2009-09-08 12:22:44

by Theodore Ts'o

Subject: [PATCH] ext4: print more sysadmin-friendly message in check_block_validity()

Drop the WARN_ON(1), as he stack trace is not appropriate, since it is
triggered by file system corruption, and it misleads users into
thinking there is a kernel bug. In addition, change the message
displayed by ext4_error() to make it clear that this is a file system
corruption problem.

Signed-off-by: "Theodore Ts'o" <[email protected]>
---
fs/ext4/inode.c | 16 ++++++++--------
1 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3400961..4d3fd0e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1121,16 +1121,15 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
ext4_discard_preallocations(inode);
}

-static int check_block_validity(struct inode *inode, sector_t logical,
- sector_t phys, int len)
+static int check_block_validity(struct inode *inode, const char *msg,
+ sector_t logical, sector_t phys, int len)
{
if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), phys, len)) {
- ext4_error(inode->i_sb, "check_block_validity",
+ ext4_error(inode->i_sb, msg,
"inode #%lu logical block %llu mapped to %llu "
"(size %d)", inode->i_ino,
(unsigned long long) logical,
(unsigned long long) phys, len);
- WARN_ON(1);
return -EIO;
}
return 0;
@@ -1182,8 +1181,8 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
up_read((&EXT4_I(inode)->i_data_sem));

if (retval > 0 && buffer_mapped(bh)) {
- int ret = check_block_validity(inode, block,
- bh->b_blocknr, retval);
+ int ret = check_block_validity(inode, "file system corruption",
+ block, bh->b_blocknr, retval);
if (ret != 0)
return ret;
}
@@ -1264,8 +1263,9 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,

up_write((&EXT4_I(inode)->i_data_sem));
if (retval > 0 && buffer_mapped(bh)) {
- int ret = check_block_validity(inode, block,
- bh->b_blocknr, retval);
+ int ret = check_block_validity(inode, "file system "
+ "corruption after allocation",
+ block, bh->b_blocknr, retval);
if (ret != 0)
return ret;
}
--
1.6.3.2.1.gb9f7d.dirty

2009-09-08 13:19:54

by Nageswara R Sastry

Subject: Re: [PATCH] ext4: print more sysadmin-friendly message in check_block_validity()

I have tested this and it's working fine. I am not seeing any kernel
stack/call traces.

Theodore Ts'o wrote:
> Drop the WARN_ON(1), as he stack trace is not appropriate, since it is
> triggered by file system corruption, and it misleads users into
> thinking there is a kernel bug. In addition, change the message
> displayed by ext4_error() to make it clear that this is a file system
> corruption problem.
>
> Signed-off-by: "Theodore Ts'o" <[email protected]>
Tested-by: Nageswara R Sastry <[email protected]>
> ---
> fs/ext4/inode.c | 16 ++++++++--------
> 1 files changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index 3400961..4d3fd0e 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -1121,16 +1121,15 @@ static void ext4_da_update_reserve_space(struct inode *inode, int used)
> ext4_discard_preallocations(inode);
> }
>
> -static int check_block_validity(struct inode *inode, sector_t logical,
> - sector_t phys, int len)
> +static int check_block_validity(struct inode *inode, const char *msg,
> + sector_t logical, sector_t phys, int len)
> {
> if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), phys, len)) {
> - ext4_error(inode->i_sb, "check_block_validity",
> + ext4_error(inode->i_sb, msg,
> "inode #%lu logical block %llu mapped to %llu "
> "(size %d)", inode->i_ino,
> (unsigned long long) logical,
> (unsigned long long) phys, len);
> - WARN_ON(1);
> return -EIO;
> }
> return 0;
> @@ -1182,8 +1181,8 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
> up_read((&EXT4_I(inode)->i_data_sem));
>
> if (retval > 0 && buffer_mapped(bh)) {
> - int ret = check_block_validity(inode, block,
> - bh->b_blocknr, retval);
> + int ret = check_block_validity(inode, "file system corruption",
> + block, bh->b_blocknr, retval);
> if (ret != 0)
> return ret;
> }
> @@ -1264,8 +1263,9 @@ int ext4_get_blocks(handle_t *handle, struct inode *inode, sector_t block,
>
> up_write((&EXT4_I(inode)->i_data_sem));
> if (retval > 0 && buffer_mapped(bh)) {
> - int ret = check_block_validity(inode, block,
> - bh->b_blocknr, retval);
> + int ret = check_block_validity(inode, "file system "
> + "corruption after allocation",
> + block, bh->b_blocknr, retval);
> if (ret != 0)
> return ret;
> }