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Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c6
-rw-r--r--fs/overlayfs/dir.c20
-rw-r--r--fs/overlayfs/inode.c20
-rw-r--r--fs/overlayfs/namei.c33
-rw-r--r--fs/overlayfs/overlayfs.h4
-rw-r--r--fs/overlayfs/ovl_entry.h3
-rw-r--r--fs/overlayfs/readdir.c17
-rw-r--r--fs/overlayfs/super.c30
-rw-r--r--fs/overlayfs/util.c24
9 files changed, 95 insertions, 62 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index aad97b30d5e6..c441f9387a1b 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -561,10 +561,8 @@ static int ovl_do_copy_up(struct ovl_copy_up_ctx *c)
c->tmpfile = true;
err = ovl_copy_up_locked(c);
} else {
- err = -EIO;
- if (lock_rename(c->workdir, c->destdir) != NULL) {
- pr_err("overlayfs: failed to lock workdir+upperdir\n");
- } else {
+ err = ovl_lock_rename_workdir(c->workdir, c->destdir);
+ if (!err) {
err = ovl_copy_up_locked(c);
unlock_rename(c->workdir, c->destdir);
}
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 3309b1912241..cc961a3bd3bd 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -216,26 +216,6 @@ out_unlock:
return err;
}
-static int ovl_lock_rename_workdir(struct dentry *workdir,
- struct dentry *upperdir)
-{
- /* Workdir should not be the same as upperdir */
- if (workdir == upperdir)
- goto err;
-
- /* Workdir should not be subdir of upperdir and vice versa */
- if (lock_rename(workdir, upperdir) != NULL)
- goto err_unlock;
-
- return 0;
-
-err_unlock:
- unlock_rename(workdir, upperdir);
-err:
- pr_err("overlayfs: failed to lock workdir+upperdir\n");
- return -EIO;
-}
-
static struct dentry *ovl_clear_empty(struct dentry *dentry,
struct list_head *list)
{
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index a619addecafc..321511ed8c42 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -598,18 +598,30 @@ static bool ovl_verify_inode(struct inode *inode, struct dentry *lowerdentry,
return true;
}
-struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry)
+struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry,
+ struct dentry *index)
{
struct dentry *lowerdentry = ovl_dentry_lower(dentry);
struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
struct inode *inode;
+ /* Already indexed or could be indexed on copy up? */
+ bool indexed = (index || (ovl_indexdir(dentry->d_sb) && !upperdentry));
+
+ if (WARN_ON(upperdentry && indexed && !lowerdentry))
+ return ERR_PTR(-EIO);
if (!realinode)
realinode = d_inode(lowerdentry);
- if (!S_ISDIR(realinode->i_mode) &&
- (upperdentry || (lowerdentry && ovl_indexdir(dentry->d_sb)))) {
- struct inode *key = d_inode(lowerdentry ?: upperdentry);
+ /*
+ * Copy up origin (lower) may exist for non-indexed upper, but we must
+ * not use lower as hash key in that case.
+ * Hash inodes that are or could be indexed by origin inode and
+ * non-indexed upper inodes that could be hard linked by upper inode.
+ */
+ if (!S_ISDIR(realinode->i_mode) && (upperdentry || indexed)) {
+ struct inode *key = d_inode(indexed ? lowerdentry :
+ upperdentry);
unsigned int nlink;
inode = iget5_locked(dentry->d_sb, (unsigned long) key,
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index c3addd1114f1..a12dc10bf726 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -405,14 +405,13 @@ int ovl_verify_index(struct dentry *index, struct path *lowerstack,
* be treated as stale (i.e. after unlink of the overlay inode).
* We don't know the verification rules for directory and whiteout
* index entries, because they have not been implemented yet, so return
- * EROFS if those entries are found to avoid corrupting an index that
- * was created by a newer kernel.
+ * EINVAL if those entries are found to abort the mount to avoid
+ * corrupting an index that was created by a newer kernel.
