fuse: invalidation reverse calls
Add notification messages that allow the filesystem to invalidate VFS
caches.
Two notifications are added:
1) inode invalidation
- invalidate cached attributes
- invalidate a range of pages in the page cache (this is optional)
2) dentry invalidation
- try to invalidate a subtree in the dentry cache
Care must be taken while accessing the 'struct super_block' for the
mount, as it can go away while an invalidation is in progress. To
prevent this, introduce a rw-semaphore, that is taken for read during
the invalidation and taken for write in the ->kill_sb callback.
Cc: Csaba Henk <csaba@gluster.com>
Cc: Anand Avati <avati@zresearch.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 8a11a8c..f58ecbc 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -849,6 +849,81 @@
return err;
}
+static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_inval_inode_out outarg;
+ int err = -EINVAL;
+
+ if (size != sizeof(outarg))
+ goto err;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ goto err;
+ fuse_copy_finish(cs);
+
+ down_read(&fc->killsb);
+ err = -ENOENT;
+ if (!fc->sb)
+ goto err_unlock;
+
+ err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
+ outarg.off, outarg.len);
+
+err_unlock:
+ up_read(&fc->killsb);
+ return err;
+
+err:
+ fuse_copy_finish(cs);
+ return err;
+}
+
+static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
+ struct fuse_copy_state *cs)
+{
+ struct fuse_notify_inval_entry_out outarg;
+ int err = -EINVAL;
+ char buf[FUSE_NAME_MAX+1];
+ struct qstr name;
+
+ if (size < sizeof(outarg))
+ goto err;
+
+ err = fuse_copy_one(cs, &outarg, sizeof(outarg));
+ if (err)
+ goto err;
+
+ err = -ENAMETOOLONG;
+ if (outarg.namelen > FUSE_NAME_MAX)
+ goto err;
+
+ name.name = buf;
+ name.len = outarg.namelen;
+ err = fuse_copy_one(cs, buf, outarg.namelen + 1);
+ if (err)
+ goto err;
+ fuse_copy_finish(cs);
+ buf[outarg.namelen] = 0;
+ name.hash = full_name_hash(name.name, name.len);
+
+ down_read(&fc->killsb);
+ err = -ENOENT;
+ if (!fc->sb)
+ goto err_unlock;
+
+ err = fuse_reverse_inval_entry(fc->sb, outarg.parent, &name);
+
+err_unlock:
+ up_read(&fc->killsb);
+ return err;
+
+err:
+ fuse_copy_finish(cs);
+ return err;
+}
+
static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
unsigned int size, struct fuse_copy_state *cs)
{
@@ -856,6 +931,12 @@
case FUSE_NOTIFY_POLL:
return fuse_notify_poll(fc, size, cs);
+ case FUSE_NOTIFY_INVAL_INODE:
+ return fuse_notify_inval_inode(fc, size, cs);
+
+ case FUSE_NOTIFY_INVAL_ENTRY:
+ return fuse_notify_inval_entry(fc, size, cs);
+
default:
fuse_copy_finish(cs);
return -EINVAL;
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 6b70073..e703654 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -859,6 +859,43 @@
return err;
}
+int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
+ struct qstr *name)
+{
+ int err = -ENOTDIR;
+ struct inode *parent;
+ struct dentry *dir;
+ struct dentry *entry;
+
+ parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
+ if (!parent)
+ return -ENOENT;
+
+ mutex_lock(&parent->i_mutex);
+ if (!S_ISDIR(parent->i_mode))
+ goto unlock;
+
+ err = -ENOENT;
+ dir = d_find_alias(parent);
+ if (!dir)
+ goto unlock;
+
+ entry = d_lookup(dir, name);
+ dput(dir);
+ if (!entry)
+ goto unlock;
+
+ fuse_invalidate_attr(parent);
+ fuse_invalidate_entry(entry);
+ dput(entry);
+ err = 0;
+
+ unlock:
+ mutex_unlock(&parent->i_mutex);
+ iput(parent);
+ return err;
+}
+
/*
* Calling into a user-controlled filesystem gives the filesystem
* daemon ptrace-like capabilities over the requester process. This
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index ede4f77..52b641f 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -484,6 +484,12 @@
/** Called on final put */
void (*release)(struct fuse_conn *);
+
+ /** Super block for this connection. */
+ struct super_block *sb;
+
+ /** Read/write semaphore to hold when accessing sb. */
+ struct rw_semaphore killsb;
};
static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
@@ -512,6 +518,11 @@
extern const struct dentry_operations fuse_dentry_operations;
/**
+ * Inode to nodeid comparison.
