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path: root/fs/overlayfs/dir.c
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Diffstat (limited to 'fs/overlayfs/dir.c')
-rw-r--r--fs/overlayfs/dir.c310
1 files changed, 150 insertions, 160 deletions
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 08e683917d12..dbd63a74df4b 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -24,7 +24,8 @@ MODULE_PARM_DESC(redirect_max,
static int ovl_set_redirect(struct dentry *dentry, bool samedir);
-int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry)
+static int ovl_cleanup_locked(struct ovl_fs *ofs, struct inode *wdir,
+ struct dentry *wdentry)
{
int err;
@@ -43,6 +44,21 @@ int ovl_cleanup(struct ovl_fs *ofs, struct inode *wdir, struct dentry *wdentry)
return err;
}
+int ovl_cleanup(struct ovl_fs *ofs, struct dentry *workdir,
+ struct dentry *wdentry)
+{
+ int err;
+
+ err = ovl_parent_lock(workdir, wdentry);
+ if (err)
+ return err;
+
+ ovl_cleanup_locked(ofs, workdir->d_inode, wdentry);
+ ovl_parent_unlock(workdir);
+
+ return 0;
+}
+
struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir)
{
struct dentry *temp;
@@ -62,7 +78,6 @@ struct dentry *ovl_lookup_temp(struct ovl_fs *ofs, struct dentry *workdir)
return temp;
}
-/* caller holds i_mutex on workdir */
static struct dentry *ovl_whiteout(struct ovl_fs *ofs)
{
int err;
@@ -70,47 +85,52 @@ static struct dentry *ovl_whiteout(struct ovl_fs *ofs)
struct dentry *workdir = ofs->workdir;
struct inode *wdir = workdir->d_inode;
+ guard(mutex)(&ofs->whiteout_lock);
+
if (!ofs->whiteout) {
+ inode_lock_nested(wdir, I_MUTEX_PARENT);
whiteout = ovl_lookup_temp(ofs, workdir);
- if (IS_ERR(whiteout))
- goto out;
-
- err = ovl_do_whiteout(ofs, wdir, whiteout);
- if (err) {
- dput(whiteout);
- whiteout = ERR_PTR(err);
- goto out;
+ if (!IS_ERR(whiteout)) {
+ err = ovl_do_whiteout(ofs, wdir, whiteout);
+ if (err) {
+ dput(whiteout);
+ whiteout = ERR_PTR(err);
+ }
}
+ inode_unlock(wdir);
+ if (IS_ERR(whiteout))
+ return whiteout;
ofs->whiteout = whiteout;
}
if (!ofs->no_shared_whiteout) {
+ inode_lock_nested(wdir, I_MUTEX_PARENT);
whiteout = ovl_lookup_temp(ofs, workdir);
- if (IS_ERR(whiteout))
- goto out;
-
- err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout);
- if (!err)
- goto out;
-
- if (err != -EMLINK) {
- pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%i)\n",
- ofs->whiteout->d_inode->i_nlink, err);
+ if (!IS_ERR(whiteout)) {
+ err = ovl_do_link(ofs, ofs->whiteout, wdir, whiteout);
+ if (err) {
+ dput(whiteout);
+ whiteout = ERR_PTR(err);
+ }
+ }
+ inode_unlock(wdir);
+ if (!IS_ERR(whiteout))
+ return whiteout;
+ if (PTR_ERR(whiteout) != -EMLINK) {
+ pr_warn("Failed to link whiteout - disabling whiteout inode sharing(nlink=%u, err=%lu)\n",
+ ofs->whiteout->d_inode->i_nlink,
+ PTR_ERR(whiteout));
ofs->no_shared_whiteout = true;
}
- dput(whiteout);
}
whiteout = ofs->whiteout;
ofs->whiteout = NULL;
-out:
return whiteout;
}
-/* Caller must hold i_mutex on both workdir and dir */
-int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
+int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct dentry *dir,
struct dentry *dentry)
{
- struct inode *wdir = ofs->workdir->d_inode;
struct dentry *whiteout;
int err;
int flags = 0;
@@ -123,55 +143,29 @@ int ovl_cleanup_and_whiteout(struct ovl_fs *ofs, struct inode *dir,
if (d_is_dir(dentry))
flags = RENAME_EXCHANGE;
- err = ovl_do_rename(ofs, wdir, whiteout, dir, dentry, flags);
+ err = ovl_lock_rename_workdir(ofs->workdir, whiteout, dir, dentry);
+ if (!err) {
+ err = ovl_do_rename(ofs, ofs->workdir, whiteout, dir, dentry, flags);
+ unlock_rename(ofs->workdir, dir);
+ }
if (err)
goto kill_whiteout;
if (flags)
- ovl_cleanup(ofs, wdir, dentry);
+ ovl_cleanup(ofs, ofs->workdir, dentry);
out:
dput(whiteout);
return err;
kill_whiteout:
- ovl_cleanup(ofs, wdir, whiteout);
+ ovl_cleanup(ofs, ofs->workdir, whiteout);
goto out;
}
-int ovl_mkdir_real(struct ovl_fs *ofs, struct inode *dir,
- struct dentry **newdentry, umode_t mode)
-{
- int err;
- struct dentry *d, *dentry = *newdentry;
-
- err = ovl_do_mkdir(ofs, dir, dentry, mode);
- if (err)
- return err;
-
- if (likely(!d_unhashed(dentry)))
- return 0;
-
- /*
- * vfs_mkdir() may succeed and leave the dentry passed
- * to it unhashed and negative. If that happens, try to
- * lookup a new hashed and positive dentry.
