gluster: add fallocate fop support

Implement support for the fallocate file operation. fallocate
allocates blocks for a particular inode such that future writes
to the associated region of the file are guaranteed not to fail
with ENOSPC.

This patch adds fallocate support to the following areas:

	- libglusterfs
	- mount/fuse
	- io-stats
	- performance/md-cache,open-behind
	- quota
	- cluster/afr,dht,stripe
	- rpc/xdr
	- protocol/client,server
	- io-threads
	- marker
	- storage/posix
	- libgfapi

BUG: 949242
Change-Id: Ice8e61351f9d6115c5df68768bc844abbf0ce8bd
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-on: http://review.gluster.org/4969
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Anand Avati <avati@redhat.com>

1 files changed, 67 insertions, 0 deletions

diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 93577cf54fc..36883403790 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -561,6 +561,72 @@ out:
         return 0;
 }
 
+static int32_t
+_posix_fallocate(call_frame_t *frame, xlator_t *this, fd_t *fd, int32_t keep_size,
+		off_t offset, size_t len, dict_t *xdata)
+{
+	int32_t        op_ret    = -1;
+        int32_t        op_errno  = 0;
+        struct iatt    statpre     = {0,};
+        struct iatt    statpost    = {0,};
+        struct posix_fd *pfd = NULL;
+        int32_t          ret = -1;
+	int32_t		flags = 0;
+
+        DECLARE_OLD_FS_ID_VAR;
+
+        SET_FS_ID (frame->root->uid, frame->root->gid);
+
+        VALIDATE_OR_GOTO (frame, out);
+        VALIDATE_OR_GOTO (this, out);
+        VALIDATE_OR_GOTO (fd, out);
+
+        ret = posix_fd_ctx_get (fd, this, &pfd);
+        if (ret < 0) {
+                op_errno = -ret;
+                gf_log (this->name, GF_LOG_DEBUG,
+                        "pfd is NULL from fd=%p", fd);
+                goto out;
+        }
+
+        op_ret = posix_fdstat (this, pfd->fd, &statpre);
+        if (op_ret == -1) {
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_ERROR,
+                        "fallocate (fstat) failed on fd=%p: %s", fd,
+                        strerror (op_errno));
+                goto out;
+        }
+
+	if (keep_size)
+		flags = FALLOC_FL_KEEP_SIZE;
+
+	op_ret = sys_fallocate(pfd->fd, flags, offset, len);
+	if (op_ret == -1) {
+		op_errno = errno;
+		goto out;
+	}
+
+        op_ret = posix_fdstat (this, pfd->fd, &statpost);
+        if (op_ret == -1) {
+                op_errno = errno;
+                gf_log (this->name, GF_LOG_ERROR,
+                        "fallocate (fstat) failed on fd=%p: %s", fd,
+                        strerror (op_errno));
+                goto out;
+        }
+
+        op_ret = 0;
+
+out:
+        SET_TO_OLD_FS_ID ();
+
+        STACK_UNWIND_STRICT (fallocate, frame, op_ret, op_errno,
+                             &statpre, &statpost, NULL);
+
+        return 0;
+}
+
 int32_t
 posix_opendir (call_frame_t *frame, xlator_t *this,
                loc_t *loc, fd_t *fd, dict_t *xdata)
@@ -4659,6 +4725,7 @@ struct xlator_fops fops = {
         .fxattrop    = posix_fxattrop,
         .setattr     = posix_setattr,
         .fsetattr    = posix_fsetattr,
+	.fallocate   = _posix_fallocate,
 };
 
 struct xlator_cbks cbks = {