gfapi: POSIX locking support

Change-Id: I37d9e1fb4a715094876be6af3856c1b4cf398021
BUG: 953694
Signed-off-by: Anand Avati <avati@redhat.com>
Reviewed-on: http://review.gluster.org/4881
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

5 files changed, 90 insertions, 0 deletions

diff --git a/api/src/glfs-fops.c b/api/src/glfs-fops.c
index 3ce930f2745..61c524eaf78 100644
--- a/api/src/glfs-fops.c
+++ b/api/src/glfs-fops.c
@@ -2315,3 +2315,49 @@ out:
 
 	return buf;
 }
+
+
+static void
+gf_flock_to_flock (struct gf_flock *gf_flock, struct flock *flock)
+{
+	flock->l_type   = gf_flock->l_type;
+	flock->l_whence = gf_flock->l_whence;
+	flock->l_start  = gf_flock->l_start;
+	flock->l_len    = gf_flock->l_len;
+	flock->l_pid    = gf_flock->l_pid;
+}
+
+
+static void
+gf_flock_from_flock (struct gf_flock *gf_flock, struct flock *flock)
+{
+	gf_flock->l_type   = flock->l_type;
+	gf_flock->l_whence = flock->l_whence;
+	gf_flock->l_start  = flock->l_start;
+	gf_flock->l_len    = flock->l_len;
+	gf_flock->l_pid    = flock->l_pid;
+}
+
+
+int
+glfs_posix_lock (struct glfs_fd *glfd, int cmd, struct flock *flock)
+{
+	int              ret = -1;
+	xlator_t        *subvol = NULL;
+	struct gf_flock  gf_flock = {0, };
+
+	__glfs_entry_fd (glfd);
+
+	subvol = glfs_fd_subvol (glfd);
+	if (!subvol) {
+		ret = -1;
+		errno = EIO;
+		goto out;
+	}
+
+	gf_flock_from_flock (&gf_flock, flock);
+	ret = syncop_lk (subvol, glfd->fd, cmd, &gf_flock);
+	gf_flock_to_flock (&gf_flock, flock);
+out:
+	return ret;
+}
diff --git a/api/src/glfs.c b/api/src/glfs.c
index 21cded39c69..01c3494e28e 100644
--- a/api/src/glfs.c
+++ b/api/src/glfs.c
@@ -11,6 +11,7 @@
 
 /*
   TODO:
+  - merge locks in glfs_posix_lock for lock self-healing
   - refresh fs->cwd inode on graph switch
   - set proper pid/lk_owner to call frames (currently buried in syncop)
   - fix logging.c/h to store logfp and loglevel in glusterfs_ctx_t and
diff --git a/api/src/glfs.h b/api/src/glfs.h
index 06849d0c731..7fecffb697a 100644
--- a/api/src/glfs.h
+++ b/api/src/glfs.h
@@ -453,6 +453,12 @@ int glfs_fchdir (glfs_fd_t *fd);
 
 char *glfs_realpath (glfs_t *fs, const char *path, char *resolved_path);
 
+/*
+ * @cmd and @flock are as specified in man fcntl(2).
+ */
+int glfs_posix_lock (glfs_fd_t *fd, int cmd, struct flock *flock);
+
+
 __END_DECLS
 
 #endif /* !_GLFS_H */
diff --git a/libglusterfs/src/syncop.c b/libglusterfs/src/syncop.c
index 1a335d147e9..4e3c93a45f8 100644
--- a/libglusterfs/src/syncop.c
+++ b/libglusterfs/src/syncop.c
@@ -1803,3 +1803,37 @@ syncop_access (xlator_t *subvol, loc_t *loc, int32_t mask)
         errno = args.op_errno;
         return args.op_ret;
 }
+
+
+int
+syncop_lk_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
+	       int op_ret, int op_errno, struct gf_flock *flock,
+	       dict_t *xdata)
+{
+        struct syncargs *args = NULL;
+
+        args = cookie;
+
+        args->op_ret   = op_ret;
+        args->op_errno = op_errno;
+	if (flock)
+		args->flock = *flock;
+        __wake (args);
+
+        return 0;
+}
+
+
+int
+syncop_lk (xlator_t *subvol, fd_t *fd, int cmd, struct gf_flock *flock)
+{
+        struct syncargs args = {0, };
+
+        SYNCOP (subvol, (&args), syncop_lk_cbk, subvol->fops->lk,
+                fd, cmd, flock, NULL);
+
+        errno = args.op_errno;
+	*flock = args.flock;
+
+        return args.op_ret;
+}
diff --git a/libglusterfs/src/syncop.h b/libglusterfs/src/syncop.h
index 0bb34a24156..cf044d40f36 100644
--- a/libglusterfs/src/syncop.h
+++ b/libglusterfs/src/syncop.h
@@ -120,6 +120,7 @@ struct syncargs {
         struct iobref      *iobref;
         char               *buffer;
         dict_t             *xdata;
+	struct gf_flock     flock;
 
         /* some more _cbk needs */
         uuid_t              uuid;
@@ -325,4 +326,6 @@ int syncop_access (xlator_t *subvol, loc_t *loc, int32_t mask);
 
 int syncop_rename (xlator_t *subvol, loc_t *oldloc, loc_t *newloc);
 
+int syncop_lk (xlator_t *subvol, fd_t *fd, int cmd, struct gf_flock *flock);
+
 #endif /* _SYNCOP_H */