| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * linux/fs/9p/vfs_super.c |
| * |
| * This file contians superblock ops for 9P2000. It is intended that |
| * you mount this file system on directories. |
| * |
| * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> |
| * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/errno.h> |
| #include <linux/fs.h> |
| #include <linux/file.h> |
| #include <linux/stat.h> |
| #include <linux/string.h> |
| #include <linux/inet.h> |
| #include <linux/pagemap.h> |
| #include <linux/mount.h> |
| #include <linux/idr.h> |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/statfs.h> |
| #include <linux/magic.h> |
| #include <net/9p/9p.h> |
| #include <net/9p/client.h> |
| |
| #include "v9fs.h" |
| #include "v9fs_vfs.h" |
| #include "fid.h" |
| #include "xattr.h" |
| #include "acl.h" |
| |
| static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; |
| |
| /** |
| * v9fs_set_super - set the superblock |
| * @s: super block |
| * @data: file system specific data |
| * |
| */ |
| |
| static int v9fs_set_super(struct super_block *s, void *data) |
| { |
| s->s_fs_info = data; |
| return set_anon_super(s, data); |
| } |
| |
| /** |
| * v9fs_fill_super - populate superblock with info |
| * @sb: superblock |
| * @v9ses: session information |
| * @flags: flags propagated from v9fs_mount() |
| * |
| */ |
| |
| static int |
| v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, |
| int flags) |
| { |
| int ret; |
| |
| sb->s_maxbytes = MAX_LFS_FILESIZE; |
| sb->s_blocksize_bits = fls(v9ses->maxdata - 1); |
| sb->s_blocksize = 1 << sb->s_blocksize_bits; |
| sb->s_magic = V9FS_MAGIC; |
| if (v9fs_proto_dotl(v9ses)) { |
| sb->s_op = &v9fs_super_ops_dotl; |
| sb->s_xattr = v9fs_xattr_handlers; |
| } else { |
| sb->s_op = &v9fs_super_ops; |
| sb->s_time_max = U32_MAX; |
| } |
| |
| sb->s_time_min = 0; |
| |
| ret = super_setup_bdi(sb); |
| if (ret) |
| return ret; |
| |
| if (!v9ses->cache) { |
| sb->s_bdi->ra_pages = 0; |
| sb->s_bdi->io_pages = 0; |
| } |
| |
| sb->s_flags |= SB_ACTIVE | SB_DIRSYNC; |
| if (!v9ses->cache) |
| sb->s_flags |= SB_SYNCHRONOUS; |
| |
| #ifdef CONFIG_9P_FS_POSIX_ACL |
| if ((v9ses->flags & V9FS_ACL_MASK) == V9FS_POSIX_ACL) |
| sb->s_flags |= SB_POSIXACL; |
| #endif |
| |
| return 0; |
| } |
| |
| /** |
| * v9fs_mount - mount a superblock |
| * @fs_type: file system type |
| * @flags: mount flags |
| * @dev_name: device name that was mounted |
| * @data: mount options |
| * |
| */ |
| |
| static struct dentry *v9fs_mount(struct file_system_type *fs_type, int flags, |
| const char *dev_name, void *data) |
| { |
| struct super_block *sb = NULL; |
| struct inode *inode = NULL; |
| struct dentry *root = NULL; |
| struct v9fs_session_info *v9ses = NULL; |
| umode_t mode = S_IRWXUGO | S_ISVTX; |
| struct p9_fid *fid; |
| int retval = 0; |
| |
| p9_debug(P9_DEBUG_VFS, "\n"); |
| |
| v9ses = kzalloc(sizeof(struct v9fs_session_info), GFP_KERNEL); |
| if (!v9ses) |
| return ERR_PTR(-ENOMEM); |
| |
