From: Zhang Yi Date: Mon, 12 May 2025 06:33:16 +0000 (+0800) Subject: ext4: correct the journal credits calculations of allocating blocks X-Git-Tag: v6.16-rc1~139^2~20 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=0e32d86170121c2d43508e923cb171fb58953b42;p=thirdparty%2Fkernel%2Flinux.git ext4: correct the journal credits calculations of allocating blocks The journal credits calculation in ext4_ext_index_trans_blocks() is currently inadequate. It only multiplies the depth of the extents tree and doesn't account for the blocks that may be required for adding the leaf extents themselves. After enabling large folios, we can easily run out of handle credits, triggering a warning in jbd2_journal_dirty_metadata() on filesystems with a 1KB block size. This occurs because we may need more extents when iterating through each large folio in ext4_do_writepages()->mpage_map_and_submit_extent(). Therefore, we should modify ext4_ext_index_trans_blocks() to include a count of the leaf extents in the worst case as well. Signed-off-by: Zhang Yi Link: https://patch.msgid.link/20250512063319.3539411-6-yi.zhang@huaweicloud.com Signed-off-by: Theodore Ts'o --- diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index c42472fd4b63e..ddc3a75299613 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2409,9 +2409,10 @@ int ext4_ext_index_trans_blocks(struct inode *inode, int extents) * the time we actually modify the tree. Assume the worst case. */ if (extents <= 1) - index = EXT4_MAX_EXTENT_DEPTH * 2; + index = (EXT4_MAX_EXTENT_DEPTH * 2) + extents; else - index = EXT4_MAX_EXTENT_DEPTH * 3; + index = (EXT4_MAX_EXTENT_DEPTH * 3) + + DIV_ROUND_UP(extents, ext4_ext_space_block(inode, 0)); return index; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 3a46f2822cf02..18651f39a80bb 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5844,18 +5844,16 @@ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, int ret; /* - * How many index blocks need to touch to map @lblocks logical blocks - * to @pextents physical extents? + * How many index and lead blocks need to touch to map @lblocks + * logical blocks to @pextents physical extents? */ idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents); - ret = idxblocks; - /* * Now let's see how many group bitmaps and group descriptors need * to account */ - groups = idxblocks + pextents; + groups = idxblocks; gdpblocks = groups; if (groups > ngroups) groups = ngroups; @@ -5863,7 +5861,7 @@ static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; /* bitmaps and block group descriptor blocks */ - ret += groups + gdpblocks; + ret = idxblocks + groups + gdpblocks; /* Blocks for super block, inode, quota and xattr blocks */ ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);