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-rw-r--r--fs/aufs/vfsub.c848
1 files changed, 848 insertions, 0 deletions
diff --git a/fs/aufs/vfsub.c b/fs/aufs/vfsub.c
new file mode 100644
index 000000000..d2af7ce8d
--- /dev/null
+++ b/fs/aufs/vfsub.c
@@ -0,0 +1,848 @@
+/*
+ * Copyright (C) 2005-2015 Junjiro R. Okajima
+ *
+ * This program, aufs is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ * sub-routines for VFS
+ */
+
+#include <linux/namei.h>
+#include <linux/security.h>
+#include <linux/splice.h>
+#include "aufs.h"
+
+int vfsub_update_h_iattr(struct path *h_path, int *did)
+{
+ int err;
+ struct kstat st;
+ struct super_block *h_sb;
+
+ /* for remote fs, leave work for its getattr or d_revalidate */
+ /* for bad i_attr fs, handle them in aufs_getattr() */
+ /* still some fs may acquire i_mutex. we need to skip them */
+ err = 0;
+ if (!did)
+ did = &err;
+ h_sb = h_path->dentry->d_sb;
+ *did = (!au_test_fs_remote(h_sb) && au_test_fs_refresh_iattr(h_sb));
+ if (*did)
+ err = vfs_getattr(h_path, &st);
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct file *vfsub_dentry_open(struct path *path, int flags)
+{
+ struct file *file;
+
+ file = dentry_open(path, flags /* | __FMODE_NONOTIFY */,
+ current_cred());
+ if (!IS_ERR_OR_NULL(file)
+ && (file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ)
+ i_readcount_inc(d_inode(path->dentry));
+
+ return file;
+}
+
+struct file *vfsub_filp_open(const char *path, int oflags, int mode)
+{
+ struct file *file;
+
+ lockdep_off();
+ file = filp_open(path,
+ oflags /* | __FMODE_NONOTIFY */,
+ mode);
+ lockdep_on();
+ if (IS_ERR(file))
+ goto out;
+ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
+
+out:
+ return file;
+}
+
+/*
+ * Ideally this function should call VFS:do_last() in order to keep all its
+ * checkings. But it is very hard for aufs to regenerate several VFS internal
+ * structure such as nameidata. This is a second (or third) best approach.
+ * cf. linux/fs/namei.c:do_last(), lookup_open() and atomic_open().
+ */
+int vfsub_atomic_open(struct inode *dir, struct dentry *dentry,
+ struct vfsub_aopen_args *args, struct au_branch *br)
+{
+ int err;
+ struct file *file = args->file;
+ /* copied from linux/fs/namei.c:atomic_open() */
+ struct dentry *const DENTRY_NOT_SET = (void *)-1UL;
+
+ IMustLock(dir);
+ AuDebugOn(!dir->i_op->atomic_open);
+
+ err = au_br_test_oflag(args->open_flag, br);
+ if (unlikely(err))
+ goto out;
+
+ args->file->f_path.dentry = DENTRY_NOT_SET;
+ args->file->f_path.mnt = au_br_mnt(br);
+ err = dir->i_op->atomic_open(dir, dentry, file, args->open_flag,
+ args->create_mode, args->opened);
+ if (err >= 0) {
+ /* some filesystems don't set FILE_CREATED while succeeded? */
+ if (*args->opened & FILE_CREATED)
+ fsnotify_create(dir, dentry);
+ } else
+ goto out;
+
+
+ if (!err) {
+ /* todo: call VFS:may_open() here */
+ err = open_check_o_direct(file);
+ /* todo: ima_file_check() too? */
+ if (!err && (args->open_flag & __FMODE_EXEC))
+ err = deny_write_access(file);
+ if (unlikely(err))
+ /* note that the file is created and still opened */
+ goto out;
+ }
+
+ atomic_inc(&br->br_count);
+ fsnotify_open(file);
+
+out:
+ return err;
+}
+
+int vfsub_kern_path(const char *name, unsigned int flags, struct path *path)
+{
+ int err;
+
+ err = kern_path(name, flags, path);
+ if (!err && d_is_positive(path->dentry))
