58 lines
1.9 KiB
Diff
58 lines
1.9 KiB
Diff
From: Miklos Szeredi <mszeredi@suse.cz>
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Date: Thu, 14 May 2015 10:04:44 +0200
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Subject: [PATCH] ovl: don't remove non-empty opaque directory
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When removing an opaque directory we can't just call rmdir() to check for
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emptiness, because the directory will need to be replaced with a whiteout.
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The replacement is done with RENAME_EXCHANGE, which doesn't check
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emptiness.
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Solution is just to check emptiness by reading the directory. In the
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future we could add a new rename flag to check for emptiness even for
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RENAME_EXCHANGE to optimize this case.
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Reported-by: Vincent Batts <vbatts@gmail.com>
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Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
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Tested-by: Jordi Pujol Palomer <jordipujolp@gmail.com>
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Fixes: 263b4a0fee43 ("ovl: dont replace opaque dir")
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Cc: <stable@vger.kernel.org> # v4.0+
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---
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fs/overlayfs/dir.c | 24 +++++++++++++++++++-----
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1 file changed, 19 insertions(+), 5 deletions(-)
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diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
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index d139405d2bfa..2578a0c0677d 100644
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--- a/fs/overlayfs/dir.c
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+++ b/fs/overlayfs/dir.c
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@@ -506,11 +506,25 @@ static int ovl_remove_and_whiteout(struct dentry *dentry, bool is_dir)
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struct dentry *opaquedir = NULL;
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int err;
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- if (is_dir && OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
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- opaquedir = ovl_check_empty_and_clear(dentry);
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- err = PTR_ERR(opaquedir);
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- if (IS_ERR(opaquedir))
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- goto out;
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+ if (is_dir) {
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+ if (OVL_TYPE_MERGE_OR_LOWER(ovl_path_type(dentry))) {
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+ opaquedir = ovl_check_empty_and_clear(dentry);
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+ err = PTR_ERR(opaquedir);
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+ if (IS_ERR(opaquedir))
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+ goto out;
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+ } else {
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+ LIST_HEAD(list);
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+
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+ /*
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+ * When removing an empty opaque directory, then it
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+ * makes no sense to replace it with an exact replica of
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+ * itself. But emptiness still needs to be checked.
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+ */
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+ err = ovl_check_empty_dir(dentry, &list);
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+ ovl_cache_free(&list);
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+ if (err)
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+ goto out;
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+ }
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}
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err = ovl_lock_rename_workdir(workdir, upperdir);
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