Commit a9ff4f87 authored by Miklos Szeredi's avatar Miklos Szeredi Committed by Linus Torvalds
Browse files

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: default avatarMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 6ff958ed
......@@ -699,7 +699,8 @@ static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
}
static void fuse_lk_fill(struct fuse_req *req, struct file *file,
const struct file_lock *fl, int opcode, pid_t pid)
const struct file_lock *fl, int opcode, pid_t pid,
int flock)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
......@@ -712,6 +713,8 @@ static void fuse_lk_fill(struct fuse_req *req, struct file *file,
arg->lk.end = fl->fl_end;
arg->lk.type = fl->fl_type;
arg->lk.pid = pid;
if (flock)
arg->lk_flags |= FUSE_LK_FLOCK;
req->in.h.opcode = opcode;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
......@@ -731,7 +734,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
if (IS_ERR(req))
return PTR_ERR(req);
fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
fuse_lk_fill(req, file, fl, FUSE_GETLK, 0, 0);
req->out.numargs = 1;
req->out.args[0].size = sizeof(outarg);
req->out.args[0].value = &outarg;
......@@ -744,7 +747,7 @@ static int fuse_getlk(struct file *file, struct file_lock *fl)
return err;
}
static int fuse_setlk(struct file *file, struct file_lock *fl)
static int fuse_setlk(struct file *file, struct file_lock *fl, int flock)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
......@@ -761,7 +764,7 @@ static int fuse_setlk(struct file *file, struct file_lock *fl)
if (IS_ERR(req))
return PTR_ERR(req);
fuse_lk_fill(req, file, fl, opcode, pid);
fuse_lk_fill(req, file, fl, opcode, pid, flock);
request_send(fc, req);
err = req->out.h.error;
/* locking is restartable */
......@@ -787,11 +790,28 @@ static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
if (fc->no_lock)
err = posix_lock_file_wait(file, fl);
else
err = fuse_setlk(file, fl);
err = fuse_setlk(file, fl, 0);
}
return err;
}
static int fuse_file_flock(struct file *file, int cmd, struct file_lock *fl)
{
struct inode *inode = file->f_path.dentry->d_inode;
struct fuse_conn *fc = get_fuse_conn(inode);
int err;
if (fc->no_lock) {
err = flock_lock_file_wait(file, fl);
} else {
/* emulate flock with POSIX locks */
fl->fl_owner = (fl_owner_t) file;
err = fuse_setlk(file, fl, 1);
}
return err;
}
static sector_t fuse_bmap(struct address_space *mapping, sector_t block)
{
struct inode *inode = mapping->host;
......@@ -840,6 +860,7 @@ static const struct file_operations fuse_file_operations = {
.release = fuse_release,
.fsync = fuse_fsync,
.lock = fuse_file_lock,
.flock = fuse_file_flock,
.splice_read = generic_file_splice_read,
};
......@@ -852,6 +873,7 @@ static const struct file_operations fuse_direct_io_file_operations = {
.release = fuse_release,
.fsync = fuse_fsync,
.lock = fuse_file_lock,
.flock = fuse_file_flock,
/* no mmap and splice_read */
};
......
......@@ -13,6 +13,7 @@
*
* 7.9:
* - new fuse_getattr_in input argument of GETATTR
* - add lk_flags in fuse_lk_in
*/
#include <asm/types.h>
......@@ -113,6 +114,11 @@ struct fuse_file_lock {
*/
#define FUSE_GETATTR_FH (1 << 0)
/**
* Lock flags
*/
#define FUSE_LK_FLOCK (1 << 0)
enum fuse_opcode {
FUSE_LOOKUP = 1,
FUSE_FORGET = 2, /* no reply */
......@@ -295,6 +301,8 @@ struct fuse_lk_in {
__u64 fh;
__u64 owner;
struct fuse_file_lock lk;
__u32 lk_flags;
__u32 padding;
};
struct fuse_lk_out {
......
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