/*
* linux/fs/revoke.c
- *
+ *
* Written by Stephen C. Tweedie <sct@redhat.com>, 2000
*
* Copyright 2000 Red Hat corp --- All Rights Reserved
* Revoke is the mechanism used to prevent old log records for deleted
* metadata from being replayed on top of newer data using the same
* blocks. The revoke mechanism is used in two separate places:
- *
+ *
* + Commit: during commit we write the entire list of the current
* transaction's revoked blocks to the journal
- *
+ *
* + Recovery: during recovery we record the transaction ID of all
* revoked blocks. If there are multiple revoke records in the log
* for a single block, only the last one counts, and if there is a log
* single transaction:
*
* Block is revoked and then journaled:
- * The desired end result is the journaling of the new block, so we
+ * The desired end result is the journaling of the new block, so we
* cancel the revoke before the transaction commits.
*
* Block is journaled and then revoked:
- * The revoke must take precedence over the write of the block, so
- * we need either to cancel the journal entry or to write the revoke
+ * The revoke must take precedence over the write of the block, so we
+ * need either to cancel the journal entry or to write the revoke
* later in the log than the log block. In this case, we choose the
- * former: the commit code must skip any block that has the Revoke bit
- * set.
+ * latter: journaling a block cancels any revoke record for that block
+ * in the current transaction, so any revoke for that block in the
+ * transaction must have happened after the block was journaled and so
+ * the revoke must take precedence.
*
- * Block is revoked and then written as data:
+ * Block is revoked and then written as data:
* The data write is allowed to succeed, but the revoke is _not_
* cancelled. We still need to prevent old log records from
* overwriting the new data. We don't even need to clear the revoke
* Revoke information on buffers is a tri-state value:
*
* RevokeValid clear: no cached revoke status, need to look it up
- * RevokeValid set, Revoke clear:
+ * RevokeValid set, Revoked clear:
* buffer has not been revoked, and cancel_revoke
* need do nothing.
- * RevokeValid set, Revoke set:
+ * RevokeValid set, Revoked set:
* buffer has been revoked.
*/
#ifndef __KERNEL__
+#include "config.h"
#include "jfs_user.h"
#else
#include <linux/sched.h>
#include <linux/fs.h>
-#include <linux/jfs.h>
+#include <linux/jbd.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/locks.h>
-#include <linux/buffer.h>
#include <linux/list.h>
+#include <linux/smp_lock.h>
+#include <linux/init.h>
#endif
-static kmem_cache_t *revoke_record_cache;
-static kmem_cache_t *revoke_table_cache;
+static lkmem_cache_t *revoke_record_cache;
+static lkmem_cache_t *revoke_table_cache;
/* Each revoke record represents one single revoked block. During
journal replay, this involves recording the transaction ID of the
last transaction to revoke this block. */
-struct jfs_revoke_record_s
+struct jbd_revoke_record_s
{
struct list_head hash;
tid_t sequence; /* Used for recovery only */
- unsigned long blocknr;
+ unsigned long blocknr;
};
/* The revoke table is just a simple hash table of revoke records. */
-struct jfs_revoke_table_s
+struct jbd_revoke_table_s
{
/* It is conceivable that we might want a larger hash table
* for recovery. Must be a power of two. */
- int hash_size;
- int hash_shift;
+ int hash_size;
+ int hash_shift;
struct list_head *hash_table;
};
#ifdef __KERNEL__
static void write_one_revoke_record(journal_t *, transaction_t *,
- struct buffer_head **, int *,
- struct jfs_revoke_record_s *);
-static void flush_descriptor(journal_t *, struct buffer_head *, int);
