[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/fs/overlayfs/readdir.c b/src/kernel/linux/v4.14/fs/overlayfs/readdir.c
new file mode 100644
index 0000000..1d4f999
--- /dev/null
+++ b/src/kernel/linux/v4.14/fs/overlayfs/readdir.c
@@ -0,0 +1,1069 @@
+/*
+ *
+ * Copyright (C) 2011 Novell Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/fs.h>
+#include <linux/slab.h>
+#include <linux/namei.h>
+#include <linux/file.h>
+#include <linux/xattr.h>
+#include <linux/rbtree.h>
+#include <linux/security.h>
+#include <linux/cred.h>
+#include <linux/ratelimit.h>
+#include "overlayfs.h"
+
+struct ovl_cache_entry {
+ unsigned int len;
+ unsigned int type;
+ u64 real_ino;
+ u64 ino;
+ struct list_head l_node;
+ struct rb_node node;
+ struct ovl_cache_entry *next_maybe_whiteout;
+ bool is_whiteout;
+ char name[];
+};
+
+struct ovl_dir_cache {
+ long refcount;
+ u64 version;
+ struct list_head entries;
+ struct rb_root root;
+};
+
+struct ovl_readdir_data {
+ struct dir_context ctx;
+ struct dentry *dentry;
+ bool is_lowest;
+ struct rb_root *root;
+ struct list_head *list;
+ struct list_head middle;
+ struct ovl_cache_entry *first_maybe_whiteout;
+ int count;
+ int err;
+ bool is_upper;
+ bool d_type_supported;
+};
+
+struct ovl_dir_file {
+ bool is_real;
+ bool is_upper;
+ struct ovl_dir_cache *cache;
+ struct list_head *cursor;
+ struct file *realfile;
+ struct file *upperfile;
+};
+
+static struct ovl_cache_entry *ovl_cache_entry_from_node(struct rb_node *n)
+{
+ return rb_entry(n, struct ovl_cache_entry, node);
+}
+
+static bool ovl_cache_entry_find_link(const char *name, int len,
+ struct rb_node ***link,
+ struct rb_node **parent)
+{
+ bool found = false;
+ struct rb_node **newp = *link;
+
+ while (!found && *newp) {
+ int cmp;
+ struct ovl_cache_entry *tmp;
+
+ *parent = *newp;
+ tmp = ovl_cache_entry_from_node(*newp);
+ cmp = strncmp(name, tmp->name, len);
+ if (cmp > 0)
+ newp = &tmp->node.rb_right;
+ else if (cmp < 0 || len < tmp->len)
+ newp = &tmp->node.rb_left;
+ else
+ found = true;
+ }
+ *link = newp;
+
+ return found;
+}
+
+static struct ovl_cache_entry *ovl_cache_entry_find(struct rb_root *root,
+ const char *name, int len)
+{
+ struct rb_node *node = root->rb_node;
+ int cmp;
+
+ while (node) {
+ struct ovl_cache_entry *p = ovl_cache_entry_from_node(node);
+
+ cmp = strncmp(name, p->name, len);
+ if (cmp > 0)
+ node = p->node.rb_right;
+ else if (cmp < 0 || len < p->len)
+ node = p->node.rb_left;
+ else
+ return p;
+ }
+
+ return NULL;
+}
+
+static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd,
+ struct ovl_cache_entry *p)
+{
+ /* Don't care if not doing ovl_iter() */
+ if (!rdd->dentry)
+ return false;
+
+ /* Always recalc d_ino for parent */
+ if (strcmp(p->name, "..") == 0)
+ return true;
+
+ /* If this is lower, then native d_ino will do */
+ if (!rdd->is_upper)
+ return false;
+
+ /*
+ * Recalc d_ino for '.' and for all entries if dir is impure (contains
+ * copied up entries)
+ */
+ if ((p->name[0] == '.' && p->len == 1) ||
+ ovl_test_flag(OVL_IMPURE, d_inode(rdd->dentry)))
+ return true;
+
+ return false;
+}
+
+static struct ovl_cache_entry *ovl_cache_entry_new(struct ovl_readdir_data *rdd,
+ const char *name, int len,
