}
}
-static int fuse_reconfigure(struct fs_context *fc)
+static int fuse_reconfigure(struct fs_context *fsc)
{
- struct super_block *sb = fc->root->d_sb;
+ struct super_block *sb = fsc->root->d_sb;
sync_filesystem(sb);
- if (fc->sb_flags & SB_MANDLOCK)
+ if (fsc->sb_flags & SB_MANDLOCK)
return -EINVAL;
return 0;
return err;
}
+static struct fuse_sync_bucket *fuse_sync_bucket_alloc(void)
+{
+ struct fuse_sync_bucket *bucket;
+
+ bucket = kzalloc(sizeof(*bucket), GFP_KERNEL | __GFP_NOFAIL);
+ if (bucket) {
+ init_waitqueue_head(&bucket->waitq);
+ /* Initial active count */
+ atomic_set(&bucket->count, 1);
+ }
+ return bucket;
+}
+
+static void fuse_sync_fs_writes(struct fuse_conn *fc)
+{
+ struct fuse_sync_bucket *bucket, *new_bucket;
+ int count;
+
+ new_bucket = fuse_sync_bucket_alloc();
+ spin_lock(&fc->lock);
+ bucket = rcu_dereference_protected(fc->curr_bucket, 1);
+ count = atomic_read(&bucket->count);
+ WARN_ON(count < 1);
+ /* No outstanding writes? */
+ if (count == 1) {
+ spin_unlock(&fc->lock);
+ kfree(new_bucket);
+ return;
+ }
+
+ /*
+ * Completion of new bucket depends on completion of this bucket, so add
+ * one more count.
+ */
+ atomic_inc(&new_bucket->count);
+ rcu_assign_pointer(fc->curr_bucket, new_bucket);
+ spin_unlock(&fc->lock);
+ /*
+ * Drop initial active count. At this point if all writes in this and
+ * ancestor buckets complete, the count will go to zero and this task
+ * will be woken up.
+ */
+ atomic_dec(&bucket->count);
+
+ wait_event(bucket->waitq, atomic_read(&bucket->count) == 0);
+
+ /* Drop temp count on descendant bucket */
+ fuse_sync_bucket_dec(new_bucket);
+ kfree_rcu(bucket, rcu);
+}
+
static int fuse_sync_fs(struct super_block *sb, int wait)
{
struct fuse_mount *fm = get_fuse_mount_super(sb);
if (!fc->sync_fs)
return 0;
+ fuse_sync_fs_writes(fc);
+
memset(&inarg, 0, sizeof(inarg));
args.in_numargs = 1;
args.in_args[0].size = sizeof(inarg);
{}
};
-static int fuse_parse_param(struct fs_context *fc, struct fs_parameter *param)
+static int fuse_parse_param(struct fs_context *fsc, struct fs_parameter *param)
{
struct fs_parse_result result;
- struct fuse_fs_context *ctx = fc->fs_private;
+ struct fuse_fs_context *ctx = fsc->fs_private;
int opt;
- if (fc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
+ if (fsc->purpose == FS_CONTEXT_FOR_RECONFIGURE) {
/*
* Ignore options coming from mount(MS_REMOUNT) for backward
* compatibility.
