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authorJens Axboe <axboe@kernel.dk>2018-11-21 10:32:39 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-12-08 08:46:55 +0100
commit1d8e40836044aeff3192f072425ea19f5c5807eb (patch)
tree935cd65cbb4353568237f2b8a8dbf1234d6e8a1c /include
parentb63ee2febedce876d31baa2bf345850e3b00b5ee (diff)
fs: add fget_many() and fput_many()
commit 091141a42e15fe47ada737f3996b317072afcefb upstream. Some uses cases repeatedly get and put references to the same file, but the only exposed interface is doing these one at the time. As each of these entail an atomic inc or dec on a shared structure, that cost can add up. Add fget_many(), which works just like fget(), except it takes an argument for how many references to get on the file. Ditto fput_many(), which can drop an arbitrary number of references to a file. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'include')
-rw-r--r--include/linux/file.h2
-rw-r--r--include/linux/fs.h4
2 files changed, 5 insertions, 1 deletions
diff --git a/include/linux/file.h b/include/linux/file.h
index 279720db984a..d26462b127a3 100644
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -13,6 +13,7 @@
struct file;
extern void fput(struct file *);
+extern void fput_many(struct file *, unsigned int);
struct file_operations;
struct vfsmount;
@@ -41,6 +42,7 @@ static inline void fdput(struct fd fd)
}
extern struct file *fget(unsigned int fd);
+extern struct file *fget_many(unsigned int fd, unsigned int refs);
extern struct file *fget_raw(unsigned int fd);
extern unsigned long __fdget(unsigned int fd);
extern unsigned long __fdget_raw(unsigned int fd);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 309c151decd8..1084f1335c9f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -908,7 +908,9 @@ static inline struct file *get_file(struct file *f)
atomic_long_inc(&f->f_count);
return f;
}
-#define get_file_rcu(x) atomic_long_inc_not_zero(&(x)->f_count)
+#define get_file_rcu_many(x, cnt) \
+ atomic_long_add_unless(&(x)->f_count, (cnt), 0)
+#define get_file_rcu(x) get_file_rcu_many((x), 1)
#define fput_atomic(x) atomic_long_add_unless(&(x)->f_count, -1, 1)
#define file_count(x) atomic_long_read(&(x)->f_count)