From: Theodore Ts'o Date: Fri, 1 May 2009 16:52:25 +0000 (-0400) Subject: ext4: Use separate super_operations structure for no_journal filesystems X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=9ca92389c5312a51e819c15c762f0abdc7f3129b;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git ext4: Use separate super_operations structure for no_journal filesystems 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" --- diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7c7a08a..68c3a44 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -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; }