer_head *bh_in) |
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{ |
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struct buffer_head *bh = NULL; |
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journal_t *journal; |
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struct block_device *bdev; |
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int err; |
|
|
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might_sleep(); |
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if (bh_in) |
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BUFFER_TRACE(bh_in, "enter"); |
|
|
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journal = handle->h_transaction->t_journal; |
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if (!jbd2_journal_set_features(journal, 0, 0, JBD2_FEATURE_INCOMPAT_REVOKE)){ |
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J_ASSERT (!"Cannot set revoke feature!"); |
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return -EINVAL; |
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} |
|
|
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bdev = journal->j_fs_dev; |
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bh = bh_in; |
|
|
|
if (!bh) { |
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bh = __find_get_block(bdev, blocknr, journal->j_blocksize); |
|
if (bh) |
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BUFFER_TRACE(bh, "found on hash"); |
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} |
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#ifdef JBD2_EXPENSIVE_CHECKING |
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else { |
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struct buffer_head *bh2; |
|
|
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/* If there is a different buffer_head lying around in |
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* memory anywhere... */ |
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bh2 = __find_get_block(bdev, blocknr, journal->j_blocksize); |
|
if (bh2) { |
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/* ... and it has RevokeValid status... */ |
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if (bh2 != bh && buffer_revokevalid(bh2)) |
|
/* ...then it better be revoked too, |
|
* since it's illegal to create a revoke |
|
* record against a buffer_head which is |
|
* not marked revoked --- that would |
|
* risk missing a subsequent revoke |
|
* cancel. */ |
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J_ASSERT_BH(bh2, buffer_revoked(bh2)); |
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put_bh(bh2); |
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} |
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} |
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#endif |
|
|
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if (WARN_ON_ONCE(handle->h_revoke_credits <= 0)) { |
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if (!bh_in) |
|
brelse(bh); |
|
return -EIO; |
|
} |
|
/* We really ought not ever to revoke twice in a row without |
|
first having the revoke cancelled: it's illegal to free a |
|
block twice without allocating it in between! */ |
|
if (bh) { |
|
if (!J_EXPECT_BH(bh, !buffer_revoked(bh), |
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"inconsistent data on disk")) { |
|
if (!bh_in) |
|
brelse(bh); |
|
return -EIO; |
|
} |
|
set_buffer_revoked(bh); |
|
set_buffer_revokevalid(bh); |
|
if (bh_in) { |
|
BUFFER_TRACE(bh_in, "call jbd2_journal_forget"); |
|
jbd2_journal_forget(handle, bh_in); |
|
} else { |
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BUFFER_TRACE(bh, "call brelse"); |
