4 files changed, 178 insertions, 4 deletions

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 1d59af306b28..d9a8289297c0 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -160,6 +160,18 @@ static int fuse_release(struct inode *inode, struct file *file)
         return fuse_release_common(inode, file, 0);
 }
 
+/*
+ * It would be nice to scramble the ID space, so that the value of the
+ * files_struct pointer is not exposed to userspace.  Symmetric crypto
+ * functions are overkill, since the inverse function doesn't need to
+ * be implemented (though it does have to exist).  Is there something
+ * simpler?
+ */
+static inline u64 fuse_lock_owner_id(fl_owner_t id)
+{
+        return (unsigned long) id;
+}
+
 static int fuse_flush(struct file *file, fl_owner_t id)
 {
         struct inode *inode = file->f_dentry->d_inode;
@@ -181,11 +193,13 @@ static int fuse_flush(struct file *file, fl_owner_t id)
 
         memset(&inarg, 0, sizeof(inarg));
         inarg.fh = ff->fh;
+        inarg.lock_owner = fuse_lock_owner_id(id);
         req->in.h.opcode = FUSE_FLUSH;
         req->in.h.nodeid = get_node_id(inode);
         req->in.numargs = 1;
         req->in.args[0].size = sizeof(inarg);
         req->in.args[0].value = &inarg;
+        req->force = 1;
         request_send(fc, req);
         err = req->out.h.error;
         fuse_put_request(fc, req);
@@ -604,6 +618,122 @@ static int fuse_set_page_dirty(struct page *page)
         return 0;
 }
 
+static int convert_fuse_file_lock(const struct fuse_file_lock *ffl,
+                                  struct file_lock *fl)
+{
+        switch (ffl->type) {
+        case F_UNLCK:
+                break;
+
+        case F_RDLCK:
+        case F_WRLCK:
+                if (ffl->start > OFFSET_MAX || ffl->end > OFFSET_MAX ||
+                    ffl->end < ffl->start)
+                        return -EIO;
+
+                fl->fl_start = ffl->start;
+                fl->fl_end = ffl->end;
+                fl->fl_pid = ffl->pid;
+                break;
+
+        default:
+                return -EIO;
+        }
+        fl->fl_type = ffl->type;
+        return 0;
+}
+
+static void fuse_lk_fill(struct fuse_req *req, struct file *file,
+                         const struct file_lock *fl, int opcode, pid_t pid)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        struct fuse_file *ff = file->private_data;
+        struct fuse_lk_in *arg = &req->misc.lk_in;
+
+        arg->fh = ff->fh;
+        arg->owner = fuse_lock_owner_id(fl->fl_owner);
+        arg->lk.start = fl->fl_start;
+        arg->lk.end = fl->fl_end;
+        arg->lk.type = fl->fl_type;
+        arg->lk.pid = pid;
+        req->in.h.opcode = opcode;
+        req->in.h.nodeid = get_node_id(inode);
+        req->in.numargs = 1;
+        req->in.args[0].size = sizeof(*arg);
+        req->in.args[0].value = arg;
+}
+
+static int fuse_getlk(struct file *file, struct file_lock *fl)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+        struct fuse_req *req;
+        struct fuse_lk_out outarg;
+        int err;
+
+        req = fuse_get_req(fc);
+        if (IS_ERR(req))
+                return PTR_ERR(req);
+
+        fuse_lk_fill(req, file, fl, FUSE_GETLK, 0);
+        req->out.numargs = 1;
+        req->out.args[0].size = sizeof(outarg);
+        req->out.args[0].value = &outarg;
+        request_send(fc, req);
+        err = req->out.h.error;
+        fuse_put_request(fc, req);
+        if (!err)
+                err = convert_fuse_file_lock(&outarg.lk, fl);
+
+        return err;
+}
+
+static int fuse_setlk(struct file *file, struct file_lock *fl)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+        struct fuse_req *req;
+        int opcode = (fl->fl_flags & FL_SLEEP) ? FUSE_SETLKW : FUSE_SETLK;
+        pid_t pid = fl->fl_type != F_UNLCK ? current->tgid : 0;
+        int err;
+
+        /* Unlock on close is handled by the flush method */
+        if (fl->fl_flags & FL_CLOSE)
+                return 0;
+
+        req = fuse_get_req(fc);
+        if (IS_ERR(req))
+                return PTR_ERR(req);
+
+        fuse_lk_fill(req, file, fl, opcode, pid);
+        request_send(fc, req);
+        err = req->out.h.error;
+        fuse_put_request(fc, req);
+        return err;
+}
+
+static int fuse_file_lock(struct file *file, int cmd, struct file_lock *fl)
+{
+        struct inode *inode = file->f_dentry->d_inode;
+        struct fuse_conn *fc = get_fuse_conn(inode);
+        int err;
+
+        if (cmd == F_GETLK) {
+                if (fc->no_lock) {
+                        if (!posix_test_lock(file, fl, fl))
+                                fl->fl_type = F_UNLCK;
+                        err = 0;
+                } else
+                        err = fuse_getlk(file, fl);
+        } else {
+                if (fc->no_lock)
+                        err = posix_lock_file_wait(file, fl);
+                else
+                        err = fuse_setlk(file, fl);
+        }
+        return err;
+}
+
 static const struct file_operations fuse_file_operations = {
         .llseek         = generic_file_llseek,
         .read           = generic_file_read,
@@ -613,6 +743,7 @@ static const struct file_operations fuse_file_operations = {
         .flush          = fuse_flush,
         .release        = fuse_release,
         .fsync          = fuse_fsync,
+        .lock           = fuse_file_lock,
         .sendfile       = generic_file_sendfile,
 };
 
