linux-aio: fixes while setting O_DIRECT flag

Linux AIO needs O_DIRECT to be set for effective operation. O_DIRECT
in turn has constraints on when it can work (offset, size alignment)

So use O_DIRECT (unless instructed by application) only when offset
and size alignments match. Else, io_submit() will happen over
non-O_DIRECT fd, effectively blocking till the completion of the IO.

Also fix a multithreading bug where detection/setting of O_DIRECT
for a request was not atomic with io_submit() of that request.

Change-Id: I190017e8bc78217429aff0714dca224cbe6f251d
BUG: 859406
Signed-off-by: Amar Tumballi <amarts@redhat.com>
Reviewed-on: http://review.gluster.org/4006
Tested-by: Amar Tumballi <amarts@redhat.com>
Original-Author: Anand Avati <avati@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/61
Reviewed-by: Vijay Bellur <vbellur@redhat.com>
Tested-by: Vijay Bellur <vbellur@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/1874

1 files changed, 0 insertions, 32 deletions

diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 7d419cd9222..2e7bce3ed7b 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -1060,35 +1060,3 @@ posix_fd_ctx_get (fd_t *fd, xlator_t *this, struct posix_fd **pfd)
 
         return ret;
 }
-
-
-int
-posix_fd_ctx_get_off (fd_t *fd, xlator_t *this, struct posix_fd **pfd,
-                      off_t offset)
-{
-        int   ret;
-        int   flags;
-
-        LOCK (&fd->inode->lock);
-        {
-                ret = __posix_fd_ctx_get (fd, this, pfd);
-                if (ret)
-                        goto unlock;
-
-                if ((offset & 0xfff) && (*pfd)->odirect) {
-                        flags = fcntl ((*pfd)->fd, F_GETFL);
-                        ret = fcntl ((*pfd)->fd, F_SETFL, (flags & (~O_DIRECT)));
-                        (*pfd)->odirect = 0;
-                }
-
-                if (((offset & 0xfff) == 0) && (!(*pfd)->odirect)) {
-                        flags = fcntl ((*pfd)->fd, F_GETFL);
-                        ret = fcntl ((*pfd)->fd, F_SETFL, (flags | O_DIRECT));
-                        (*pfd)->odirect = 1;
-                }
-        }
-unlock:
-        UNLOCK (&fd->inode->lock);
-
-        return ret;
-}