+ struct journal_head **, int *,
+ struct jbd_revoke_record_s *);
+static void flush_descriptor(journal_t *, struct journal_head *, 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)
{
- struct jfs_revoke_table_s *table = journal->j_revoke;
+ struct jbd_revoke_table_s *table = journal->j_revoke;
int hash_shift = table->hash_shift;
-
+
return ((block << (hash_shift - 6)) ^
(block >> 13) ^
(block << (hash_shift - 12))) & (table->hash_size - 1);
}
-int insert_revoke_hash(journal_t *journal, unsigned long blocknr, tid_t seq)
+static int insert_revoke_hash(journal_t *journal, unsigned long blocknr,
+ tid_t seq)
{
struct list_head *hash_list;
- struct jfs_revoke_record_s *record;
-
- record = kmem_cache_alloc(revoke_record_cache, GFP_KERNEL);
+ struct jbd_revoke_record_s *record;
+
+#ifdef __KERNEL__
+repeat:
+#endif
+ record = kmem_cache_alloc(revoke_record_cache, GFP_NOFS);
if (!record)
- return -ENOMEM;
+ goto oom;
record->sequence = seq;
record->blocknr = blocknr;
hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
list_add(&record->hash, hash_list);
return 0;
+
+oom:
+#ifdef __KERNEL__
+ if (!journal_oom_retry)
+ return -ENOMEM;
+ jbd_debug(1, "ENOMEM in " __FUNCTION__ ", retrying.\n");
+ current->policy |= SCHED_YIELD;
+ schedule();
+ goto repeat;
+#else
+ return -ENOMEM;
+#endif
}
/* Find a revoke record in the journal's hash table. */
-static struct jfs_revoke_record_s *find_revoke_record(journal_t *journal,
+static struct jbd_revoke_record_s *find_revoke_record(journal_t *journal,
unsigned long blocknr)
{
struct list_head *hash_list;
- struct jfs_revoke_record_s *record;
-
+ struct jbd_revoke_record_s *record;
+
hash_list = &journal->j_revoke->hash_table[hash(journal, blocknr)];
- record = (struct jfs_revoke_record_s *) hash_list->next;
+ record = (struct jbd_revoke_record_s *) hash_list->next;
while (&(record->hash) != hash_list) {
if (record->blocknr == blocknr)
return record;
- record = (struct jfs_revoke_record_s *) record->hash.next;
+ record = (struct jbd_revoke_record_s *) record->hash.next;
}
return NULL;
}
+int __init journal_init_revoke_caches(void)
+{
+ revoke_record_cache = kmem_cache_create("revoke_record",
+ sizeof(struct jbd_revoke_record_s),
+ 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
+ if (revoke_record_cache == 0)
+ return -ENOMEM;
+ revoke_table_cache = kmem_cache_create("revoke_table",
+ sizeof(struct jbd_revoke_table_s),
+ 0, 0, NULL, NULL);
+ if (revoke_table_cache == 0) {
+ kmem_cache_destroy(revoke_record_cache);
+ revoke_record_cache = NULL;
+ return -ENOMEM;
+ }
+ return 0;
+}
+
+void journal_destroy_revoke_caches(void)
+{
+ kmem_cache_destroy(revoke_record_cache);
+ revoke_record_cache = 0;
+ kmem_cache_destroy(revoke_table_cache);
+ revoke_table_cache = 0;
+}
/* Initialise the revoke table for a given journal to a given size. */
int journal_init_revoke(journal_t *journal, int hash_size)
{
int shift, tmp;
-
+
J_ASSERT (journal->j_revoke == NULL);
-
- if (!revoke_record_cache)
- revoke_record_cache =
- kmem_cache_create ("revoke_record",
- sizeof(struct jfs_revoke_record_s),
- 0, SLAB_HWCACHE_ALIGN, NULL, NULL);
-
- if (!revoke_table_cache)
- revoke_table_cache =
- kmem_cache_create ("revoke_table",
- sizeof(struct jfs_revoke_table_s),
- 0, 0, NULL, NULL);
- if (!revoke_record_cache || !revoke_table_cache)
- return -ENOMEM;
-
journal->j_revoke = kmem_cache_alloc(revoke_table_cache, GFP_KERNEL);
if (!journal->j_revoke)
return -ENOMEM;
-
+
/* Check that the hash_size is a power of two */
J_ASSERT ((hash_size & (hash_size-1)) == 0);
journal->j_revoke = NULL;
return -ENOMEM;
}
-
+
for (tmp = 0; tmp < hash_size; tmp++)
