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>

1 files changed, 3 insertions, 3 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index d62150418b91..0b5cbd644fdd 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -4393,7 +4393,7 @@ SYSCALL_DEFINE4(cachestat, unsigned int, fd,
 	struct cachestat cs;
 	pgoff_t first_index, last_index;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
 	if (copy_from_user(&csr, cstat_range,
@@ -4403,7 +4403,7 @@ SYSCALL_DEFINE4(cachestat, unsigned int, fd,
 	}
 
 	/* hugetlbfs is not supported */
-	if (is_file_hugepages(f.file)) {
+	if (is_file_hugepages(fd_file(f))) {
 		fdput(f);
 		return -EOPNOTSUPP;
 	}
@@ -4417,7 +4417,7 @@ SYSCALL_DEFINE4(cachestat, unsigned int, fd,
 	last_index =
 		csr.len == 0 ? ULONG_MAX : (csr.off + csr.len - 1) >> PAGE_SHIFT;
 	memset(&cs, 0, sizeof(struct cachestat));
-	mapping = f.file->f_mapping;
+	mapping = fd_file(f)->f_mapping;
 	filemap_cachestat(mapping, first_index, last_index, &cs);
 	fdput(f);