fuse: add support for mandatory locking
For mandatory locking the userspace filesystem needs to know the lock
ownership for read, write and truncate operations.
This patch adds the necessary fields to the protocol.
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>
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 052327b..6c83ed0 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -1108,6 +1108,11 @@
inarg.valid |= FATTR_FH;
inarg.fh = ff->fh;
}
+ if (attr->ia_valid & ATTR_SIZE) {
+ /* For mandatory locking in truncate */
+ inarg.valid |= FATTR_LOCKOWNER;
+ inarg.lock_owner = fuse_lock_owner_id(fc, current->files);
+ }
req->in.h.opcode = FUSE_SETATTR;
req->in.h.nodeid = get_node_id(inode);
req->in.numargs = 1;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 2b589de..0fcdba9 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -189,7 +189,7 @@
* Scramble the ID space with XTEA, so that the value of the files_struct
* pointer is not exposed to userspace.
*/
-static u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
+u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id)
{
u32 *k = fc->scramble_key;
u64 v = (unsigned long) id;
@@ -308,11 +308,19 @@
}
static size_t fuse_send_read(struct fuse_req *req, struct file *file,
- struct inode *inode, loff_t pos, size_t count)
+ struct inode *inode, loff_t pos, size_t count,
+ fl_owner_t owner)
{
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_file *ff = file->private_data;
+
fuse_read_fill(req, ff, inode, pos, count, FUSE_READ);
+ if (owner != NULL) {
+ struct fuse_read_in *inarg = &req->misc.read_in;
+
+ inarg->read_flags |= FUSE_READ_LOCKOWNER;
+ inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+ }
request_send(fc, req);
return req->out.args[0].size;
}
@@ -336,7 +344,8 @@
req->out.page_zeroing = 1;
req->num_pages = 1;
req->pages[0] = page;
- fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE);
+ fuse_send_read(req, file, inode, page_offset(page), PAGE_CACHE_SIZE,
+ NULL);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err)
@@ -447,6 +456,7 @@
struct inode *inode, loff_t pos, size_t count,
int writepage)
{
+ struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_write_in *inarg = &req->misc.write.in;
struct fuse_write_out *outarg = &req->misc.write.out;
@@ -459,7 +469,10 @@
req->in.h.nodeid = get_node_id(inode);
req->in.argpages = 1;
req->in.numargs = 2;
- req->in.args[0].size = sizeof(struct fuse_write_in);
+ if (fc->minor < 9)
+ req->in.args[0].size = FUSE_COMPAT_WRITE_IN_SIZE;
+ else
+ req->in.args[0].size = sizeof(struct fuse_write_in);
req->in.args[0].value = inarg;
req->in.args[1].size = count;
req->out.numargs = 1;
@@ -468,10 +481,16 @@
}
static size_t fuse_send_write(struct fuse_req *req, struct file *file,
- struct inode *inode, loff_t pos, size_t count)
+ struct inode *inode, loff_t pos, size_t count,
+ fl_owner_t owner)
{
struct fuse_conn *fc = get_fuse_conn(inode);
fuse_write_fill(req, file->private_data, inode, pos, count, 0);
+ if (owner != NULL) {
+ struct fuse_write_in *inarg = &req->misc.write.in;
+ inarg->write_flags |= FUSE_WRITE_LOCKOWNER;
+ inarg->lock_owner = fuse_lock_owner_id(fc, owner);
+ }
request_send(fc, req);
return req->misc.write.out.size;
}
@@ -508,7 +527,7 @@
req->num_pages = 1;
req->pages[0] = page;
req->page_offset = offset;
- nres = fuse_send_write(req, file, inode, pos, count);
+ nres = fuse_send_write(req, file, inode, pos, count, NULL);
err = req->out.h.error;
fuse_put_request(fc, req);
if (!err && !nres)
@@ -609,9 +628,11 @@
nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
nbytes = min(count, nbytes);
if (write)
- nres = fuse_send_write(req, file, inode, pos, nbytes);
+ nres = fuse_send_write(req, file, inode, pos, nbytes,
+ current->files);
else
- nres = fuse_send_read(req, file, inode, pos, nbytes);
+ nres = fuse_send_read(req, file, inode, pos, nbytes,
+ current->files);
fuse_release_user_pages(req, !write);
if (req->out.h.error) {
if (!res)
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 8b64a63..6c5461d 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -591,3 +591,5 @@
* Is task allowed to perform filesystem operation?
*/
int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task);
+
+u64 fuse_lock_owner_id(struct fuse_conn *fc, fl_owner_t id);
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 6f4a312..7d4fa5b 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -14,6 +14,7 @@
* 7.9:
* - new fuse_getattr_in input argument of GETATTR
* - add lk_flags in fuse_lk_in
+ * - add lock_owner field to fuse_setattr_in, fuse_read_in and fuse_write_in
*/
#include <asm/types.h>
@@ -86,6 +87,7 @@
#define FATTR_FH (1 << 6)
#define FATTR_ATIME_NOW (1 << 7)
#define FATTR_MTIME_NOW (1 << 8)
+#define FATTR_LOCKOWNER (1 << 9)
/**
* Flags returned by the OPEN request
@@ -123,8 +125,15 @@
* WRITE flags
*
* FUSE_WRITE_CACHE: delayed write from page cache, file handle is guessed
+ * FUSE_WRITE_LOCKOWNER: lock_owner field is valid
*/
#define FUSE_WRITE_CACHE (1 << 0)
+#define FUSE_WRITE_LOCKOWNER (1 << 1)
+
+/**
+ * Read flags
+ */
+#define FUSE_READ_LOCKOWNER (1 << 1)
enum fuse_opcode {
FUSE_LOOKUP = 1,
@@ -219,7 +228,7 @@
__u32 padding;
__u64 fh;
__u64 size;
- __u64 unused1;
+ __u64 lock_owner;
__u64 atime;
__u64 mtime;
__u64 unused2;
@@ -262,14 +271,18 @@
__u64 fh;
__u64 offset;
__u32 size;
- __u32 padding;
+ __u32 read_flags;
+ __u64 lock_owner;
};
+#define FUSE_COMPAT_WRITE_IN_SIZE 24
+
struct fuse_write_in {
__u64 fh;
__u64 offset;
__u32 size;
__u32 write_flags;
+ __u64 lock_owner;
};
struct fuse_write_out {