lkml.org 
[lkml]   [2012]   [Apr]   [4]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] btrfs/extent_io.c: return -ENOMEM instead of BUG_ON on allocation failure in set_extent_bit if __GFP_WAIT is set in the mask
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 03/31/2012 03:25 AM, Wang Sheng-Hui wrote:
> If __GFP_WAIT is set in the mask, set_extent_bit should return
> -ENOMEM to its caller to decide what to do on allocation failure,
> instead of BUG_ON.
>
> Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com> ---
> fs/btrfs/extent_io.c | 3 ++- 1 files changed, 2 insertions(+), 1
> deletions(-)
>
> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index
> b67814c..fd2411e 100644 --- a/fs/btrfs/extent_io.c +++
> b/fs/btrfs/extent_io.c @@ -720,7 +720,8 @@ int
> set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end,
> again: if (!prealloc && (mask & __GFP_WAIT)) { prealloc =
> alloc_extent_state(mask); - BUG_ON(!prealloc); + if (!prealloc) +
> return -ENOMEM; }
>
> spin_lock(&tree->lock);

Hi Sheng-Hui -

Do you have a follow-on series to this? With the exception of the
set_extent_dirty call in end_bio_extent_readpage, every set_extent_bit
caller uses GFP_NOFS, which includes __GFP_WAIT. If we return a
failure here, we need to catch the failure in the call sites.
Otherwise, the failure will just be ignored and we'll end up with an
inconsistent extent state tree.

- -Jeff

- --
Jeff Mahoney
SUSE Labs
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.18 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/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=Pxwh
-----END PGP SIGNATURE-----

\
 
 \ /
  Last update: 2012-04-04 15:33    [W:0.040 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site