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authorKotresh HR <khiremat@redhat.com>2018-06-01 01:48:31 -0400
committerShyamsundar Ranganathan <srangana@redhat.com>2018-06-08 12:56:57 +0000
commitacd9a863e80a7f56e25b3ed151a4711126de3208 (patch)
treebcf8474d7661760914fb09341ef145a89385bac6
parent9757ee891cf45abd6380fd693639f5c4cd199c2f (diff)
posix/ctime: Fix fops racing in updating mtime/atime
In distributed systems, there could be races with fops updating mtime/atime which could result in different mtime/atime for same file. So updating them only if time is greater than the existing makes sure, only the highest time is retained. If the mtime/atime update comes from the explicit utime syscall, it is allowed to set to previous time. Thanks Xavi for helping in rooting the issue. Backport of: > Patch: https://review.gluster.org/#/c/20120/ > BUG: 1584981 > Change-Id: If1230a75b96d7f9a828795189fcc699049e7826e > Signed-off-by: Kotresh HR <khiremat@redhat.com> (cherry picked from commit a6f0e7a4f1ca203762cae2ed5e426b52124c74dc) fixes: bz#1585894 Change-Id: If1230a75b96d7f9a828795189fcc699049e7826e Signed-off-by: Kotresh HR <khiremat@redhat.com>
-rw-r--r--xlators/storage/posix/src/posix-metadata.c42
1 files changed, 31 insertions, 11 deletions
diff --git a/xlators/storage/posix/src/posix-metadata.c b/xlators/storage/posix/src/posix-metadata.c
index 5da46d6..eb2f24d 100644
--- a/xlators/storage/posix/src/posix-metadata.c
+++ b/xlators/storage/posix/src/posix-metadata.c
@@ -353,7 +353,8 @@ posix_compare_timespec (struct timespec *first, struct timespec *second)
static int
posix_set_mdata_xattr (xlator_t *this, const char *real_path, int fd,
inode_t *inode, struct timespec *time,
- struct iatt *stbuf, posix_mdata_flag_t *flag)
+ struct iatt *stbuf, posix_mdata_flag_t *flag,
+ gf_boolean_t update_utime)
{
posix_mdata_t *mdata = NULL;
int ret = -1;
@@ -428,14 +429,31 @@ posix_set_mdata_xattr (xlator_t *this, const char *real_path, int fd,
* allowed to changed to older date.
*/
if (flag->ctime &&
- posix_compare_timespec (time, &mdata->ctime) > 0) {
+ posix_compare_timespec (time, &mdata->ctime) > 0) {
mdata->ctime = *time;
}
- if (flag->mtime) {
- mdata->mtime = *time;
- }
- if (flag->atime) {
- mdata->atime = *time;
+ /* In distributed systems, there could races with fops updating
+ * mtime/atime which could result in different mtime/atime
+ * for same file. So this makes sure, only the highest time is
+ * retained. If the mtime/atime update comes from the explicit
+ * utime syscall, it is allowed to set to previous time
+ */
+ if (update_utime) {
+ if (flag->mtime) {
+ mdata->mtime = *time;
+ }
+ if (flag->atime) {
+ mdata->atime = *time;
+ }
+ } else {
+ if (flag->mtime &&
+ posix_compare_timespec (time, &mdata->mtime) > 0) {
+ mdata->mtime = *time;
+ }
+ if (flag->atime &&
+ posix_compare_timespec (time, &mdata->atime) > 0) {
+ mdata->atime = *time;
+ }
}
if (inode->ia_type == IA_INVAL) {
@@ -507,7 +525,7 @@ posix_update_utime_in_mdata (xlator_t *this, const char *real_path, int fd,
flag.mtime = 0;
flag.atime = 1;
ret = posix_set_mdata_xattr (this, real_path, -1, inode, &tv, NULL,
- &flag);
+ &flag, _gf_true);
if (ret) {
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_SETMDATA_FAILED,
@@ -526,7 +544,7 @@ posix_update_utime_in_mdata (xlator_t *this, const char *real_path, int fd,
flag.atime = 0;
ret = posix_set_mdata_xattr (this, real_path, -1, inode, &tv, NULL,
- &flag);
+ &flag, _gf_true);
if (ret) {
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_SETMDATA_FAILED,
@@ -602,7 +620,8 @@ posix_set_ctime (call_frame_t *frame, xlator_t *this, const char* real_path,
}
ret = posix_set_mdata_xattr (this, real_path, fd, inode,
- &frame->root->ctime, stbuf, &flag);
+ &frame->root->ctime, stbuf, &flag,
+ _gf_false);
if (ret) {
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_SETMDATA_FAILED,
@@ -629,7 +648,8 @@ posix_set_parent_ctime (call_frame_t *frame, xlator_t *this,
if (inode && priv->ctime) {
(void) posix_get_parent_mdata_flag (frame->root->flags, &flag);
ret = posix_set_mdata_xattr (this, real_path, fd, inode,
- &frame->root->ctime, stbuf, &flag);
+ &frame->root->ctime, stbuf, &flag,
+ _gf_false);
if (ret) {
gf_msg (this->name, GF_LOG_WARNING, errno,
P_MSG_SETMDATA_FAILED,