- */
- d = ovl_lookup_upper(ofs, dentry->d_name.name, dentry->d_parent,
- dentry->d_name.len);
- if (IS_ERR(d)) {
- pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
- dentry, err);
- return PTR_ERR(d);
- }
- dput(dentry);
- *newdentry = d;
-
- return 0;
-}
-
-struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
+struct dentry *ovl_create_real(struct ovl_fs *ofs, struct dentry *parent,
struct dentry *newdentry, struct ovl_cattr *attr)
{
+ struct inode *dir = parent->d_inode;
int err;
if (IS_ERR(newdentry))
@@ -191,7 +185,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
case S_IFDIR:
/* mkdir is special... */
- err = ovl_mkdir_real(ofs, dir, &newdentry, attr->mode);
+ newdentry = ovl_do_mkdir(ofs, dir, newdentry, attr->mode);
+ err = PTR_ERR_OR_ZERO(newdentry);
break;
case S_IFCHR:
@@ -219,7 +214,8 @@ struct dentry *ovl_create_real(struct ovl_fs *ofs, struct inode *dir,
}
out:
if (err) {
- dput(newdentry);
+ if (!IS_ERR(newdentry))
+ dput(newdentry);
return ERR_PTR(err);
}
return newdentry;
@@ -228,8 +224,12 @@ out:
struct dentry *ovl_create_temp(struct ovl_fs *ofs, struct dentry *workdir,
struct ovl_cattr *attr)
{
- return ovl_create_real(ofs, d_inode(workdir),
- ovl_lookup_temp(ofs, workdir), attr);
+ struct dentry *ret;
+ inode_lock_nested(workdir->d_inode, I_MUTEX_PARENT);
+ ret = ovl_create_real(ofs, workdir,
+ ovl_lookup_temp(ofs, workdir), attr);
+ inode_unlock(workdir->d_inode);
+ return ret;
}
static int ovl_set_opaque_xerr(struct dentry *dentry, struct dentry *upper,
@@ -282,7 +282,8 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
* XXX: if we ever use ovl_obtain_alias() to decode directory
* file handles, need to use ovl_get_inode_locked() and
* d_instantiate_new() here to prevent from creating two
- * hashed directory inode aliases.
+ * hashed directory inode aliases. We then need to return
+ * the obtained alias to ovl_mkdir().