|
__brelse(bh); |
|
} |
|
} |
|
handle->h_revoke_credits--; |
|
|
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jbd_debug(2, "insert revoke for block %llu, bh_in=%p\n",blocknr, bh_in); |
|
err = insert_revoke_hash(journal, blocknr, |
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handle->h_transaction->t_tid); |
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BUFFER_TRACE(bh_in, "exit"); |
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return err; |
|
} |
|
|
|
/* |
|
* Cancel an outstanding revoke. For use only internally by the |
|
* journaling code (called from jbd2_journal_get_write_access). |
|
* |
|
* We trust buffer_revoked() on the buffer if the buffer is already |
|
* being journaled: if there is no revoke pending on the buffer, then we |
|
* don't do anything here. |
|
* |
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* This would break if it were possible for a buffer to be revoked and |
|
* discarded, and then reallocated within the same transaction. In such |
|
* a case we would have lost the revoked bit, but when we arrived here |
|
* the second time we would still have a pending revoke to cancel. So, |
|
* do not trust the Revoked bit on buffers unless RevokeValid is also |
|
* set. |
|
*/ |
|
int jbd2_journal_cancel_revoke(handle_t *handle, struct journal_head *jh) |
|
{ |
|
struct jbd2_revoke_record_s *record; |
|
journal_t *journal = handle->h_transaction->t_journal; |
|
int need_cancel; |
|
int did_revoke = 0; /* akpm: debug */ |
|
struct buffer_head *bh = jh2bh(jh); |
|
|
|
jbd_debug(4, "journal_head %p, cancelling revoke\n", jh); |
|
|
|
/* Is the existing Revoke bit valid? If so, we trust it, and |
|
* only perform the full cancel if the revoke bit is set. If |
|
* not, we can't trust the revoke bit, and we need to do the |
|
* full search for a revoke record. */ |
|
if (test_set_buffer_revokevalid(bh)) { |
|
need_cancel = test_clear_buffer_revoked(bh); |
|
} else { |
|
need_cancel = 1; |
|
clear_buffer_revoked(bh); |
|
} |
|
|
|
if (need_cancel) { |
|
record = find_revoke_record(journal, bh->b_blocknr); |
|
if (record) { |
|
jbd_debug(4, "cancelled existing revoke on " |
|
"blocknr %llu\n", (unsigned long long)bh->b_blocknr); |
|
spin_lock(&journal->j_revoke_lock); |
|
list_del(&record->hash); |
|
spin_unlock(&journal->j_revoke_lock); |
|
kmem_cache_free(jbd2_revoke_record_cache, record); |
|
did_revoke = 1; |
|
} |
|
} |
|
|
|
#ifdef JBD2_EXPENSIVE_CHECKING |
|
/* There better not be one left behind by now! */ |
|
record = find_revoke_record(journal, bh->b_blocknr); |
|
J_ASSERT_JH(jh, record == NULL); |
|
#endif |
|
|
|
/* Finally, have we just cleared revoke on an unhashed |
|
* buffer_head? If so, we'd better make sure we clear the |
|
* revoked status on any hashed alias too, otherwise the revoke |
|
* state machine will get very upset later on. */ |
|
if (need_cancel) { |
|
struct buffer_head *bh2; |
|
bh2 = __find_get_block(bh->b_bdev, bh->b_blocknr, bh->b_size); |
|
if (bh2) { |
|
if (bh2 != bh) |
|
clear_buffer_revoked(bh2); |
|
__brelse(bh2); |
|
} |
|
} |
|
return did_revoke; |
|
} |
|
|
|
/* |
|
* journal_clear_revoked_flag clears revoked flag of buffers in |
|
* revoke table to reflect there is no revoked buffers in the next |
|
* transaction which is going to be started. |
|
*/ |
|
void jbd2_clear_buffer_revoked_flags(journal_t *journal) |
|
{ |
|
struct jbd2_revoke_table_s *revoke = journal->j_revoke; |
|
int i = 0; |
|
|
|
for (i = 0; i < revoke->hash_size; i++) { |
|
struct list_head *hash_list; |
|
struct list_head *list_entry; |
|
hash_list = &revoke->hash_table[i]; |
|
|
|
list_for_each(list_entry, hash_list) { |
|
