diff options
Diffstat (limited to 'fs/fuse/inode.c')
| -rw-r--r-- | fs/fuse/inode.c | 179 |
1 files changed, 177 insertions, 2 deletions
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 3141690558c8..d2249f174e20 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -18,6 +18,7 @@ #include <linux/statfs.h> #include <linux/random.h> #include <linux/sched.h> +#include <linux/exportfs.h> MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>"); MODULE_DESCRIPTION("Filesystem in Userspace"); @@ -552,6 +553,174 @@ static struct inode *get_root_inode(struct super_block *sb, unsigned mode) return fuse_iget(sb, 1, 0, &attr, 0, 0); } +struct fuse_inode_handle +{ + u64 nodeid; + u32 generation; +}; + +static struct dentry *fuse_get_dentry(struct super_block *sb, + struct fuse_inode_handle *handle) +{ + struct fuse_conn *fc = get_fuse_conn_super(sb); + struct inode *inode; + struct dentry *entry; + int err = -ESTALE; + + if (handle->nodeid == 0) + goto out_err; + + inode = ilookup5(sb, handle->nodeid, fuse_inode_eq, &handle->nodeid); + if (!inode) { + struct fuse_entry_out outarg; + struct qstr name; + + if (!fc->export_support) + goto out_err; + + name.len = 1; + name.name = "."; + err = fuse_lookup_name(sb, handle->nodeid, &name, &outarg, + &inode); + if (err && err != -ENOENT) + goto out_err; + if (err || !inode) { + err = -ESTALE; + goto out_err; + } + err = -EIO; + if (get_node_id(inode) != handle->nodeid) + goto out_iput; + } + err = -ESTALE; + if (inode->i_generation != handle->generation) + goto out_iput; + + entry = d_alloc_anon(inode); + err = -ENOMEM; + if (!entry) + goto out_iput; + + if (get_node_id(inode) != FUSE_ROOT_ID) { + entry->d_op = &fuse_dentry_operations; + fuse_invalidate_entry_cache(entry); + } + + return entry; + + out_iput: + iput(inode); + out_err: + return ERR_PTR(err); +} + +static int fuse_encode_fh(struct dentry *dentry, u32 *fh, int *max_len, + int connectable) +{ + struct inode *inode = dentry->d_inode; + bool encode_parent = connectable && !S_ISDIR(inode->i_mode); + int len = encode_parent ? 6 : 3; + u64 nodeid; + u32 generation; + + if (*max_len < len) + return 255; + + nodeid = get_fuse_inode(inode)->nodeid; + generation = inode->i_generation; + + fh[0] = (u32)(nodeid >> 32); + fh[1] = (u32)(nodeid & 0xffffffff); + fh[2] = generation; + + if (encode_parent) { + struct inode *parent; + + spin_lock(&dentry->d_lock); + parent = dentry->d_parent->d_inode; + nodeid = get_fuse_inode(parent)->nodeid; + generation = parent->i_generation; + spin_unlock(&dentry->d_lock); + + fh[3] = (u32)(nodeid >> 32); + fh[4] = (u32)(nodeid & 0xffffffff); + fh[5] = generation; + } + + *max_len = len; + return encode_parent ? 0x82 : 0x81; +} + +static struct dentry *fuse_fh_to_dentry(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + struct fuse_inode_handle handle; + + if ((fh_type != 0x81 && fh_type != 0x82) || fh_len < 3) + return NULL; + + handle.nodeid = (u64) fid->raw[0] << 32; + handle.nodeid |= (u64) fid->raw[1]; + handle.generation = fid->raw[2]; + return fuse_get_dentry(sb, &handle); +} + +static struct dentry *fuse_fh_to_parent(struct super_block *sb, + struct fid *fid, int fh_len, int fh_type) +{ + struct fuse_inode_handle parent; + + if (fh_type != 0x82 || fh_len < 6) + return NULL; + + parent.nodeid = (u64) fid->raw[3] << 32; + parent.nodeid |= (u64) fid->raw[4]; + parent.generation = fid->raw[5]; + return fuse_get_dentry(sb, &parent); +} + +static struct dentry *fuse_get_parent(struct dentry *child) +{ + struct inode *child_inode = child->d_inode; + struct fuse_conn *fc = get_fuse_conn(child_inode); + struct inode *inode; + struct dentry *parent; + struct fuse_entry_out outarg; + struct qstr name; + int err; + + if (!fc->export_support) + return ERR_PTR(-ESTALE); + + name.len = 2; + name.name = ".."; + err = fuse_lookup_name(child_inode->i_sb, get_node_id(child_inode), + &name, &outarg, &inode); + if (err && err != -ENOENT) + return ERR_PTR(err); + if (err || !inode) + return ERR_PTR(-ESTALE); + + parent = d_alloc_anon(inode); + if (!parent) { + iput(inode); + return ERR_PTR(-ENOMEM); + } + if (get_node_id(inode) != FUSE_ROOT_ID) { + parent->d_op = &fuse_dentry_operations; + fuse_invalidate_entry_cache(parent); + } + + return parent; +} + +static const struct export_operations fuse_export_operations = { + .fh_to_dentry = fuse_fh_to_dentry, + .fh_to_parent = fuse_fh_to_parent, + .encode_fh = fuse_encode_fh, + .get_parent = fuse_get_parent, +}; + static const struct super_operations fuse_super_operations = { .alloc_inode = fuse_alloc_inode, .destroy_inode = fuse_destroy_inode, @@ -581,6 +750,11 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) fc->no_lock = 1; if (arg->flags & FUSE_ATOMIC_O_TRUNC) fc->atomic_o_trunc = 1; + if (arg->minor >= 9) { + /* LOOKUP has dependency on proto version */ + if (arg->flags & FUSE_EXPORT_SUPPORT) + fc->export_support = 1; + } if (arg->flags & FUSE_BIG_WRITES) fc->big_writes = 1; } else { @@ -607,7 +781,7 @@ static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req) arg->minor = FUSE_KERNEL_MINOR_VERSION; arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE; arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS | FUSE_ATOMIC_O_TRUNC | - FUSE_BIG_WRITES; + FUSE_EXPORT_SUPPORT | FUSE_BIG_WRITES; req->in.h.opcode = FUSE_INIT; req->in.numargs = 1; req->in.args[0].size = sizeof(*arg); @@ -652,6 +826,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) sb->s_magic = FUSE_SUPER_MAGIC; sb->s_op = &fuse_super_operations; sb->s_maxbytes = MAX_LFS_FILESIZE; + sb->s_export_op = &fuse_export_operations; file = fget(d.fd); if (!file) @@ -781,7 +956,7 @@ static inline void unregister_fuseblk(void) } #endif -static void fuse_inode_init_once(struct kmem_cache *cachep, void *foo) +static void fuse_inode_init_once(void *foo) { struct inode * inode = foo; |