| Message ID | 1426624683-3085-3-git-send-email-jbacik@fb.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On Tue, Mar 17, 2015 at 04:38:01PM -0400, Josef Bacik wrote: > If we fail during our sanity tests we could get NULL deref's because we unload > the module before the dummy extent buffers are free'd via RCU. So check for > this case and just free the things directly. Thanks, > > Signed-off-by: Josef Bacik <jbacik@fb.com> > --- > fs/btrfs/extent_io.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > index 29850d4..d13cead 100644 > --- a/fs/btrfs/extent_io.c > +++ b/fs/btrfs/extent_io.c > @@ -4968,6 +4968,12 @@ static int release_extent_buffer(struct extent_buffer *eb) > > /* Should be safe to release our pages at this point */ > btrfs_release_extent_buffer_page(eb); > +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS Please use btrfs_test_is_dummy_root, it's there to avoid the #ifdefs > + if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) { > + __free_extent_buffer(eb); > + return 1; > + } > +#endif > call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); > return 1; > } -- 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
On 03/18/2015 09:56 AM, David Sterba wrote: > On Tue, Mar 17, 2015 at 04:38:01PM -0400, Josef Bacik wrote: >> If we fail during our sanity tests we could get NULL deref's because we unload >> the module before the dummy extent buffers are free'd via RCU. So check for >> this case and just free the things directly. Thanks, >> >> Signed-off-by: Josef Bacik <jbacik@fb.com> >> --- >> fs/btrfs/extent_io.c | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c >> index 29850d4..d13cead 100644 >> --- a/fs/btrfs/extent_io.c >> +++ b/fs/btrfs/extent_io.c >> @@ -4968,6 +4968,12 @@ static int release_extent_buffer(struct extent_buffer *eb) >> >> /* Should be safe to release our pages at this point */ >> btrfs_release_extent_buffer_page(eb); >> +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS > > Please use btrfs_test_is_dummy_root, it's there to avoid the #ifdefs Don't have a root here. Thanks, Josef -- 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
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 29850d4..d13cead 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4968,6 +4968,12 @@ static int release_extent_buffer(struct extent_buffer *eb) /* Should be safe to release our pages at this point */ btrfs_release_extent_buffer_page(eb); +#ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS + if (unlikely(test_bit(EXTENT_BUFFER_DUMMY, &eb->bflags))) { + __free_extent_buffer(eb); + return 1; + } +#endif call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu); return 1; }
If we fail during our sanity tests we could get NULL deref's because we unload the module before the dummy extent buffers are free'd via RCU. So check for this case and just free the things directly. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> --- fs/btrfs/extent_io.c | 6 ++++++ 1 file changed, 6 insertions(+)