*/
- err = -EROFS;
+ err = -EINVAL;
if (d_is_dir(index) || ovl_is_whiteout(index))
goto fail;
- err = -EINVAL;
if (index->d_name.len < sizeof(struct ovl_fh)*2)
goto fail;
@@ -506,6 +505,11 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
index = lookup_one_len_unlocked(name.name, ofs->indexdir, name.len);
if (IS_ERR(index)) {
+ err = PTR_ERR(index);
+ if (err == -ENOENT) {
+ index = NULL;
+ goto out;
+ }
pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%*s, err=%i);\n"
"overlayfs: mount with '-o index=off' to disable inodes index.\n",
d_inode(origin)->i_ino, name.len, name.name,
@@ -515,18 +519,9 @@ static struct dentry *ovl_lookup_index(struct dentry *dentry,
inode = d_inode(index);
if (d_is_negative(index)) {
- if (upper && d_inode(origin)->i_nlink > 1) {
- pr_warn_ratelimited("overlayfs: hard link with origin but no index (ino=%lu).\n",
- d_inode(origin)->i_ino);
- goto fail;
- }
-
- dput(index);
- index = NULL;
+ goto out_dput;
} else if (upper && d_inode(upper) != inode) {
- pr_warn_ratelimited("overlayfs: wrong index found (index=%pd2, ino=%lu, upper ino=%lu).\n",
- index, inode->i_ino, d_inode(upper)->i_ino);
- goto fail;
+ goto out_dput;
} else if (ovl_dentry_weird(index) || ovl_is_whiteout(index) ||
((inode->i_mode ^ d_inode(origin)->i_mode) & S_IFMT)) {
/*
@@ -546,6 +541,11 @@ out:
kfree(name.name);
return index;
+out_dput:
+ dput(index);
+ index = NULL;
+ goto out;
+
fail:
dput(index);
index = ERR_PTR(-EIO);
@@ -634,6 +634,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
}
if (d.redirect) {
+ err = -ENOMEM;
upperredirect = kstrdup(d.redirect, GFP_KERNEL);
if (!upperredirect)
goto out_put_upper;
@@ -708,7 +709,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
upperdentry = dget(index);
if (upperdentry || ctr) {
- inode = ovl_get_inode(dentry, upperdentry);
+ inode = ovl_get_inode(dentry, upperdentry, index);
err = PTR_ERR(inode);
if (IS_ERR(inode))
goto out_free_oe;
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index d4e8c1a08fb0..d9a0edd4e57e 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -235,6 +235,7 @@ bool ovl_inuse_trylock(struct dentry *dentry);
void ovl_inuse_unlock(struct dentry *dentry);
int ovl_nlink_start(struct dentry *dentry, bool *locked);
void ovl_nlink_end(struct dentry *dentry, bool locked);
+int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir);
static inline bool ovl_is_impuredir(struct dentry *dentry)
{
@@ -285,7 +286,8 @@ int ovl_update_time(struct inode *inode, struct timespec *ts, int flags);
bool ovl_is_private_xattr(const char *name);
struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
-struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry);
+struct inode *ovl_get_inode(struct dentry *dentry, struct dentry *upperdentry,
+ struct dentry *index);
static inline void ovl_copyattr(struct inode *from, struct inode *to)
{
to->i_uid = from->i_uid;
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index 878a750986dd..25d9b5adcd42 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -37,6 +37,9 @@ struct ovl_fs {
bool noxattr;
/* sb common to all layers */
struct super_block *same_sb;
+ /* Did we take the inuse lock? */
+ bool upperdir_locked;
+ bool workdir_locked;
};
/* private information held for every overlayfs dentry */
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 62e9b22a2077..698b74dd750e 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -988,6 +988,7 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
struct path *lowerstack, unsigned int numlower)
{
int err;
+ struct dentry *index = NULL;
struct inode *dir = dentry->d_inode;
struct path path = { .mnt = mnt, .dentry = dentry };
LIST_HEAD(list);
@@ -1007,8 +1008,6 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
inode_lock_nested(dir, I_MUTEX_PARENT);
list_for_each_entry(p, &list, l_node) {
- struct dentry *index;
-
if (p->name[0] == '.') {
if (p->len == 1)
continue;
@@ -1018,18 +1017,20 @@ int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
index = lookup_one_len(p->name, dentry, p->len);
if (IS_ERR(index)) {
err = PTR_ERR(index);
