linux-kernel - [PATCH 08/13] vfs: Use idr_tag_get() in fd_is

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Date:   Fri, 28 Apr 2017 00:41:26 +0530
From:   Sandhya Bankar <bankarsandhya512@...il.com>
To:     linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
        viro@...iv.linux.org.uk, mawmilcox@...rosoft.com,
        keescook@...omium.org, adobriyan@...il.com, re.emese@...il.com,
        riel@...riel.com
Subject: [PATCH 08/13] vfs: Use idr_tag_get() in fd_is_open().

Use idr_tag_get() in fd_is_open() to know whether a given fd is
allocated.  Also move fd_is_open() to file.c and make it static
as it is only called from one place.

Signed-off-by: Sandhya Bankar <bankarsandhya512@...il.com>
Signed-off-by: Matthew Wilcox <mawilcox@...rosoft.com>
---
 fs/file.c               | 7 ++++++-
 include/linux/fdtable.h | 5 -----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/fs/file.c b/fs/file.c
index e8c6ada..8d67968 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -222,6 +222,11 @@ static int expand_files(struct files_struct *files, unsigned int nr)
 	return expanded;
 }
 
+static inline bool fd_is_open(unsigned int fd, struct files_struct *files)
+{
+	return !idr_tag_get(&files->fd_idr, fd, IDR_FREE);
+}
+
 static inline void __set_close_on_exec(unsigned int fd, struct fdtable *fdt)
 {
 	__set_bit(fd, fdt->close_on_exec);
@@ -778,7 +783,7 @@ static int do_dup2(struct files_struct *files,
 	 */
 	fdt = files_fdtable(files);
 	tofree = idr_find(&files->fd_idr, fd);
-	if (!tofree && fd_is_open(fd, fdt))
+	if (!tofree && fd_is_open(fd, files))
 		goto Ebusy;
 	get_file(file);
 	if (tofree) {
diff --git a/include/linux/fdtable.h b/include/linux/fdtable.h
index 6bece35..67259f4 100644
--- a/include/linux/fdtable.h
+++ b/include/linux/fdtable.h
@@ -34,11 +34,6 @@ static inline bool close_on_exec(unsigned int fd, const struct fdtable *fdt)
 	return test_bit(fd, fdt->close_on_exec);
 }
 
-static inline bool fd_is_open(unsigned int fd, const struct fdtable *fdt)
-{
-	return test_bit(fd, fdt->open_fds);
-}
-
 /*
  * Open file table structure
  */
-- 
1.8.3.1