+ */
+int fuse_inode_eq(struct inode *inode, void *_nodeidp);
+
+/**
* Get a filled in inode
*/
struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
@@ -711,6 +722,19 @@
u64 fuse_get_attr_version(struct fuse_conn *fc);
+/**
+ * File-system tells the kernel to invalidate cache for the given node id.
+ */
+int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
+ loff_t offset, loff_t len);
+
+/**
+ * File-system tells the kernel to invalidate parent attributes and
+ * the dentry matching parent/name.
+ */
+int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
+ struct qstr *name);
+
int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
bool isdir);
ssize_t fuse_direct_io(struct file *file, const char __user *buf,
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 6cc501b..f91ccc4 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -206,7 +206,7 @@
BUG();
}
-static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
+int fuse_inode_eq(struct inode *inode, void *_nodeidp)
{
u64 nodeid = *(u64 *) _nodeidp;
if (get_node_id(inode) == nodeid)
@@ -257,6 +257,31 @@
return inode;
}
+int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
+ loff_t offset, loff_t len)
+{
+ struct inode *inode;
+ pgoff_t pg_start;
+ pgoff_t pg_end;
+
+ inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
+ if (!inode)
+ return -ENOENT;
+
+ fuse_invalidate_attr(inode);
+ if (offset >= 0) {
+ pg_start = offset >> PAGE_CACHE_SHIFT;
+ if (len <= 0)
+ pg_end = -1;
+ else
+ pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
+ invalidate_inode_pages2_range(inode->i_mapping,
+ pg_start, pg_end);
+ }
+ iput(inode);
+ return 0;
+}
+
static void fuse_umount_begin(struct super_block *sb)
{
fuse_abort_conn(get_fuse_conn_super(sb));
@@ -480,6 +505,7 @@
memset(fc, 0, sizeof(*fc));
spin_lock_init(&fc->lock);
mutex_init(&fc->inst_mutex);
+ init_rwsem(&fc->killsb);
atomic_set(&fc->count, 1);
init_waitqueue_head(&fc->waitq);
init_waitqueue_head(&fc->blocked_waitq);
@@ -862,6 +888,7 @@
fuse_conn_init(fc);
fc->dev = sb->s_dev;
+ fc->sb = sb;
err = fuse_bdi_init(fc, sb);
if (err)
goto err_put_conn;
@@ -948,12 +975,25 @@
return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
}
+static void fuse_kill_sb_anon(struct super_block *sb)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+
+ if (fc) {
+ down_write(&fc->killsb);
+ fc->sb = NULL;
+ up_write(&fc->killsb);
+ }
+
+ kill_anon_super(sb);
+}
+
static struct file_system_type fuse_fs_type = {
.owner = THIS_MODULE,
.name = "fuse",
.fs_flags = FS_HAS_SUBTYPE,
.get_sb = fuse_get_sb,
- .kill_sb = kill_anon_super,
+ .kill_sb = fuse_kill_sb_anon,
};
#ifdef CONFIG_BLOCK
@@ -965,11 +1005,24 @@
mnt);
}
+static void fuse_kill_sb_blk(struct super_block *sb)
+{
+ struct fuse_conn *fc = get_fuse_conn_super(sb);
+
+ if (fc) {
+ down_write(&fc->killsb);
+ fc->sb = NULL;
+ up_write(&fc->killsb);
+ }
+
+ kill_block_super(sb);
+}
+
static struct file_system_type fuseblk_fs_type = {
.owner = THIS_MODULE,
.name = "fuseblk",
.get_sb = fuse_get_sb_blk,
- .kill_sb = kill_block_super,
+ .kill_sb = fuse_kill_sb_blk,
.fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
};