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authorLinus Torvalds <torvalds@linux-foundation.org>2018-09-14 08:21:40 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-09-14 08:21:40 +0300
commit48751b562bce96c4284885571da1bdda7673f38e (patch)
treedbd845b16b7213cec7a42f6080193499a78cb850 /fs/overlayfs/file.c
parent4d8d9f540b780f7a3688a72275aecd8fd99c99e5 (diff)
parent8c25741aaad8be6fbe51510e917c740e0059cf83 (diff)
downloadlinux-48751b562bce96c4284885571da1bdda7673f38e.tar.xz
Merge tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi: "This fixes a regression in the recent file stacking update, reported and fixed by Amir Goldstein. The fix is fairly trivial, but involves adding a fadvise() f_op and the associated churn in the vfs. As discussed on -fsdevel, there are other possible uses for this method, than allowing proper stacking for overlays. And there's one other fix for a syzkaller detected oops" * tag 'ovl-fixes-4.19-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix oopses in ovl_fill_super() failure paths ovl: add ovl_fadvise() vfs: implement readahead(2) using POSIX_FADV_WILLNEED vfs: add the fadvise() file operation Documentation/filesystems: update documentation of file_operations ovl: fix GPF in swapfile_activate of file from overlayfs over xfs ovl: respect FIEMAP_FLAG_SYNC flag
Diffstat (limited to 'fs/overlayfs/file.c')
-rw-r--r--fs/overlayfs/file.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 32e9282893c9..aeaefd2a551b 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -131,9 +131,6 @@ static int ovl_open(struct inode *inode, struct file *file)
if (IS_ERR(realfile))
return PTR_ERR(realfile);
- /* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
- file->f_mapping = realfile->f_mapping;
-
file->private_data = realfile;
return 0;
@@ -334,6 +331,25 @@ static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len
return ret;
}
+static int ovl_fadvise(struct file *file, loff_t offset, loff_t len, int advice)
+{
+ struct fd real;
+ const struct cred *old_cred;
+ int ret;
+
+ ret = ovl_real_fdget(file, &real);
+ if (ret)
+ return ret;
+
+ old_cred = ovl_override_creds(file_inode(file)->i_sb);
+ ret = vfs_fadvise(real.file, offset, len, advice);
+ revert_creds(old_cred);
+
+ fdput(real);
+
+ return ret;
+}
+
static long ovl_real_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
@@ -502,6 +518,7 @@ const struct file_operations ovl_file_operations = {
.fsync = ovl_fsync,
.mmap = ovl_mmap,
.fallocate = ovl_fallocate,
+ .fadvise = ovl_fadvise,
.unlocked_ioctl = ovl_ioctl,
.compat_ioctl = ovl_compat_ioctl,