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path: root/fs/overlayfs/readdir.c
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Diffstat (limited to 'fs/overlayfs/readdir.c')
-rw-r--r--fs/overlayfs/readdir.c128
1 files changed, 98 insertions, 30 deletions
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 62e9b22a2077..c11f5c0906c3 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -26,6 +26,7 @@ struct ovl_cache_entry {
struct list_head l_node;
struct rb_node node;
struct ovl_cache_entry *next_maybe_whiteout;
+ bool is_upper;
bool is_whiteout;
char name[];
};
@@ -158,6 +159,7 @@ static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
/* Defer setting d_ino for upper entry to ovl_iterate() */
if (ovl_calc_d_ino(rdd, p))
p->ino = 0;
+ p->is_upper = rdd->is_upper;
p->is_whiteout = false;
if (d_type == DT_CHR) {
@@ -316,21 +318,37 @@ static inline int ovl_dir_read(struct path *realpath,
return err;
}
+/*
+ * Can we iterate real dir directly?
+ *
+ * Non-merge dir may contain whiteouts from a time it was a merge upper, before
+ * lower dir was removed under it and possibly before it was rotated from upper
+ * to lower layer.
+ */
+static bool ovl_dir_is_real(struct dentry *dir)
+{
+ return !ovl_test_flag(OVL_WHITEOUTS, d_inode(dir));
+}
+
static void ovl_dir_reset(struct file *file)
{
struct ovl_dir_file *od = file->private_data;
struct ovl_dir_cache *cache = od->cache;
struct dentry *dentry = file->f_path.dentry;
- enum ovl_path_type type = ovl_path_type(dentry);
+ bool is_real;
if (cache && ovl_dentry_version_get(dentry) != cache->version) {
ovl_cache_put(od, dentry);
od->cache = NULL;
od->cursor = NULL;
}
- WARN_ON(!od->is_real && !OVL_TYPE_MERGE(type));
- if (od->is_real && OVL_TYPE_MERGE(type))
+ is_real = ovl_dir_is_real(dentry);
+ if (od->is_real != is_real) {
+ /* is_real can only become false when dir is copied up */
+ if (WARN_ON(is_real))
+ return;
od->is_real = false;
+ }
}
static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
@@ -481,7 +499,7 @@ out:
return err;
fail:
- pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n",
+ pr_warn_ratelimited("overlayfs: failed to look up (%s) for ino (%i)\n",
p->name, err);
goto out;
}
@@ -575,8 +593,15 @@ static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path)
return ERR_PTR(res);
}
if (list_empty(&cache->entries)) {
- /* Good oportunity to get rid of an unnecessary "impure" flag */
- ovl_do_removexattr(ovl_dentry_upper(dentry), OVL_XATTR_IMPURE);
+ /*
+ * A good opportunity to get rid of an unneeded "impure" flag.
+ * Removing the "impure" xattr is best effort.