INIT_LIST_HEAD(&journal->j_revoke->hash_table[tmp]);
-
+
return 0;
}
void journal_destroy_revoke(journal_t *journal)
{
- struct jfs_revoke_table_s *table;
+ struct jbd_revoke_table_s *table;
struct list_head *hash_list;
int i;
-
+
table = journal->j_revoke;
if (!table)
return;
-
+
for (i=0; i<table->hash_size; i++) {
hash_list = &table->hash_table[i];
J_ASSERT (list_empty(hash_list));
}
-
+
kfree(table->hash_table);
kmem_cache_free(revoke_table_cache, table);
journal->j_revoke = NULL;
#ifdef __KERNEL__
-/*
+/*
* journal_revoke: revoke a given buffer_head from the journal. This
* prevents the block from being replayed during recovery if we take a
* crash after this current transaction commits. Any subsequent
* metadata writes of the buffer in this transaction cancel the
- * revoke.
+ * revoke.
*
* Note that this call may block --- it is up to the caller to make
* sure that there are no further calls to journal_write_metadata
* before the revoke is complete. In ext3, this implies calling the
* revoke before clearing the block bitmap when we are deleting
- * metadata.
+ * metadata.
*
* Revoke performs a journal_forget on any buffer_head passed in as a
* parameter, but does _not_ forget the buffer_head if the bh was only
- * found implicitly.
+ * found implicitly.
+ *
+ * bh_in may not be a journalled buffer - it may have come off
+ * the hash tables without an attached journal_head.
*
- * Revoke must observe the same synchronisation rules as bforget: it
- * must not discard the buffer once it has blocked.
+ * If bh_in is non-zero, journal_revoke() will decrement its b_count
+ * by one.
*/
-int journal_revoke(handle_t *handle, unsigned long blocknr,
+int journal_revoke(handle_t *handle, unsigned long blocknr,
struct buffer_head *bh_in)
{
- struct buffer_head *bh;
+ struct buffer_head *bh = NULL;
journal_t *journal;
kdev_t dev;
int err;
+ if (bh_in)
+ BUFFER_TRACE(bh_in, "enter");
+
journal = handle->h_transaction->t_journal;
if (!journal_set_features(journal, 0, 0, JFS_FEATURE_INCOMPAT_REVOKE)){
J_ASSERT (!"Cannot set revoke feature!");
return -EINVAL;
}
-
- dev = journal->j_dev;
+
+ dev = journal->j_fs_dev;
bh = bh_in;
- if (!bh)
+ if (!bh) {
bh = get_hash_table(dev, blocknr, journal->j_blocksize);
+ if (bh)
+ BUFFER_TRACE(bh, "found on hash");
+ }
+#ifdef JBD_EXPENSIVE_CHECKING
+ else {
+ struct buffer_head *bh2;
+
+ /* If there is a different buffer_head lying around in
+ * memory anywhere... */
+ bh2 = get_hash_table(dev, blocknr, journal->j_blocksize);
+ if (bh2) {
+ /* ... and it has RevokeValid status... */
+ if ((bh2 != bh) &&
+ test_bit(BH_RevokeValid, &bh2->b_state))
+ /* ...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. */
+ J_ASSERT_BH(bh2, test_bit(BH_Revoked, &
+ bh2->b_state));
+ __brelse(bh2);
+ }
+ }
+#endif
/* 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) {
- J_ASSERT (!test_and_set_bit(BH_Revoked, &bh->b_state));
+ J_ASSERT_BH(bh, !test_bit(BH_Revoked, &bh->b_state));
+ set_bit(BH_Revoked, &bh->b_state);
set_bit(BH_RevokeValid, &bh->b_state);
- if (bh_in)
+ if (bh_in) {
+ BUFFER_TRACE(bh_in, "call journal_forget");
journal_forget(handle, bh_in);
- else
- brelse(bh);
+ } else {
+ BUFFER_TRACE(bh, "call brelse");
+ __brelse(bh);
+ }
}
lock_journal(journal);
- err = insert_revoke_hash(journal, blocknr,
- handle->h_transaction->t_tid);
+ jbd_debug(2, "insert revoke for block %lu, bh_in=%p\n", blocknr, bh_in);
+ err = insert_revoke_hash(journal, blocknr,
+ handle->h_transaction->t_tid);
unlock_journal(journal);
-
+ BUFFER_TRACE(bh_in, "exit");
return err;
}
-
/*
* Cancel an outstanding revoke. For use only internally by the
* journaling code (called from journal_get_write_access).
