diff options
Diffstat (limited to 'fs/jbd/revoke.c')
| -rw-r--r-- | fs/jbd/revoke.c | 106 |
1 files changed, 76 insertions, 30 deletions
diff --git a/fs/jbd/revoke.c b/fs/jbd/revoke.c index c7bd649bbbd..8898bbd2b61 100644 --- a/fs/jbd/revoke.c +++ b/fs/jbd/revoke.c @@ -47,6 +47,10 @@ * overwriting the new data. We don't even need to clear the revoke * bit here. * + * We cache revoke status of a buffer in the current transaction in b_states + * bits. As the name says, revokevalid flag indicates that the cached revoke + * status of a buffer is valid and we can rely on the cached status. + * * Revoke information on buffers is a tri-state value: * * RevokeValid clear: no cached revoke status, need to look it up @@ -55,6 +59,25 @@ * need do nothing. * RevokeValid set, Revoked set: * buffer has been revoked. + * + * Locking rules: + * We keep two hash tables of revoke records. One hashtable belongs to the + * running transaction (is pointed to by journal->j_revoke), the other one + * belongs to the committing transaction. Accesses to the second hash table + * happen only from the kjournald and no other thread touches this table. Also + * journal_switch_revoke_table() which switches which hashtable belongs to the + * running and which to the committing transaction is called only from + * kjournald. Therefore we need no locks when accessing the hashtable belonging + * to the committing transaction. + * + * All users operating on the hash table belonging to the running transaction + * have a handle to the transaction. Therefore they are safe from kjournald + * switching hash tables under them. For operations on the lists of entries in + * the hash table j_revoke_lock is used. + * + * Finally, also replay code uses the hash tables but at this moment no one else + * can touch them (filesystem isn't mounted yet) and hence no locking is + * needed. */ #ifndef __KERNEL__ @@ -67,6 +90,7 @@ #include <linux/slab.h> #include <linux/list.h> #include <linux/init.h> +#include <linux/bio.h> #endif #include <linux/log2.h> @@ -81,7 +105,7 @@ struct jbd_revoke_record_s { struct list_head hash; tid_t sequence; /* Used for recovery only */ - unsigned long blocknr; + unsigned int blocknr; }; @@ -99,14 +123,14 @@ struct jbd_revoke_table_s #ifdef __KERNEL__ static void write_one_revoke_record(journal_t *, transaction_t *, struct journal_head **, int *, - struct jbd_revoke_record_s *); -static void flush_descriptor(journal_t *, struct journal_head *, int); + struct jbd_revoke_record_s *, int); +static void flush_descriptor(journal_t *, struct journal_head *, int, int); #endif /* Utility functions to maintain the revoke table */ /* Borrowed from buffer.c: this is a tried and tested block hash function */ -static inline int hash(journal_t *journal, unsigned long block) +static inline int hash(journal_t *journal, unsigned int block) { struct jbd_revoke_table_s *table = journal->j_revoke; int hash_shift = table->hash_shift; @@ -116,7 +140,7 @@ static inline int hash(journal_t *journal, unsigned long block) (block << (hash_shift - 12))) & (table->hash_size - 1); } -static int insert_revoke_hash(journal_t *journal, unsigned long blocknr, +static int insert_revoke_hash(journal_t *journal, unsigned int blocknr, tid_t seq) { struct list_head *hash_list; @@ -146,7 +170,7 @@ oom: /* Find a revoke record in the journal's hash table. */ static struct jbd_revoke_record_s *find_revoke_record(journal_t *journal, - unsigned long blocknr) + unsigned int blocknr) { struct list_head *hash_list; struct jbd_revoke_record_s *record; @@ -207,19 +231,15 @@ record_cache_failure: static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size) { - int shift = 0; - int tmp = hash_size; + int i; struct jbd_revoke_table_s *table; table = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL); if (!table) goto out; - while((tmp >>= 1UL) != 0UL) - shift++; - table->hash_size = hash_size; - table->hash_shift = shift; + table->hash_shift = ilog2(hash_size); table->hash_table = kmalloc(hash_size * sizeof(struct list_head), GFP_KERNEL); if (!table->hash_table) { @@ -228,8 +248,8 @@ static struct