path: root/Documentation
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authorLinus Torvalds <torvalds@linux-foundation.org>2017-10-06 08:52:53 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-10-06 08:52:53 -0700
commit8d4ef4e15ec57eec5d24fb109fbc220eea9f0caf (patch)
treea3e047f8f3670b06a367a211d1bb5f1785302736 /Documentation
parentMerge tag 'powerpc-4.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux (diff)
parentovl: fix regression caused by exclusive upper/work dir protection (diff)
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs fixes from Miklos Szeredi: "Fix a regression in 4.14 and one in 4.13. The latter is a case when Docker is doing something it really shouldn't and gets away with it. We now print a warning instead of erroring out. There are also fixes to several error paths" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix regression caused by exclusive upper/work dir protection ovl: fix missing unlock_rename() in ovl_do_copy_up() ovl: fix dentry leak in ovl_indexdir_cleanup() ovl: fix dput() of ERR_PTR in ovl_cleanup_index() ovl: fix error value printed in ovl_lookup_index() ovl: fix may_write_real() for overlayfs directories
Diffstat (limited to 'Documentation')
1 files changed, 4 insertions, 1 deletions
diff --git a/Documentation/filesystems/overlayfs.txt b/Documentation/filesystems/overlayfs.txt
index 36f528a7fdd6..8caa60734647 100644
--- a/Documentation/filesystems/overlayfs.txt
+++ b/Documentation/filesystems/overlayfs.txt
@@ -210,8 +210,11 @@ path as another overlay mount and it may use a lower layer path that is
beneath or above the path of another overlay lower layer path.
Using an upper layer path and/or a workdir path that are already used by
-another overlay mount is not allowed and will fail with EBUSY. Using
+another overlay mount is not allowed and may fail with EBUSY. Using
partially overlapping paths is not allowed but will not fail with EBUSY.
+If files are accessed from two overlayfs mounts which share or overlap the
+upper layer and/or workdir path the behavior of the overlay is undefined,
+though it will not result in a crash or deadlock.
Mounting an overlay using an upper layer path, where the upper layer path
was previously used by another mounted overlay in combination with a