Commit 3b463ae0 authored by John Muir's avatar John Muir Committed by Miklos Szeredi

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: default avatarMiklos Szeredi <mszeredi@suse.cz>
parent e0a43ddc
......@@ -849,6 +849,81 @@ err:
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 @@ static int fuse_notify(struct fuse_conn *fc, enum fuse_notify_code code,
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;
......
......@@ -859,6 +859,43 @@ int fuse_update_attributes(struct inode *inode, struct kstat *stat,
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
......
......@@ -484,6 +484,12 @@ struct fuse_conn {
/** 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)
......@@ -511,6 +517,11 @@ extern const struct file_operations fuse_dev_operations;
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
*/
......@@ -711,6 +722,19 @@ void fuse_release_nowrite(struct inode *inode);
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,
......
......@@ -206,7 +206,7 @@ static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
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 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
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 @@ void fuse_conn_init(struct fuse_conn *fc)
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 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
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 @@ static int fuse_get_sb(struct file_system_type *fs_type,
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 @@ static int fuse_get_sb_blk(struct file_system_type *fs_type,
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,
};
......
......@@ -28,6 +28,8 @@
*
* 7.12
* - add umask flag to input argument of open, mknod and mkdir
* - add notification messages for invalidation of inodes and
* directory entries
*/
#ifndef _LINUX_FUSE_H
......@@ -229,6 +231,8 @@ enum fuse_opcode {
enum fuse_notify_code {
FUSE_NOTIFY_POLL = 1,
FUSE_NOTIFY_INVAL_INODE = 2,
FUSE_NOTIFY_INVAL_ENTRY = 3,
FUSE_NOTIFY_CODE_MAX,
};
......@@ -524,4 +528,16 @@ struct fuse_dirent {
#define FUSE_DIRENT_SIZE(d) \
FUSE_DIRENT_ALIGN(FUSE_NAME_OFFSET + (d)->namelen)
struct fuse_notify_inval_inode_out {
__u64 ino;
__s64 off;
__s64 len;
};
struct fuse_notify_inval_entry_out {
__u64 parent;
__u32 namelen;
__u32 padding;
};
#endif /* _LINUX_FUSE_H */
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