aboutsummaryrefslogtreecommitdiffstats
path: root/fs/overlayfs
diff options
context:
space:
mode:
Diffstat (limited to 'fs/overlayfs')
-rw-r--r--fs/overlayfs/copy_up.c2
-rw-r--r--fs/overlayfs/dir.c2
-rw-r--r--fs/overlayfs/export.c2
-rw-r--r--fs/overlayfs/file.c12
-rw-r--r--fs/overlayfs/inode.c12
-rw-r--r--fs/overlayfs/namei.c8
-rw-r--r--fs/overlayfs/ovl_entry.h2
-rw-r--r--fs/overlayfs/readdir.c8
-rw-r--r--fs/overlayfs/super.c47
9 files changed, 76 insertions, 19 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index b801c6353100..ec5eca5a96f4 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -40,7 +40,7 @@ int ovl_copy_xattr(struct dentry *old, struct dentry *new)
{
ssize_t list_size, size, value_size = 0;
char *buf, *name, *value = NULL;
- int uninitialized_var(error);
+ int error = 0;
size_t slen;
if (!(old->d_inode->i_opflags & IOP_XATTR) ||
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 702aa63f6774..29abdb1d3b5c 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -1170,7 +1170,7 @@ static int ovl_rename(struct inode *olddir, struct dentry *old,
if (newdentry == trap)
goto out_dput;
- if (WARN_ON(olddentry->d_inode == newdentry->d_inode))
+ if (olddentry->d_inode == newdentry->d_inode)
goto out_dput;
err = 0;
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
index 73c9775215b3..11dd8177770d 100644
--- a/fs/overlayfs/export.c
+++ b/fs/overlayfs/export.c
@@ -482,7 +482,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
if (IS_ERR_OR_NULL(this))
return this;
- if (WARN_ON(ovl_dentry_real_at(this, layer->idx) != real)) {
+ if (ovl_dentry_real_at(this, layer->idx) != real) {
dput(this);
this = ERR_PTR(-EIO);
}
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index e235a635d9ec..7a08a576f7b2 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -21,13 +21,16 @@ static char ovl_whatisit(struct inode *inode, struct inode *realinode)
return 'm';
}
+/* No atime modificaton nor notify on underlying */
+#define OVL_OPEN_FLAGS (O_NOATIME | FMODE_NONOTIFY)
+
static struct file *ovl_open_realfile(const struct file *file,
struct inode *realinode)
{
struct inode *inode = file_inode(file);
struct file *realfile;
const struct cred *old_cred;
- int flags = file->f_flags | O_NOATIME | FMODE_NONOTIFY;
+ int flags = file->f_flags | OVL_OPEN_FLAGS;
old_cred = ovl_override_creds(inode->i_sb);
realfile = open_with_fake_path(&file->f_path, flags, realinode,
@@ -48,8 +51,7 @@ static int ovl_change_flags(struct file *file, unsigned int flags)
struct inode *inode = file_inode(file);
int err;
- /* No atime modificaton on underlying */
- flags |= O_NOATIME | FMODE_NONOTIFY;
+ flags |= OVL_OPEN_FLAGS;
/* If some flag changed that cannot be changed then something's amiss */
if (WARN_ON((file->f_flags ^ flags) & ~OVL_SETFL_MASK))
@@ -102,7 +104,7 @@ static int ovl_real_fdget_meta(const struct file *file, struct fd *real,
}
/* Did the flags change since open? */
- if (unlikely((file->f_flags ^ real->file->f_flags) & ~O_NOATIME))
+ if (unlikely((file->f_flags ^ real->file->f_flags) & ~OVL_OPEN_FLAGS))
return ovl_change_flags(real->file, file->f_flags);
return 0;
@@ -146,7 +148,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
struct inode *inode = file_inode(file);
struct fd real;
const struct cred *old_cred;
- ssize_t ret;
+ loff_t ret;
/*
* The two special cases below do not need to involve real fs,
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index bc14781886bf..bb980721502d 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -200,8 +200,14 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) ||
(!ovl_verify_lower(dentry->d_sb) &&
(is_dir || lowerstat.nlink == 1))) {
- stat->ino = lowerstat.ino;
lower_layer = ovl_layer_lower(dentry);
+ /*
+ * Cannot use origin st_dev;st_ino because
+ * origin inode content may differ from overlay
+ * inode content.
+ */
+ if (samefs || lower_layer->fsid)
+ stat->ino = lowerstat.ino;
}
/*
@@ -875,7 +881,7 @@ struct inode *ovl_get_inode(struct super_block *sb,
struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry,
oip->index);
- int fsid = bylower ? oip->lowerpath->layer->fsid : 0;
+ int fsid = bylower ? lowerpath->layer->fsid : 0;
bool is_dir, metacopy = false;
unsigned long ino = 0;
int err = oip->newinode ? -EEXIST : -ENOMEM;
@@ -925,6 +931,8 @@ struct inode *ovl_get_inode(struct super_block *sb,
err = -ENOMEM;
goto out_err;
}
+ ino = realinode->i_ino;
+ fsid = lowerpath->layer->fsid;
}
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
ovl_inode_init(inode, upperdentry, lowerdentry, oip->lowerdata);
diff --git a/fs/overlayfs/namei.c b/fs/overlayfs/namei.c
index e9717c2f7d45..f47c591402d7 100644
--- a/fs/overlayfs/namei.c
+++ b/fs/overlayfs/namei.c
@@ -325,6 +325,14 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
int i;
for (i = 0; i < ofs->numlower; i++) {
+ /*
+ * If lower fs uuid is not unique among lower fs we cannot match
+ * fh->uuid to layer.
