Unverified Commit 3e15dcf7 authored by Amir Goldstein's avatar Amir Goldstein Committed by Christian Brauner
Browse files

fs: rename __mnt_{want,drop}_write*() helpers 



Before exporting these helpers to modules, make their names more
meaningful.

The names mnt_{get,put)_write_access*() were chosen, because they rhyme
with the inode {get,put)_write_access() helpers, which have a very close
meaning for the inode object.

Suggested-by: default avatarChristian Brauner <brauner@kernel.org>
Link: https://lore.kernel.org/r/20230817-anfechtbar-ruhelosigkeit-8c6cca8443fc@brauner/


Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Message-Id: <20230908132900.2983519-2-amir73il@gmail.com>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 0bb80ecc

fs/inode.c

+4 −4
Original line number Diff line number Diff line
@@ -2006,7 +2006,7 @@ void touch_atime(const struct path *path) 
	if (!sb_start_write_trylock(inode->i_sb))

		return;



	if (__mnt_want_write(mnt) != 0)

	if (mnt_get_write_access(mnt) != 0)

		goto skip_update;

	/*

	 * File systems can error out when updating inodes if they need to
@@ -2018,7 +2018,7 @@ void touch_atime(const struct path *path) 
	 * of the fs read only, e.g. subvolumes in Btrfs.

	 */

	inode_update_time(inode, S_ATIME);

	__mnt_drop_write(mnt);

	mnt_put_write_access(mnt);

skip_update:

	sb_end_write(inode->i_sb);

}
@@ -2173,9 +2173,9 @@ static int __file_update_time(struct file *file, int sync_mode) 
	struct inode *inode = file_inode(file);



	/* try to update time settings */

	if (!__mnt_want_write_file(file)) {

	if (!mnt_get_write_access_file(file)) {

		ret = inode_update_time(inode, sync_mode);

		__mnt_drop_write_file(file);

		mnt_put_write_access_file(file);

	}



	return ret;

fs/internal.h

+6 −6
Original line number Diff line number Diff line
@@ -73,8 +73,8 @@ extern int sb_prepare_remount_readonly(struct super_block *); 


extern void __init mnt_init(void);



extern int __mnt_want_write_file(struct file *);

extern void __mnt_drop_write_file(struct file *);

int mnt_get_write_access_file(struct file *file);

void mnt_put_write_access_file(struct file *file);



extern void dissolve_on_fput(struct vfsmount *);

extern bool may_mount(void);
@@ -101,7 +101,7 @@ static inline void put_file_access(struct file *file) 
		i_readcount_dec(file->f_inode);

	} else if (file->f_mode & FMODE_WRITER) {

		put_write_access(file->f_inode);

		__mnt_drop_write(file->f_path.mnt);

		mnt_put_write_access(file->f_path.mnt);

	}

}
@@ -130,9 +130,9 @@ static inline void sb_start_ro_state_change(struct super_block *sb) 
	 * mnt_is_readonly() making sure if mnt_is_readonly() sees SB_RDONLY

	 * cleared, it will see s_readonly_remount set.

	 * For RW->RO transition, the barrier pairs with the barrier in

	 * __mnt_want_write() before the mnt_is_readonly() check. The barrier

	 * makes sure if __mnt_want_write() sees MNT_WRITE_HOLD already

	 * cleared, it will see s_readonly_remount set.

	 * mnt_get_write_access() before the mnt_is_readonly() check.

	 * The barrier makes sure if mnt_get_write_access() sees MNT_WRITE_HOLD

	 * already cleared, it will see s_readonly_remount set.

	 */

	smp_wmb();

}

fs/namespace.c

+17 −17
Original line number Diff line number Diff line
@@ -330,16 +330,16 @@ static int mnt_is_readonly(struct vfsmount *mnt) 
 * can determine when writes are able to occur to a filesystem.

 */

/**

 * __mnt_want_write - get write access to a mount without freeze protection

 * mnt_get_write_access - get write access to a mount without freeze protection

 * @m: the mount on which to take a write

 *

 * This tells the low-level filesystem that a write is about to be performed to

 * it, and makes sure that writes are allowed (mnt it read-write) before

 * returning success. This operation does not protect against filesystem being

 * frozen. When the write operation is finished, __mnt_drop_write() must be

 * frozen. When the write operation is finished, mnt_put_write_access() must be

 * called. This is effectively a refcount.