+ index = NULL;
break;
}
err = ovl_verify_index(index, lowerstack, numlower);
- if (err) {
- if (err == -EROFS)
- break;
+ /* Cleanup stale and orphan index entries */
+ if (err && (err == -ESTALE || err == -ENOENT))
err = ovl_cleanup(dir, index);
- if (err)
- break;
- }
+ if (err)
+ break;
+
dput(index);
+ index = NULL;
}
+ dput(index);
inode_unlock(dir);
out:
ovl_cache_free(&list);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index fd5ea4facc62..f5738e96a052 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -174,6 +174,9 @@ static struct inode *ovl_alloc_inode(struct super_block *sb)
{
struct ovl_inode *oi = kmem_cache_alloc(ovl_inode_cachep, GFP_KERNEL);
+ if (!oi)
+ return NULL;
+
oi->cache = NULL;
oi->redirect = NULL;
oi->version = 0;
@@ -211,9 +214,10 @@ static void ovl_put_super(struct super_block *sb)
dput(ufs->indexdir);
dput(ufs->workdir);
- ovl_inuse_unlock(ufs->workbasedir);
+ if (ufs->workdir_locked)
+ ovl_inuse_unlock(ufs->workbasedir);
dput(ufs->workbasedir);
- if (ufs->upper_mnt)
+ if (ufs->upper_mnt && ufs->upperdir_locked)
ovl_inuse_unlock(ufs->upper_mnt->mnt_root);
mntput(ufs->upper_mnt);
for (i = 0; i < ufs->numlower; i++)
@@ -881,9 +885,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
goto out_put_upperpath;
err = -EBUSY;
- if (!ovl_inuse_trylock(upperpath.dentry)) {
- pr_err("overlayfs: upperdir is in-use by another mount\n");
+ if (ovl_inuse_trylock(upperpath.dentry)) {
+ ufs->upperdir_locked = true;
+ } else if (ufs->config.index) {
+ pr_err("overlayfs: upperdir is in-use by another mount, mount with '-o index=off' to override exclusive upperdir protection.\n");
goto out_put_upperpath;
+ } else {
+ pr_warn("overlayfs: upperdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
}
err = ovl_mount_dir(ufs->config.workdir, &workpath);
@@ -901,9 +909,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
}
err = -EBUSY;
- if (!ovl_inuse_trylock(workpath.dentry)) {
- pr_err("overlayfs: workdir is in-use by another mount\n");
+ if (ovl_inuse_trylock(workpath.dentry)) {
+ ufs->workdir_locked = true;
+ } else if (ufs->config.index) {
+ pr_err("overlayfs: workdir is in-use by another mount, mount with '-o index=off' to override exclusive workdir protection.\n");
goto out_put_workpath;
+ } else {
+ pr_warn("overlayfs: workdir is in-use by another mount, accessing files from both mounts will result in undefined behavior.\n");
}
ufs->workbasedir = workpath.dentry;
@@ -1156,11 +1168,13 @@ out_put_lowerpath:
out_free_lowertmp:
kfree(lowertmp);
out_unlock_workdentry:
- ovl_inuse_unlock(workpath.dentry);
+ if (ufs->workdir_locked)
+ ovl_inuse_unlock(workpath.dentry);
out_put_workpath:
path_put(&workpath);
out_unlock_upperdentry:
- ovl_inuse_unlock(upperpath.dentry);
+ if (ufs->upperdir_locked)
+ ovl_inuse_unlock(upperpath.dentry);
out_put_upperpath:
path_put(&upperpath);
out_free_config:
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 117794582f9f..b9b239fa5cfd 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -430,7 +430,7 @@ void ovl_inuse_unlock(struct dentry *dentry)
}
}
-/* Called must hold OVL_I(inode)->oi_lock */
+/* Caller must hold OVL_I(inode)->lock */
static void ovl_cleanup_index(struct dentry *dentry)
{
struct inode *dir = ovl_indexdir(dentry->d_sb)->d_inode;
@@ -469,6 +469,9 @@ static void ovl_cleanup_index(struct dentry *dentry)
err = PTR_ERR(index);
if (!IS_ERR(index))
err = ovl_cleanup(dir, index);
+ else
+ index = NULL;
+
inode_unlock(dir);
if (err)
goto fail;
@@ -557,3 +560,22 @@ void ovl_nlink_end(struct dentry *dentry, bool locked)
mutex_unlock(&OVL_I(d_inode(dentry))->lock);
}
}
+
+int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
+{
+ /* Workdir should not be the same as upperdir */
+ if (workdir == upperdir)
+ goto err;
+
+ /* Workdir should not be subdir of upperdir and vice versa */
+ if (lock_rename(workdir, upperdir) != NULL)
+ goto err_unlock;
+
+ return 0;
+
+err_unlock:
+ unlock_rename(workdir, upperdir);
+err:
+ pr_err("overlayfs: failed to lock workdir+upperdir\n");
+ return -EIO;
+}
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