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| author | Miklos Szeredi <miklos@szeredi.hu> | 2013-09-05 14:39:11 +0200 |
|---|---|---|
| committer | Maciej Wereski <m.wereski@partner.samsung.com> | 2015-03-18 09:47:14 +0100 |
| commit | aefc2bf8ec7d61dfdf3a30fd5f3ea26cb2309af7 (patch) | |
| tree | 61c8fdf679a9cf12106f918f7c72d7eb78c5039d /fs/internal.h | |
| parent | fa8ba7e4eead9930011e41745e95619b6c1688c0 (diff) | |
| download | linux-3.10-aefc2bf8ec7d61dfdf3a30fd5f3ea26cb2309af7.tar.gz linux-3.10-aefc2bf8ec7d61dfdf3a30fd5f3ea26cb2309af7.tar.bz2 linux-3.10-aefc2bf8ec7d61dfdf3a30fd5f3ea26cb2309af7.zip | |
vfs: check unlinked ancestors before mount
We check submounts before doing d_drop() on a non-empty directory dentry in
NFS (have_submounts()), but we do not exclude a racing mount. Nor do we
prevent mounts to be added to the disconnected subtree using relative paths
after the d_drop().
This patch fixes these issues by checking for unlinked (unhashed, non-root)
ancestors before proceeding with the mount. This is done with rename
seqlock taken for write and with ->d_lock grabbed on each ancestor in turn,
including our dentry itself. This ensures that the only one of
check_submounts_and_drop() or has_unlinked_ancestor() can succeed.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/internal.h')
| -rw-r--r-- | fs/internal.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/internal.h b/fs/internal.h index 68121584ae3..237f2205a3d 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -125,6 +125,7 @@ extern int invalidate_inodes(struct super_block *, bool); * dcache.c */ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *); +extern int d_set_mounted(struct dentry *dentry); /* * read_write.c |