Wang Sheng-Hui
2012-Mar-31 07:25 UTC
[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
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);
--
1.7.1
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Jeff Mahoney
2012-Apr-04 13:29 UTC
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
-----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/ 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----- -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Wang Sheng-Hui
2012-Apr-05 02:10 UTC
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
On 2012年04月04日 21:29, Jeff Mahoney wrote:> -----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 >Hi Jeff, I''ll review the code and provide a list of patches later. Currently we can skip it, I think. Thanks, Sheng-Hui> - -- > 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-----