+ vfsub_update_h_iattr(path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+struct dentry *vfsub_lookup_one_len(const char *name, struct dentry *parent,
+ int len)
+{
+ struct path path = {
+ .mnt = NULL
+ };
+
+ /* VFS checks it too, but by WARN_ON_ONCE() */
+ IMustLock(d_inode(parent));
+
+ path.dentry = lookup_one_len(name, parent, len);
+ if (IS_ERR(path.dentry))
+ goto out;
+ if (d_is_positive(path.dentry))
+ vfsub_update_h_iattr(&path, /*did*/NULL); /*ignore*/
+
+out:
+ AuTraceErrPtr(path.dentry);
+ return path.dentry;
+}
+
+void vfsub_call_lkup_one(void *args)
+{
+ struct vfsub_lkup_one_args *a = args;
+ *a->errp = vfsub_lkup_one(a->name, a->parent);
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct dentry *vfsub_lock_rename(struct dentry *d1, struct au_hinode *hdir1,
+ struct dentry *d2, struct au_hinode *hdir2)
+{
+ struct dentry *d;
+
+ lockdep_off();
+ d = lock_rename(d1, d2);
+ lockdep_on();
+ au_hn_suspend(hdir1);
+ if (hdir1 != hdir2)
+ au_hn_suspend(hdir2);
+
+ return d;
+}
+
+void vfsub_unlock_rename(struct dentry *d1, struct au_hinode *hdir1,
+ struct dentry *d2, struct au_hinode *hdir2)
+{
+ au_hn_resume(hdir1);
+ if (hdir1 != hdir2)
+ au_hn_resume(hdir2);
+ lockdep_off();
+ unlock_rename(d1, d2);
+ lockdep_on();
+}
+
+/* ---------------------------------------------------------------------- */
+
+int vfsub_create(struct inode *dir, struct path *path, int mode, bool want_excl)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_mknod(path, d, mode, 0);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_create(dir, path->dentry, mode, want_excl);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = *path;
+ int did;
+
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = path->dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+int vfsub_symlink(struct inode *dir, struct path *path, const char *symname)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_symlink(path, d, symname);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_symlink(dir, path->dentry, symname);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = *path;
+ int did;
+
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = path->dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+int vfsub_mknod(struct inode *dir, struct path *path, int mode, dev_t dev)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_mknod(path, d, mode, new_encode_dev(dev));
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_mknod(dir, path->dentry, mode, dev);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = *path;
+ int did;
+
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = path->dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+static int au_test_nlink(struct inode *inode)
+{
+ const unsigned int link_max = UINT_MAX >> 1; /* rough margin */
+
+ if (!au_test_fs_no_limit_nlink(inode->i_sb)
+ || inode->i_nlink < link_max)
+ return 0;
+ return -EMLINK;
+}
+
+int vfsub_link(struct dentry *src_dentry, struct inode *dir, struct path *path,
+ struct inode **delegated_inode)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ err = au_test_nlink(d_inode(src_dentry));
+ if (unlikely(err))
+ return err;
+
+ /* we don't call may_linkat() */
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_link(src_dentry, path, d);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_link(src_dentry, dir, path->dentry, delegated_inode);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = *path;
