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authorJ. Bruce Fields <bfields@redhat.com>2011-09-21 10:58:13 -0400
committerroot <root@serles.lst.de>2011-10-28 14:59:00 +0200
commitf3c7691e8d30d88899b514675c7c86d19057b5fd (patch)
tree0065bcc05b19a99d8785ce523f992a48fe573e79 /fs/open.c
parent79835a710d6ff811659c8de46f89c7577c3b8cc6 (diff)
downloadop-kernel-dev-f3c7691e8d30d88899b514675c7c86d19057b5fd.zip
op-kernel-dev-f3c7691e8d30d88899b514675c7c86d19057b5fd.tar.gz
leases: fix write-open/read-lease race
In setlease, we use i_writecount to decide whether we can give out a read lease. In open, we break leases before incrementing i_writecount. There is therefore a window between the break lease and the i_writecount increment when setlease could add a new read lease. This would leave us with a simultaneous write open and read lease, which shouldn't happen. Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/open.c')
-rw-r--r--fs/open.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/open.c b/fs/open.c
index f711921..22c41b5 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -685,6 +685,10 @@ static struct file *__dentry_open(struct dentry *dentry, struct vfsmount *mnt,
if (error)
goto cleanup_all;
+ error = break_lease(inode, f->f_flags);
+ if (error)
+ goto cleanup_all;
+
if (!open && f->f_op)
open = f->f_op->open;
if (open) {
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