Commit a0375156 authored by Theodore Ts'o's avatar Theodore Ts'o
Browse files

ext4: Clean up s_dirt handling 



We don't need to set s_dirt in most of the ext4 code when journaling
is enabled.  In ext3/4 some of the summary statistics for # of free
inodes, blocks, and directories are calculated from the per-block
group statistics when the file system is mounted or unmounted.  As a
result the superblock doesn't have to be updated, either via the
journal or by setting s_dirt.  There are a few exceptions, most
notably when resizing the file system, where the superblock needs to
be modified --- and in that case it should be done as a journalled
operation if possible, and s_dirt set only in no-journal mode.

This patch will optimize out some unneeded disk writes when using ext4
with a journal.

Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 7e27d6e7

fs/ext4/balloc.c

+1 −5
Original line number Original line Diff line number Diff line
@@ -377,14 +377,11 @@ void ext4_add_groupblocks(handle_t *handle, struct super_block *sb, 
	ext4_grpblk_t bit;

	ext4_grpblk_t bit;

	unsigned int i;

	unsigned int i;

	struct ext4_group_desc *desc;

	struct ext4_group_desc *desc;

	struct ext4_super_block *es;

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct ext4_sb_info *sbi;

	int err = 0, ret, blk_free_count;

	int err = 0, ret, blk_free_count;

	ext4_grpblk_t blocks_freed;

	ext4_grpblk_t blocks_freed;

	struct ext4_group_info *grp;

	struct ext4_group_info *grp;





	sbi = EXT4_SB(sb);

	es = sbi->s_es;

	ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);

	ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1);





	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);

	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
@@ -477,7 +474,6 @@ void ext4_add_groupblocks(handle_t *handle, struct super_block *sb, 
	ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);

	ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh);

	if (!err)

	if (!err)

		err = ret;

		err = ret;

	sb->s_dirt = 1;





error_return:

error_return:

	brelse(bitmap_bh);

	brelse(bitmap_bh);

fs/ext4/ext4.h

+6 −0
Original line number Original line Diff line number Diff line
@@ -1860,6 +1860,12 @@ static inline void ext4_unlock_group(struct super_block *sb, 
	spin_unlock(ext4_group_lock_ptr(sb, group));

	spin_unlock(ext4_group_lock_ptr(sb, group));

}

}





static inline void ext4_mark_super_dirty(struct super_block *sb)

{

	if (EXT4_SB(sb)->s_journal == NULL)

		sb->s_dirt =1;

}



/*

/*

 * Inodes and files operations

 * Inodes and files operations

 */

 */

fs/ext4/ext4_jbd2.c

+16 −0
Original line number Original line Diff line number Diff line
@@ -143,3 +143,19 @@ int __ext4_handle_dirty_metadata(const char *where, handle_t *handle, 
	}

	}

	return err;

	return err;

}

}



int __ext4_handle_dirty_super(const char *where, handle_t *handle,

			      struct super_block *sb)

{

	struct buffer_head *bh = EXT4_SB(sb)->s_sbh;

	int err = 0;



	if (ext4_handle_valid(handle)) {

		err = jbd2_journal_dirty_metadata(handle, bh);

		if (err)

			ext4_journal_abort_handle(where, __func__, bh,

						  handle, err);

	} else

		sb->s_dirt = 1;

	return err;

}

fs/ext4/ext4_jbd2.h

+5 −0
Original line number Original line Diff line number Diff line
@@ -141,6 +141,9 @@ int __ext4_journal_get_create_access(const char *where, 
int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,

int __ext4_handle_dirty_metadata(const char *where, handle_t *handle,

				 struct inode *inode, struct buffer_head *bh);

				 struct inode *inode, struct buffer_head *bh);





int __ext4_handle_dirty_super(const char *where, handle_t *handle,

			      struct super_block *sb);



#define ext4_journal_get_undo_access(handle, bh) \

#define ext4_journal_get_undo_access(handle, bh) \

	__ext4_journal_get_undo_access(__func__, (handle), (bh))

	__ext4_journal_get_undo_access(__func__, (handle), (bh))

#define ext4_journal_get_write_access(handle, bh) \

#define ext4_journal_get_write_access(handle, bh) \
@@ -152,6 +155,8 @@ int __ext4_handle_dirty_metadata(const char *where, handle_t *handle, 
	__ext4_journal_get_create_access(__func__, (handle), (bh))

	__ext4_journal_get_create_access(__func__, (handle), (bh))

#define ext4_handle_dirty_metadata(handle, inode, bh) \

#define ext4_handle_dirty_metadata(handle, inode, bh) \

	__ext4_handle_dirty_metadata(__func__, (handle), (inode), (bh))

	__ext4_handle_dirty_metadata(__func__, (handle), (inode), (bh))

#define ext4_handle_dirty_super(handle, sb) \

	__ext4_handle_dirty_super(__func__, (handle), (sb))





handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);

handle_t *ext4_journal_start_sb(struct super_block *sb, int nblocks);

int __ext4_journal_stop(const char *where, handle_t *handle);

int __ext4_journal_stop(const char *where, handle_t *handle);

fs/ext4/file.c

+1 −1
Original line number Original line Diff line number Diff line
@@ -123,7 +123,7 @@ static int ext4_file_open(struct inode * inode, struct file * filp) 
		if (!IS_ERR(cp)) {

		if (!IS_ERR(cp)) {

			memcpy(sbi->s_es->s_last_mounted, cp,

			memcpy(sbi->s_es->s_last_mounted, cp,

			       sizeof(sbi->s_es->s_last_mounted));

			       sizeof(sbi->s_es->s_last_mounted));

			sb->s_dirt = 1;

			ext4_mark_super_dirty(sb);

		}

		}

	}

	}

	return dquot_file_open(inode, filp);

	return dquot_file_open(inode, filp);

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