On Wed, May 18, 2016 at 11:41:05AM +0200, David Sterba wrote: > On Tue, May 17, 2016 at 05:21:48PM -0700, Liu Bo wrote: > > btrfs's fiemap is supposed to return 0 on success and > > return < 0 on error, however, ret becomes 1 after looking > > up the last file extent, and if the offset is beyond EOF, > > we can return 1. > > > > This may confuse applications using ioctl(FIEL_IOC_FIEMAP). > > > > Signed-off-by: Liu Bo <bo.li....@oracle.com> > > Reviewed-by: David Sterba <dste...@suse.com> > > > --- > > fs/btrfs/extent_io.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c > > index d247fc0..16ece52 100644 > > --- a/fs/btrfs/extent_io.c > > +++ b/fs/btrfs/extent_io.c > > @@ -4379,8 +4379,12 @@ int extent_fiemap(struct inode *inode, struct > > fiemap_extent_info *fieinfo, > > if (ret < 0) { > > btrfs_free_path(path); > > return ret; > > + } else { > > + WARN_ON(!ret); > > + if (ret == 1) > > + ret = 0; > > } > > So, ret == 1 can end up here from btrfs_lookup_file_extent -> > btrfs_search_slot(..., ins_len=0, cow=0) and the offset does not exist, > we'll get path pointed to the slot where it would be inserted and ret is 1.
Sounds better than the commit log, would you like me to update it? Thanks, -liubo -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html