forked from Minki/linux
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>
This commit is contained in:
parent
e0a43ddcc0
commit
3b463ae0c6
@ -849,6 +849,81 @@ err:
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return err;
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}
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static int fuse_notify_inval_inode(struct fuse_conn *fc, unsigned int size,
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struct fuse_copy_state *cs)
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{
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struct fuse_notify_inval_inode_out outarg;
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int err = -EINVAL;
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if (size != sizeof(outarg))
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goto err;
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err = fuse_copy_one(cs, &outarg, sizeof(outarg));
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if (err)
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goto err;
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fuse_copy_finish(cs);
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down_read(&fc->killsb);
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err = -ENOENT;
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if (!fc->sb)
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goto err_unlock;
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err = fuse_reverse_inval_inode(fc->sb, outarg.ino,
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outarg.off, outarg.len);
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err_unlock:
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up_read(&fc->killsb);
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return err;
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err:
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fuse_copy_finish(cs);
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return err;
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}
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static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
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struct fuse_copy_state *cs)
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{
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struct fuse_notify_inval_entry_out outarg;
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int err = -EINVAL;
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char buf[FUSE_NAME_MAX+1];
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struct qstr name;
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if (size < sizeof(outarg))
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goto err;
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err = fuse_copy_one(cs, &outarg, sizeof(outarg));
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if (err)
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goto err;
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err = -ENAMETOOLONG;
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if (outarg.namelen > FUSE_NAME_MAX)
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goto err;
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name.name = buf;
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name.len = outarg.namelen;
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err = fuse_copy_one(cs, buf, outarg.namelen + 1);
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if (err)
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goto err;
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fuse_copy_finish(cs);
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buf[outarg.namelen] = 0;
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name.hash = full_name_hash(name.name, name.len);
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down_read(&fc->killsb);
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err = -ENOENT;
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if (!fc->sb)
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goto err_unlock;
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err = fuse_reverse_inval_entry(fc->sb, outarg.parent, &name);
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err_unlock:
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up_read(&fc->killsb);
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return err;
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err:
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fuse_copy_finish(cs);
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return err;
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}
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static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
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unsigned int size, struct fuse_copy_state *cs)
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{
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@ -856,6 +931,12 @@ static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
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case FUSE_NOTIFY_POLL:
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return fuse_notify_poll(fc, size, cs);
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case FUSE_NOTIFY_INVAL_INODE:
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return fuse_notify_inval_inode(fc, size, cs);
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case FUSE_NOTIFY_INVAL_ENTRY:
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return fuse_notify_inval_entry(fc, size, cs);
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default:
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fuse_copy_finish(cs);
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return -EINVAL;
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@ -859,6 +859,43 @@ int fuse_update_attributes(struct inode *inode, struct kstat *stat,
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return err;
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}
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int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
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struct qstr *name)
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{
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int err = -ENOTDIR;
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struct inode *parent;
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struct dentry *dir;
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struct dentry *entry;
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parent = ilookup5(sb, parent_nodeid, fuse_inode_eq, &parent_nodeid);
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if (!parent)
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return -ENOENT;
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mutex_lock(&parent->i_mutex);
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if (!S_ISDIR(parent->i_mode))
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goto unlock;
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err = -ENOENT;
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dir = d_find_alias(parent);
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if (!dir)
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goto unlock;
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entry = d_lookup(dir, name);
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dput(dir);
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if (!entry)
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goto unlock;
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fuse_invalidate_attr(parent);
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fuse_invalidate_entry(entry);
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dput(entry);
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err = 0;
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unlock:
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mutex_unlock(&parent->i_mutex);
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iput(parent);
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return err;
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}
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/*
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* Calling into a user-controlled filesystem gives the filesystem
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* daemon ptrace-like capabilities over the requester process. This
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@ -484,6 +484,12 @@ struct fuse_conn {
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/** Called on final put */
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void (*release)(struct fuse_conn *);
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/** Super block for this connection. */
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struct super_block *sb;
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/** Read/write semaphore to hold when accessing sb. */
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struct rw_semaphore killsb;
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};
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static inline struct fuse_conn *get_fuse_conn_super(struct super_block *sb)
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@ -511,6 +517,11 @@ extern const struct file_operations fuse_dev_operations;
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extern const struct dentry_operations fuse_dentry_operations;
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/**
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* Inode to nodeid comparison.
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*/
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int fuse_inode_eq(struct inode *inode, void *_nodeidp);
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/**
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* Get a filled in inode
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*/
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@ -711,6 +722,19 @@ void fuse_release_nowrite(struct inode *inode);
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u64 fuse_get_attr_version(struct fuse_conn *fc);
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/**
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* File-system tells the kernel to invalidate cache for the given node id.