 */

int __mnt_want_write(struct vfsmount *m)

int mnt_get_write_access(struct vfsmount *m)

{

	struct mount *mnt = real_mount(m);

	int ret = 0;
@@ -401,7 +401,7 @@ int mnt_want_write(struct vfsmount *m) 
	int ret;



	sb_start_write(m->mnt_sb);

	ret = __mnt_want_write(m);

	ret = mnt_get_write_access(m);

	if (ret)

		sb_end_write(m->mnt_sb);

	return ret;
@@ -409,15 +409,15 @@ int mnt_want_write(struct vfsmount *m) 
EXPORT_SYMBOL_GPL(mnt_want_write);



/**

 * __mnt_want_write_file - get write access to a file's mount

 * mnt_get_write_access_file - get write access to a file's mount

 * @file: the file who's mount on which to take a write

 *

 * This is like __mnt_want_write, but if the file is already open for writing it

 * This is like mnt_get_write_access, but if @file is already open for write it

 * skips incrementing mnt_writers (since the open file already has a reference)

 * and instead only does the check for emergency r/o remounts.  This must be

 * paired with __mnt_drop_write_file.

 * paired with mnt_put_write_access_file.

 */

int __mnt_want_write_file(struct file *file)

int mnt_get_write_access_file(struct file *file)

{

	if (file->f_mode & FMODE_WRITER) {

		/*
@@ -428,7 +428,7 @@ int __mnt_want_write_file(struct file *file) 
			return -EROFS;

		return 0;

	}

	return __mnt_want_write(file->f_path.mnt);

	return mnt_get_write_access(file->f_path.mnt);

}



/**
@@ -445,7 +445,7 @@ int mnt_want_write_file(struct file *file) 
	int ret;



	sb_start_write(file_inode(file)->i_sb);

	ret = __mnt_want_write_file(file);

	ret = mnt_get_write_access_file(file);

	if (ret)

		sb_end_write(file_inode(file)->i_sb);

	return ret;
@@ -453,14 +453,14 @@ int mnt_want_write_file(struct file *file) 
EXPORT_SYMBOL_GPL(mnt_want_write_file);



/**

 * __mnt_drop_write - give up write access to a mount

 * mnt_put_write_access - give up write access to a mount

 * @mnt: the mount on which to give up write access

 *

 * Tells the low-level filesystem that we are done

 * performing writes to it.  Must be matched with

 * __mnt_want_write() call above.

 * mnt_get_write_access() call above.

 */

void __mnt_drop_write(struct vfsmount *mnt)

void mnt_put_write_access(struct vfsmount *mnt)

{

	preempt_disable();

	mnt_dec_writers(real_mount(mnt));
@@ -477,20 +477,20 @@ void __mnt_drop_write(struct vfsmount *mnt) 
 */

void mnt_drop_write(struct vfsmount *mnt)

{

	__mnt_drop_write(mnt);

	mnt_put_write_access(mnt);

	sb_end_write(mnt->mnt_sb);

}

EXPORT_SYMBOL_GPL(mnt_drop_write);



void __mnt_drop_write_file(struct file *file)

void mnt_put_write_access_file(struct file *file)

{

	if (!(file->f_mode & FMODE_WRITER))

		__mnt_drop_write(file->f_path.mnt);

		mnt_put_write_access(file->f_path.mnt);

}



void mnt_drop_write_file(struct file *file)

{

	__mnt_drop_write_file(file);

	mnt_put_write_access_file(file);

	sb_end_write(file_inode(file)->i_sb);

}

EXPORT_SYMBOL(mnt_drop_write_file);

fs/open.c

+1 −1
Original line number Diff line number Diff line
@@ -895,7 +895,7 @@ static int do_dentry_open(struct file *f, 
		error = get_write_access(inode);

		if (unlikely(error))

			goto cleanup_file;

		error = __mnt_want_write(f->f_path.mnt);

		error = mnt_get_write_access(f->f_path.mnt);

		if (unlikely(error)) {

			put_write_access(inode);

			goto cleanup_file;

include/linux/mount.h

+2 −2
Original line number Diff line number Diff line
@@ -92,8 +92,8 @@ extern bool __mnt_is_readonly(struct vfsmount *mnt); 
extern bool mnt_may_suid(struct vfsmount *mnt);



extern struct vfsmount *clone_private_mount(const struct path *path);

extern int __mnt_want_write(struct vfsmount *);

extern void __mnt_drop_write(struct vfsmount *);

int mnt_get_write_access(struct vfsmount *mnt);

void mnt_put_write_access(struct vfsmount *mnt);



extern struct vfsmount *fc_mount(struct fs_context *fc);

extern struct vfsmount *vfs_create_mount(struct fs_context *fc);