From 8360037701788d49471cc0228fa873aa18382023 Mon Sep 17 00:00:00 2001 From: Anand Avati Date: Wed, 24 Jul 2013 03:53:16 -0700 Subject: afr: treat appending writes as stable writes. Durability of appending writes is implicit in the file size. Therefore performing an explicit fsync() is unnecessary in such cases as self-heal can check for the size of file when pending changelog is not unambiguous. Change-Id: I05446180a91d20e0dbee5de5a7085b87d57f178a BUG: 927146 Signed-off-by: Anand Avati Reviewed-on: http://review.gluster.org/5501 Tested-by: Gluster Build System Reviewed-by: Pranith Kumar Karampuri --- xlators/storage/posix/src/posix.c | 41 +++++++++++++++++++++++++++++++++++++-- 1 file changed, 39 insertions(+), 2 deletions(-) (limited to 'xlators/storage') diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c index 49d1effbc..fc7c259e9 100644 --- a/xlators/storage/posix/src/posix.c +++ b/xlators/storage/posix/src/posix.c @@ -2199,7 +2199,7 @@ err: } dict_t* -_fill_open_fd_count (fd_t *fd, dict_t *xdata, xlator_t *this) +_fill_writev_xdata (fd_t *fd, dict_t *xdata, xlator_t *this, int is_append) { dict_t *rsp_xdata = NULL; int32_t ret = 0; @@ -2229,6 +2229,14 @@ _fill_open_fd_count (fd_t *fd, dict_t *xdata, xlator_t *this) "dictionary value for %s", uuid_utoa (fd->inode->gfid), GLUSTERFS_OPEN_FD_COUNT); } + + ret = dict_set_uint32 (rsp_xdata, GLUSTERFS_WRITE_IS_APPEND, + is_append); + if (ret < 0) { + gf_log (this->name, GF_LOG_WARNING, "%s: Failed to set " + "dictionary value for %s", uuid_utoa (fd->inode->gfid), + GLUSTERFS_WRITE_IS_APPEND); + } out: return rsp_xdata; } @@ -2247,6 +2255,8 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, struct iatt postop = {0,}; int ret = -1; dict_t *rsp_xdata = NULL; + int is_append = 0; + gf_boolean_t locked = _gf_false; VALIDATE_OR_GOTO (frame, out); VALIDATE_OR_GOTO (this, out); @@ -2268,6 +2278,17 @@ 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. + + So lock before preop-stat and unlock after write. + */ + locked = _gf_true; + LOCK(&fd->inode->lock); + } + op_ret = posix_fdstat (this, _fd, &preop); if (op_ret == -1) { op_errno = errno; @@ -2277,8 +2298,19 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, goto out; } + if (locked) { + if (preop.ia_size == offset || (fd->flags & O_APPEND)) + is_append = 1; + } + op_ret = __posix_writev (_fd, vector, count, offset, (pfd->flags & O_DIRECT)); + + if (locked) { + UNLOCK (&fd->inode->lock); + locked = _gf_false; + } + if (op_ret < 0) { op_errno = -op_ret; op_ret = -1; @@ -2294,7 +2326,7 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, UNLOCK (&priv->lock); if (op_ret >= 0) { - rsp_xdata = _fill_open_fd_count (fd, xdata, this); + 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 */ @@ -2324,6 +2356,11 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, out: + if (locked) { + UNLOCK (&fd->inode->lock); + locked = _gf_false; + } + STACK_UNWIND_STRICT (writev, frame, op_ret, op_errno, &preop, &postop, rsp_xdata); -- cgit