Merge tag 'pm-5.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

[thirdparty/linux.git] / fs / open.c

diff --git a/fs/open.c b/fs/open.c
index b69d6eed67e6a93753cce13080ebb2208dee3a0b..6cd48a61cda3b969c0717c30c8bed879efa3d8cc 100644 (file)
--- a/fs/open.c
+++ b/fs/open.c
@@ -345,21 +345,14 @@ SYSCALL_DEFINE4(fallocate, int, fd, int, mode, loff_t, offset, loff_t, len)
  * We do this by temporarily clearing all FS-related capabilities and
  * switching the fsuid/fsgid around to the real ones.
  */
-long do_faccessat(int dfd, const char __user *filename, int mode)
+static const struct cred *access_override_creds(void)
 {
        const struct cred *old_cred;
        struct cred *override_cred;
-       struct path path;
-       struct inode *inode;
-       int res;
-       unsigned int lookup_flags = LOOKUP_FOLLOW;
-
-       if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
-               return -EINVAL;
 
        override_cred = prepare_creds();
        if (!override_cred)
-               return -ENOMEM;
+               return NULL;
 
        override_cred->fsuid = override_cred->uid;
        override_cred->fsgid = override_cred->gid;
@@ -394,6 +387,38 @@ long do_faccessat(int dfd, const char __user *filename, int mode)
        override_cred->non_rcu = 1;
 
        old_cred = override_creds(override_cred);
+
+       /* override_cred() gets its own ref */
+       put_cred(override_cred);
+
+       return old_cred;
+}
+
+long do_faccessat(int dfd, const char __user *filename, int mode, int flags)
+{
+       struct path path;
+       struct inode *inode;
+       int res;
+       unsigned int lookup_flags = LOOKUP_FOLLOW;
+       const struct cred *old_cred = NULL;
+
+       if (mode & ~S_IRWXO)    /* where's F_OK, X_OK, W_OK, R_OK? */
+               return -EINVAL;
+
+       if (flags & ~(AT_EACCESS | AT_SYMLINK_NOFOLLOW | AT_EMPTY_PATH))
+               return -EINVAL;
+
+       if (flags & AT_SYMLINK_NOFOLLOW)
+               lookup_flags &= ~LOOKUP_FOLLOW;
+       if (flags & AT_EMPTY_PATH)
+               lookup_flags |= LOOKUP_EMPTY;
+
+       if (!(flags & AT_EACCESS)) {
+               old_cred = access_override_creds();
+               if (!old_cred)
+                       return -ENOMEM;
+       }
+
 retry:
        res = user_path_at(dfd, filename, lookup_flags, &path);
        if (res)
@@ -435,19 +460,26 @@ out_path_release:
                goto retry;
        }
 out:
-       revert_creds(old_cred);
-       put_cred(override_cred);
+       if (old_cred)
+               revert_creds(old_cred);
+
        return res;
 }
 
 SYSCALL_DEFINE3(faccessat, int, dfd, const char __user *, filename, int, mode)
 {
-       return do_faccessat(dfd, filename, mode);
+       return do_faccessat(dfd, filename, mode, 0);
+}
+
+SYSCALL_DEFINE4(faccessat2, int, dfd, const char __user *, filename, int, mode,
+               int, flags)
+{
+       return do_faccessat(dfd, filename, mode, flags);
 }
 
 SYSCALL_DEFINE2(access, const char __user *, filename, int, mode)
 {
-       return do_faccessat(AT_FDCWD, filename, mode);
+       return do_faccessat(AT_FDCWD, filename, mode, 0);
 }
 
 int ksys_chdir(const char __user *filename)
@@ -743,9 +775,8 @@ static int do_dentry_open(struct file *f,
        path_get(&f->f_path);
        f->f_inode = inode;
        f->f_mapping = inode->i_mapping;
-
-       /* Ensure that we skip any errors that predate opening of the file */
        f->f_wb_err = filemap_sample_wb_err(f->f_mapping);
+       f->f_sb_err = file_sample_sb_err(f);
 
        if (unlikely(f->f_flags & O_PATH)) {
                f->f_mode = FMODE_PATH | FMODE_OPENED;
@@ -1046,8 +1077,10 @@ inline int build_open_flags(const struct open_how *how, struct open_flags *op)
 
        if (flags & O_CREAT) {
                op->intent |= LOOKUP_CREATE;
-               if (flags & O_EXCL)
+               if (flags & O_EXCL) {
                        op->intent |= LOOKUP_EXCL;
+                       flags |= O_NOFOLLOW;
+               }
        }
 
        if (flags & O_DIRECTORY)