Hello,
On Fri 02-01-15 17:08:11, Fabian Frederick wrote:
> xfstests/ltp/fsx version (fsx file -d -Z -r 4096 -w 4096)
> always ends up with filesystem being remounted read-only due to a
> write operation done beyond truncate offset.
>
> affs debug:
> affs: error (device sdd1): get_block(): strange block request 136
> affs: Remounting filesystem read-only
>
> Fsx report:
> "
> 129(129 mod 256): TRUNCATE DOWN from 0x3ff01 to 0xb3f6
> 130(130 mod 256): WRITE 0x22000 thru 0x2dfff (0xc000 bytes) HOLE
> "
>
> Error in affs_get_block:
> if (block >= AFFS_I(inode)->i_blkcnt) {
> if (block > AFFS_I(inode)->i_blkcnt || !create)
> goto err_big;
> } else
> create = 0;
>
> When I display values there, block is 136; i_blkcnt: 45
>
> It seems operations are mixed up and especially truncate/get_block.
> I tried the patch below to add truncate mutex featuring in some other
> filesystems but problem remains the same.
> Is there something else I could do to avoid such problem ?
As I wrote in another email I think this is a problem with direct IO
write beyond EOF. Specifically, I don't think this is a problem with
locking since fsx is singlethreaded...
Honza
> ---
> fs/affs/affs.h | 1 +
> fs/affs/file.c | 10 +++++++++-
> fs/affs/super.c | 1 +
> 3 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/fs/affs/affs.h b/fs/affs/affs.h
> index ff44ff3..c7942d9 100644
> --- a/fs/affs/affs.h
> +++ b/fs/affs/affs.h
> @@ -56,6 +56,7 @@ struct affs_inode_info {
> u32 i_protect; /* unused attribute bits */
> u32 i_lastalloc; /* last allocated block */
> int i_pa_cnt; /* number of preallocated blocks */
> + struct mutex truncate_mutex;
> struct inode vfs_inode;
> };
>
> diff --git a/fs/affs/file.c b/fs/affs/file.c
> index 8faa659..7e1ab3e 100644
> --- a/fs/affs/file.c
> +++ b/fs/affs/file.c
> @@ -321,7 +321,10 @@ affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_resul
> map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
>
> if (create) {
> - u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
> + u32 blocknr;
> +
> + mutex_lock(&AFFS_I(inode)->truncate_mutex);
> + blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
> if (!blocknr)
> goto err_alloc;
> set_buffer_new(bh_result);
> @@ -349,6 +352,7 @@ affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_resul
>
> affs_brelse(ext_bh);
> //unlock cache
> + mutex_unlock(&AFFS_I(inode)->truncate_mutex);
> affs_unlock_ext(inode);
> return 0;
>
> @@ -365,6 +369,7 @@ err_alloc:
> clear_buffer_mapped(bh_result);
> bh_result->b_bdev = NULL;
> // unlock cache
> + mutex_unlock(&AFFS_I(inode)->truncate_mutex);
> affs_unlock_ext(inode);
> return -ENOSPC;
> }
> @@ -860,6 +865,7 @@ affs_truncate(struct inode *inode)
>
> // lock cache
> ext_bh = affs_get_extblock(inode, ext);
> + mutex_lock(&AFFS_I(inode)->truncate_mutex);
> if (IS_ERR(ext_bh)) {
> affs_warning(sb, "truncate",
> "unexpected read error for ext block %u (%ld)",
> @@ -912,6 +918,7 @@ affs_truncate(struct inode *inode)
> affs_warning(sb, "truncate",
> "unexpected read error for last block %u (%ld)",
> (unsigned int)ext, PTR_ERR(bh));
> + mutex_unlock(&AFFS_I(inode)->truncate_mutex);
> return;
> }
> tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
> @@ -938,6 +945,7 @@ affs_truncate(struct inode *inode)
> affs_brelse(ext_bh);
> }
> affs_free_prealloc(inode);
> + mutex_unlock(&AFFS_I(inode)->truncate_mutex);
> }
>
> int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
> diff --git a/fs/affs/super.c b/fs/affs/super.c
> index f754ab6..66c74df 100644
> --- a/fs/affs/super.c
> +++ b/fs/affs/super.c
> @@ -123,6 +123,7 @@ static void init_once(void *foo)
>
> sema_init(&ei->i_link_lock, 1);
> sema_init(&ei->i_ext_lock, 1);
> + mutex_init(&ei->truncate_mutex);
> inode_init_once(&ei->vfs_inode);
> }
>
> --
> 2.1.0
>
--
Jan Kara <jack@xxxxxxx>
SUSE Labs, CR
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