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*/
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int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
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loff_t offset, loff_t len);
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/**
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* File-system tells the kernel to invalidate parent attributes and
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* the dentry matching parent/name.
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*/
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int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
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struct qstr *name);
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int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
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bool isdir);
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ssize_t fuse_direct_io(struct file *file, const char __user *buf,
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@ -206,7 +206,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
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BUG();
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}
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static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
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int fuse_inode_eq(struct inode *inode, void *_nodeidp)
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{
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u64 nodeid = *(u64 *) _nodeidp;
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if (get_node_id(inode) == nodeid)
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@ -257,6 +257,31 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
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return inode;
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}
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int fuse_reverse_inval_inode(struct super_block *sb, u64 nodeid,
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loff_t offset, loff_t len)
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{
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struct inode *inode;
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pgoff_t pg_start;
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pgoff_t pg_end;
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inode = ilookup5(sb, nodeid, fuse_inode_eq, &nodeid);
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if (!inode)
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return -ENOENT;
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fuse_invalidate_attr(inode);
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if (offset >= 0) {
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pg_start = offset >> PAGE_CACHE_SHIFT;
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if (len <= 0)
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pg_end = -1;
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else
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pg_end = (offset + len - 1) >> PAGE_CACHE_SHIFT;
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invalidate_inode_pages2_range(inode->i_mapping,
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pg_start, pg_end);
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}
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iput(inode);
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return 0;
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}
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static void fuse_umount_begin(struct super_block *sb)
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{
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fuse_abort_conn(get_fuse_conn_super(sb));
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@ -480,6 +505,7 @@ void fuse_conn_init(struct fuse_conn *fc)
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memset(fc, 0, sizeof(*fc));
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spin_lock_init(&fc->lock);
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mutex_init(&fc->inst_mutex);
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init_rwsem(&fc->killsb);
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atomic_set(&fc->count, 1);
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init_waitqueue_head(&fc->waitq);
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init_waitqueue_head(&fc->blocked_waitq);
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@ -862,6 +888,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
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fuse_conn_init(fc);
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fc->dev = sb->s_dev;
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fc->sb = sb;
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err = fuse_bdi_init(fc, sb);
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if (err)
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goto err_put_conn;
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@ -948,12 +975,25 @@ static int fuse_get_sb(struct file_system_type *fs_type,
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return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
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}
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static void fuse_kill_sb_anon(struct super_block *sb)
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{
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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if (fc) {
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down_write(&fc->killsb);
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fc->sb = NULL;
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up_write(&fc->killsb);
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}
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kill_anon_super(sb);
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}
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static struct file_system_type fuse_fs_type = {
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.owner = THIS_MODULE,
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.name = "fuse",
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.fs_flags = FS_HAS_SUBTYPE,
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.get_sb = fuse_get_sb,
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.kill_sb = kill_anon_super,
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.kill_sb = fuse_kill_sb_anon,
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};
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#ifdef CONFIG_BLOCK
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@ -965,11 +1005,24 @@ static int fuse_get_sb_blk(struct file_system_type *fs_type,
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mnt);
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}
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static void fuse_kill_sb_blk(struct super_block *sb)
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{
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struct fuse_conn *fc = get_fuse_conn_super(sb);
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if (fc) {
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down_write(&fc->killsb);
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fc->sb = NULL;
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up_write(&fc->killsb);
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}
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kill_block_super(sb);
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}
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static struct file_system_type fuseblk_fs_type = {
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.owner = THIS_MODULE,
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.name = "fuseblk",
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.get_sb = fuse_get_sb_blk,
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.kill_sb = kill_block_super,
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.kill_sb = fuse_kill_sb_blk,
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.fs_flags = FS_REQUIRES_DEV | FS_HAS_SUBTYPE,
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};
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@ -28,6 +28,8 @@
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*
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* 7.12
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* - add umask flag to input argument of open, mknod and mkdir
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* - add notification messages for invalidation of inodes and
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* directory entries
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*/
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#ifndef _LINUX_FUSE_H
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@ -229,6 +231,8 @@ enum fuse_opcode {
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enum fuse_notify_code {
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FUSE_NOTIFY_POLL = 1,
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FUSE_NOTIFY_INVAL_INODE = 2,
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FUSE_NOTIFY_INVAL_ENTRY = 3,
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FUSE_NOTIFY_CODE_MAX,
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};
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@ -524,4 +528,16 @@ struct fuse_dirent {
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#define FUSE_DIRENT_SIZE(d) \
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FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
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struct fuse_notify_inval_inode_out {
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__u64 ino;
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__s64 off;
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__s64 len;
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};
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struct fuse_notify_inval_entry_out {
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__u64 parent;
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__u32 namelen;
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__u32 padding;
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};
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#endif /* _LINUX_FUSE_H */
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