introduce fd_file(), convert all accessors to it.

	For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
	Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
	This commit converts (almost) all of f.file to
fd_file(f).  It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).

	NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).

[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 15 insertions, 15 deletions

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f04f43af651c..e7c1d3ae33fe 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -1068,10 +1068,10 @@ void ima_kexec_cmdline(int kernel_fd, const void *buf, int size)
 		return;
 
 	f = fdget(kernel_fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return;
 
-	process_buffer_measurement(file_mnt_idmap(f.file), file_inode(f.file),
+	process_buffer_measurement(file_mnt_idmap(fd_file(f)), file_inode(fd_file(f)),
 				   buf, size, "kexec-cmdline", KEXEC_CMDLINE, 0,
 				   NULL, false, NULL, 0);
 	fdput(f);
diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c
index ccc8bc6c1584..00b63971ab64 100644
--- a/security/landlock/syscalls.c
+++ b/security/landlock/syscalls.c
@@ -238,19 +238,19 @@ static struct landlock_ruleset *get_ruleset_from_fd(const int fd,
 	struct landlock_ruleset *ruleset;
 
 	ruleset_f = fdget(fd);
-	if (!ruleset_f.file)
+	if (!fd_file(ruleset_f))
 		return ERR_PTR(-EBADF);
 
 	/* Checks FD type and access right. */
-	if (ruleset_f.file->f_op != &ruleset_fops) {
+	if (fd_file(ruleset_f)->f_op != &ruleset_fops) {
 		ruleset = ERR_PTR(-EBADFD);
 		goto out_fdput;
 	}
-	if (!(ruleset_f.file->f_mode & mode)) {
+	if (!(fd_file(ruleset_f)->f_mode & mode)) {
 		ruleset = ERR_PTR(-EPERM);
 		goto out_fdput;
 	}
-	ruleset = ruleset_f.file->private_data;
+	ruleset = fd_file(ruleset_f)->private_data;
 	if (WARN_ON_ONCE(ruleset->num_layers != 1)) {
 		ruleset = ERR_PTR(-EINVAL);
 		goto out_fdput;
@@ -277,22 +277,22 @@ static int get_path_from_fd(const s32 fd, struct path *const path)
 
 	/* Handles O_PATH. */
 	f = fdget_raw(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 	/*
 	 * Forbids ruleset FDs, internal filesystems (e.g. nsfs), including
 	 * pseudo filesystems that will never be mountable (e.g. sockfs,
 	 * pipefs).
 	 */
-	if ((f.file->f_op == &ruleset_fops) ||
-	    (f.file->f_path.mnt->mnt_flags & MNT_INTERNAL) ||
-	    (f.file->f_path.dentry->d_sb->s_flags & SB_NOUSER) ||
-	    d_is_negative(f.file->f_path.dentry) ||
-	    IS_PRIVATE(d_backing_inode(f.file->f_path.dentry))) {
+	if ((fd_file(f)->f_op == &ruleset_fops) ||
+	    (fd_file(f)->f_path.mnt->mnt_flags & MNT_INTERNAL) ||
+	    (fd_file(f)->f_path.dentry->d_sb->s_flags & SB_NOUSER) ||
+	    d_is_negative(fd_file(f)->f_path.dentry) ||
+	    IS_PRIVATE(d_backing_inode(fd_file(f)->f_path.dentry))) {
 		err = -EBADFD;
 		goto out_fdput;
 	}
-	*path = f.file->f_path;
+	*path = fd_file(f)->f_path;
 	path_get(path);
 
 out_fdput:
diff --git a/security/loadpin/loadpin.c b/security/loadpin/loadpin.c
index 93fd4d47b334..02144ec39f43 100644
--- a/security/loadpin/loadpin.c
+++ b/security/loadpin/loadpin.c
@@ -296,7 +296,7 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 		return -EPERM;
 
 	f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EINVAL;
 
 	data = kzalloc(SZ_4K, GFP_KERNEL);
@@ -305,7 +305,7 @@ static int read_trusted_verity_root_digests(unsigned int fd)
 		goto err;
 	}
 
-	rc = kernel_read_file(f.file, 0, (void **)&data, SZ_4K - 1, NULL, READING_POLICY);
+	rc = kernel_read_file(fd_file(f), 0, (void **)&data, SZ_4K - 1, NULL, READING_POLICY);
 	if (rc < 0)
 		goto err;