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authorAmir Goldstein <amir73il@gmail.com>2020-06-18 18:43:53 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-07-22 09:33:12 +0200
commit09b696bd214915ca72a5d0925690580292bde00c (patch)
treea4fa26abc5b0a79e818ae01a0fd2236afb67d089
parent93f75b0f0d3b1cbd9503170674f0a65370247c27 (diff)
ovl: fix unneeded call to ovl_change_flags()
commit 81a33c1ee941c3bb9ffc6bac8f676be13351344e upstream. The check if user has changed the overlay file was wrong, causing unneeded call to ovl_change_flags() including taking f_lock on every file access. Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path") Cc: <stable@vger.kernel.org> # v4.19+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/overlayfs/file.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 15e4fa288475..7a08a576f7b2 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -21,13 +21,16 @@ static char ovl_whatisit(struct inode *inode, struct inode *realinode)
return 'm';
}
+/* No atime modificaton nor notify on underlying */
+#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
+
static struct file *ovl_open_realfile(const struct file *file,
struct inode *realinode)
{
struct inode *inode = file_inode(file);
struct file *realfile;
const struct cred *old_cred;
- int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY;
+ int flags = file->f_flags | OVL_OPEN_FLAGS;
old_cred = ovl_override_creds(inode->i_sb);
realfile = open_with_fake_path(&file->f_path, flags, realinode,
@@ -48,8 +51,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
struct inode *inode = file_inode(file);
int err;
- /* No atime modificaton on underlying */
- flags |= O_NOATIME | FMODE_NONOTIFY;
+ flags |= OVL_OPEN_FLAGS;
/* If some flag changed that cannot be changed then something's amiss */
if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
@@ -102,7 +104,7 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
}
/* Did the flags change since open? */
- if (unlikely((file->f_flags ^ real->file->f_flags) & ~O_NOATIME))
+ if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
return ovl_change_flags(real->file, file->f_flags);
return 0;