+ u64 ino, unsigned int d_type)
+{
+ struct ovl_cache_entry *p;
+ size_t size = offsetof(struct ovl_cache_entry, name[len + 1]);
+
+ p = kmalloc(size, GFP_KERNEL);
+ if (!p)
+ return NULL;
+
+ memcpy(p->name, name, len);
+ p->name[len] = '\0';
+ p->len = len;
+ p->type = d_type;
+ p->real_ino = ino;
+ p->ino = ino;
+ /* Defer setting d_ino for upper entry to ovl_iterate() */
+ if (ovl_calc_d_ino(rdd, p))
+ p->ino = 0;
+ p->is_whiteout = false;
+
+ if (d_type == DT_CHR) {
+ p->next_maybe_whiteout = rdd->first_maybe_whiteout;
+ rdd->first_maybe_whiteout = p;
+ }
+ return p;
+}
+
+static int ovl_cache_entry_add_rb(struct ovl_readdir_data *rdd,
+ const char *name, int len, u64 ino,
+ unsigned int d_type)
+{
+ struct rb_node **newp = &rdd->root->rb_node;
+ struct rb_node *parent = NULL;
+ struct ovl_cache_entry *p;
+
+ if (ovl_cache_entry_find_link(name, len, &newp, &parent))
+ return 0;
+
+ p = ovl_cache_entry_new(rdd, name, len, ino, d_type);
+ if (p == NULL) {
+ rdd->err = -ENOMEM;
+ return -ENOMEM;
+ }
+
+ list_add_tail(&p->l_node, rdd->list);
+ rb_link_node(&p->node, parent, newp);
+ rb_insert_color(&p->node, rdd->root);
+
+ return 0;
+}
+
+static int ovl_fill_lowest(struct ovl_readdir_data *rdd,
+ const char *name, int namelen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct ovl_cache_entry *p;
+
+ p = ovl_cache_entry_find(rdd->root, name, namelen);
+ if (p) {
+ list_move_tail(&p->l_node, &rdd->middle);
+ } else {
+ p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
+ if (p == NULL)
+ rdd->err = -ENOMEM;
+ else
+ list_add_tail(&p->l_node, &rdd->middle);
+ }
+
+ return rdd->err;
+}
+
+void ovl_cache_free(struct list_head *list)
+{
+ struct ovl_cache_entry *p;
+ struct ovl_cache_entry *n;
+
+ list_for_each_entry_safe(p, n, list, l_node)
+ kfree(p);
+
+ INIT_LIST_HEAD(list);
+}
+
+void ovl_dir_cache_free(struct inode *inode)
+{
+ struct ovl_dir_cache *cache = ovl_dir_cache(inode);
+
+ if (cache) {
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ }
+}
+
+static void ovl_cache_put(struct ovl_dir_file *od, struct dentry *dentry)
+{
+ struct ovl_dir_cache *cache = od->cache;
+
+ WARN_ON(cache->refcount <= 0);
+ cache->refcount--;
+ if (!cache->refcount) {
+ if (ovl_dir_cache(d_inode(dentry)) == cache)
+ ovl_set_dir_cache(d_inode(dentry), NULL);
+
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ }
+}
+
+static int ovl_fill_merge(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_readdir_data *rdd =
+ container_of(ctx, struct ovl_readdir_data, ctx);
+
+ rdd->count++;
+ if (!rdd->is_lowest)
+ return ovl_cache_entry_add_rb(rdd, name, namelen, ino, d_type);
+ else
+ return ovl_fill_lowest(rdd, name, namelen, offset, ino, d_type);
+}
+
+static int ovl_check_whiteouts(struct dentry *dir, struct ovl_readdir_data *rdd)
+{
+ int err;
+ struct ovl_cache_entry *p;
+ struct dentry *dentry;
+ const struct cred *old_cred;
+
+ old_cred = ovl_override_creds(rdd->dentry->d_sb);
+
+ err = down_write_killable(&dir->d_inode->i_rwsem);
+ if (!err) {
+ while (rdd->first_maybe_whiteout) {
+ p = rdd->first_maybe_whiteout;
+ rdd->first_maybe_whiteout = p->next_maybe_whiteout;
+ dentry = lookup_one_len(p->name, dir, p->len);
+ if (!IS_ERR(dentry)) {
