Unverified Commit 95101401 authored by Amir Goldstein's avatar Amir Goldstein Committed by Christian Brauner
Browse files

fsnotify: use accessor to set FMODE_NONOTIFY_* 



The FMODE_NONOTIFY_* bits are a 2-bits mode.  Open coding manipulation
of those bits is risky.  Use an accessor file_set_fsnotify_mode() to
set the mode.

Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers()
to make way for the simple accessor name.

Signed-off-by: default avatarAmir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com


Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 2cc02059

drivers/tty/pty.c

+1 −1
Original line number Diff line number Diff line
@@ -798,7 +798,7 @@ static int ptmx_open(struct inode *inode, struct file *filp) 
	nonseekable_open(inode, filp);



	/* We refuse fsnotify events on ptmx, since it's a shared resource */

	filp->f_mode |= FMODE_NONOTIFY;

	file_set_fsnotify_mode(filp, FMODE_NONOTIFY);



	retval = tty_alloc_file(filp);

	if (retval)

fs/notify/fsnotify.c

+12 −6
Original line number Diff line number Diff line
@@ -648,7 +648,7 @@ EXPORT_SYMBOL_GPL(fsnotify); 
 * Later, fsnotify permission hooks do not check if there are permission event

 * watches, but that there were permission event watches at open time.

 */

void file_set_fsnotify_mode(struct file *file)

void file_set_fsnotify_mode_from_watchers(struct file *file)

{

	struct dentry *dentry = file->f_path.dentry, *parent;

	struct super_block *sb = dentry->d_sb;
@@ -665,7 +665,7 @@ void file_set_fsnotify_mode(struct file *file) 
	 */

	if (likely(!fsnotify_sb_has_priority_watchers(sb,

						FSNOTIFY_PRIO_CONTENT))) {

		file->f_mode |= FMODE_NONOTIFY_PERM;

		file_set_fsnotify_mode(file, FMODE_NONOTIFY_PERM);

		return;

	}
@@ -676,7 +676,7 @@ void file_set_fsnotify_mode(struct file *file) 
	if ((!d_is_dir(dentry) && !d_is_reg(dentry)) ||

	    likely(!fsnotify_sb_has_priority_watchers(sb,

						FSNOTIFY_PRIO_PRE_CONTENT))) {

		file->f_mode |= FMODE_NONOTIFY | FMODE_NONOTIFY_PERM;

		file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM);

		return;

	}
@@ -686,19 +686,25 @@ void file_set_fsnotify_mode(struct file *file) 
	 */

	mnt_mask = READ_ONCE(real_mount(file->f_path.mnt)->mnt_fsnotify_mask);

	if (unlikely(fsnotify_object_watched(d_inode(dentry), mnt_mask,

				     FSNOTIFY_PRE_CONTENT_EVENTS)))

				     FSNOTIFY_PRE_CONTENT_EVENTS))) {

		/* Enable pre-content events */

		file_set_fsnotify_mode(file, 0);

		return;

	}



	/* Is parent watching for pre-content events on this file? */

	if (dentry->d_flags & DCACHE_FSNOTIFY_PARENT_WATCHED) {

		parent = dget_parent(dentry);

		p_mask = fsnotify_inode_watches_children(d_inode(parent));

		dput(parent);

		if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS)

		if (p_mask & FSNOTIFY_PRE_CONTENT_EVENTS) {

			/* Enable pre-content events */

			file_set_fsnotify_mode(file, 0);

			return;

		}

	}

	/* Nobody watching for pre-content events from this file */

	file->f_mode |= FMODE_NONOTIFY | FMODE_NONOTIFY_PERM;

	file_set_fsnotify_mode(file, FMODE_NONOTIFY | FMODE_NONOTIFY_PERM);

}

#endif

fs/open.c

+4 −3
Original line number Diff line number Diff line
@@ -905,7 +905,8 @@ static int do_dentry_open(struct file *f, 
	f->f_sb_err = file_sample_sb_err(f);



	if (unlikely(f->f_flags & O_PATH)) {

		f->f_mode = FMODE_PATH | FMODE_OPENED | FMODE_NONOTIFY;

		f->f_mode = FMODE_PATH | FMODE_OPENED;

		file_set_fsnotify_mode(f, FMODE_NONOTIFY);

		f->f_op = &empty_fops;

		return 0;

	}
@@ -938,7 +939,7 @@ static int do_dentry_open(struct file *f, 
	 * If FMODE_NONOTIFY was already set for an fanotify fd, this doesn't

	 * change anything.

	 */

	file_set_fsnotify_mode(f);

	file_set_fsnotify_mode_from_watchers(f);

	error = fsnotify_open_perm(f);

	if (error)

		goto cleanup_all;
@@ -1122,7 +1123,7 @@ struct file *dentry_open_nonotify(const struct path *path, int flags, 
	if (!IS_ERR(f)) {

		int error;



		f->f_mode |= FMODE_NONOTIFY;

		file_set_fsnotify_mode(f, FMODE_NONOTIFY);

		error = vfs_open(path, f);

		if (error) {

			fput(f);

include/linux/fs.h

+6 −1
Original line number Diff line number Diff line
@@ -222,7 +222,6 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, 
#define FMODE_FSNOTIFY_HSM(mode)	0

#endif





/*

 * Attribute flags.  These should be or-ed together to figure out what

 * has been changed!
@@ -3140,6 +3139,12 @@ static inline void exe_file_allow_write_access(struct file *exe_file) 
	allow_write_access(exe_file);

}



static inline void file_set_fsnotify_mode(struct file *file, fmode_t mode)

{

	file->f_mode &= ~FMODE_FSNOTIFY_MASK;

	file->f_mode |= mode;

}



static inline bool inode_is_open_for_write(const struct inode *inode)

{

	return atomic_read(&inode->i_writecount) > 0;

include/linux/fsnotify.h

+2 −2
Original line number Diff line number Diff line
@@ -129,7 +129,7 @@ static inline int fsnotify_file(struct file *file, __u32 mask) 


#ifdef CONFIG_FANOTIFY_ACCESS_PERMISSIONS



void file_set_fsnotify_mode(struct file *file);

void file_set_fsnotify_mode_from_watchers(struct file *file);



/*

 * fsnotify_file_area_perm - permission hook before access to file range
@@ -213,7 +213,7 @@ static inline int fsnotify_open_perm(struct file *file) 
}



#else

static inline void file_set_fsnotify_mode(struct file *file)

static inline void file_set_fsnotify_mode_from_watchers(struct file *file)

{

}