*/
inode = ovl_get_inode(dentry->d_sb, &oip);
if (IS_ERR(inode))
@@ -331,13 +332,13 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
int err;
inode_lock_nested(udir, I_MUTEX_PARENT);
- newdentry = ovl_create_real(ofs, udir,
+ newdentry = ovl_create_real(ofs, upperdir,
ovl_lookup_upper(ofs, dentry->d_name.name,
upperdir, dentry->d_name.len),
attr);
- err = PTR_ERR(newdentry);
+ inode_unlock(udir);
if (IS_ERR(newdentry))
- goto out_unlock;
+ return PTR_ERR(newdentry);
if (ovl_type_merge(dentry->d_parent) && d_is_dir(newdentry) &&
!ovl_allow_offline_changes(ofs)) {
@@ -349,14 +350,12 @@ static int ovl_create_upper(struct dentry *dentry, struct inode *inode,
err = ovl_instantiate(dentry, inode, newdentry, !!attr->hardlink, NULL);
if (err)
goto out_cleanup;
-out_unlock:
- inode_unlock(udir);
- return err;
+ return 0;
out_cleanup:
- ovl_cleanup(ofs, udir, newdentry);
+ ovl_cleanup(ofs, upperdir, newdentry);
dput(newdentry);
- goto out_unlock;
+ return err;
}
static struct dentry *ovl_clear_empty(struct dentry *dentry,
@@ -364,9 +363,7 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
{
struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
struct dentry *workdir = ovl_workdir(dentry);
- struct inode *wdir = workdir->d_inode;
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
- struct inode *udir = upperdir->d_inode;
struct path upperpath;
struct dentry *upper;
struct dentry *opaquedir;
@@ -376,27 +373,25 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
if (WARN_ON(!workdir))
return ERR_PTR(-EROFS);
- err = ovl_lock_rename_workdir(workdir, upperdir);
- if (err)
- goto out;
-
ovl_path_upper(dentry, &upperpath);
err = vfs_getattr(&upperpath, &stat,
STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
if (err)
- goto out_unlock;
+ goto out;
err = -ESTALE;
if (!S_ISDIR(stat.mode))
- goto out_unlock;
+ goto out;
upper = upperpath.dentry;
- if (upper->d_parent->d_inode != udir)
- goto out_unlock;
opaquedir = ovl_create_temp(ofs, workdir, OVL_CATTR(stat.mode));
err = PTR_ERR(opaquedir);
if (IS_ERR(opaquedir))
- goto out_unlock;
+ goto out;
+
+ err = ovl_lock_rename_workdir(workdir, opaquedir, upperdir, upper);
+ if (err)
+ goto out_cleanup_unlocked;
err = ovl_copy_xattr(dentry->d_sb, &upperpath, opaquedir);
if (err)
@@ -412,13 +407,13 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
if (err)
goto out_cleanup;
- err = ovl_do_rename(ofs, wdir, opaquedir, udir, upper, RENAME_EXCHANGE);
+ err = ovl_do_rename(ofs, workdir, opaquedir, upperdir, upper, RENAME_EXCHANGE);
+ unlock_rename(workdir, upperdir);
if (err)
- goto out_cleanup;
+ goto out_cleanup_unlocked;
ovl_cleanup_whiteouts(ofs, upper, list);
- ovl_cleanup(ofs, wdir, upper);
- unlock_rename(workdir, upperdir);
+ ovl_cleanup(ofs, workdir, upper);
/* dentry's upper doesn't match now, get rid of it */
d_drop(dentry);
@@ -426,10 +421,10 @@ static struct dentry *ovl_clear_empty(struct dentry *dentry,
return opaquedir;
out_cleanup:
- ovl_cleanup(ofs, wdir, opaquedir);
- dput(opaquedir);
-out_unlock:
unlock_rename(workdir, upperdir);
+out_cleanup_unlocked:
+ ovl_cleanup(ofs, workdir, opaquedir);
+ dput(opaquedir);
out:
return ERR_PTR(err);
}
@@ -448,9 +443,7 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
{
struct ovl_fs *ofs = OVL_FS(dentry->d_sb);
struct dentry *workdir = ovl_workdir(dentry);
- struct inode *wdir = workdir->d_inode;
struct dentry *upperdir = ovl_dentry_upper(dentry->d_parent);
- struct inode *udir = upperdir->d_inode;
struct dentry *upper;
struct dentry *newdentry;
int err;
@@ -467,15 +460,11 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
return err;
}
- err = ovl_lock_rename_workdir(workdir, upperdir);
- if (err)
- goto out;
-
- upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir,
- dentry->d_name.len);