+ p->is_whiteout = ovl_is_whiteout(dentry);
+ dput(dentry);
+ }
+ }
+ inode_unlock(dir->d_inode);
+ }
+ revert_creds(old_cred);
+
+ return err;
+}
+
+static inline int ovl_dir_read(struct path *realpath,
+ struct ovl_readdir_data *rdd)
+{
+ struct file *realfile;
+ int err;
+
+ realfile = ovl_path_open(realpath, O_RDONLY | O_DIRECTORY);
+ if (IS_ERR(realfile))
+ return PTR_ERR(realfile);
+
+ rdd->first_maybe_whiteout = NULL;
+ rdd->ctx.pos = 0;
+ do {
+ rdd->count = 0;
+ rdd->err = 0;
+ err = iterate_dir(realfile, &rdd->ctx);
+ if (err >= 0)
+ err = rdd->err;
+ } while (!err && rdd->count);
+
+ if (!err && rdd->first_maybe_whiteout && rdd->dentry)
+ err = ovl_check_whiteouts(realpath->dentry, rdd);
+
+ fput(realfile);
+
+ return err;
+}
+
+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);
+
+ 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))
+ od->is_real = false;
+}
+
+static int ovl_dir_read_merged(struct dentry *dentry, struct list_head *list,
+ struct rb_root *root)
+{
+ int err;
+ struct path realpath;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_fill_merge,
+ .dentry = dentry,
+ .list = list,
+ .root = root,
+ .is_lowest = false,
+ };
+ int idx, next;
+
+ for (idx = 0; idx != -1; idx = next) {
+ next = ovl_path_next(idx, dentry, &realpath);
+ rdd.is_upper = ovl_dentry_upper(dentry) == realpath.dentry;
+
+ if (next != -1) {
+ err = ovl_dir_read(&realpath, &rdd);
+ if (err)
+ break;
+ } else {
+ /*
+ * Insert lowest layer entries before upper ones, this
+ * allows offsets to be reasonably constant
+ */
+ list_add(&rdd.middle, rdd.list);
+ rdd.is_lowest = true;
+ err = ovl_dir_read(&realpath, &rdd);
+ list_del(&rdd.middle);
+ }
+ }
+ return err;
+}
+
+static void ovl_seek_cursor(struct ovl_dir_file *od, loff_t pos)
+{
+ struct list_head *p;
+ loff_t off = 0;
+
+ list_for_each(p, &od->cache->entries) {
+ if (off >= pos)
+ break;
+ off++;
+ }
+ /* Cursor is safe since the cache is stable */
+ od->cursor = p;
+}
+
+static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
+{
+ int res;
+ struct ovl_dir_cache *cache;
+
+ cache = ovl_dir_cache(d_inode(dentry));
+ if (cache && ovl_dentry_version_get(dentry) == cache->version) {
+ WARN_ON(!cache->refcount);
+ cache->refcount++;
+ return cache;
+ }
+ ovl_set_dir_cache(d_inode(dentry), NULL);
+
+ cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
+ if (!cache)
+ return ERR_PTR(-ENOMEM);
+
+ cache->refcount = 1;
+ INIT_LIST_HEAD(&cache->entries);
+ cache->root = RB_ROOT;
+
+ res = ovl_dir_read_merged(dentry, &cache->entries, &cache->root);
+ if (res) {
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ return ERR_PTR(res);
+ }
+
+ cache->version = ovl_dentry_version_get(dentry);
+ ovl_set_dir_cache(d_inode(dentry), cache);
+
+ return cache;
+}
+
+/*
+ * Set d_ino for upper entries. Non-upper entries should always report
+ * the uppermost real inode ino and should not call this function.
+ *
+ * When not all layer are on same fs, report real ino also for upper.
+ *
+ * When all layers are on the same fs, and upper has a reference to
+ * copy up origin, call vfs_getattr() on the overlay entry to make
+ * sure that d_ino will be consistent with st_ino from stat(2).