+ int did;
+
+ /* fuse has different memory inode for the same inumber */
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = path->dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ tmp.dentry = src_dentry;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+int vfsub_rename(struct inode *src_dir, struct dentry *src_dentry,
+ struct inode *dir, struct path *path,
+ struct inode **delegated_inode)
+{
+ int err;
+ struct path tmp = {
+ .mnt = path->mnt
+ };
+ struct dentry *d;
+
+ IMustLock(dir);
+ IMustLock(src_dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ tmp.dentry = src_dentry->d_parent;
+ err = security_path_rename(&tmp, src_dentry, path, d, /*flags*/0);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_rename(src_dir, src_dentry, dir, path->dentry,
+ delegated_inode, /*flags*/0);
+ lockdep_on();
+ if (!err) {
+ int did;
+
+ tmp.dentry = d->d_parent;
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = src_dentry;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ tmp.dentry = src_dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+int vfsub_mkdir(struct inode *dir, struct path *path, int mode)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_mkdir(path, d, mode);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_mkdir(dir, path->dentry, mode);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = *path;
+ int did;
+
+ vfsub_update_h_iattr(&tmp, &did);
+ if (did) {
+ tmp.dentry = path->dentry->d_parent;
+ vfsub_update_h_iattr(&tmp, /*did*/NULL);
+ }
+ /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+int vfsub_rmdir(struct inode *dir, struct path *path)
+{
+ int err;
+ struct dentry *d;
+
+ IMustLock(dir);
+
+ d = path->dentry;
+ path->dentry = d->d_parent;
+ err = security_path_rmdir(path, d);
+ path->dentry = d;
+ if (unlikely(err))
+ goto out;
+
+ lockdep_off();
+ err = vfs_rmdir(dir, path->dentry);
+ lockdep_on();
+ if (!err) {
+ struct path tmp = {
+ .dentry = path->dentry->d_parent,
+ .mnt = path->mnt
+ };
+
+ vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
+ }
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+/* todo: support mmap_sem? */
+ssize_t vfsub_read_u(struct file *file, char __user *ubuf, size_t count,
+ loff_t *ppos)
+{
+ ssize_t err;
+
+ lockdep_off();
+ err = vfs_read(file, ubuf, count, ppos);
+ lockdep_on();
+ if (err >= 0)
+ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+/* todo: kernel_read()? */
+ssize_t vfsub_read_k(struct file *file, void *kbuf, size_t count,
+ loff_t *ppos)
+{
+ ssize_t err;
+ mm_segment_t oldfs;
+ union {
+ void *k;
+ char __user *u;
+ } buf;
+
+ buf.k = kbuf;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = vfsub_read_u(file, buf.u, count, ppos);
+ set_fs(oldfs);
+ return err;
+}
+
+ssize_t vfsub_write_u(struct file *file, const char __user *ubuf, size_t count,
+ loff_t *ppos)
+{
+ ssize_t err;
+
+ lockdep_off();
+ err = vfs_write(file, ubuf, count, ppos);
+ lockdep_on();
+ if (err >= 0)
+ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+ssize_t vfsub_write_k(struct file *file, void *kbuf, size_t count, loff_t *ppos)
+{
+ ssize_t err;
+ mm_segment_t oldfs;
+ union {
+ void *k;
+ const char __user *u;
+ } buf;
+
+ buf.k = kbuf;
+ oldfs = get_fs();
+ set_fs(KERNEL_DS);