| fid = v9fs_session_init(v9ses, dev_name, data); |
| if (IS_ERR(fid)) { |
| retval = PTR_ERR(fid); |
| goto free_session; |
| } |
| |
| sb = sget(fs_type, NULL, v9fs_set_super, flags, v9ses); |
| if (IS_ERR(sb)) { |
| retval = PTR_ERR(sb); |
| goto clunk_fid; |
| } |
| retval = v9fs_fill_super(sb, v9ses, flags); |
| if (retval) |
| goto release_sb; |
| |
| if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) |
| sb->s_d_op = &v9fs_cached_dentry_operations; |
| else |
| sb->s_d_op = &v9fs_dentry_operations; |
| |
| inode = v9fs_get_inode(sb, S_IFDIR | mode, 0); |
| if (IS_ERR(inode)) { |
| retval = PTR_ERR(inode); |
| goto release_sb; |
| } |
| |
| root = d_make_root(inode); |
| if (!root) { |
| retval = -ENOMEM; |
| goto release_sb; |
| } |
| sb->s_root = root; |
| if (v9fs_proto_dotl(v9ses)) { |
| struct p9_stat_dotl *st = NULL; |
| st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); |
| if (IS_ERR(st)) { |
| retval = PTR_ERR(st); |
| goto release_sb; |
| } |
| d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); |
| v9fs_stat2inode_dotl(st, d_inode(root), 0); |
| kfree(st); |
| } else { |
| struct p9_wstat *st = NULL; |
| st = p9_client_stat(fid); |
| if (IS_ERR(st)) { |
| retval = PTR_ERR(st); |
| goto release_sb; |
| } |
| |
| d_inode(root)->i_ino = v9fs_qid2ino(&st->qid); |
| v9fs_stat2inode(st, d_inode(root), sb, 0); |
| |
| p9stat_free(st); |
| kfree(st); |
| } |
| retval = v9fs_get_acl(inode, fid); |
| if (retval) |
| goto release_sb; |
| v9fs_fid_add(root, fid); |
| |
| p9_debug(P9_DEBUG_VFS, " simple set mount, return 0\n"); |
| return dget(sb->s_root); |
| |
| clunk_fid: |
| p9_client_clunk(fid); |
| v9fs_session_close(v9ses); |
| free_session: |
| kfree(v9ses); |
| return ERR_PTR(retval); |
| |
| release_sb: |
| /* |
| * we will do the session_close and root dentry release |
| * in the below call. But we need to clunk fid, because we haven't |
| * attached the fid to dentry so it won't get clunked |
| * automatically. |
| */ |
| p9_client_clunk(fid); |
| deactivate_locked_super(sb); |
| return ERR_PTR(retval); |
| } |
| |
| /** |
| * v9fs_kill_super - Kill Superblock |
| * @s: superblock |
| * |
| */ |
| |
| static void v9fs_kill_super(struct super_block *s) |
| { |
| struct v9fs_session_info *v9ses = s->s_fs_info; |
| |
| p9_debug(P9_DEBUG_VFS, " %p\n", s); |
| |
| kill_anon_super(s); |
| |
| v9fs_session_cancel(v9ses); |
| v9fs_session_close(v9ses); |
| kfree(v9ses); |
| s->s_fs_info = NULL; |
| p9_debug(P9_DEBUG_VFS, "exiting kill_super\n"); |
| } |
| |
| static void |
| v9fs_umount_begin(struct super_block *sb) |
| { |
| struct v9fs_session_info *v9ses; |
| |
| v9ses = sb->s_fs_info; |
| v9fs_session_begin_cancel(v9ses); |
| } |
| |
| static int v9fs_statfs(struct dentry *dentry, struct kstatfs *buf) |
| { |
| struct v9fs_session_info *v9ses; |
| struct p9_fid *fid; |
| struct p9_rstatfs rs; |
| int res; |
| |
| fid = v9fs_fid_lookup(dentry); |
| if (IS_ERR(fid)) { |
| res = PTR_ERR(fid); |
| goto done; |
| } |
| |
| v9ses = v9fs_dentry2v9ses(dentry); |