+ */
+static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
+
+{
+ struct dentry *dir = path->dentry;
+ struct dentry *this = NULL;
+ enum ovl_path_type type;
+ u64 ino = p->real_ino;
+ int err = 0;
+
+ if (!ovl_same_sb(dir->d_sb))
+ goto out;
+
+ if (p->name[0] == '.') {
+ if (p->len == 1) {
+ this = dget(dir);
+ goto get;
+ }
+ if (p->len == 2 && p->name[1] == '.') {
+ /* we shall not be moved */
+ this = dget(dir->d_parent);
+ goto get;
+ }
+ }
+ this = lookup_one_len(p->name, dir, p->len);
+ if (IS_ERR_OR_NULL(this) || !this->d_inode) {
+ if (IS_ERR(this)) {
+ err = PTR_ERR(this);
+ this = NULL;
+ goto fail;
+ }
+ goto out;
+ }
+
+get:
+ type = ovl_path_type(this);
+ if (OVL_TYPE_ORIGIN(type)) {
+ struct kstat stat;
+ struct path statpath = *path;
+
+ statpath.dentry = this;
+ err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
+ if (err)
+ goto fail;
+
+ WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
+ ino = stat.ino;
+ }
+
+out:
+ p->ino = ino;
+ dput(this);
+ return err;
+
+fail:
+ pr_warn_ratelimited("overlay: failed to look up (%s) for ino (%i)\n",
+ p->name, err);
+ goto out;
+}
+
+static int ovl_fill_plain(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_cache_entry *p;
+ struct ovl_readdir_data *rdd =
+ container_of(ctx, struct ovl_readdir_data, ctx);
+
+ rdd->count++;
+ p = ovl_cache_entry_new(rdd, name, namelen, ino, d_type);
+ if (p == NULL) {
+ rdd->err = -ENOMEM;
+ return -ENOMEM;
+ }
+ list_add_tail(&p->l_node, rdd->list);
+
+ return 0;
+}
+
+static int ovl_dir_read_impure(struct path *path, struct list_head *list,
+ struct rb_root *root)
+{
+ int err;
+ struct path realpath;
+ struct ovl_cache_entry *p, *n;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_fill_plain,
+ .list = list,
+ .root = root,
+ };
+
+ INIT_LIST_HEAD(list);
+ *root = RB_ROOT;
+ ovl_path_upper(path->dentry, &realpath);
+
+ err = ovl_dir_read(&realpath, &rdd);
+ if (err)
+ return err;
+
+ list_for_each_entry_safe(p, n, list, l_node) {
+ if (strcmp(p->name, ".") != 0 &&
+ strcmp(p->name, "..") != 0) {
+ err = ovl_cache_update_ino(path, p);
+ if (err)
+ return err;
+ }
+ if (p->ino == p->real_ino) {
+ list_del(&p->l_node);
+ kfree(p);
+ } else {
+ struct rb_node **newp = &root->rb_node;
+ struct rb_node *parent = NULL;
+
+ if (WARN_ON(ovl_cache_entry_find_link(p->name, p->len,
+ &newp, &parent)))
+ return -EIO;
+
+ rb_link_node(&p->node, parent, newp);
+ rb_insert_color(&p->node, root);
+ }
+ }
+ return 0;
+}
+
+static struct ovl_dir_cache *ovl_cache_get_impure(struct path *path)
+{
+ int res;
+ struct dentry *dentry = path->dentry;
+ struct ovl_dir_cache *cache;
+
+ cache = ovl_dir_cache(d_inode(dentry));
+ if (cache && ovl_dentry_version_get(dentry) == cache->version)
+ return cache;
+
+ /* Impure cache is not refcounted, free it here */
+ ovl_dir_cache_free(d_inode(dentry));
+ ovl_set_dir_cache(d_inode(dentry), NULL);
+
+ cache = kzalloc(sizeof(struct ovl_dir_cache), GFP_KERNEL);
+ if (!cache)
+ return ERR_PTR(-ENOMEM);
+
+ res = ovl_dir_read_impure(path, &cache->entries, &cache->root);
+ if (res) {
+ ovl_cache_free(&cache->entries);
+ kfree(cache);
+ return ERR_PTR(res);
+ }
+ if (list_empty(&cache->entries)) {
+ /*
+ * 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;
+ }
+
+ cache->version = ovl_dentry_version_get(dentry);
+ ovl_set_dir_cache(d_inode(dentry), cache);
+
+ return cache;
+}
+
+struct ovl_readdir_translate {
+ struct dir_context *orig_ctx;
+ struct ovl_dir_cache *cache;
+ struct dir_context ctx;
+ u64 parent_ino;
+};
+
+static int ovl_fill_real(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_readdir_translate *rdt =
+ container_of(ctx, struct ovl_readdir_translate, ctx);
+ struct dir_context *orig_ctx = rdt->orig_ctx;
+
+ if (rdt->parent_ino && strcmp(name, "..") == 0)
+ ino = rdt->parent_ino;
+ else if (rdt->cache) {
+ struct ovl_cache_entry *p;
+
+ p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
+ if (p)
+ ino = p->ino;
+ }
+
+ return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
+}
+
+static bool ovl_is_impure_dir(struct file *file)
+{
+ struct ovl_dir_file *od = file->private_data;
+ struct inode *dir = d_inode(file->f_path.dentry);
+
+ /*
+ * Only upper dir can be impure, but if we are in the middle of
+ * iterating a lower real dir, dir could be copied up and marked
+ * impure. We only want the impure cache if we started iterating
+ * a real upper dir to begin with.