struct jbd2_revoke_record_s *record; |
|
struct buffer_head *bh; |
|
record = (struct jbd2_revoke_record_s *)list_entry; |
|
bh = __find_get_block(journal->j_fs_dev, |
|
record->blocknr, |
|
journal->j_blocksize); |
|
if (bh) { |
|
clear_buffer_revoked(bh); |
|
__brelse(bh); |
|
} |
|
} |
|
} |
|
} |
|
|
|
/* journal_switch_revoke table select j_revoke for next transaction |
|
* we do not want to suspend any processing until all revokes are |
|
* written -bzzz |
|
*/ |
|
void jbd2_journal_switch_revoke_table(journal_t *journal) |
|
{ |
|
int i; |
|
|
|
if (journal->j_revoke == journal->j_revoke_table[0]) |
|
journal->j_revoke = journal->j_revoke_table[1]; |
|
else |
|
journal->j_revoke = journal->j_revoke_table[0]; |
|
|
|
for (i = 0; i < journal->j_revoke->hash_size; i++) |
|
INIT_LIST_HEAD(&journal->j_revoke->hash_table[i]); |
|
} |
|
|
|
/* |
|
* Write revoke records to the journal for all entries in the current |
|
* revoke hash, deleting the entries as we go. |
|
*/ |
|
void jbd2_journal_write_revoke_records(transaction_t *transaction, |
|
struct list_head *log_bufs) |
|
{ |
|
journal_t *journal = transaction->t_journal; |
|
struct buffer_head *descriptor; |
|
struct jbd2_revoke_record_s *record; |
|
struct jbd2_revoke_table_s *revoke; |
|
struct list_head *hash_list; |
|
int i, offset, count; |
|
|
|
descriptor = NULL; |
|
offset = 0; |
|
count = 0; |
|
|
|
/* select revoke table for committing transaction */ |
|
revoke = journal->j_revoke == journal->j_revoke_table[0] ? |
|
journal->j_revoke_table[1] : journal->j_revoke_table[0]; |
|
|
|
for (i = 0; i < revoke->hash_size; i++) { |
|
hash_list = &revoke->hash_table[i]; |
|
|
|
while (!list_empty(hash_list)) { |
|
record = (struct jbd2_revoke_record_s *) |
|
hash_list->next; |
|
write_one_revoke_record(transaction, log_bufs, |
|
&descriptor, &offset, record); |
|
count++; |
|
list_del(&record->hash); |
|
kmem_cache_free(jbd2_revoke_record_cache, record); |
|
} |
|
} |
|
if (descriptor) |
|
flush_descriptor(journal, descriptor, offset); |
|
jbd_debug(1, "Wrote %d revoke records\n", count); |
|
} |
|
|
|
/* |
|
* Write out one revoke record. We need to create a new descriptor |
|
* block if the old one is full or if we have not already created one. |
|
*/ |
|
|
|
static void write_one_revoke_record(transaction_t *transaction, |
|
struct list_head *log_bufs, |
|
struct buffer_head **descriptorp, |
|
int *offsetp, |
|
struct jbd2_revoke_record_s *record) |
|
{ |
|
journal_t *journal = transaction->t_journal; |
|
int csum_size = 0; |
|
struct buffer_head *descriptor; |
|
int sz, offset; |
|
|
|
/* If we are already aborting, this all becomes a noop. We |
|
still need to go round the loop in |
|
jbd2_journal_write_revoke_records in order to free all of the |
|
revoke records: only the IO to the journal is omitted. */ |
|
if (is_journal_aborted(journal)) |
|
return; |
|
|
|
descriptor = *descriptorp; |
|
offset = *offsetp; |
|
|
|
/* Do we need to leave space at the end for a checksum? */ |
|
if (jbd2_journal_has_csum_v2or3(journal)) |
|
csum_size = sizeof(struct jbd2_journal_block_tail); |
|
|
|
if (jbd2_has_feature_64bit(journal)) |
|
sz = 8; |
|
else |
|
sz = 4; |
|
|
|
/* Make sure we have a descriptor with space left for the record */ |
|
if (descriptor) { |
|
if (offset + sz > journal->j_blocksize - csum_size) { |
|
flush_descriptor(journal, descriptor, offset); |
|
descriptor = NULL; |
|
} |
|
} |
|
|
|
if (!descriptor) { |
|
descriptor = jbd2_journal_get_descriptor_buffer(transaction, |
|
JBD2_REVOKE_BLOCK); |
|
if (!descriptor) |
|
return; |
|
|
|
/* Record it so that we can wait for IO completion later */ |
|
BUFFER_TRACE(descriptor, "file in log_bufs"); |
|
