mirror_zfs/module
Alyssa Ross c074a7de13
Return required size when encode_fh size too small
Quoting <linux/exportfs.h>:

> encode_fh() should return the fileid_type on success and on error
> returns 255 (if the space needed to encode fh is greater than
> @max_len*4 bytes). On error @max_len contains the minimum size (in 4
> byte unit) needed to encode the file handle.

ZFS was not setting max_len in the case where the handle was too
small.  As a result of this, the `t_name_to_handle_at.c' example in
name_to_handle_at(2) did not work on ZFS.

zfsctl_fid() will itself set max_len if called with a fid that is too
small, so if we give zfs_fid() that behavior as well, the fix is quite
easy: if the handle is too small, just use a zero-size fid instead of
the handle.

Tested by running t_name_to_handle_at on a normal file, a directory, a
.zfs directory, and a snapshot.

Thanks-to: Puck Meerburg <puck@puckipedia.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Tony Nguyen <tony.nguyen@delphix.com>
Signed-off-by: Alyssa Ross <hi@alyssa.is>
Closes #11995
2021-05-07 15:08:16 -07:00
..
avl Fix various typos 2021-04-02 18:52:15 -07:00
icp ICP: Silence objtool "stack pointer realignment" warnings 2021-04-17 13:11:18 -07:00
lua cppcheck: integrete cppcheck 2021-01-26 16:12:26 -08:00
nvpair Links in Source Files 2020-09-02 09:42:12 -07:00
os Return required size when encode_fh size too small 2021-05-07 15:08:16 -07:00
spl Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
unicode Fix various typos 2021-04-02 18:52:15 -07:00
zcommon Fix AVX512BW Fletcher code on AVX512-but-not-BW machines 2021-04-26 12:42:42 -07:00
zfs Simplify/fix dnode_move() for dn_zfetch 2021-05-07 15:07:03 -07:00
zstd Fix various typos 2021-04-02 18:52:15 -07:00
.gitignore Cleanup linux module kbuild files 2020-06-10 09:24:15 -07:00
Kbuild.in Add zstd support to zfs 2020-08-20 10:30:06 -07:00
Makefile.bsd Restore FreeBSD resource usage accounting 2021-02-19 22:34:33 -08:00
Makefile.in FreeBSD module --enable-debug --enable-invariants 2021-03-05 12:16:41 -08:00