+ */
+ return od->is_upper && ovl_test_flag(OVL_IMPURE, dir);
+
+}
+
+static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
+{
+ int err;
+ struct ovl_dir_file *od = file->private_data;
+ struct dentry *dir = file->f_path.dentry;
+ struct ovl_readdir_translate rdt = {
+ .ctx.actor = ovl_fill_real,
+ .orig_ctx = ctx,
+ };
+
+ if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
+ struct kstat stat;
+ struct path statpath = file->f_path;
+
+ statpath.dentry = dir->d_parent;
+ err = vfs_getattr(&statpath, &stat, STATX_INO, 0);
+ if (err)
+ return err;
+
+ WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
+ rdt.parent_ino = stat.ino;
+ }
+
+ if (ovl_is_impure_dir(file)) {
+ rdt.cache = ovl_cache_get_impure(&file->f_path);
+ if (IS_ERR(rdt.cache))
+ return PTR_ERR(rdt.cache);
+ }
+
+ err = iterate_dir(od->realfile, &rdt.ctx);
+ ctx->pos = rdt.ctx.pos;
+
+ return err;
+}
+
+
+static int ovl_iterate(struct file *file, struct dir_context *ctx)
+{
+ struct ovl_dir_file *od = file->private_data;
+ struct dentry *dentry = file->f_path.dentry;
+ struct ovl_cache_entry *p;
+ int err;
+
+ if (!ctx->pos)
+ ovl_dir_reset(file);
+
+ if (od->is_real) {
+ /*
+ * If parent is merge, then need to adjust d_ino for '..', if
+ * dir is impure then need to adjust d_ino for copied up
+ * entries.
+ */
+ if (ovl_same_sb(dentry->d_sb) &&
+ (ovl_is_impure_dir(file) ||
+ OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) {
+ return ovl_iterate_real(file, ctx);
+ }
+ return iterate_dir(od->realfile, ctx);
+ }
+
+ if (!od->cache) {
+ struct ovl_dir_cache *cache;
+
+ cache = ovl_cache_get(dentry);
+ if (IS_ERR(cache))
+ return PTR_ERR(cache);
+
+ od->cache = cache;
+ ovl_seek_cursor(od, ctx->pos);
+ }
+
+ while (od->cursor != &od->cache->entries) {
+ p = list_entry(od->cursor, struct ovl_cache_entry, l_node);
+ if (!p->is_whiteout) {
+ if (!p->ino) {
+ err = ovl_cache_update_ino(&file->f_path, p);
+ if (err)
+ return err;
+ }
+ if (!dir_emit(ctx, p->name, p->len, p->ino, p->type))
+ break;
+ }
+ od->cursor = p->l_node.next;
+ ctx->pos++;
+ }
+ return 0;
+}
+
+static loff_t ovl_dir_llseek(struct file *file, loff_t offset, int origin)
+{
+ loff_t res;
+ struct ovl_dir_file *od = file->private_data;
+
+ inode_lock(file_inode(file));
+ if (!file->f_pos)
+ ovl_dir_reset(file);
+
+ if (od->is_real) {
+ res = vfs_llseek(od->realfile, offset, origin);
+ file->f_pos = od->realfile->f_pos;
+ } else {
+ res = -EINVAL;
+
+ switch (origin) {
+ case SEEK_CUR:
+ offset += file->f_pos;
+ break;
+ case SEEK_SET:
+ break;
+ default:
+ goto out_unlock;
+ }
+ if (offset < 0)