* set.
*
* The caller must have the journal locked.
- * */
-
-void journal_cancel_revoke(handle_t *handle, struct buffer_head *bh)
+ */
+int journal_cancel_revoke(handle_t *handle, struct journal_head *jh)
{
- struct jfs_revoke_record_s *record;
+ struct jbd_revoke_record_s *record;
journal_t *journal = handle->h_transaction->t_journal;
int need_cancel;
-
- J_ASSERT (journal->j_locked);
-
+ 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
need_cancel = 1;
clear_bit(BH_Revoked, &bh->b_state);
}
-
+
if (need_cancel) {
record = find_revoke_record(journal, bh->b_blocknr);
if (record) {
+ jbd_debug(4, "cancelled existing revoke on "
+ "blocknr %lu\n", bh->b_blocknr);
list_del(&record->hash);
kmem_cache_free(revoke_record_cache, record);
+ did_revoke = 1;
}
}
+
+#ifdef JBD_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 && !bh->b_pprev) {
+ struct buffer_head *bh2;
+ bh2 = get_hash_table(bh->b_dev, bh->b_blocknr, bh->b_size);
+ if (bh2) {
+ clear_bit(BH_Revoked, &bh2->b_state);
+ __brelse(bh2);
+ }
+ }
+
+ return did_revoke;
}
* Called with the journal lock held.
*/
-void journal_write_revoke_records(journal_t *journal,
+void journal_write_revoke_records(journal_t *journal,
transaction_t *transaction)
{
- struct buffer_head *descriptor;
- struct jfs_revoke_record_s *record;
- struct jfs_revoke_table_s *revoke;
+ struct journal_head *descriptor;
+ struct jbd_revoke_record_s *record;
+ struct jbd_revoke_table_s *revoke;
struct list_head *hash_list;
int i, offset, count;
-
- descriptor = NULL;
+
+ descriptor = NULL;
offset = 0;
count = 0;
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 jfs_revoke_record_s *)
+ record = (struct jbd_revoke_record_s *)
hash_list->next;
write_one_revoke_record(journal, transaction,
- &descriptor, &offset,
+ &descriptor, &offset,
record);
count++;
list_del(&record->hash);
kmem_cache_free(revoke_record_cache, record);
}
}
- if (descriptor)
+ if (descriptor)
flush_descriptor(journal, descriptor, offset);
- jfs_debug(1, "Wrote %d revoke records\n", count);
+ 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.
+ * block if the old one is full or if we have not already created one.