| if (v9fs_proto_dotl(v9ses)) { |
| res = p9_client_statfs(fid, &rs); |
| if (res == 0) { |
| buf->f_type = rs.type; |
| buf->f_bsize = rs.bsize; |
| buf->f_blocks = rs.blocks; |
| buf->f_bfree = rs.bfree; |
| buf->f_bavail = rs.bavail; |
| buf->f_files = rs.files; |
| buf->f_ffree = rs.ffree; |
| buf->f_fsid = u64_to_fsid(rs.fsid); |
| buf->f_namelen = rs.namelen; |
| } |
| if (res != -ENOSYS) |
| goto done; |
| } |
| res = simple_statfs(dentry, buf); |
| done: |
| return res; |
| } |
| |
| static int v9fs_drop_inode(struct inode *inode) |
| { |
| struct v9fs_session_info *v9ses; |
| v9ses = v9fs_inode2v9ses(inode); |
| if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) |
| return generic_drop_inode(inode); |
| /* |
| * in case of non cached mode always drop the |
| * the inode because we want the inode attribute |
| * to always match that on the server. |
| */ |
| return 1; |
| } |
| |
| static int v9fs_write_inode(struct inode *inode, |
| struct writeback_control *wbc) |
| { |
| int ret; |
| struct p9_wstat wstat; |
| struct v9fs_inode *v9inode; |
| /* |
| * send an fsync request to server irrespective of |
| * wbc->sync_mode. |
| */ |
| p9_debug(P9_DEBUG_VFS, "%s: inode %p\n", __func__, inode); |
| v9inode = V9FS_I(inode); |
| if (!v9inode->writeback_fid) |
| return 0; |
| v9fs_blank_wstat(&wstat); |
| |
| ret = p9_client_wstat(v9inode->writeback_fid, &wstat); |
| if (ret < 0) { |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| return ret; |
| } |
| return 0; |
| } |
| |
| static int v9fs_write_inode_dotl(struct inode *inode, |
| struct writeback_control *wbc) |
| { |
| int ret; |
| struct v9fs_inode *v9inode; |
| /* |
| * send an fsync request to server irrespective of |
| * wbc->sync_mode. |
| */ |
| v9inode = V9FS_I(inode); |
| p9_debug(P9_DEBUG_VFS, "%s: inode %p, writeback_fid %p\n", |
| __func__, inode, v9inode->writeback_fid); |
| if (!v9inode->writeback_fid) |
| return 0; |
| |
| ret = p9_client_fsync(v9inode->writeback_fid, 0); |
| if (ret < 0) { |
| __mark_inode_dirty(inode, I_DIRTY_DATASYNC); |
| return ret; |
| } |
| return 0; |
| } |
| |
| static const struct super_operations v9fs_super_ops = { |
| .alloc_inode = v9fs_alloc_inode, |
| .free_inode = v9fs_free_inode, |
| .statfs = simple_statfs, |
| .evict_inode = v9fs_evict_inode, |
| .show_options = v9fs_show_options, |
| .umount_begin = v9fs_umount_begin, |
| .write_inode = v9fs_write_inode, |
| }; |
| |
| static const struct super_operations v9fs_super_ops_dotl = { |
| .alloc_inode = v9fs_alloc_inode, |
| .free_inode = v9fs_free_inode, |
| .statfs = v9fs_statfs, |
| .drop_inode = v9fs_drop_inode, |
| .evict_inode = v9fs_evict_inode, |
| .show_options = v9fs_show_options, |
| .umount_begin = v9fs_umount_begin, |
| .write_inode = v9fs_write_inode_dotl, |
| }; |
| |
| struct file_system_type v9fs_fs_type = { |
| .name = "9p", |
| .mount = v9fs_mount, |
| .kill_sb = v9fs_kill_super, |
| .owner = THIS_MODULE, |
| .fs_flags = FS_RENAME_DOES_D_MOVE, |
| }; |
| MODULE_ALIAS_FS("9p"); |