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authorRaghavendra Talur <rtalur@redhat.com>2016-11-02 19:51:26 +0530
committerRaghavendra Talur <rtalur@redhat.com>2016-11-08 02:37:54 -0800
commitf593a4d7d1cd972e2fa65d1dac471d0bebee7235 (patch)
tree82834eca252ce308a780185c73dc69ac4f5b49c3
parentd6029f801bccdd4579698c78c849abce9ede9916 (diff)
gfapi: async fops should unref in callbacks
If fd is unref'd at the end of async call then the unref in cbks would lead to double unref and possible crash. Removing duplicate unrefs. Added unref only in failure cases. This backport to 3.7 branch does not have tests because gfapi tests are not configured properly on 3.7 branch. Details: All glfd based calls in libgfapi, except for glfs_open and glfs_close, behave in the same way. At the start of the operation, they take a ref on glfd and fd. At the end of the operation, they unref it. Async calls are a little different as they unref in the cbk function. A successfull open call does not unref either the glfd or fd, thereby functioning as a reference for a OPEN file object. glfs_close makes a syncop_flush call sandwiched between a fd ref and unref(this can be removed, more on this below), followed by a call to glfs_mark_glfd_for_deletion which unrefs glfd and also calls glfs_fd_destroy as a release function thereby doing a unref on fd too. Functionally, there is no problem with how everything works when as described above. However, it is a little non-intuitive that we need to perform a fd_unref as a consequence of a implicit fd_ref that happens within glfs_resolve_fd. As we perform a GF_REF_GET(glfd) at the start of every operation, it would be worthwhile to remove the fd_ref that glfs_resovle_fd takes and do away with explicit fd_unref()s at the end of every operation. This is the same reason why we don't need the fd_ref in glfs_close. This is however not in the scope of this patch. Change-Id: I86b1d3b2ad846b16ea527d541dc82b5e90b0ba85 BUG: 1392289 Signed-off-by: Raghavendra Talur <rtalur@redhat.com> Reviewed-on: http://review.gluster.org/15768 Smoke: Gluster Build System <jenkins@build.gluster.org> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org> Reviewed-by: Rajesh Joseph <rjoseph@redhat.com> Reviewed-by: Xavier Hernandez <xhernandez@datalab.es> Reviewed-by: soumya k <skoduri@redhat.com> Reviewed-by: Prasanna Kumar Kalever <pkalever@redhat.com> CentOS-regression: Gluster Build System <jenkins@build.gluster.org> Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com> (cherry picked from commit e65738818dd22462ec00dda021566654d1c702b1) Reviewed-on: http://review.gluster.org/15780
-rw-r--r--api/src/glfs-fops.c30
1 files changed, 12 insertions, 18 deletions
diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index be1077a..ec2fbb2 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -869,10 +869,9 @@ pub_glfs_preadv_async (struct glfs_fd *glfd, const struct iovec *iovec,
offset, flags, NULL);
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
if (gio) {
@@ -1187,10 +1186,9 @@ pub_glfs_pwritev_async (struct glfs_fd *glfd, const struct iovec *iovec,
ret = 0;
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
GF_FREE (gio);
@@ -1374,10 +1372,9 @@ glfs_fsync_async_common (struct glfs_fd *glfd, glfs_io_cbk fn, void *data,
subvol->fops->fsync, fd, dataonly, NULL);
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
GF_FREE (gio);
@@ -1628,10 +1625,9 @@ pub_glfs_ftruncate_async (struct glfs_fd *glfd, off_t offset, glfs_io_cbk fn,
ret = 0;
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
GF_FREE (gio);
@@ -2487,10 +2483,9 @@ pub_glfs_discard_async (struct glfs_fd *glfd, off_t offset, size_t len,
ret = 0;
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
GF_FREE (gio);
@@ -2575,10 +2570,9 @@ pub_glfs_zerofill_async (struct glfs_fd *glfd, off_t offset, off_t len,
subvol->fops->zerofill, fd, offset, len, NULL);
ret = 0;
out:
- if (fd)
- fd_unref (fd);
-
if (ret) {
+ if (fd)
+ fd_unref (fd);
if (glfd)
GF_REF_PUT (glfd);
GF_FREE (gio);