+ upper = ovl_lookup_upper_unlocked(ofs, dentry->d_name.name, upperdir,
+ dentry->d_name.len);
err = PTR_ERR(upper);
if (IS_ERR(upper))
- goto out_unlock;
+ goto out;
err = -ESTALE;
if (d_is_negative(upper) || !ovl_upper_is_whiteout(ofs, upper))
@@ -486,6 +475,10 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
if (IS_ERR(newdentry))
goto out_dput;
+ err = ovl_lock_rename_workdir(workdir, newdentry, upperdir, upper);
+ if (err)
+ goto out_cleanup_unlocked;
+
/*
* mode could have been mutilated due to umask (e.g. sgid directory)
*/
@@ -519,27 +512,27 @@ static int ovl_create_over_whiteout(struct dentry *dentry, struct inode *inode,
if (err)
goto out_cleanup;
- err = ovl_do_rename(ofs, wdir, newdentry, udir, upper,
+ err = ovl_do_rename(ofs, workdir, newdentry, upperdir, upper,
RENAME_EXCHANGE);
+ unlock_rename(workdir, upperdir);
if (err)
- goto out_cleanup;
+ goto out_cleanup_unlocked;
- ovl_cleanup(ofs, wdir, upper);
+ ovl_cleanup(ofs, workdir, upper);
} else {
- err = ovl_do_rename(ofs, wdir, newdentry, udir, upper, 0);
+ err = ovl_do_rename(ofs, workdir, newdentry, upperdir, upper, 0);
+ unlock_rename(workdir, upperdir);
if (err)
- goto out_cleanup;
+ goto out_cleanup_unlocked;
}
ovl_dir_modified(dentry->d_parent, false);
err = ovl_instantiate(dentry, inode, newdentry, hardlink, NULL);
if (err) {
- ovl_cleanup(ofs, udir, newdentry);
+ ovl_cleanup(ofs, upperdir, newdentry);
dput(newdentry);
}
out_dput:
dput(upper);
-out_unlock:
- unlock_rename(workdir, upperdir);
out:
if (!hardlink) {
posix_acl_release(acl);
@@ -548,7 +541,9 @@ out:
return err;
out_cleanup:
- ovl_cleanup(ofs, wdir, newdentry);
+ unlock_rename(workdir, upperdir);
+out_cleanup_unlocked:
+ ovl_cleanup(ofs, workdir, newdentry);
dput(newdentry);
goto out_dput;
}
@@ -575,12 +570,12 @@ static const struct cred *ovl_setup_cred_for_create(struct dentry *dentry,
}
/*
- * Caller is going to match this with revert_creds_light() and drop
+ * Caller is going to match this with revert_creds() and drop
* referenec on the returned creds.
* We must be called with creator creds already, otherwise we risk
* leaking creds.
*/
- old_cred = override_creds_light(override_cred);
+ old_cred = override_creds(override_cred);
WARN_ON_ONCE(old_cred != ovl_creds(dentry->d_sb));
return override_cred;
@@ -687,10 +682,10 @@ static int ovl_create(struct mnt_idmap *idmap, struct inode *dir,
return ovl_create_object(dentry, (mode & 07777) | S_IFREG, 0, NULL);
}
-static int ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir,
- struct dentry *dentry, umode_t mode)
+static struct dentry *ovl_mkdir(struct mnt_idmap *idmap, struct inode *dir,
+ struct dentry *dentry, umode_t mode)
{
- return ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL);
+ return ERR_PTR(ovl_create_object(dentry, (mode & 07777) | S_IFDIR, 0, NULL));
}
static int ovl_mknod(struct mnt_idmap *idmap, struct inode *dir,
@@ -785,15 +780,11 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
goto out;
}
- err = ovl_lock_rename_workdir(workdir, upperdir);
- if (err)
- goto out_dput;
-
- upper = ovl_lookup_upper(ofs, dentry->d_name.name, upperdir,
- dentry->d_name.len);
+ upper = ovl_lookup_upper_unlocked(ofs, dentry->d_name.name, upperdir,
+ dentry->d_name.len);
err = PTR_ERR(upper);
if (IS_ERR(upper))
- goto out_unlock;
+ goto out_dput;
err = -ESTALE;
if ((opaquedir && upper != opaquedir) ||
@@ -802,17 +793,13 @@ static int ovl_remove_and_whiteout(struct dentry *dentry,
goto out_dput_upper;
}
- err = ovl_cleanup_and_whiteout(ofs, d_inode(upperdir), upper);
- if (err)
- goto out_d_drop;
+ err = ovl_cleanup_and_whiteout(ofs, upperdir, upper);
+ if (!err)
+ ovl_dir_modified(dentry->d_parent, true);
- ovl_dir_modified(dentry->d_parent, true);
-out_d_drop:
d_drop(dentry);
out_dput_upper:
dput(upper);
-out_unlock:
- unlock_rename(workdir, upperdir);
out_dput:
dput(opaquedir);
out:
@@ -1097,9 +1084,9 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
int err;
struct dentry *old_upperdir;
struct dentry *new_upperdir;
- struct dentry *olddentry;
- struct dentry *newdentry;
- struct dentry *trap;
+ struct dentry *olddentry = NULL;
+ struct dentry *newdentry = NULL;
+ struct dentry *trap, *de;
bool old_opaque;
bool new_opaque;
bool cleanup_whiteout = false;
@@ -1212,21 +1199,23 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
goto out_revert_creds;
}
- olddentry = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir,
- old->d_name.len);
- err = PTR_ERR(olddentry);
- if (IS_ERR(olddentry))
+ de = ovl_lookup_upper(ofs, old->d_name.name, old_upperdir,
+ old->d_name.len);
+ err = PTR_ERR(de);
+ if (IS_ERR(de))
goto out_unlock;
+ olddentry = de;
err = -ESTALE;
if (!ovl_matches_upper(old, olddentry))
- goto out_dput_old;
+ goto out_unlock;
- newdentry = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir,
- new->d_name.len);
- err = PTR_ERR(newdentry);
- if (IS_ERR(newdentry))
- goto out_dput_old;
+ de = ovl_lookup_upper(ofs, new->d_name.name, new_upperdir,
+ new->d_name.len);
+ err = PTR_ERR(de);
+ if (IS_ERR(de))
+ goto out_unlock;
+ newdentry = de;
old_opaque = ovl_dentry_is_opaque(old);
new_opaque = ovl_dentry_is_opaque(new);
@@ -1235,28 +1224,28 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
if (d_inode(new) && ovl_dentry_upper(new)) {
if (opaquedir) {
if (newdentry != opaquedir)
- goto out_dput;
+ goto out_unlock;
} else {
if (!ovl_matches_upper(new, newdentry))
- goto out_dput;
+ goto out_unlock;
}
} else {
if (!d_is_negative(newdentry)) {
if (!new_opaque || !ovl_upper_is_whiteout(ofs, newdentry))
- goto out_dput;
+ goto out_unlock;
} else {
if (flags & RENAME_EXCHANGE)
- goto out_dput;
+ goto out_unlock;
}
}
if (olddentry == trap)
- goto out_dput;
+ goto out_unlock;
if (newdentry == trap)
- goto out_dput;
+ goto out_unlock;
if (olddentry->d_inode == newdentry->d_inode)
- goto out_dput;
+ goto out_unlock;
err = 0;
if (ovl_type_merge_or_lower(old))
@@ -1264,7 +1253,7 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
else if (is_dir && !old_opaque && ovl_type_merge(new->d_parent))
err = ovl_set_opaque_xerr(old, olddentry, -EXDEV);
if (err)
- goto out_dput;
+ goto out_unlock;
if (!overwrite && ovl_type_merge_or_lower(new))
err = ovl_set_redirect(new, samedir);
@@ -1272,15 +1261,16 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
ovl_type_merge(old->d_parent))
err = ovl_set_opaque_xerr(new, newdentry, -EXDEV);
if (err)
- goto out_dput;
+ goto out_unlock;
- err = ovl_do_rename(ofs, old_upperdir->d_inode, olddentry,
- new_upperdir->d_inode, newdentry, flags);
+ err = ovl_do_rename(ofs, old_upperdir, olddentry,
+ new_upperdir, newdentry, flags);
+ unlock_rename(new_upperdir, old_upperdir);
if (err)
- goto out_dput;
+ goto out_revert_creds;
if (cleanup_whiteout)
- ovl_cleanup(ofs, old_upperdir->d_inode, newdentry);
+ ovl_cleanup(ofs, old_upperdir, newdentry);
if (overwrite && d_inode(new)) {
if (new_is_dir)
@@ -1299,12 +1289,6 @@ static int ovl_rename(struct mnt_idmap *idmap, struct inode *olddir,
if (d_inode(new) && ovl_dentry_upper(new))
ovl_copyattr(d_inode(new));
-out_dput:
- dput(newdentry);
-out_dput_old:
- dput(olddentry);
-out_unlock:
- unlock_rename(new_upperdir, old_upperdir);
out_revert_creds:
ovl_revert_creds(old_cred);
if (update_nlink)
@@ -1312,9 +1296,15 @@ out_revert_creds:
else
ovl_drop_write(old);
out:
+ dput(newdentry);
+ dput(olddentry);
dput(opaquedir);
ovl_cache_free(&list);
return err;
+
+out_unlock:
+ unlock_rename(new_upperdir, old_upperdir);
+ goto out_revert_creds;
}
static int ovl_create_tmpfile(struct file *file, struct dentry *dentry,