+ goto out_unlock;
+
+ if (offset != file->f_pos) {
+ file->f_pos = offset;
+ if (od->cache)
+ ovl_seek_cursor(od, offset);
+ }
+ res = offset;
+ }
+out_unlock:
+ inode_unlock(file_inode(file));
+
+ return res;
+}
+
+static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
+ int datasync)
+{
+ struct ovl_dir_file *od = file->private_data;
+ 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) {
+ struct inode *inode = file_inode(file);
+
+ realfile = READ_ONCE(od->upperfile);
+ if (!realfile) {
+ struct path upperpath;
+
+ ovl_path_upper(dentry, &upperpath);
+ realfile = ovl_path_open(&upperpath, O_RDONLY);
+
+ inode_lock(inode);
+ if (!od->upperfile) {
+ if (IS_ERR(realfile)) {
+ inode_unlock(inode);
+ return PTR_ERR(realfile);
+ }
+ smp_store_release(&od->upperfile, realfile);
+ } else {
+ /* somebody has beaten us to it */
+ if (!IS_ERR(realfile))
+ fput(realfile);
+ realfile = od->upperfile;
+ }
+ inode_unlock(inode);
+ }
+ }
+
+ return vfs_fsync_range(realfile, start, end, datasync);
+}
+
+static int ovl_dir_release(struct inode *inode, struct file *file)
+{
+ struct ovl_dir_file *od = file->private_data;
+
+ if (od->cache) {
+ inode_lock(inode);
+ ovl_cache_put(od, file->f_path.dentry);
+ inode_unlock(inode);
+ }
+ fput(od->realfile);
+ if (od->upperfile)
+ fput(od->upperfile);
+ kfree(od);
+
+ return 0;
+}
+
+static int ovl_dir_open(struct inode *inode, struct file *file)
+{
+ struct path realpath;
+ struct file *realfile;
+ struct ovl_dir_file *od;
+ enum ovl_path_type type;
+
+ od = kzalloc(sizeof(struct ovl_dir_file), GFP_KERNEL);
+ if (!od)
+ return -ENOMEM;
+
+ type = ovl_path_real(file->f_path.dentry, &realpath);
+ realfile = ovl_path_open(&realpath, file->f_flags);
+ if (IS_ERR(realfile)) {
+ kfree(od);
+ return PTR_ERR(realfile);
+ }
+ od->realfile = realfile;
+ od->is_real = !OVL_TYPE_MERGE(type);
+ od->is_upper = OVL_TYPE_UPPER(type);
+ file->private_data = od;
+
+ return 0;
+}
+
+const struct file_operations ovl_dir_operations = {
+ .read = generic_read_dir,
+ .open = ovl_dir_open,
+ .iterate = ovl_iterate,
+ .llseek = ovl_dir_llseek,
+ .fsync = ovl_dir_fsync,
+ .release = ovl_dir_release,
+};
+
+int ovl_check_empty_dir(struct dentry *dentry, struct list_head *list)
+{
+ int err;
+ struct ovl_cache_entry *p;
+ struct rb_root root = RB_ROOT;
+
+ err = ovl_dir_read_merged(dentry, list, &root);
+ if (err)
+ return err;
+
+ err = 0;
+
+ list_for_each_entry(p, list, l_node) {
+ if (p->is_whiteout)
+ continue;
+
+ if (p->name[0] == '.') {
+ if (p->len == 1)
+ continue;
+ if (p->len == 2 && p->name[1] == '.')