*/
- if (fc->oldapi)
+ if (fsc->oldapi)
return 0;
- return invalfc(fc, "No changes allowed in reconfigure");
+ return invalfc(fsc, "No changes allowed in reconfigure");
}
- opt = fs_parse(fc, fuse_fs_parameters, param, &result);
+ opt = fs_parse(fsc, fuse_fs_parameters, param, &result);
if (opt < 0)
return opt;
switch (opt) {
case OPT_SOURCE:
- if (fc->source)
- return invalfc(fc, "Multiple sources specified");
- fc->source = param->string;
+ if (fsc->source)
+ return invalfc(fsc, "Multiple sources specified");
+ fsc->source = param->string;
param->string = NULL;
break;
case OPT_SUBTYPE:
if (ctx->subtype)
- return invalfc(fc, "Multiple subtypes specified");
+ return invalfc(fsc, "Multiple subtypes specified");
ctx->subtype = param->string;
param->string = NULL;
return 0;
case OPT_ROOTMODE:
if (!fuse_valid_type(result.uint_32))
- return invalfc(fc, "Invalid rootmode");
+ return invalfc(fsc, "Invalid rootmode");
ctx->rootmode = result.uint_32;
ctx->rootmode_present = true;
break;
case OPT_USER_ID:
- ctx->user_id = make_kuid(fc->user_ns, result.uint_32);
+ ctx->user_id = make_kuid(fsc->user_ns, result.uint_32);
if (!uid_valid(ctx->user_id))
- return invalfc(fc, "Invalid user_id");
+ return invalfc(fsc, "Invalid user_id");
ctx->user_id_present = true;
break;
case OPT_GROUP_ID:
- ctx->group_id = make_kgid(fc->user_ns, result.uint_32);
+ ctx->group_id = make_kgid(fsc->user_ns, result.uint_32);
if (!gid_valid(ctx->group_id))
- return invalfc(fc, "Invalid group_id");
+ return invalfc(fsc, "Invalid group_id");
ctx->group_id_present = true;
break;
case OPT_BLKSIZE:
if (!ctx->is_bdev)
- return invalfc(fc, "blksize only supported for fuseblk");
+ return invalfc(fsc, "blksize only supported for fuseblk");
ctx->blksize = result.uint_32;
break;
return 0;
}
-static void fuse_free_fc(struct fs_context *fc)
+static void fuse_free_fsc(struct fs_context *fsc)
{
- struct fuse_fs_context *ctx = fc->fs_private;
+ struct fuse_fs_context *ctx = fsc->fs_private;
if (ctx) {
kfree(ctx->subtype);
{
if (refcount_dec_and_test(&fc->count)) {
struct fuse_iqueue *fiq = &fc->iq;
+ struct fuse_sync_bucket *bucket;
if (IS_ENABLED(CONFIG_FUSE_DAX))
fuse_dax_conn_free(fc);
fiq->ops->release(fiq);
put_pid_ns(fc->pid_ns);
put_user_ns(fc->user_ns);
+ bucket = rcu_dereference_protected(fc->curr_bucket, 1);
+ if (bucket) {
+ WARN_ON(atomic_read(&bucket->count) != 1);
+ kfree(bucket);
+ }
fc->release(fc);
}
}
if (sb->s_flags & SB_MANDLOCK)
goto err;
+ rcu_assign_pointer(fc->curr_bucket, fuse_sync_bucket_alloc());
fuse_sb_defaults(sb);
if (ctx->is_bdev) {
static int fuse_fill_super(struct super_block *sb, struct fs_context *fsc)
{
struct fuse_fs_context *ctx = fsc->fs_private;
- struct file *file;
int err;
struct fuse_conn *fc;
struct fuse_mount *fm;
- err = -EINVAL;
- file = fget(ctx->fd);
- if (!file)
- goto err;
+ if (!ctx->file || !ctx->rootmode_present ||
+ !ctx->user_id_present || !ctx->group_id_present)
+ return -EINVAL;
/*
* Require mount to happen from the same user namespace which
* opened /dev/fuse to prevent potential attacks.
