2020-09-24 07:33:38

by Zhang Yi

Subject: [PATCH v2 5/7] ext4: introduce ext4_sb_breadahead_unmovable() to replace sb_breadahead_unmovable()

If we readahead inode tables in __ext4_get_inode_loc(), it may bypass
buffer_write_io_error() check, so introduce ext4_sb_breadahead_unmovable()
to handle this special case.

This patch also replace sb_breadahead_unmovable() in ext4_fill_super()
for the sake of unification.

Signed-off-by: zhangyi (F) <[email protected]>
---
fs/ext4/ext4.h | 1 +
fs/ext4/inode.c | 2 +-
fs/ext4/super.c | 12 +++++++++++-
3 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 75b46300a65c..6da1419f6ee7 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2829,6 +2829,7 @@ extern void ext4_read_bh_nowait(struct buffer_head *bh, int op_flags,
extern int ext4_read_bh(struct buffer_head *bh, int op_flags,
bh_end_io_t *end_io);
extern int ext4_read_bh_lock(struct buffer_head *bh, int op_flags, bool wait);
+extern void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block);
extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
extern int ext4_calculate_overhead(struct super_block *sb);
extern void ext4_superblock_csum_set(struct super_block *sb);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 171df289ef7e..e106d03e4b77 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4358,7 +4358,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
if (end > table)
end = table;
while (b <= end)
- sb_breadahead_unmovable(sb, b++);
+ ext4_sb_breadahead_unmovable(sb, b++);
}

/*
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0adba4871f57..b24e68eff48d 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -229,6 +229,16 @@ ext4_sb_bread(struct super_block *sb, sector_t block, int op_flags)
return bh;
}

+void ext4_sb_breadahead_unmovable(struct super_block *sb, sector_t block)
+{
+ struct buffer_head *bh = sb_getblk_gfp(sb, block, 0);
+
+ if (likely(bh)) {
+ ext4_read_bh_lock(bh, REQ_RAHEAD, false);
+ brelse(bh);
+ }
+}
+
static int ext4_verify_csum_type(struct super_block *sb,
struct ext4_super_block *es)
{
@@ -4545,7 +4555,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
/* Pre-read the descriptors into the buffer cache */
for (i = 0; i < db_count; i++) {
block = descriptor_loc(sb, logical_sb_block, i);
- sb_breadahead_unmovable(sb, block);
+ ext4_sb_breadahead_unmovable(sb, block);
}

for (i = 0; i < db_count; i++) {
--
2.25.4

2020-10-09 03:53:36

by Theodore Ts'o

Subject: Re: [PATCH v2 5/7] ext4: introduce ext4_sb_breadahead_unmovable() to replace sb_breadahead_unmovable()

On Thu, Sep 24, 2020 at 03:33:35PM +0800, zhangyi (F) wrote:
> If we readahead inode tables in __ext4_get_inode_loc(), it may bypass
> buffer_write_io_error() check, so introduce ext4_sb_breadahead_unmovable()
> to handle this special case.
>
> This patch also replace sb_breadahead_unmovable() in ext4_fill_super()
> for the sake of unification.
>
> Signed-off-by: zhangyi (F) <[email protected]>

Thanks, applied.

- Ted