+ continue;
+ }
+ err = -ENOTEMPTY;
+ break;
+ }
+
+ return err;
+}
+
+void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
+{
+ struct ovl_cache_entry *p;
+
+ inode_lock_nested(upper->d_inode, I_MUTEX_CHILD);
+ list_for_each_entry(p, list, l_node) {
+ struct dentry *dentry;
+
+ if (!p->is_whiteout)
+ continue;
+
+ dentry = lookup_one_len(p->name, upper, p->len);
+ if (IS_ERR(dentry)) {
+ pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n",
+ upper->d_name.name, p->len, p->name,
+ (int) PTR_ERR(dentry));
+ continue;
+ }
+ if (dentry->d_inode)
+ ovl_cleanup(upper->d_inode, dentry);
+ dput(dentry);
+ }
+ inode_unlock(upper->d_inode);
+}
+
+static int ovl_check_d_type(struct dir_context *ctx, const char *name,
+ int namelen, loff_t offset, u64 ino,
+ unsigned int d_type)
+{
+ struct ovl_readdir_data *rdd =
+ container_of(ctx, struct ovl_readdir_data, ctx);
+
+ /* Even if d_type is not supported, DT_DIR is returned for . and .. */
+ if (!strncmp(name, ".", namelen) || !strncmp(name, "..", namelen))
+ return 0;
+
+ if (d_type != DT_UNKNOWN)
+ rdd->d_type_supported = true;
+
+ return 0;
+}
+
+/*
+ * Returns 1 if d_type is supported, 0 not supported/unknown. Negative values
+ * if error is encountered.
+ */
+int ovl_check_d_type_supported(struct path *realpath)
+{
+ int err;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_check_d_type,
+ .d_type_supported = false,
+ };
+
+ err = ovl_dir_read(realpath, &rdd);
+ if (err)
+ return err;
+
+ return rdd.d_type_supported;
+}
+
+static void ovl_workdir_cleanup_recurse(struct path *path, int level)
+{
+ int err;
+ struct inode *dir = path->dentry->d_inode;
+ LIST_HEAD(list);
+ struct rb_root root = RB_ROOT;
+ struct ovl_cache_entry *p;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_fill_merge,
+ .dentry = NULL,
+ .list = &list,
+ .root = &root,
+ .is_lowest = false,
+ };
+
+ err = ovl_dir_read(path, &rdd);
+ if (err)
+ goto out;
+
+ inode_lock_nested(dir, I_MUTEX_PARENT);
+ list_for_each_entry(p, &list, l_node) {
+ struct dentry *dentry;
+
+ if (p->name[0] == '.') {
+ if (p->len == 1)
+ continue;
+ if (p->len == 2 && p->name[1] == '.')
+ continue;
+ }
+ dentry = lookup_one_len(p->name, path->dentry, p->len);
+ if (IS_ERR(dentry))
+ continue;
+ if (dentry->d_inode)
+ ovl_workdir_cleanup(dir, path->mnt, dentry, level);
+ dput(dentry);
+ }
+ inode_unlock(dir);
+out:
+ ovl_cache_free(&list);
+}
+
+void ovl_workdir_cleanup(struct inode *dir, struct vfsmount *mnt,
+ struct dentry *dentry, int level)
+{
+ int err;
+
+ if (!d_is_dir(dentry) || level > 1) {
+ ovl_cleanup(dir, dentry);
+ return;
+ }
+
+ err = ovl_do_rmdir(dir, dentry);
+ if (err) {
+ struct path path = { .mnt = mnt, .dentry = dentry };
+
+ inode_unlock(dir);
+ ovl_workdir_cleanup_recurse(&path, level + 1);
+ inode_lock_nested(dir, I_MUTEX_PARENT);
+ ovl_cleanup(dir, dentry);
+ }
+}
+
+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);
+ struct rb_root root = RB_ROOT;
+ struct ovl_cache_entry *p;
+ struct ovl_readdir_data rdd = {
+ .ctx.actor = ovl_fill_merge,
+ .dentry = NULL,
+ .list = &list,
+ .root = &root,
+ .is_lowest = false,
+ };
+
+ err = ovl_dir_read(&path, &rdd);
+ if (err)
+ goto out;
+
+ inode_lock_nested(dir, I_MUTEX_PARENT);
+ list_for_each_entry(p, &list, l_node) {
+ 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);
+ if (IS_ERR(index)) {
+ err = PTR_ERR(index);
+ index = NULL;
+ break;
+ }
+ err = ovl_verify_index(index, lowerstack, numlower);
+ /* Cleanup stale and orphan index entries */
+ if (err && (err == -ESTALE || err == -ENOENT))
+ err = ovl_cleanup(dir, index);
+ if (err)
+ break;
+
+ dput(index);
+ index = NULL;
+ }
+ dput(index);
+ inode_unlock(dir);
+out:
+ ovl_cache_free(&list);
+ if (err)
+ pr_err("overlayfs: failed index dir cleanup (%i)\n", err);
+ return err;
+}