From b5a7dd5b39845d5e58fdd257b5c2bf801c7c1c8a Mon Sep 17 00:00:00 2001 From: Pranith Kumar K Date: Fri, 23 Sep 2016 21:06:37 +0530 Subject: storage/posix: Fix race in posix_pstat Problem: When one thread is in the process of creating a file/directory and the other thread is doing readdirp, there is a chance that posix_pstat, creation fops race in the following manner which will lead to wrong stat values to be read by parent xlators like posix-acl. Creation fops posix_pstat() as part of readdirp 1) file is created with uid/gid 0/0 1) does stat of the path that is created just now. 2) Does chown to set the correct uid/gid 3) Sets the acl/user/internal xattrs 4) Sets the gfid on the entry and completes the creation of the file/dir 2) fills the gfid in the iatt If unwind of readdirp hits server xlator before creation fop, then posix-acl remembers uid/gid of the file to be root/root and fails fops like open etc on it. Fix: Reverse the order of filling gfid and filling lstat() values in posix_pstat() so that if there is gfid in iatt buffer uid/gid are valid. Change-Id: I46caa7f6da7abfa40a0b1d70e35b88de9c64959c Signed-off-by: Pranith Kumar K Reviewed-on: http://review.gluster.org/15564 NetBSD-regression: NetBSD Build System CentOS-regression: Gluster Build System Smoke: Gluster Build System Reviewed-by: Shyamsundar Ranganathan --- xlators/storage/posix/src/posix-helpers.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'xlators/storage/posix/src') diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c index becbd94c226..caa79bf5815 100644 --- a/xlators/storage/posix/src/posix-helpers.c +++ b/xlators/storage/posix/src/posix-helpers.c @@ -632,6 +632,11 @@ posix_pstat (xlator_t *this, uuid_t gfid, const char *path, priv = this->private; + if (gfid && !gf_uuid_is_null (gfid)) + gf_uuid_copy (stbuf.ia_gfid, gfid); + else + posix_fill_gfid_path (this, path, &stbuf); + ret = sys_lstat (path, &lstatbuf); if (ret != 0) { @@ -664,11 +669,6 @@ posix_pstat (xlator_t *this, uuid_t gfid, const char *path, iatt_from_stat (&stbuf, &lstatbuf); - if (gfid && !gf_uuid_is_null (gfid)) - gf_uuid_copy (stbuf.ia_gfid, gfid); - else - posix_fill_gfid_path (this, path, &stbuf); - posix_fill_ino_from_gfid (this, &stbuf); if (buf_p) -- cgit