Messages in this thread Patch in this message | | | Date | Wed, 04 Apr 2012 09:29:44 -0400 | From | Jeff Mahoney <> | Subject | Re: [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 |
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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/ iQIcBAEBAgAGBQJPfEzIAAoJEB57S2MheeWyqcoP/RagYePToMYOdgjjxVz2cwkf BLT5B0KWWaJa0KtEOpgQATmldmA4CCq6WmC7R/Omy1q9RD75rheKxaxuQY35NTFe czBSfVr3VeMy1A6dIK+wHOiAfheuT90xSgXJJMpdkjHmNjEA1g2nupAFltUE/L70 +xFxotBuoYuTe8u++QES0JGqnw8YI6FW0z3Z4buyoqRhgiX7TukNfXXgx4c2HI0/ cOkxyvYpDi2WF9EtESn/ekwf4Rjx9kNUX/9owmDWYgHD4MLjwSQsRbwZ7BrZEM3k aBe8yZGpgr3UuL9nGiPbWHsyBeAskvXaL6Y2YIczJSvsoP/DM+9SsHAwnqkVaBHv 8qQiQqUhF1mrdl3GBSvKJarGczrSmbWZ5X94oYq4MCKyi3SeTN/bcJS+p5EV1Tvs LMRqqj26leHnl+bYKGWIfJqQRuYcfbkzTOADbn54iMYj2aG2raUjI9D53TUIInuV Csm2hhKJn+HDwu2+gZX1F99W0ehs1ps86oGfkT4WA/H7fTmugiEYxsM1Dk71Ti7/ eadns62DYFZyzKk4/jP/8Rjygc4YM/T2F9qb+SX3hWGhIIZiz5qOxjgBZy91i+84 W+DDUHjZPU+O14nNlKFA3INGS9823ENklRkzpNUhLx7ffrCLOAS73O2rzHcaSmtk FSDWO4EqxIAi4t3LoL14 =Pxwh -----END PGP SIGNATURE-----
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