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authorLinus Torvalds <torvalds@linux-foundation.org>2018-09-13 19:21:40 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2018-09-13 19:21:40 -1000
commit48751b562bce96c4284885571da1bdda7673f38e (patch)
treedbd845b16b7213cec7a42f6080193499a78cb850 /fs
parent4d8d9f540b780f7a3688a72275aecd8fd99c99e5 (diff)
parent8c25741aaad8be6fbe51510e917c740e0059cf83 (diff)
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')
-rw-r--r--fs/overlayfs/file.c23
-rw-r--r--fs/overlayfs/inode.c10
-rw-r--r--fs/overlayfs/super.c26
3 files changed, 44 insertions, 15 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,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index e0bb217c01e2..b6ac545b5a32 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -467,6 +467,10 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
return -EOPNOTSUPP;
old_cred = ovl_override_creds(inode->i_sb);
+
+ if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
+ filemap_write_and_wait(realinode->i_mapping);
+
err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
revert_creds(old_cred);
@@ -500,6 +504,11 @@ static const struct inode_operations ovl_special_inode_operations = {
.update_time = ovl_update_time,
};
+const struct address_space_operations ovl_aops = {
+ /* For O_DIRECT dentry_open() checks f_mapping->a_ops->direct_IO */
+ .direct_IO = noop_direct_IO,
+};
+
/*
* It is possible to stack overlayfs instance on top of another
* overlayfs instance as lower layer. We need to annonate the
@@ -571,6 +580,7 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
case S_IFREG:
inode->i_op = &ovl_file_inode_operations;
inode->i_fop = &ovl_file_operations;
+ inode->i_mapping->a_ops = &ovl_aops;
break;
case S_IFDIR:
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 2e0fc93c2c06..30adc9d408a0 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -982,16 +982,6 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
if (err)
goto out;
- err = -EBUSY;
- if (ovl_inuse_trylock(upperpath->dentry)) {
- ofs->upperdir_locked = true;
- } else if (ofs->config.index) {
- pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
- goto out;
- } else {
- pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
- }
-
upper_mnt = clone_private_mount(upperpath);
err = PTR_ERR(upper_mnt);
if (IS_ERR(upper_mnt)) {
@@ -1002,6 +992,17 @@ static int ovl_get_upper(struct ovl_fs *ofs, struct path *upperpath)
/* Don't inherit atime flags */
upper_mnt->mnt_flags &= ~(MNT_NOATIME | MNT_NODIRATIME | MNT_RELATIME);
ofs->upper_mnt = upper_mnt;
+
+ err = -EBUSY;
+ if (ovl_inuse_trylock(ofs->upper_mnt->mnt_root)) {
+ ofs->upperdir_locked = true;
+ } else if (ofs->config.index) {
+ pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
+ goto out;
+ } else {
+ pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
+ }
+
err = 0;
out:
return err;
@@ -1101,8 +1102,10 @@ static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
goto out;
}
+ ofs->workbasedir = dget(workpath.dentry);
+
err = -EBUSY;
- if (ovl_inuse_trylock(workpath.dentry)) {
+ if (ovl_inuse_trylock(ofs->workbasedir)) {
ofs->workdir_locked = true;
} else if (ofs->config.index) {
pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
@@ -1111,7 +1114,6 @@ static int ovl_get_workdir(struct ovl_fs *ofs, struct path *upperpath)
pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
}
- ofs->workbasedir = dget(workpath.dentry);
err = ovl_make_workdir(ofs, &workpath);
if (err)
goto out;