From d15951198eaccb92c6b49e62cb72f5ff62da2236 Mon Sep 17 00:00:00 2001 From: Amir Goldstein Date: Wed, 26 Oct 2016 12:34:06 +0300 Subject: [PATCH] ovl: check for emptiness of redirect dir Before introducing redirect_dir feature, the condition !ovl_lower_positive(dentry) for a directory, implied that it is a pure upper directory, which may be removed if empty. Now that directory can be redirect, it is possible that upper does not cover any lower (i.e. !ovl_lower_positive(dentry)), but the directory is a merge (with redirected path) and maybe non empty. Check for this case in ovl_remove_upper(). This change fixes the following test case from rename-pop-dir.py of unionmount-testsuite: """Remove dir and rename old name""" d = ctx.non_empty_dir() d2 = ctx.no_dir() ctx.rmdir(d, err=ENOTEMPTY) ctx.rename(d, d2) ctx.rmdir(d, err=ENOENT) ctx.rmdir(d2, err=ENOTEMPTY) ./run --ov rename-pop-dir /mnt/a/no_dir103: Expected error (Directory not empty) was not produced Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- fs/overlayfs/dir.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c index c1de84c1c5ec..4257a4a0ed72 100644 --- a/fs/overlayfs/dir.c +++ b/fs/overlayfs/dir.c @@ -674,8 +674,17 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent); struct inode *dir = upperdir->d_inode; struct dentry *upper; + struct dentry *opaquedir = NULL; int err; + /* Redirect dir can be !ovl_lower_positive && OVL_TYPE_MERGE */ + if (is_dir && ovl_dentry_get_redirect(dentry)) { + opaquedir = ovl_check_empty_and_clear(dentry); + err = PTR_ERR(opaquedir); + if (IS_ERR(opaquedir)) + goto out; + } + inode_lock_nested(dir, I_MUTEX_PARENT); upper = lookup_one_len(dentry->d_name.name, upperdir, dentry->d_name.len); @@ -684,14 +693,15 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) goto out_unlock; err = -ESTALE; - if (upper == ovl_dentry_upper(dentry)) { - if (is_dir) - err = vfs_rmdir(dir, upper); - else - err = vfs_unlink(dir, upper, NULL); - ovl_dentry_version_inc(dentry->d_parent); - } - dput(upper); + if ((opaquedir && upper != opaquedir) || + (!opaquedir && upper != ovl_dentry_upper(dentry))) + goto out_dput_upper; + + if (is_dir) + err = vfs_rmdir(dir, upper); + else + err = vfs_unlink(dir, upper, NULL); + ovl_dentry_version_inc(dentry->d_parent); /* * Keeping this dentry hashed would mean having to release @@ -701,9 +711,12 @@ static int ovl_remove_upper(struct dentry *dentry, bool is_dir) */ if (!err) d_drop(dentry); +out_dput_upper: + dput(upper); out_unlock: inode_unlock(dir); - + dput(opaquedir); +out: return err; } -- 2.39.5