+ */
+ if (!ovl_want_write(dentry)) {
+ ovl_do_removexattr(ovl_dentry_upper(dentry),
+ OVL_XATTR_IMPURE);
+ ovl_drop_write(dentry);
+ }
ovl_clear_flag(OVL_IMPURE, d_inode(dentry));
kfree(cache);
return NULL;
@@ -645,7 +670,10 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
return PTR_ERR(rdt.cache);
}
- return iterate_dir(od->realfile, &rdt.ctx);
+ err = iterate_dir(od->realfile, &rdt.ctx);
+ ctx->pos = rdt.ctx.pos;
+
+ return err;
}
@@ -748,13 +776,17 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
struct dentry *dentry = file->f_path.dentry;
struct file *realfile = od->realfile;
+ /* Nothing to sync for lower */
+ if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
+ return 0;
+
/*
* Need to check if we started out being a lower dir, but got copied up
*/
- if (!od->is_upper && OVL_TYPE_UPPER(ovl_path_type(dentry))) {
+ if (!od->is_upper) {
struct inode *inode = file_inode(file);
- realfile = lockless_dereference(od->upperfile);
+ realfile = READ_ONCE(od->upperfile);
if (!realfile) {
struct path upperpath;
@@ -816,7 +848,7 @@ static int ovl_dir_open(struct inode *inode, struct file *file)
return PTR_ERR(realfile);
}
od->realfile = realfile;
- od->is_real = !OVL_TYPE_MERGE(type);
+ od->is_real = ovl_dir_is_real(file->f_path.dentry);
od->is_upper = OVL_TYPE_UPPER(type);
file->private_data = od;
@@ -835,27 +867,41 @@ const struct file_operations ovl_dir_operations = {
int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
{
int err;
- struct ovl_cache_entry *p;
+ struct ovl_cache_entry *p, *n;
struct rb_root root = RB_ROOT;
+ const struct cred *old_cred;
+ old_cred = ovl_override_creds(dentry->d_sb);
err = ovl_dir_read_merged(dentry, list, &root);
+ revert_creds(old_cred);
if (err)
return err;
err = 0;
- list_for_each_entry(p, list, l_node) {
- if (p->is_whiteout)
- continue;
+ list_for_each_entry_safe(p, n, list, l_node) {
+ /*
+ * Select whiteouts in upperdir, they should
+ * be cleared when deleting this directory.
+ */
+ if (p->is_whiteout) {
+ if (p->is_upper)
+ continue;
+ goto del_entry;
+ }
if (p->name[0] == '.') {
if (p->len == 1)
- continue;
+ goto del_entry;
if (p->len == 2 && p->name[1] == '.')
- continue;
+ goto del_entry;
}
err = -ENOTEMPTY;
break;
+
+del_entry:
+ list_del(&p->l_node);
+ kfree(p);
}
return err;
@@ -869,7 +915,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
list_for_each_entry(p, list, l_node) {
struct dentry *dentry;
- if (!p->is_whiteout)
+ if (WARN_ON(!p->is_whiteout || !p->is_upper))
continue;
dentry = lookup_one_len(p->name, upper, p->len);
@@ -984,12 +1030,13 @@ void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
}
}
-int ovl_indexdir_cleanup(struct dentry *dentry, struct vfsmount *mnt,
- struct path *lowerstack, unsigned int numlower)
+int ovl_indexdir_cleanup(struct ovl_fs *ofs)
{
int err;
- struct inode *dir = dentry->d_inode;
- struct path path = { .mnt = mnt, .dentry = dentry };
+ struct dentry *indexdir = ofs->indexdir;
+ struct dentry *index = NULL;
+ struct inode *dir = indexdir->d_inode;
+ struct path path = { .mnt = ofs->upper_mnt, .dentry = indexdir };
LIST_HEAD(list);
struct rb_root root = RB_ROOT;
struct ovl_cache_entry *p;
@@ -1007,29 +1054,50 @@ 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;
if (p->len == 2 && p->name[1] == '.')
continue;
}
- index = lookup_one_len(p->name, dentry, p->len);
+ index = lookup_one_len(p->name, indexdir, 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;
+ err = ovl_verify_index(ofs, index);
+ if (!err) {
+ goto next;
+ } else if (err == -ESTALE) {
+ /* Cleanup stale index entries */
+ err = ovl_cleanup(dir, index);
+ } else if (err != -ENOENT) {
+ /*
+ * Abort mount to avoid corrupting the index if
+ * an incompatible index entry was found or on out
+ * of memory.
+ */
+ break;
+ } else if (ofs->config.nfs_export) {
+ /*
+ * Whiteout orphan index to block future open by
+ * handle after overlay nlink dropped to zero.
+ */
+ err = ovl_cleanup_and_whiteout(indexdir, dir, index);
+ } else {
+ /* Cleanup orphan index entries */
err = ovl_cleanup(dir, index);
- if (err)
- break;
}
+
+ if (err)
+ break;
+
+next:
dput(index);
+ index = NULL;
}
+ dput(index);
inode_unlock(dir);
out:
ovl_cache_free(&list);
generated by cgit (git 2.34.1) at 2024-05-23 17:05:00 +0000