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cluster/dht: Fix fd check race

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There is a another race between the cached subvol
being updated in the inode_ctx and the fd being opened on
the target.

1. fop1 -> fd1 -> subvol0
2. file migrated from subvol0 to subvol1 and cached_subvol
   changed to subvol1 in inode_ctx
3. fop2 -> fd1 -> subvol1 [takes new cached subvol]
4. fop2 -> checks fd ctx (fd not open on subvol1) -> opens fd1 on subvol1
5. fop1 -> checks fd ctx (fd not open on subvol0)
   -> tries to open fd1 on subvol0 -> fails with "No such file on directory".

Fix:
If dht_fd_open_on_dst fails with ENOENT or ESTALE, wind to old subvol
and let the phase1/phase2 checks handle it.

Change-Id: I34f8011574a8b72e3bcfe03b0cc4f024b352f225
BUG: 1465075
Signed-off-by: N Balachandran <nbalacha@redhat.com>
Reviewed-on: https://review.gluster.org/17731
Smoke: Gluster Build System <jenkins@build.gluster.org>
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Raghavendra G <rgowdapp@redhat.com>
Reviewed-by: Amar Tumballi <amarts@redhat.com>
This commit is contained in:
N Balachandran 2017-07-10 09:38:54 +05:30 committed by Raghavendra G
parent a62b16b72b
commit f7a450c17f
2 changed files with 34 additions and 1 deletions
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26
xlators/cluster/dht/src/dht-helper.c
View File

@ -287,10 +287,12 @@ dht_check_and_open_fd_on_subvol_complete (int ret, call_frame_t *frame,
glusterfs_fop_t fop = 0;
dht_local_t *local = NULL;
xlator_t *subvol = NULL;
xlator_t *this = NULL;
fd_t *fd = NULL;
int op_errno = -1;
local = frame->local;
this = frame->this;
fop = local->fop;
subvol = local->cached_subvol;
fd = local->fd;
@ -379,6 +381,11 @@ dht_check_and_open_fd_on_subvol_complete (int ret, call_frame_t *frame,
break;
default:
gf_msg (this->name, GF_LOG_ERROR, 0,
DHT_MSG_UNKNOWN_FOP,
"Unknown FOP on fd (%p) on file %s @ %s",
fd, uuid_utoa (fd->inode->gfid),
subvol->name);
break;
}
@ -439,6 +446,11 @@ handle_err:
break;
default:
gf_msg (this->name, GF_LOG_ERROR, 0,
DHT_MSG_UNKNOWN_FOP,
"Unknown FOP on fd (%p) on file %s @ %s",
fd, uuid_utoa (fd->inode->gfid),
subvol->name);
break;
}
@ -502,6 +514,20 @@ dht_check_and_open_fd_on_subvol_task (void *data)
" (%p, flags=0%o) on file %s @ %s",
fd, fd->flags, uuid_utoa (fd->inode->gfid),
subvol->name);
/* This can happen if the cached subvol was updated in the
* inode_ctx and the fd was opened on the new cached suvol
* after this fop was wound on the old cached subvol.
* As we do not close the fd on the old subvol (a leak)
* don't treat ENOENT as an error and allow the phase1/phase2
* checks to handle it.
*/
if ((-ret != ENOENT) && (-ret != ESTALE)) {
local->op_errno = -ret;
ret = -1;
} else {
ret = 0;
}
local->op_errno = -ret;
ret = -1;

9
xlators/cluster/dht/src/dht-messages.h
View File

@ -40,7 +40,7 @@
*/
#define GLFS_DHT_BASE GLFS_MSGID_COMP_DHT
#define GLFS_DHT_NUM_MESSAGES 124
#define GLFS_DHT_NUM_MESSAGES 125
#define GLFS_MSGID_END (GLFS_DHT_BASE + GLFS_DHT_NUM_MESSAGES + 1)
/* Messages with message IDs */
@ -1127,5 +1127,12 @@
*/
#define DHT_MSG_LOC_FAILED (GLFS_DHT_BASE + 124)
/*
* @messageid 109125
* @diagnosis
* @recommendedaction None
*/
#define DHT_MSG_UNKNOWN_FOP (GLFS_DHT_BASE + 125)
#define glfs_msg_end_x GLFS_MSGID_END, "Invalid: End of messages"
#endif /* _DHT_MESSAGES_H_ */