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authorAl Viro <viro@zeniv.linux.org.uk>2014-03-04 23:54:22 +0400
committerAl Viro <viro@zeniv.linux.org.uk>2014-03-10 19:44:42 +0400
commitbd2a31d522344b3ac2fb680bd2366e77a9bd8209 (patch)
treed08be6aea75b2f41bebf516bfc33187d0673bfce
parent00e188ef6a7e7bf2883bcffc30d89e98a0bb76b3 (diff)
downloadlinux-bd2a31d522344b3ac2fb680bd2366e77a9bd8209.tar.xz
get rid of fget_light()
instead of returning the flags by reference, we can just have the low-level primitive return those in lower bits of unsigned long, with struct file * derived from the rest. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r--fs/file.c56
-rw-r--r--fs/read_write.c16
-rw-r--r--include/linux/file.h21
-rw-r--r--include/linux/fs.h2
4 files changed, 56 insertions, 39 deletions
diff --git a/fs/file.c b/fs/file.c
index db25c2bdfe46..60a45e9f5323 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -683,35 +683,65 @@ EXPORT_SYMBOL(fget_raw);
* The fput_needed flag returned by fget_light should be passed to the
* corresponding fput_light.
*/
-struct file *__fget_light(unsigned int fd, fmode_t mask, int *fput_needed)
+static unsigned long __fget_light(unsigned int fd, fmode_t mask)
{
struct files_struct *files = current->files;
struct file *file;
- *fput_needed = 0;
if (atomic_read(&files->count) == 1) {
file = __fcheck_files(files, fd);
- if (file && (file->f_mode & mask))
- file = NULL;
+ if (!file || unlikely(file->f_mode & mask))
+ return 0;
+ return (unsigned long)file;
} else {
file = __fget(fd, mask);
- if (file)
- *fput_needed = 1;
+ if (!file)
+ return 0;
+ return FDPUT_FPUT | (unsigned long)file;
}
-
- return file;
}
-struct file *fget_light(unsigned int fd, int *fput_needed)
+unsigned long __fdget(unsigned int fd)
{
- return __fget_light(fd, FMODE_PATH, fput_needed);
+ return __fget_light(fd, FMODE_PATH);
}
-EXPORT_SYMBOL(fget_light);
+EXPORT_SYMBOL(__fdget);
-struct file *fget_raw_light(unsigned int fd, int *fput_needed)
+unsigned long __fdget_raw(unsigned int fd)
{
- return __fget_light(fd, 0, fput_needed);
+ return __fget_light(fd, 0);
+}
+
+unsigned long __fdget_pos(unsigned int fd)
+{
+ struct files_struct *files = current->files;
+ struct file *file;
+ unsigned long v;
+
+ if (atomic_read(&files->count) == 1) {
+ file = __fcheck_files(files, fd);
+ v = 0;
+ } else {
+ file = __fget(fd, 0);
+ v = FDPUT_FPUT;
+ }
+ if (!file)
+ return 0;
+
+ if (file->f_mode & FMODE_ATOMIC_POS) {
+ if (file_count(file) > 1) {
+ v |= FDPUT_POS_UNLOCK;
+ mutex_lock(&file->f_pos_lock);
+ }
+ }
+ return v | (unsigned long)file;
}
+/*
+ * We only lock f_pos if we have threads or if the file might be
+ * shared with another process. In both cases we'll have an elevated
+ * file count (done either by fdget() or by fork()).
+ */
+
void set_close_on_exec(unsigned int fd, int flag)
{
struct files_struct *files = current->files;
diff --git a/fs/read_write.c b/fs/read_write.c
index 932bb3414a96..54e19b9392dc 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -264,23 +264,9 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
}
EXPORT_SYMBOL(vfs_llseek);
-/*
- * We only lock f_pos if we have threads or if the file might be
- * shared with another process. In both cases we'll have an elevated
- * file count (done either by fdget() or by fork()).
- */
static inline struct fd fdget_pos(int fd)
{
- struct fd f = fdget(fd);
- struct file *file = f.file;
-
- if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
- if (file_count(file) > 1) {
- f.flags |= FDPUT_POS_UNLOCK;
- mutex_lock(&file->f_pos_lock);
- }
- }
- return f;
+ return __to_fd(__fdget_pos(fd));
}
static inline void fdput_pos(struct fd f)
diff --git a/include/linux/file.h b/include/linux/file.h
index f2517fa2d610..4d69123377a2 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -40,23 +40,24 @@ static inline void fdput(struct fd fd)
}
extern struct file *fget(unsigned int fd);
-extern struct file *fget_light(unsigned int fd, int *fput_needed);
+extern struct file *fget_raw(unsigned int fd);
+extern unsigned long __fdget(unsigned int fd);
+extern unsigned long __fdget_raw(unsigned int fd);
+extern unsigned long __fdget_pos(unsigned int fd);
-static inline struct fd fdget(unsigned int fd)
+static inline struct fd __to_fd(unsigned long v)
{
- int b;
- struct file *f = fget_light(fd, &b);
- return (struct fd){f,b};
+ return (struct fd){(struct file *)(v & ~3),v & 3};
}
-extern struct file *fget_raw(unsigned int fd);
-extern struct file *fget_raw_light(unsigned int fd, int *fput_needed);
+static inline struct fd fdget(unsigned int fd)
+{
+ return __to_fd(__fdget(fd));
+}
static inline struct fd fdget_raw(unsigned int fd)
{
- int b;
- struct file *f = fget_raw_light(fd, &b);
- return (struct fd){f,b};
+ return __to_fd(__fdget_raw(fd));
}
extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ebfde04bca06..23b2a35d712e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -812,7 +812,7 @@ struct file {
#ifdef CONFIG_DEBUG_WRITECOUNT
unsigned long f_mnt_write_state;
#endif
-};
+} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
struct file_handle {
__u32 handle_bytes;