linux/fs/afs
David Howells fe4d774c84 afs: Fix missing cursor clearance
afs_select_fileserver() ends the address cursor it is using in the case in
which we get some sort of network error and run out of addresses to iterate
through, before it jumps to try the next server.  This also needs to be
done when the server aborts with some sort of error that means we should
try the next server.

Fix this by:

 (1) Move the iterate_address afs_end_cursor() call to the next_server
     case.

 (2) End the cursor in the failed case.

 (3) Make afs_end_cursor() clear the ->begun flag and ->addr pointer in the
     address cursor.

 (4) Make afs_end_cursor() able to be called on an already cleared cursor.

Without this, something like the following oops may occur:

	AFS: Assertion failed
	18446612134397189888 == 0 is false
	0xffff88007c279f00 == 0x0 is false
	------------[ cut here ]------------
	kernel BUG at fs/afs/rotate.c:360!
	RIP: 0010:afs_select_fileserver+0x79b/0xa30 [kafs]
	Call Trace:
	 afs_statfs+0xcc/0x180 [kafs]
	 ? p9_client_statfs+0x9e/0x110 [9pnet]
	 ? _cond_resched+0x19/0x40
	 statfs_by_dentry+0x6d/0x90
	 vfs_statfs+0x1b/0xc0
	 user_statfs+0x4b/0x80
	 SYSC_statfs+0x15/0x30
	 SyS_statfs+0xe/0x10
	 entry_SYSCALL_64_fastpath+0x20/0x83

Fixes: d2ddc776a4 ("afs: Overhaul volume and server record caching and fileserver rotation")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: stable@vger.kernel.org
2018-02-06 14:36:54 +00:00
..
addr_list.c afs: Fix missing cursor clearance 2018-02-06 14:36:54 +00:00
afs_cm.h afs: support the CB.ProbeUuid RPC op 2008-04-29 08:06:26 -07:00
afs_fs.h afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00
afs_vl.h afs: Make use of the YFS service upgrade to fully support IPv6 2017-11-13 15:38:19 +00:00
afs.h afs: Overhaul permit caching 2017-11-13 15:38:18 +00:00
cache.c afs: Update the cache index structure 2017-11-13 15:38:17 +00:00
callback.c afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00
cell.c afs: cell: Remove unnecessary code in afs_lookup_cell 2017-11-24 13:55:45 +00:00
cmservice.c afs: Protect call->state changes against signals 2017-11-13 15:38:21 +00:00
dir.c afs: Fix unlink 2018-01-02 10:02:19 +00:00
file.c afs: Trace page dirty/clean 2017-11-13 15:38:21 +00:00
flock.c afs: Fix file locking 2017-11-17 10:06:13 +00:00
fsclient.c afs: convert to new i_version API 2018-01-29 06:42:20 -05:00
inode.c inode->i_version rework for v4.16 2018-01-29 13:33:53 -08:00
internal.h afs: Properly reset afs_vnode (inode) fields 2017-12-01 11:51:24 +00:00
Kconfig fs/afs: remove depends on CONFIG_EXPERIMENTAL 2013-01-21 14:39:04 -08:00
main.c afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00
Makefile afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00
misc.c afs: Consolidate abort_to_error translators 2017-11-13 15:38:17 +00:00
mntpt.c afs: Add metadata xattrs 2017-07-09 14:40:12 -07:00
netdevices.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
proc.c afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00
rotate.c afs: Fix missing cursor clearance 2018-02-06 14:36:54 +00:00
rxrpc.c afs: Potential uninitialized variable in afs_extract_data() 2018-01-02 10:02:19 +00:00
security.c afs: Fix permit refcounting 2017-12-01 11:40:43 +00:00
server_list.c afs: Fix file locking 2017-11-17 10:06:13 +00:00
server.c afs: Make use of the YFS service upgrade to fully support IPv6 2017-11-13 15:38:19 +00:00
super.c afs: Properly reset afs_vnode (inode) fields 2017-12-01 11:51:24 +00:00
vlclient.c afs: Trace the initiation and completion of client calls 2017-11-13 15:38:19 +00:00
volume.c afs: Add missing afs_put_cell() 2018-02-06 14:22:03 +00:00
write.c afs: Fix missing error handling in afs_write_end() 2018-01-02 10:02:19 +00:00
xattr.c afs: Overhaul volume and server record caching and fileserver rotation 2017-11-13 15:38:19 +00:00