+ err = vfsub_write_u(file, buf.u, count, ppos);
+ set_fs(oldfs);
+ return err;
+}
+
+int vfsub_flush(struct file *file, fl_owner_t id)
+{
+ int err;
+
+ err = 0;
+ if (file->f_op->flush) {
+ if (!au_test_nfs(file->f_path.dentry->d_sb))
+ err = file->f_op->flush(file, id);
+ else {
+ lockdep_off();
+ err = file->f_op->flush(file, id);
+ lockdep_on();
+ }
+ if (!err)
+ vfsub_update_h_iattr(&file->f_path, /*did*/NULL);
+ /*ignore*/
+ }
+ return err;
+}
+
+int vfsub_iterate_dir(struct file *file, struct dir_context *ctx)
+{
+ int err;
+
+ AuDbg("%pD, ctx{%pf, %llu}\n", file, ctx->actor, ctx->pos);
+
+ lockdep_off();
+ err = iterate_dir(file, ctx);
+ lockdep_on();
+ if (err >= 0)
+ vfsub_update_h_iattr(&file->f_path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+long vfsub_splice_to(struct file *in, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len,
+ unsigned int flags)
+{
+ long err;
+
+ lockdep_off();
+ err = do_splice_to(in, ppos, pipe, len, flags);
+ lockdep_on();
+ file_accessed(in);
+ if (err >= 0)
+ vfsub_update_h_iattr(&in->f_path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+long vfsub_splice_from(struct pipe_inode_info *pipe, struct file *out,
+ loff_t *ppos, size_t len, unsigned int flags)
+{
+ long err;
+
+ lockdep_off();
+ err = do_splice_from(pipe, out, ppos, len, flags);
+ lockdep_on();
+ if (err >= 0)
+ vfsub_update_h_iattr(&out->f_path, /*did*/NULL); /*ignore*/
+ return err;
+}
+
+int vfsub_fsync(struct file *file, struct path *path, int datasync)
+{
+ int err;
+
+ /* file can be NULL */
+ lockdep_off();
+ err = vfs_fsync(file, datasync);
+ lockdep_on();
+ if (!err) {
+ if (!path) {
+ AuDebugOn(!file);
+ path = &file->f_path;
+ }
+ vfsub_update_h_iattr(path, /*did*/NULL); /*ignore*/
+ }
+ return err;
+}
+
+/* cf. open.c:do_sys_truncate() and do_sys_ftruncate() */
+int vfsub_trunc(struct path *h_path, loff_t length, unsigned int attr,
+ struct file *h_file)
+{
+ int err;
+ struct inode *h_inode;
+ struct super_block *h_sb;
+
+ if (!h_file) {
+ err = vfsub_truncate(h_path, length);
+ goto out;
+ }
+
+ h_inode = d_inode(h_path->dentry);
+ h_sb = h_inode->i_sb;
+ lockdep_off();
+ sb_start_write(h_sb);
+ lockdep_on();
+ err = locks_verify_truncate(h_inode, h_file, length);
+ if (!err)
+ err = security_path_truncate(h_path);
+ if (!err) {
+ lockdep_off();
+ err = do_truncate(h_path->dentry, length, attr, h_file);
+ lockdep_on();
+ }
+ lockdep_off();
+ sb_end_write(h_sb);
+ lockdep_on();
+
+out:
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct au_vfsub_mkdir_args {
+ int *errp;
+ struct inode *dir;
+ struct path *path;
+ int mode;
+};
+
+static void au_call_vfsub_mkdir(void *args)
+{
+ struct au_vfsub_mkdir_args *a = args;
+ *a->errp = vfsub_mkdir(a->dir, a->path, a->mode);
+}
+
+int vfsub_sio_mkdir(struct inode *dir, struct path *path, int mode)
+{
+ int err, do_sio, wkq_err;
+
+ do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
+ if (!do_sio) {
+ lockdep_off();
+ err = vfsub_mkdir(dir, path, mode);
+ lockdep_on();
+ } else {
+ struct au_vfsub_mkdir_args args = {
+ .errp = &err,
+ .dir = dir,
+ .path = path,
+ .mode = mode
+ };
+ wkq_err = au_wkq_wait(au_call_vfsub_mkdir, &args);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+ }
+
+ return err;
+}
+
+struct au_vfsub_rmdir_args {
+ int *errp;
+ struct inode *dir;
+ struct path *path;
+};
+
+static void au_call_vfsub_rmdir(void *args)
