fix to rm of large file blocking other operations on the same directory containing file (ref: rt #779)

posix_unlink follows the below procedure to avoid client noticing delay during
unlink of large file
1. open file
2. unlink file
3. stack_unwind
4. close file

Signed-off-by: Anand V. Avati <avati@amp.gluster.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 534db05fd..c20c7fec4 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -853,6 +853,7 @@ posix_unlink (call_frame_t *frame, xlator_t *this,
         int32_t op_ret    = -1;
         int32_t op_errno  = 0;
         char *  real_path = NULL;
+        int32_t fd = -1;
 
         DECLARE_OLD_FS_ID_VAR;
 
@@ -863,6 +864,15 @@ posix_unlink (call_frame_t *frame, xlator_t *this,
         SET_FS_ID (frame->root->uid, frame->root->gid);
         MAKE_REAL_PATH (real_path, this, loc->path);
 
+        fd = open (real_path, O_RDONLY);
+        if (fd == -1) {
+                op_ret = -1;
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_WARNING,
+                        "open of %s failed: %s", loc->path, strerror (op_errno));
+                goto out;
+        }
+
         op_ret = unlink (real_path);
         if (op_ret == -1) {
                 op_errno = errno;
@@ -876,8 +886,13 @@ posix_unlink (call_frame_t *frame, xlator_t *this,
  out:
         SET_TO_OLD_FS_ID ();
         frame->root->rsp_refs = NULL;
+
         STACK_UNWIND (frame, op_ret, op_errno);
 
+        if (fd != -1) {
+                close (fd);
+        }
+
         return 0;
 }