jbd2_file_log_bh(log_bufs, descriptor); |
|
|
|
offset = sizeof(jbd2_journal_revoke_header_t); |
|
*descriptorp = descriptor; |
|
} |
|
|
|
if (jbd2_has_feature_64bit(journal)) |
|
* ((__be64 *)(&descriptor->b_data[offset])) = |
|
cpu_to_be64(record->blocknr); |
|
else |
|
* ((__be32 *)(&descriptor->b_data[offset])) = |
|
cpu_to_be32(record->blocknr); |
|
offset += sz; |
|
|
|
*offsetp = offset; |
|
} |
|
|
|
/* |
|
* Flush a revoke descriptor out to the journal. If we are aborting, |
|
* this is a noop; otherwise we are generating a buffer which needs to |
|
* be waited for during commit, so it has to go onto the appropriate |
|
* journal buffer list. |
|
*/ |
|
|
|
static void flush_descriptor(journal_t *journal, |
|
struct buffer_head *descriptor, |
|
int offset) |
|
{ |
|
jbd2_journal_revoke_header_t *header; |
|
|
|
if (is_journal_aborted(journal)) |
|
return; |
|
|
|
header = (jbd2_journal_revoke_header_t *)descriptor->b_data; |
|
header->r_count = cpu_to_be32(offset); |
|
jbd2_descriptor_block_csum_set(journal, descriptor); |
|
|
|
set_buffer_jwrite(descriptor); |
|
BUFFER_TRACE(descriptor, "write"); |
|
set_buffer_dirty(descriptor); |
|
write_dirty_buffer(descriptor, REQ_SYNC); |
|
} |
|
#endif |
|
|
|
/* |
|
* Revoke support for recovery. |
|
* |
|
* Recovery needs to be able to: |
|
* |
|
* record all revoke records, including the tid of the latest instance |
|
* of each revoke in the journal |
|
* |
|
* check whether a given block in a given transaction should be replayed |
|
* (ie. has not been revoked by a revoke record in that or a subsequent |
|
* transaction) |
|
* |
|
* empty the revoke table after recovery. |
|
*/ |
|
|
|
/* |
|
* First, setting revoke records. We create a new revoke record for |
|
* every block ever revoked in the log as we scan it for recovery, and |
|
* we update the existing records if we find multiple revokes for a |
|
* single block. |
|
*/ |
|
|
|
int jbd2_journal_set_revoke(journal_t *journal, |
|
unsigned long long blocknr, |
|
tid_t sequence) |
|
{ |
|
struct jbd2_revoke_record_s *record; |
|
|
|
record = find_revoke_record(journal, blocknr); |
|
if (record) { |
|
/* If we have multiple occurrences, only record the |
|
* latest sequence number in the hashed record */ |
|
if (tid_gt(sequence, record->sequence)) |
|
record->sequence = sequence; |
|
return 0; |
|
} |
|
return insert_revoke_hash(journal, blocknr, sequence); |
|
} |
|
|
|
/* |
|
* Test revoke records. For a given block referenced in the log, has |
|
* that block been revoked? A revoke record with a given transaction |
|
* sequence number revokes all blocks in that transaction and earlier |
|
* ones, but later transactions still need replayed. |
|
*/ |
|
|
|
int jbd2_journal_test_revoke(journal_t *journal, |
|
unsigned long long blocknr, |
|
tid_t sequence) |
|
{ |
|
struct jbd2_revoke_record_s *record; |
|
|
|
record = find_revoke_record(journal, blocknr); |
|
if (!record) |
|
return 0; |
|
if (tid_gt(sequence, record->sequence)) |
|
return 0; |
|
return 1; |
|
} |
|
|
|
/* |
|
* Finally, once recovery is over, we need to clear the revoke table so |
|
* that it can be reused by the running filesystem. |
|
*/ |
|
|
|
void jbd2_journal_clear_revoke(journal_t *journal) |
|
{ |
|
int i; |
|
struct list_head *hash_list; |
|
struct jbd2_revoke_record_s *record; |
|
struct jbd2_revoke_table_s *revoke; |
|
|
|
revoke = journal->j_revoke; |
|
|
|
for (i = 0; i < revoke->hash_size; i++) { |
|
hash_list = &revoke->hash_table[i]; |
|
while (!list_empty(hash_list)) { |
|
record = (struct jbd2_revoke_record_s*) hash_list->next; |
|
list_del(&record->hash); |
|
kmem_cache_free(jbd2_revoke_record_cache, record); |
|
} |
|
} |
|
}
|
|
|