forked from mirrors/linux
		
	fuse: support BSD locking semantics
It is trivial to add support for flock(2) semantics to the existing protocol, by setting the lock owner field to the file pointer, and passing a new FUSE_LK_FLOCK flag with the locking request. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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					 2 changed files with 35 additions and 5 deletions
				
			
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			@ -699,7 +699,8 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
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}
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static void fuse_lk_fill(struct fuse_req *req, struct file *file,
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			 const struct file_lock *fl, int opcode, pid_t pid)
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			 const struct file_lock *fl, int opcode, pid_t pid,
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			 int flock)
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{
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	struct inode *inode = file->f_path.dentry->d_inode;
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	struct fuse_conn *fc = get_fuse_conn(inode);
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			@ -712,6 +713,8 @@ static void fuse_lk_fill(struct fuse_req *req, struct file *file,
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	arg->lk.end = fl->fl_end;
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	arg->lk.type = fl->fl_type;
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	arg->lk.pid = pid;
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	if (flock)
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		arg->lk_flags |= FUSE_LK_FLOCK;
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	req->in.h.opcode = opcode;
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	req->in.h.nodeid = get_node_id(inode);
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	req->in.numargs = 1;
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			@ -731,7 +734,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
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	if (IS_ERR(req))
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		return PTR_ERR(req);
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	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
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	fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
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	req->out.numargs = 1;
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	req->out.args[0].size = sizeof(outarg);
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	req->out.args[0].value = &outarg;
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			@ -744,7 +747,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
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	return err;
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}
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static int fuse_setlk(struct file *file, struct file_lock *fl)
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static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
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{
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	struct inode *inode = file->f_path.dentry->d_inode;
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	struct fuse_conn *fc = get_fuse_conn(inode);
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			@ -761,7 +764,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl)
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	if (IS_ERR(req))
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		return PTR_ERR(req);
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	fuse_lk_fill(req, file, fl, opcode, pid);
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	fuse_lk_fill(req, file, fl, opcode, pid, flock);
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	request_send(fc, req);
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	err = req->out.h.error;
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	/* locking is restartable */
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			@ -787,11 +790,28 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
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		if (fc->no_lock)
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			err = posix_lock_file_wait(file, fl);
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		else
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			err = fuse_setlk(file, fl);
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			err = fuse_setlk(file, fl, 0);
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	}
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	return err;
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}
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static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
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{
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	struct inode *inode = file->f_path.dentry->d_inode;
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	struct fuse_conn *fc = get_fuse_conn(inode);
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	int err;
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	if (fc->no_lock) {
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		err = flock_lock_file_wait(file, fl);
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	} else {
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		/* emulate flock with POSIX locks */
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		fl->fl_owner = (fl_owner_t) file;
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		err = fuse_setlk(file, fl, 1);
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	}
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	return err;
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}
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static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
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{
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	struct inode *inode = mapping->host;
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			@ -840,6 +860,7 @@ static const struct file_operations fuse_file_operations = {
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	.release	= fuse_release,
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	.fsync		= fuse_fsync,
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	.lock		= fuse_file_lock,
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	.flock		= fuse_file_flock,
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	.splice_read	= generic_file_splice_read,
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};
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			@ -852,6 +873,7 @@ static const struct file_operations fuse_direct_io_file_operations = {
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	.release	= fuse_release,
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	.fsync		= fuse_fsync,
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	.lock		= fuse_file_lock,
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	.flock		= fuse_file_flock,
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	/* no mmap and splice_read */
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};
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			@ -13,6 +13,7 @@
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 *
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 * 7.9:
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 *  - new fuse_getattr_in input argument of GETATTR
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 *  - add lk_flags in fuse_lk_in
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 */
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#include <asm/types.h>
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			@ -113,6 +114,11 @@ struct fuse_file_lock {
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 */
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#define FUSE_GETATTR_FH		(1 << 0)
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/**
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 * Lock flags
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 */
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#define FUSE_LK_FLOCK		(1 << 0)
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enum fuse_opcode {
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	FUSE_LOOKUP	   = 1,
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	FUSE_FORGET	   = 2,  /* no reply */
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			@ -295,6 +301,8 @@ struct fuse_lk_in {
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	__u64	fh;
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	__u64	owner;
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	struct fuse_file_lock lk;
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	__u32	lk_flags;
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	__u32	padding;
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};
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struct fuse_lk_out {
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