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authorWang YanQing <udknight@gmail.com>2015-06-23 12:54:45 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2015-07-01 07:50:06 +0200
commit1af95de6f0119d5bde02d3a811a9f3a3661e954e (patch)
tree703a419f2f4c0203683b9030450d54bfaf1f76d8
parentvfs: avoid creation of inode number 0 in get_next_ino (diff)
downloadlinux-1af95de6f0119d5bde02d3a811a9f3a3661e954e.tar.xz
linux-1af95de6f0119d5bde02d3a811a9f3a3661e954e.zip
fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
Execution of get_anon_bdev concurrently and preemptive kernel all could bring race condition, it isn't enough to check dev against its upper limitation with equality operator only. This patch fix it. Signed-off-by: Wang YanQing <udknight@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/super.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/super.c b/fs/super.c
index 928c20f47af9..b61372354f2b 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -842,7 +842,7 @@ int get_anon_bdev(dev_t *p)
else if (error)
return -EAGAIN;
- if (dev == (1 << MINORBITS)) {
+ if (dev >= (1 << MINORBITS)) {
spin_lock(&unnamed_dev_lock);
ida_remove(&unnamed_dev_ida, dev);
if (unnamed_dev_start > dev)