*/
-static void write_one_revoke_record(journal_t *journal,
+static void write_one_revoke_record(journal_t *journal,
transaction_t *transaction,
- struct buffer_head **descriptorp,
+ struct journal_head **descriptorp,
int *offsetp,
- struct jfs_revoke_record_s *record)
+ struct jbd_revoke_record_s *record)
{
- struct buffer_head *descriptor;
+ struct journal_head *descriptor;
int offset;
journal_header_t *header;
-
+
/* If we are already aborting, this all becomes a noop. We
still need to go round the loop in
journal_write_revoke_records in order to free all of the
revoke records: only the IO to the journal is omitted. */
- if (is_journal_abort(journal))
+ if (is_journal_aborted(journal))
return;
descriptor = *descriptorp;
offset = *offsetp;
-
+
/* Make sure we have a descriptor with space left for the record */
if (descriptor) {
if (offset == journal->j_blocksize) {
descriptor = NULL;
}
}
-
+
if (!descriptor) {
descriptor = journal_get_descriptor_buffer(journal);
- header = (journal_header_t *) &descriptor->b_data[0];
+ if (!descriptor)
+ return;
+ header = (journal_header_t *) &jh2bh(descriptor)->b_data[0];
header->h_magic = htonl(JFS_MAGIC_NUMBER);
header->h_blocktype = htonl(JFS_REVOKE_BLOCK);
header->h_sequence = htonl(transaction->t_tid);
/* Record it so that we can wait for IO completion later */
+ JBUFFER_TRACE(descriptor, "file as BJ_LogCtl");
journal_file_buffer(descriptor, transaction, BJ_LogCtl);
-
+
offset = sizeof(journal_revoke_header_t);
*descriptorp = descriptor;
}
-
- * ((unsigned int *)(&descriptor->b_data[offset])) =
+
+ * ((unsigned int *)(&jh2bh(descriptor)->b_data[offset])) =
htonl(record->blocknr);
offset += 4;
*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,
+static void flush_descriptor(journal_t *journal,
+ struct journal_head *descriptor,
int offset)
{
journal_revoke_header_t *header;
-
- if (is_journal_abort(journal)) {
- brelse(descriptor);
+
+ if (is_journal_aborted(journal)) {
+ JBUFFER_TRACE(descriptor, "brelse");
+ __brelse(jh2bh(descriptor));
return;
}
-
- header = (journal_revoke_header_t *) descriptor->b_data;
+
+ header = (journal_revoke_header_t *) jh2bh(descriptor)->b_data;
header->r_count = htonl(offset);
- set_bit(BH_JWrite, &descriptor->b_state);
- ll_rw_block (WRITE, 1, &descriptor);
+ set_bit(BH_JWrite, &jh2bh(descriptor)->b_state);
+ {
+ struct buffer_head *bh = jh2bh(descriptor);
+ BUFFER_TRACE(bh, "write");
+ ll_rw_block (WRITE, 1, &bh);
+ }
}
#endif
-/*
+/*
* Revoke support for recovery.
*
* Recovery needs to be able to:
* 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.
+ * single block.
*/
-int journal_set_revoke(journal_t *journal,
- unsigned long blocknr,
+int journal_set_revoke(journal_t *journal,
+ unsigned long blocknr,
tid_t sequence)
{
- struct jfs_revoke_record_s *record;
-
+ struct jbd_revoke_record_s *record;
+
record = find_revoke_record(journal, blocknr);
if (record) {
/* If we have multiple occurences, only record the
* latest sequence number in the hashed record */
- if (tid_ge(sequence, record->sequence))
+ 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 journal_test_revoke(journal_t *journal,
+int journal_test_revoke(journal_t *journal,
unsigned long blocknr,
tid_t sequence)
{
- struct jfs_revoke_record_s *record;
-
+ struct jbd_revoke_record_s *record;
+
record = find_revoke_record(journal, blocknr);
if (!record)
return 0;
- if (tid_ge(sequence, record->sequence))
+ if (tid_gt(sequence, record->sequence))
return 0;
return 1;
}
{
int i;
struct list_head *hash_list;
- struct jfs_revoke_record_s *record;
- struct jfs_revoke_table_s *revoke;
-
+ struct jbd_revoke_record_s *record;
+ struct jbd_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 jfs_revoke_record_s*) hash_list->next;
+ record = (struct jbd_revoke_record_s*) hash_list->next;
list_del(&record->hash);
kmem_cache_free(revoke_record_cache, record);
}
git://git.whamcloud.com / tools / e2fsprogs.git / blobdiff