Commit 8a3c84b6 authored by Darrick J. Wong's avatar Darrick J. Wong
Browse files

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: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 22843291

fs/aio.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

fs/io_uring.c

+1 −2
Original line number Diff line number Diff line
@@ -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);

	}

fs/super.c

+12 −6
Original line number Diff line number Diff line
@@ -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;

}

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

include/linux/fs.h

+11 −10
Original line number Diff line number Diff line
@@ -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)

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