Commit c431d386 authored by Kemeng Shi's avatar Kemeng Shi Committed by Theodore Ts'o
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ext4: extend ext4_mb_mark_context to support allocation under journal 



Previously, ext4_mb_mark_context is only called under fast commit
replay path, so there is no valid handle when we update block bitmap
and group descriptor. This patch try to extend ext4_mb_mark_context
to be used by code under journal. There are several improvement:
1. Add "handle_t *handle" to struct ext4_mark_context to journal block
bitmap and group descriptor update inside ext4_mb_mark_context (the
added journal code is based on ext4_mb_mark_diskspace_used where
ext4_mb_mark_context is going to be used.)
2. Adds a flag argument to ext4_mb_mark_context() which controls
a. EXT4_MB_BITMAP_MARKED_CHECK - whether block bitmap checking is needed.
b. EXT4_MB_SYNC_UPDATE - whether dirty buffers (bitmap and group
descriptor) needs sync.

Signed-off-by: default avatarKemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: default avatar"Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20230928160407.142069-5-shikemeng@huaweicloud.com


Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 26d0f87b

fs/ext4/mballoc.c

+49 −15
Original line number Diff line number Diff line
@@ -3943,26 +3943,47 @@ void ext4_exit_mballoc(void) 
	ext4_groupinfo_destroy_slabs();

}



#define EXT4_MB_BITMAP_MARKED_CHECK 0x0001

#define EXT4_MB_SYNC_UPDATE 0x0002

static int

ext4_mb_mark_context(struct super_block *sb, bool state, ext4_group_t group,

		     ext4_grpblk_t blkoff, ext4_grpblk_t len)

ext4_mb_mark_context(handle_t *handle, struct super_block *sb, bool state,

		     ext4_group_t group, ext4_grpblk_t blkoff,

		     ext4_grpblk_t len, int flags, ext4_grpblk_t *ret_changed)

{

	struct ext4_sb_info *sbi = EXT4_SB(sb);

	struct buffer_head *bitmap_bh = NULL;

	struct ext4_group_desc *gdp;

	struct buffer_head *gdp_bh;

	int err;

	unsigned int i, already, changed;

	unsigned int i, already, changed = len;



	if (ret_changed)

		*ret_changed = 0;

	bitmap_bh = ext4_read_block_bitmap(sb, group);

	if (IS_ERR(bitmap_bh))

		return PTR_ERR(bitmap_bh);



	if (handle) {

		BUFFER_TRACE(bitmap_bh, "getting write access");

		err = ext4_journal_get_write_access(handle, sb, bitmap_bh,

						    EXT4_JTR_NONE);

		if (err)

			goto out_err;

	}



	err = -EIO;

	gdp = ext4_get_group_desc(sb, group, &gdp_bh);

	if (!gdp)

		goto out_err;



	if (handle) {

		BUFFER_TRACE(gdp_bh, "get_write_access");

		err = ext4_journal_get_write_access(handle, sb, gdp_bh,

						    EXT4_JTR_NONE);

		if (err)

			goto out_err;

	}



	ext4_lock_group(sb, group);

	if (ext4_has_group_desc_csum(sb) &&

	    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
@@ -3971,12 +3992,14 @@ ext4_mb_mark_context(struct super_block *sb, bool state, ext4_group_t group, 
			ext4_free_clusters_after_init(sb, group, gdp));

	}



	if (flags & EXT4_MB_BITMAP_MARKED_CHECK) {

		already = 0;

		for (i = 0; i < len; i++)

			if (mb_test_bit(blkoff + i, bitmap_bh->b_data) ==

					state)

				already++;

		changed = len - already;

	}



	if (state) {

		mb_set_bits(bitmap_bh->b_data, blkoff, len);
@@ -3991,6 +4014,8 @@ ext4_mb_mark_context(struct super_block *sb, bool state, ext4_group_t group, 
	ext4_block_bitmap_csum_set(sb, gdp, bitmap_bh);

	ext4_group_desc_csum_set(sb, group, gdp);

	ext4_unlock_group(sb, group);

	if (ret_changed)

		*ret_changed = changed;



	if (sbi->s_log_groups_per_flex) {

		ext4_group_t flex_group = ext4_flex_group(sbi, group);
@@ -4003,15 +4028,17 @@ ext4_mb_mark_context(struct super_block *sb, bool state, ext4_group_t group, 
			atomic64_add(changed, &fg->free_clusters);

	}



	err = ext4_handle_dirty_metadata(NULL, NULL, bitmap_bh);

	err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh);

	if (err)

		goto out_err;

	err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);

	err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh);

	if (err)

		goto out_err;



	if (flags & EXT4_MB_SYNC_UPDATE) {

		sync_dirty_buffer(bitmap_bh);

		sync_dirty_buffer(gdp_bh);

	}



out_err:

	brelse(bitmap_bh);
@@ -4171,7 +4198,11 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, 
			break;

		}



		err = ext4_mb_mark_context(sb, state, group, blkoff, clen);

		err = ext4_mb_mark_context(NULL, sb, state,

					   group, blkoff, clen,

					   EXT4_MB_BITMAP_MARKED_CHECK |

					   EXT4_MB_SYNC_UPDATE,

					   NULL);

		if (err)

			break;
@@ -6363,7 +6394,10 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block, 
	ext4_grpblk_t blkoff;



	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);

	ext4_mb_mark_context(sb, false, group, blkoff, count);

	ext4_mb_mark_context(NULL, sb, false, group, blkoff, count,

			     EXT4_MB_BITMAP_MARKED_CHECK |

			     EXT4_MB_SYNC_UPDATE,

			     NULL);

}



/**