vfs: separate __sb_start_write into blocking and non-blocking helpers

Break this function into two helpers so that it's obvious that the
trylock versions return a value that must be checked, and the blocking
versions don't require that.  While we're at it, clean up the return
type mismatch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/aio.c b/fs/aio.c
index c45c20d..6a21d89 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1572,7 +1572,7 @@ static int aio_write(struct kiocb *req, const struct iocb *iocb,
                 * we return to userspace.
                 */
                if (S_ISREG(file_inode(file)->i_mode)) {
-                       __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+                       sb_start_write(file_inode(file)->i_sb);
                        __sb_writers_release(file_inode(file)->i_sb, SB_FREEZE_WRITE);
                }
                req->ki_flags |= IOCB_WRITE;

diff --git a/fs/io_uring.c b/fs/io_uring.c
index b42dfa0..4cbaddf 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -3532,8 +3532,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
         * we return to userspace.
         */
        if (req->flags & REQ_F_ISREG) {
-               __sb_start_write(file_inode(req->file)->i_sb,
-                                       SB_FREEZE_WRITE, true);
+               sb_start_write(file_inode(req->file)->i_sb);
                __sb_writers_release(file_inode(req->file)->i_sb,
                                        SB_FREEZE_WRITE);
        }

diff --git a/fs/super.c b/fs/super.c
index e1fd667..59aa592 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -1645,16 +1645,22 @@ EXPORT_SYMBOL(__sb_end_write);
  * This is an internal function, please use sb_start_{write,pagefault,intwrite}
  * instead.
  */
-int __sb_start_write(struct super_block *sb, int level, bool wait)
+void __sb_start_write(struct super_block *sb, int level)
 {
-       if (!wait)
-               return percpu_down_read_trylock(sb->s_writers.rw_sem + level-1);
-
-       percpu_down_read(sb->s_writers.rw_sem + level-1);
-       return 1;
+       percpu_down_read(sb->s_writers.rw_sem + level - 1);
 }
 EXPORT_SYMBOL(__sb_start_write);
 
+/*
+ * This is an internal function, please use sb_start_{write,pagefault,intwrite}
+ * instead.
+ */
+bool __sb_start_write_trylock(struct super_block *sb, int level)
+{
+       return percpu_down_read_trylock(sb->s_writers.rw_sem + level - 1);
+}
+EXPORT_SYMBOL_GPL(__sb_start_write_trylock);
+
 /**
  * sb_wait_write - wait until all writers to given file system finish
  * @sb: the super for which we wait

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0bd1264..305989a 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1581,7 +1581,8 @@ extern struct timespec64 current_time(struct inode *inode);
  */
 
 void __sb_end_write(struct super_block *sb, int level);
-int __sb_start_write(struct super_block *sb, int level, bool wait);
+void __sb_start_write(struct super_block *sb, int level);
+bool __sb_start_write_trylock(struct super_block *sb, int level);
 
 #define __sb_writers_acquired(sb, lev) \
        percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)
@@ -1645,12 +1646,12 @@ static inline void sb_end_intwrite(struct super_block *sb)
  */
 static inline void sb_start_write(struct super_block *sb)
 {
-       __sb_start_write(sb, SB_FREEZE_WRITE, true);
+       __sb_start_write(sb, SB_FREEZE_WRITE);
 }
 
-static inline int sb_start_write_trylock(struct super_block *sb)
+static inline bool sb_start_write_trylock(struct super_block *sb)
 {
-       return __sb_start_write(sb, SB_FREEZE_WRITE, false);
+       return __sb_start_write_trylock(sb, SB_FREEZE_WRITE);
 }
 
 /**
@@ -1674,7 +1675,7 @@ static inline int sb_start_write_trylock(struct super_block *sb)
  */
 static inline void sb_start_pagefault(struct super_block *sb)
 {
-       __sb_start_write(sb, SB_FREEZE_PAGEFAULT, true);
+       __sb_start_write(sb, SB_FREEZE_PAGEFAULT);
 }
 
 /*
@@ -1692,12 +1693,12 @@ static inline void sb_start_pagefault(struct super_block *sb)
  */
 static inline void sb_start_intwrite(struct super_block *sb)
 {
-       __sb_start_write(sb, SB_FREEZE_FS, true);
+       __sb_start_write(sb, SB_FREEZE_FS);
 }
 
-static inline int sb_start_intwrite_trylock(struct super_block *sb)
+static inline bool sb_start_intwrite_trylock(struct super_block *sb)
 {
-       return __sb_start_write(sb, SB_FREEZE_FS, false);
+       return __sb_start_write_trylock(sb, SB_FREEZE_FS);
 }
 
 
@@ -2756,14 +2757,14 @@ static inline void file_start_write(struct file *file)
 {
        if (!S_ISREG(file_inode(file)->i_mode))
                return;
-       __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+       sb_start_write(file_inode(file)->i_sb);
 }
 
 static inline bool file_start_write_trylock(struct file *file)
 {
        if (!S_ISREG(file_inode(file)->i_mode))
                return true;
-       return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
+       return sb_start_write_trylock(file_inode(file)->i_sb);
 }
 
 static inline void file_end_write(struct file *file)