diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2023-08-16 16:47:59 +0300 |
|---|---|---|
| committer | Amir Goldstein <amir73il@gmail.com> | 2023-10-31 00:12:57 +0200 |
| commit | 5b02bfc1e7e3811c5bf7f0fa626a0694d0dbbd77 (patch) | |
| tree | 508405693acdfdf8200f5890f4930e9a48e49cde /fs/overlayfs/super.c | |
| parent | c63e56a4a6523fcb1358e1878607d77a40b534bb (diff) | |
ovl: do not encode lower fh with upper sb_writers held
When lower fs is a nested overlayfs, calling encode_fh() on a lower
directory dentry may trigger copy up and take sb_writers on the upper fs
of the lower nested overlayfs.
The lower nested overlayfs may have the same upper fs as this overlayfs,
so nested sb_writers lock is illegal.
Move all the callers that encode lower fh to before ovl_want_write().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Diffstat (limited to 'fs/overlayfs/super.c')
| -rw-r--r-- | fs/overlayfs/super.c | 20 |
1 files changed, 14 insertions, 6 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 6cd949c59fed..5476dbfef6e5 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -887,15 +887,20 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, { struct vfsmount *mnt = ovl_upper_mnt(ofs); struct dentry *indexdir; + struct dentry *origin = ovl_lowerstack(oe)->dentry; + const struct ovl_fh *fh; int err; + fh = ovl_get_origin_fh(ofs, origin); + if (IS_ERR(fh)) + return PTR_ERR(fh); + err = mnt_want_write(mnt); if (err) - return err; + goto out_free_fh; /* Verify lower root is upper root origin */ - err = ovl_verify_origin(ofs, upperpath->dentry, - ovl_lowerstack(oe)->dentry, true); + err = ovl_verify_origin_fh(ofs, upperpath->dentry, fh, true); if (err) { pr_err("failed to verify upper root origin\n"); goto out; @@ -927,9 +932,10 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, * directory entries. */ if (ovl_check_origin_xattr(ofs, ofs->indexdir)) { - err = ovl_verify_set_fh(ofs, ofs->indexdir, - OVL_XATTR_ORIGIN, - upperpath->dentry, true, false); + err = ovl_verify_origin_xattr(ofs, ofs->indexdir, + OVL_XATTR_ORIGIN, + upperpath->dentry, true, + false); if (err) pr_err("failed to verify index dir 'origin' xattr\n"); } @@ -947,6 +953,8 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, out: mnt_drop_write(mnt); +out_free_fh: + kfree(fh); return err; } |