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authorKrutika Dhananjay <kdhananj@redhat.com>2015-06-22 17:06:07 +0530
committerPranith Kumar Karampuri <pkarampu@redhat.com>2015-06-27 04:03:52 -0700
commitea1039c177ec781506fdae01132a7a876620693f (patch)
treea59b7da6252ed6531a9d67a5bba6898b14624c4b /xlators/storage/posix/src/posix.c
parent6800068bb94137e25e2cab9cf5f999f05461c7a1 (diff)
storage/posix: Introduce flag instructing posix to perform prestat, writev and poststat atomically
Backport of: http://review.gluster.org/11345 Change-Id: I0d7e3a851c744777083974ec4cdb01b08c23727b BUG: 1236271 Signed-off-by: Krutika Dhananjay <kdhananj@redhat.com> Reviewed-on: http://review.gluster.org/11439 Tested-by: NetBSD Build System <jenkins@build.gluster.org> Tested-by: Gluster Build System <jenkins@build.gluster.com> Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Diffstat (limited to 'xlators/storage/posix/src/posix.c')
-rw-r--r--xlators/storage/posix/src/posix.c95
1 files changed, 58 insertions, 37 deletions
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 42b1d0f112f..008fd004cdb 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -2830,6 +2830,8 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
dict_t *rsp_xdata = NULL;
int is_append = 0;
gf_boolean_t locked = _gf_false;
+ gf_boolean_t write_append = _gf_false;
+ gf_boolean_t update_atomic = _gf_false;
VALIDATE_OR_GOTO (frame, out);
VALIDATE_OR_GOTO (this, out);
@@ -2851,16 +2853,32 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
_fd = pfd->fd;
- if (xdata && dict_get (xdata, GLUSTERFS_WRITE_IS_APPEND)) {
- /* The write_is_append check and write must happen
- atomically. Else another write can overtake this
- write after the check and get written earlier.
+ if (xdata) {
+ if (dict_get (xdata, GLUSTERFS_WRITE_IS_APPEND))
+ write_append = _gf_true;
+ if (dict_get (xdata, GLUSTERFS_WRITE_UPDATE_ATOMIC))
+ update_atomic = _gf_true;
+ }
- So lock before preop-stat and unlock after write.
- */
+ /* The write_is_append check and write must happen
+ atomically. Else another write can overtake this
+ write after the check and get written earlier.
+
+ So lock before preop-stat and unlock after write.
+ */
+
+ /*
+ * The update_atomic option is to instruct posix to do prestat,
+ * write and poststat atomically. This is to prevent any modification to
+ * ia_size and ia_blocks until poststat and the diff in their values
+ * between pre and poststat could be of use for some translators (shard
+ * as of today).
+ */
+
+ if (write_append || update_atomic) {
locked = _gf_true;
LOCK(&fd->inode->lock);
- }
+ }
op_ret = posix_fdstat (this, _fd, &preop);
if (op_ret == -1) {
@@ -2870,7 +2888,7 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
goto out;
}
- if (locked) {
+ if (locked && write_append) {
if (preop.ia_size == offset || (fd->flags & O_APPEND))
is_append = 1;
}
@@ -2878,7 +2896,7 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
op_ret = __posix_writev (_fd, vector, count, offset,
(pfd->flags & O_DIRECT));
- if (locked) {
+ if (locked && (!update_atomic)) {
UNLOCK (&fd->inode->lock);
locked = _gf_false;
}
@@ -2892,43 +2910,46 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd,
goto out;
}
- LOCK (&priv->lock);
- {
- priv->write_value += op_ret;
- }
- UNLOCK (&priv->lock);
+ rsp_xdata = _fill_writev_xdata (fd, xdata, this, is_append);
+ /* writev successful, we also need to get the stat of
+ * the file we wrote to
+ */
- if (op_ret >= 0) {
- rsp_xdata = _fill_writev_xdata (fd, xdata, this, is_append);
- /* wiretv successful, we also need to get the stat of
- * the file we wrote to
- */
+ ret = posix_fdstat (this, _fd, &postop);
+ if (ret == -1) {
+ op_ret = -1;
+ op_errno = errno;
+ gf_msg (this->name, GF_LOG_ERROR, errno,
+ P_MSG_FSTAT_FAILED,
+ "post-operation fstat failed on fd=%p",
+ fd);
+ goto out;
+ }
- if (flags & (O_SYNC|O_DSYNC)) {
- ret = fsync (_fd);
- if (ret) {
- gf_msg (this->name, GF_LOG_ERROR, errno,
- P_MSG_WRITEV_FAILED,
- "fsync() in writev on fd %d failed",
- _fd);
- op_ret = -1;
- op_errno = errno;
- goto out;
- }
- }
+ if (locked) {
+ UNLOCK (&fd->inode->lock);
+ locked = _gf_false;
+ }
- ret = posix_fdstat (this, _fd, &postop);
- if (ret == -1) {
+ if (flags & (O_SYNC|O_DSYNC)) {
+ ret = fsync (_fd);
+ if (ret) {
+ gf_msg (this->name, GF_LOG_ERROR, errno,
+ P_MSG_WRITEV_FAILED,
+ "fsync() in writev on fd %d failed",
+ _fd);
op_ret = -1;
op_errno = errno;
- gf_msg (this->name, GF_LOG_ERROR, errno,
- P_MSG_FSTAT_FAILED,
- "post-operation fstat failed on fd=%p",
- fd);
goto out;
}
}
+ LOCK (&priv->lock);
+ {
+ priv->write_value += op_ret;
+ }
+ UNLOCK (&priv->lock);
+
out:
if (locked) {