@@ -624,6 +755,7 @@ static const struct file_operations fuse_direct_io_file_operations = {
         .flush          = fuse_flush,
         .release        = fuse_release,
         .fsync          = fuse_fsync,
+        .lock           = fuse_file_lock,
         /* no mmap and sendfile */
 };
 
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index ac12b01f4446..eb3166625ca9 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -190,6 +190,7 @@ struct fuse_req {
                 struct fuse_init_in init_in;
                 struct fuse_init_out init_out;
                 struct fuse_read_in read_in;
+                struct fuse_lk_in lk_in;
         } misc;
 
         /** page vector */
@@ -307,6 +308,9 @@ struct fuse_conn {
         /** Is removexattr not implemented by fs? */
         unsigned no_removexattr : 1;
 
+        /** Are file locking primitives not implemented by fs? */
+        unsigned no_lock : 1;
+
         /** Is access not implemented by fs? */
         unsigned no_access : 1;
 
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 13a7e8ab7a78..412892905838 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -98,6 +98,14 @@ static void fuse_clear_inode(struct inode *inode)
         }
 }
 
+static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+        if (*flags & MS_MANDLOCK)
+                return -EINVAL;
+
+        return 0;
+}
+
 void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
 {
         if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
@@ -409,6 +417,7 @@ static struct super_operations fuse_super_operations = {
         .destroy_inode  = fuse_destroy_inode,
         .read_inode     = fuse_read_inode,
         .clear_inode    = fuse_clear_inode,
+        .remount_fs     = fuse_remount_fs,
         .put_super      = fuse_put_super,
         .umount_begin   = fuse_umount_begin,
         .statfs         = fuse_statfs,
@@ -428,8 +437,12 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
                         ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
                         if (arg->flags & FUSE_ASYNC_READ)
                                 fc->async_read = 1;
-                } else
+                        if (!(arg->flags & FUSE_POSIX_LOCKS))
+                                fc->no_lock = 1;
+                } else {
                         ra_pages = fc->max_read / PAGE_CACHE_SIZE;
+                        fc->no_lock = 1;
+                }
 
                 fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
                 fc->minor = arg->minor;
@@ -447,7 +460,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
         arg->major = FUSE_KERNEL_VERSION;
         arg->minor = FUSE_KERNEL_MINOR_VERSION;
         arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
-        arg->flags |= FUSE_ASYNC_READ;
+        arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
         req->in.h.opcode = FUSE_INIT;
         req->in.numargs = 1;
         req->in.args[0].size = sizeof(*arg);
@@ -479,6 +492,9 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
         struct fuse_req *init_req;
         int err;
 
+        if (sb->s_flags & MS_MANDLOCK)
+                return -EINVAL;
+
         if (!parse_fuse_opt((char *) data, &d))
                 return -EINVAL;
 
diff --git a/include/linux/fuse.h b/include/linux/fuse.h
index 8e4319614bef..e7a76ec0f05c 100644
--- a/include/linux/fuse.h
+++ b/include/linux/fuse.h
@@ -1,6 +1,6 @@
 /*
     FUSE: Filesystem in Userspace
-    Copyright (C) 2001-2005  Miklos Szeredi <miklos@szeredi.hu>
+    Copyright (C) 2001-2006  Miklos Szeredi <miklos@szeredi.hu>
 
     This program can be distributed under the terms of the GNU GPL.
     See the file COPYING.
@@ -15,7 +15,7 @@
 #define FUSE_KERNEL_VERSION 7
 
 /** Minor version number of this interface */
-#define FUSE_KERNEL_MINOR_VERSION 6
+#define FUSE_KERNEL_MINOR_VERSION 7
 
 /** The node ID of the root inode */
 #define FUSE_ROOT_ID 1
@@ -59,6 +59,13 @@ struct fuse_kstatfs {
         __u32   spare[6];
 };
 
+struct fuse_file_lock {
+        __u64   start;
+        __u64   end;
+        __u32   type;
+        __u32   pid; /* tgid */
+};
+
 /**
  * Bitmasks for fuse_setattr_in.valid
  */
@@ -83,6 +90,7 @@ struct fuse_kstatfs {
  * INIT request/reply flags
  */
 #define FUSE_ASYNC_READ         (1 << 0)
+#define FUSE_POSIX_LOCKS        (1 << 1)
 
 enum fuse_opcode {
         FUSE_LOOKUP        = 1,
@@ -113,6 +121,9 @@ enum fuse_opcode {
         FUSE_READDIR       = 28,
         FUSE_RELEASEDIR    = 29,
         FUSE_FSYNCDIR      = 30,
+        FUSE_GETLK         = 31,
+        FUSE_SETLK         = 32,
+        FUSE_SETLKW        = 33,
         FUSE_ACCESS        = 34,
         FUSE_CREATE        = 35
 };
@@ -200,6 +211,7 @@ struct fuse_flush_in {
         __u64   fh;
         __u32   flush_flags;
         __u32   padding;
+        __u64   lock_owner;
 };
 
 struct fuse_read_in {
@@ -248,6 +260,16 @@ struct fuse_getxattr_out {
         __u32   padding;
 };
 
+struct fuse_lk_in {
+        __u64   fh;
+        __u64   owner;
+        struct fuse_file_lock lk;
+};
+
+struct fuse_lk_out {
+        struct fuse_file_lock lk;
+};
+
 struct fuse_access_in {
         __u32   mask;
         __u32   padding;