*/
- if ((file->f_op != &fuse_dev_operations) ||
- (file->f_cred->user_ns != sb->s_user_ns))
- goto err_fput;
- ctx->fudptr = &file->private_data;
+ err = -EINVAL;
+ if ((ctx->file->f_op != &fuse_dev_operations) ||
+ (ctx->file->f_cred->user_ns != sb->s_user_ns))
+ goto err;
+ ctx->fudptr = &ctx->file->private_data;
fc = kmalloc(sizeof(*fc), GFP_KERNEL);
err = -ENOMEM;
if (!fc)
- goto err_fput;
+ goto err;
fm = kzalloc(sizeof(*fm), GFP_KERNEL);
if (!fm) {
kfree(fc);
- goto err_fput;
+ goto err;
}
fuse_conn_init(fc, fm, sb->s_user_ns, &fuse_dev_fiq_ops, NULL);
err = fuse_fill_super_common(sb, ctx);
if (err)
goto err_put_conn;
- /*
- * atomic_dec_and_test() in fput() provides the necessary
- * memory barrier for file->private_data to be visible on all
- * CPUs after this
- */
- fput(file);
+ /* file->private_data shall be visible on all CPUs after this */
+ smp_mb();
fuse_send_init(get_fuse_mount_super(sb));
return 0;
fuse_conn_put(fc);
kfree(fm);
sb->s_fs_info = NULL;
- err_fput:
- fput(file);
err:
return err;
}
-static int fuse_get_tree(struct fs_context *fc)
+/*
+ * This is the path where user supplied an already initialized fuse dev. In
+ * this case never create a new super if the old one is gone.
+ */
+static int fuse_set_no_super(struct super_block *sb, struct fs_context *fsc)
{
- struct fuse_fs_context *ctx = fc->fs_private;
+ return -ENOTCONN;
+}
- if (!ctx->fd_present || !ctx->rootmode_present ||
- !ctx->user_id_present || !ctx->group_id_present)
- return -EINVAL;
+static int fuse_test_super(struct super_block *sb, struct fs_context *fsc)
+{
-#ifdef CONFIG_BLOCK
- if (ctx->is_bdev)
- return get_tree_bdev(fc, fuse_fill_super);
-#endif
+ return fsc->sget_key == get_fuse_conn_super(sb);
+}
+
+static int fuse_get_tree(struct fs_context *fsc)
+{
+ struct fuse_fs_context *ctx = fsc->fs_private;
+ struct fuse_dev *fud;
+ struct super_block *sb;
+ int err;
- return get_tree_nodev(fc, fuse_fill_super);
+ if (ctx->fd_present)
+ ctx->file = fget(ctx->fd);
+
+ if (IS_ENABLED(CONFIG_BLOCK) && ctx->is_bdev) {
+ err = get_tree_bdev(fsc, fuse_fill_super);
+ goto out_fput;
+ }
+ /*
+ * While block dev mount can be initialized with a dummy device fd
+ * (found by device name), normal fuse mounts can't
+ */
+ if (!ctx->file)
+ return -EINVAL;
+
+ /*
+ * Allow creating a fuse mount with an already initialized fuse
+ * connection
+ */
+ fud = READ_ONCE(ctx->file->private_data);
+ if (ctx->file->f_op == &fuse_dev_operations && fud) {
+ fsc->sget_key = fud->fc;
+ sb = sget_fc(fsc, fuse_test_super, fuse_set_no_super);
+ err = PTR_ERR_OR_ZERO(sb);
+ if (!IS_ERR(sb))
+ fsc->root = dget(sb->s_root);
+ } else {
+ err = get_tree_nodev(fsc, fuse_fill_super);
+ }
+out_fput:
+ if (ctx->file)
+ fput(ctx->file);
+ return err;
}
static const struct fs_context_operations fuse_context_ops = {
- .free = fuse_free_fc,
+ .free = fuse_free_fsc,
.parse_param = fuse_parse_param,
.reconfigure = fuse_reconfigure,
.get_tree = fuse_get_tree,
/*
* Set up the filesystem mount context.
*/
-static int fuse_init_fs_context(struct fs_context *fc)
+static int fuse_init_fs_context(struct fs_context *fsc)
{
struct fuse_fs_context *ctx;
ctx->legacy_opts_show = true;
#ifdef CONFIG_BLOCK
- if (fc->fs_type == &fuseblk_fs_type) {
+ if (fsc->fs_type == &fuseblk_fs_type) {
ctx->is_bdev = true;
ctx->destroy = true;
}
#endif
- fc->fs_private = ctx;
- fc->ops = &fuse_context_ops;
+ fsc->fs_private = ctx;
+ fsc->ops = &fuse_context_ops;
return 0;
}
projects / linux-2.6-microblaze.git / blobdiff