+ */
+ if (ofs->lower_layers[i].fsid &&
+ ofs->lower_layers[i].fs->bad_uuid)
+ continue;
+
origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
connected);
if (origin)
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index a8279280e88d..28348c44ea5b 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -22,6 +22,8 @@ struct ovl_config {
struct ovl_sb {
struct super_block *sb;
dev_t pseudo_dev;
+ /* Unusable (conflicting) uuid */
+ bool bad_uuid;
};
struct ovl_layer {
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 47a91c9733a5..7255e6a5838f 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -504,7 +504,13 @@ get:
if (err)
goto fail;
- WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
+ /*
+ * Directory inode is always on overlay st_dev.
+ * Non-dir with ovl_same_dev() could be on pseudo st_dev in case
+ * of xino bits overflow.
+ */
+ WARN_ON_ONCE(S_ISDIR(stat.mode) &&
+ dir->d_sb->s_dev != stat.dev);
ino = stat.ino;
} else if (xinobits && !OVL_TYPE_UPPER(type)) {
ino = ovl_remap_lower_ino(ino, xinobits,
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index afbcb116a7f1..d6b724beb304 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1255,17 +1255,33 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
{
unsigned int i;
- if (!ofs->config.nfs_export && !(ofs->config.index && ofs->upper_mnt))
+ if (!ofs->config.nfs_export && !ofs->upper_mnt)
return true;
+ /*
+ * We allow using single lower with null uuid for index and nfs_export
+ * for example to support those features with single lower squashfs.
+ * To avoid regressions in setups of overlay with re-formatted lower
+ * squashfs, do not allow decoding origin with lower null uuid unless
+ * user opted-in to one of the new features that require following the
+ * lower inode of non-dir upper.
+ */
+ if (!ofs->config.index && !ofs->config.metacopy && !ofs->config.xino &&
+ uuid_is_null(uuid))
+ return false;
+
for (i = 0; i < ofs->numlowerfs; i++) {
/*
* We use uuid to associate an overlay lower file handle with a
* lower layer, so we can accept lower fs with null uuid as long
* as all lower layers with null uuid are on the same fs.
+ * if we detect multiple lower fs with the same uuid, we
+ * disable lower file handle decoding on all of them.
*/
- if (uuid_equal(&ofs->lower_fs[i].sb->s_uuid, uuid))
+ if (uuid_equal(&ofs->lower_fs[i].sb->s_uuid, uuid)) {
+ ofs->lower_fs[i].bad_uuid = true;
return false;
+ }
}
return true;
}
@@ -1277,6 +1293,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
unsigned int i;
dev_t dev;
int err;
+ bool bad_uuid = false;
/* fsid 0 is reserved for upper fs even with non upper overlay */
if (ofs->upper_mnt && ofs->upper_mnt->mnt_sb == sb)
@@ -1288,11 +1305,15 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
}
if (!ovl_lower_uuid_ok(ofs, &sb->s_uuid)) {
- ofs->config.index = false;
- ofs->config.nfs_export = false;
- pr_warn("overlayfs: %s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
- uuid_is_null(&sb->s_uuid) ? "null" : "conflicting",
- path->dentry);
+ bad_uuid = true;
+ if (ofs->config.index || ofs->config.nfs_export) {
+ ofs->config.index = false;
+ ofs->config.nfs_export = false;
+ pr_warn("overlayfs: %s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
+ uuid_is_null(&sb->s_uuid) ? "null" :
+ "conflicting",
+ path->dentry);
+ }
}
err = get_anon_bdev(&dev);
@@ -1303,6 +1324,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
ofs->lower_fs[ofs->numlowerfs].sb = sb;
ofs->lower_fs[ofs->numlowerfs].pseudo_dev = dev;
+ ofs->lower_fs[ofs->numlowerfs].bad_uuid = bad_uuid;
ofs->numlowerfs++;
return ofs->numlowerfs;
@@ -1334,14 +1356,23 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
if (err < 0)
goto out;
+ /*
+ * Check if lower root conflicts with this overlay layers before
+ * checking if it is in-use as upperdir/workdir of "another"
+ * mount, because we do not bother to check in ovl_is_inuse() if
+ * the upperdir/workdir is in fact in-use by our
+ * upperdir/workdir.
+ */
err = ovl_setup_trap(sb, stack[i].dentry, &trap, "lowerdir");
if (err)
goto out;
if (ovl_is_inuse(stack[i].dentry)) {
err = ovl_report_in_use(ofs, "lowerdir");
- if (err)
+ if (err) {
+ iput(trap);
goto out;
+ }
}
mnt = clone_private_mount(&stack[i]);
generated by cgit 1.2.3-korg (git 2.39.0) at 2024-04-30 12:20:24 +0000