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ext4: Use separate super_operations structure for no_journal filesystems

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By using a separate super_operations structure for filesystems that
have and don't have journals, we can simply ext4_write_super() ---
which is only needed when no journal is present --- and ext4_freeze(),
ext4_unfreeze(), and ext4_sync_fs(), which are only needed when the
journal is present.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2009-05-01 12:52:25 -04:00
parent 7234ab2a55
commit 9ca92389c5
1 changed files with 57 additions and 51 deletions
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108
fs/ext4/super.c
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@ -995,7 +995,6 @@ static const struct super_operations ext4_sops = {
.dirty_inode = ext4_dirty_inode,
.delete_inode = ext4_delete_inode,
.put_super = ext4_put_super,
.write_super = ext4_write_super,
.sync_fs = ext4_sync_fs,
.freeze_fs = ext4_freeze,
.unfreeze_fs = ext4_unfreeze,
@ -1010,6 +1009,25 @@ static const struct super_operations ext4_sops = {
.bdev_try_to_free_page = bdev_try_to_free_page,
};
static const struct super_operations ext4_nojournal_sops = {
.alloc_inode = ext4_alloc_inode,
.destroy_inode = ext4_destroy_inode,
.write_inode = ext4_write_inode,
.dirty_inode = ext4_dirty_inode,
.delete_inode = ext4_delete_inode,
.write_super = ext4_write_super,
.put_super = ext4_put_super,
.statfs = ext4_statfs,
.remount_fs = ext4_remount,
.clear_inode = ext4_clear_inode,
.show_options = ext4_show_options,
#ifdef CONFIG_QUOTA
.quota_read = ext4_quota_read,
.quota_write = ext4_quota_write,
#endif
.bdev_try_to_free_page = bdev_try_to_free_page,
};
static const struct export_operations ext4_export_ops = {
.fh_to_dentry = ext4_fh_to_dentry,
.fh_to_parent = ext4_fh_to_parent,
@ -2615,7 +2633,11 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
/*
* set up enough so that it can read an inode
*/
sb->s_op = &ext4_sops;
if (!test_opt(sb, NOLOAD) &&
EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_HAS_JOURNAL))
sb->s_op = &ext4_sops;
else
sb->s_op = &ext4_nojournal_sops;
sb->s_export_op = &ext4_export_ops;
sb->s_xattr = ext4_xattr_handlers;
#ifdef CONFIG_QUOTA
@ -3275,19 +3297,9 @@ int ext4_force_commit(struct super_block *sb)
return ret;
}
/*
* Ext4 always journals updates to the superblock itself, so we don't
* have to propagate any other updates to the superblock on disk at this
* point if the journalling is enabled.
*/
static void ext4_write_super(struct super_block *sb)
{
if (EXT4_SB(sb)->s_journal) {
if (mutex_trylock(&sb->s_lock) != 0)
BUG();
} else {
ext4_commit_super(sb, 1);
}
ext4_commit_super(sb, 1);
}
static int ext4_sync_fs(struct super_block *sb, int wait)
@ -3296,15 +3308,9 @@ static int ext4_sync_fs(struct super_block *sb, int wait)
tid_t target;
trace_mark(ext4_sync_fs, "dev %s wait %d", sb->s_id, wait);
if (EXT4_SB(sb)->s_journal) {
if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal,
&target)) {
if (wait)
jbd2_log_wait_commit(EXT4_SB(sb)->s_journal,
target);
}
} else {
ext4_commit_super(sb, wait);
if (jbd2_journal_start_commit(EXT4_SB(sb)->s_journal, &target)) {
if (wait)
jbd2_log_wait_commit(EXT4_SB(sb)->s_journal, target);
}
return ret;
}
@ -3318,32 +3324,31 @@ static int ext4_freeze(struct super_block *sb)
int error = 0;
journal_t *journal;
if (!(sb->s_flags & MS_RDONLY)) {
journal = EXT4_SB(sb)->s_journal;
if (sb->s_flags & MS_RDONLY)
return 0;
if (journal) {
/* Now we set up the journal barrier. */
jbd2_journal_lock_updates(journal);
journal = EXT4_SB(sb)->s_journal;
/*
* We don't want to clear needs_recovery flag when we
* failed to flush the journal.
*/
error = jbd2_journal_flush(journal);
if (error < 0)
goto out;
}
/* Now we set up the journal barrier. */
jbd2_journal_lock_updates(journal);
/* Journal blocked and flushed, clear needs_recovery flag. */
EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
error = ext4_commit_super(sb, 1);
if (error)
goto out;
/*
* Don't clear the needs_recovery flag if we failed to flush
* the journal.
*/
error = jbd2_journal_flush(journal);
if (error < 0) {
out:
jbd2_journal_unlock_updates(journal);
return error;
}
/* Journal blocked and flushed, clear needs_recovery flag. */
EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
error = ext4_commit_super(sb, 1);
if (error)
goto out;
return 0;
out:
jbd2_journal_unlock_updates(journal);
return error;
}
/*
@ -3352,14 +3357,15 @@ out:
*/
static int ext4_unfreeze(struct super_block *sb)
{
if (EXT4_SB(sb)->s_journal && !(sb->s_flags & MS_RDONLY)) {
lock_super(sb);
/* Reser the needs_recovery flag before the fs is unlocked. */
EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
ext4_commit_super(sb, 1);
unlock_super(sb);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
}
if (sb->s_flags & MS_RDONLY)
return 0;
lock_super(sb);
/* Reset the needs_recovery flag before the fs is unlocked. */
EXT4_SET_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
ext4_commit_super(sb, 1);
unlock_super(sb);
jbd2_journal_unlock_updates(EXT4_SB(sb)->s_journal);
return 0;
}