+{
+ struct au_vfsub_rmdir_args *a = args;
+ *a->errp = vfsub_rmdir(a->dir, a->path);
+}
+
+int vfsub_sio_rmdir(struct inode *dir, struct path *path)
+{
+ int err, do_sio, wkq_err;
+
+ do_sio = au_test_h_perm_sio(dir, MAY_EXEC | MAY_WRITE);
+ if (!do_sio) {
+ lockdep_off();
+ err = vfsub_rmdir(dir, path);
+ lockdep_on();
+ } else {
+ struct au_vfsub_rmdir_args args = {
+ .errp = &err,
+ .dir = dir,
+ .path = path
+ };
+ wkq_err = au_wkq_wait(au_call_vfsub_rmdir, &args);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+ }
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct notify_change_args {
+ int *errp;
+ struct path *path;
+ struct iattr *ia;
+ struct inode **delegated_inode;
+};
+
+static void call_notify_change(void *args)
+{
+ struct notify_change_args *a = args;
+ struct inode *h_inode;
+
+ h_inode = d_inode(a->path->dentry);
+ IMustLock(h_inode);
+
+ *a->errp = -EPERM;
+ if (!IS_IMMUTABLE(h_inode) && !IS_APPEND(h_inode)) {
+ lockdep_off();
+ *a->errp = notify_change(a->path->dentry, a->ia,
+ a->delegated_inode);
+ lockdep_on();
+ if (!*a->errp)
+ vfsub_update_h_iattr(a->path, /*did*/NULL); /*ignore*/
+ }
+ AuTraceErr(*a->errp);
+}
+
+int vfsub_notify_change(struct path *path, struct iattr *ia,
+ struct inode **delegated_inode)
+{
+ int err;
+ struct notify_change_args args = {
+ .errp = &err,
+ .path = path,
+ .ia = ia,
+ .delegated_inode = delegated_inode
+ };
+
+ call_notify_change(&args);
+
+ return err;
+}
+
+int vfsub_sio_notify_change(struct path *path, struct iattr *ia,
+ struct inode **delegated_inode)
+{
+ int err, wkq_err;
+ struct notify_change_args args = {
+ .errp = &err,
+ .path = path,
+ .ia = ia,
+ .delegated_inode = delegated_inode
+ };
+
+ wkq_err = au_wkq_wait(call_notify_change, &args);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+
+ return err;
+}
+
+/* ---------------------------------------------------------------------- */
+
+struct unlink_args {
+ int *errp;
+ struct inode *dir;
+ struct path *path;
+ struct inode **delegated_inode;
+};
+
+static void call_unlink(void *args)
+{
+ struct unlink_args *a = args;
+ struct dentry *d = a->path->dentry;
+ struct inode *h_inode;
+ const int stop_sillyrename = (au_test_nfs(d->d_sb)
+ && au_dcount(d) == 1);
+
+ IMustLock(a->dir);
+
+ a->path->dentry = d->d_parent;
+ *a->errp = security_path_unlink(a->path, d);
+ a->path->dentry = d;
+ if (unlikely(*a->errp))
+ return;
+
+ if (!stop_sillyrename)
+ dget(d);
+ h_inode = NULL;
+ if (d_is_positive(d)) {
+ h_inode = d_inode(d);
+ ihold(h_inode);
+ }
+
+ lockdep_off();
+ *a->errp = vfs_unlink(a->dir, d, a->delegated_inode);
+ lockdep_on();
+ if (!*a->errp) {
+ struct path tmp = {
+ .dentry = d->d_parent,
+ .mnt = a->path->mnt
+ };
+ vfsub_update_h_iattr(&tmp, /*did*/NULL); /*ignore*/
+ }
+
+ if (!stop_sillyrename)
+ dput(d);
+ if (h_inode)
+ iput(h_inode);
+
+ AuTraceErr(*a->errp);
+}
+
+/*
+ * @dir: must be locked.
+ * @dentry: target dentry.
+ */
+int vfsub_unlink(struct inode *dir, struct path *path,
+ struct inode **delegated_inode, int force)
+{
+ int err;
+ struct unlink_args args = {
+ .errp = &err,
+ .dir = dir,
+ .path = path,
+ .delegated_inode = delegated_inode
+ };
+
+ if (!force)
+ call_unlink(&args);
+ else {
+ int wkq_err;
+
+ wkq_err = au_wkq_wait(call_unlink, &args);
+ if (unlikely(wkq_err))
+ err = wkq_err;
+ }
+
+ return err;
+}