jbd_revoke_table_s *journal_init_revoke_table(int hash_size) goto out; } - for (tmp = 0; tmp < hash_size; tmp++) - INIT_LIST_HEAD(&table->hash_table[tmp]); + for (i = 0; i < hash_size; i++) + INIT_LIST_HEAD(&table->hash_table[i]); out: return table; @@ -312,7 +332,7 @@ void journal_destroy_revoke(journal_t *journal) * by one. */ -int journal_revoke(handle_t *handle, unsigned long blocknr, +int journal_revoke(handle_t *handle, unsigned int blocknr, struct buffer_head *bh_in) { struct buffer_head *bh = NULL; @@ -381,7 +401,7 @@ int journal_revoke(handle_t *handle, unsigned long blocknr, } } - jbd_debug(2, "insert revoke for block %lu, bh_in=%p\n", blocknr, bh_in); + jbd_debug(2, "insert revoke for block %u, bh_in=%p\n", blocknr, bh_in); err = insert_revoke_hash(journal, blocknr, handle->h_transaction->t_tid); BUFFER_TRACE(bh_in, "exit"); @@ -402,8 +422,6 @@ int journal_revoke(handle_t *handle, unsigned long blocknr, * 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. - * - * The caller must have the journal locked. */ int journal_cancel_revoke(handle_t *handle, struct journal_head *jh) { @@ -461,6 +479,36 @@ int journal_cancel_revoke(handle_t *handle, struct journal_head *jh) return did_revoke; } +/* + * journal_clear_revoked_flags clears revoked flag of buffers in + * revoke table to reflect there is no revoked buffer in the next + * transaction which is going to be started. + */ +void journal_clear_buffer_revoked_flags(journal_t *journal) +{ + struct jbd_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 jbd_revoke_record_s *record; + struct buffer_head *bh; + record = (struct jbd_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 @@ -481,12 +529,9 @@ void journal_switch_revoke_table(journal_t *journal) /* * Write revoke records to the journal for all entries in the current * revoke hash, deleting the entries as we go. - * - * Called with the journal lock held. */ - void journal_write_revoke_records(journal_t *journal, - transaction_t *transaction) + transaction_t *transaction, int write_op) { struct journal_head *descriptor; struct jbd_revoke_record_s *record; @@ -510,14 +555,14 @@ void journal_write_revoke_records(journal_t *journal, hash_list->next; write_one_revoke_record(journal, transaction, &descriptor, &offset, - record); + record, write_op); count++; list_del(&record->hash); kmem_cache_free(revoke_record_cache, record); } } if (descriptor) - flush_descriptor(journal, descriptor, offset); + flush_descriptor(journal, descriptor, offset, write_op); jbd_debug(1, "Wrote %d revoke records\n", count); } @@ -530,7 +575,8 @@ static void write_one_revoke_record(journal_t *journal, transaction_t *transaction, struct journal_head **descriptorp, int *offsetp, - struct jbd_revoke_record_s *record) + struct jbd_revoke_record_s *record, + int write_op) { struct journal_head *descriptor; int offset; @@ -549,7 +595,7 @@ static void write_one_revoke_record(journal_t *journal, /* Make sure we have a descriptor with space left for the record */ if (descriptor) { if (offset == journal->j_blocksize) { - flush_descriptor(journal, descriptor, offset); + flush_descriptor(journal, descriptor, offset, write_op); descriptor = NULL; } } @@ -586,7 +632,7 @@ static void write_one_revoke_record(journal_t *journal, static void flush_descriptor(journal_t *journal, struct journal_head *descriptor, - int offset) + int offset, int write_op) { journal_revoke_header_t *header; struct buffer_head *bh = jh2bh(descriptor); @@ -601,7 +647,7 @@ static void flush_descriptor(journal_t *journal, set_buffer_jwrite(bh); BUFFER_TRACE(bh, "write"); set_buffer_dirty(bh); - ll_rw_block(SWRITE, 1, &bh); + write_dirty_buffer(bh, write_op); } #endif @@ -628,7 +674,7 @@ static void flush_descriptor(journal_t *journal, */ int journal_set_revoke(journal_t *journal, - unsigned long blocknr, + unsigned int blocknr, tid_t sequence) { struct jbd_revoke_record_s *record; @@ -652,7 +698,7 @@ int journal_set_revoke(journal_t *journal, */ int journal_test_revoke(journal_t *journal, - unsigned long blocknr, + unsigned int blocknr, tid_t sequence) { struct jbd_revoke_record_s *record; |