diff options
Diffstat (limited to 'xlators/storage/posix/src/posix-helpers.c')
-rw-r--r-- | xlators/storage/posix/src/posix-helpers.c | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c index 616664a3d8d..2fa55eda0ac 100644 --- a/xlators/storage/posix/src/posix-helpers.c +++ b/xlators/storage/posix/src/posix-helpers.c @@ -901,6 +901,74 @@ unlock: UNLOCK (&priv->lock); } +static int +is_fresh_file (struct stat *stat) +{ + struct timeval tv; + + gettimeofday (&tv, NULL); + + if ((stat->st_ctime >= (tv.tv_sec - 1)) + && (stat->st_ctime <= tv.tv_sec)) + return 1; + + return 0; +} + + +int +posix_gfid_heal (xlator_t *this, const char *path, loc_t *loc, dict_t *xattr_req) +{ + /* The purpose of this function is to prevent a race + where an inode creation FOP (like mkdir/mknod/create etc) + races with lookup in the following way: + + {create thread} | {lookup thread} + | + t0 + mkdir ("name") | + t1 + | posix_gfid_set ("name", 2); + t2 + posix_gfid_set ("name", 1); | + t3 + lstat ("name"); | lstat ("name"); + + In the above case mkdir FOP would have resulted with GFID 2 while + it should have been GFID 1. It matters in the case where GFID would + have gotten set to 1 on other subvolumes of replciate/distribute + + The "solution" here is that, if we detect lookup is attempting to + set a GFID on a file which is created very recently, but does not + yet have a GFID (i.e, between t1 and t2), then "fake" it as though + posix_gfid_heal was called at t0 instead. + */ + + uuid_t uuid_curr; + int ret = 0; + struct stat stat = {0, }; + + if (!xattr_req) + goto out; + + if (sys_lstat (path, &stat) != 0) + goto out; + + ret = sys_lgetxattr (path, GFID_XATTR_KEY, uuid_curr, 16); + if (ret != 16) { + if (is_fresh_file (&stat)) { + ret = -1; + errno = ENOENT; + goto out; + } + } + + ret = posix_gfid_set (this, path, loc, xattr_req); +out: + return ret; +} + + int posix_acl_xattr_set (xlator_t *this, const char *path, dict_t *xattr_req) { |