diff options
Diffstat (limited to 'fs/9p/vfs_inode.c')
| -rw-r--r-- | fs/9p/vfs_inode.c | 1487 |
1 files changed, 1487 insertions, 0 deletions
diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c new file mode 100644 index 000000000..72b779bc0 --- /dev/null +++ b/fs/9p/vfs_inode.c @@ -0,0 +1,1487 @@ +/* + * linux/fs/9p/vfs_inode.c + * + * This file contains vfs inode ops for the 9P2000 protocol. + * + * Copyright (C) 2004 by Eric Van Hensbergen <ericvh@gmail.com> + * Copyright (C) 2002 by Ron Minnich <rminnich@lanl.gov> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to: + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02111-1301 USA + * + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/module.h> +#include <linux/errno.h> +#include <linux/fs.h> +#include <linux/file.h> +#include <linux/pagemap.h> +#include <linux/stat.h> +#include <linux/string.h> +#include <linux/inet.h> +#include <linux/namei.h> +#include <linux/idr.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/xattr.h> +#include <linux/posix_acl.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> + +#include "v9fs.h" +#include "v9fs_vfs.h" +#include "fid.h" +#include "cache.h" +#include "xattr.h" +#include "acl.h" + +static const struct inode_operations v9fs_dir_inode_operations; +static const struct inode_operations v9fs_dir_inode_operations_dotu; +static const struct inode_operations v9fs_file_inode_operations; +static const struct inode_operations v9fs_symlink_inode_operations; + +/** + * unixmode2p9mode - convert unix mode bits to plan 9 + * @v9ses: v9fs session information + * @mode: mode to convert + * + */ + +static u32 unixmode2p9mode(struct v9fs_session_info *v9ses, umode_t mode) +{ + int res; + res = mode & 0777; + if (S_ISDIR(mode)) + res |= P9_DMDIR; + if (v9fs_proto_dotu(v9ses)) { + if (v9ses->nodev == 0) { + if (S_ISSOCK(mode)) + res |= P9_DMSOCKET; + if (S_ISFIFO(mode)) + res |= P9_DMNAMEDPIPE; + if (S_ISBLK(mode)) + res |= P9_DMDEVICE; + if (S_ISCHR(mode)) + res |= P9_DMDEVICE; + } + + if ((mode & S_ISUID) == S_ISUID) + res |= P9_DMSETUID; + if ((mode & S_ISGID) == S_ISGID) + res |= P9_DMSETGID; + if ((mode & S_ISVTX) == S_ISVTX) + res |= P9_DMSETVTX; + } + return res; +} + +/** + * p9mode2perm- convert plan9 mode bits to unix permission bits + * @v9ses: v9fs session information + * @stat: p9_wstat from which mode need to be derived + * + */ +static int p9mode2perm(struct v9fs_session_info *v9ses, + struct p9_wstat *stat) +{ + int res; + int mode = stat->mode; + + res = mode & S_IALLUGO; + if (v9fs_proto_dotu(v9ses)) { + if ((mode & P9_DMSETUID) == P9_DMSETUID) + res |= S_ISUID; + + if ((mode & P9_DMSETGID) == P9_DMSETGID) + res |= S_ISGID; + + if ((mode & P9_DMSETVTX) == P9_DMSETVTX) + res |= S_ISVTX; + } + return res; +} + +/** + * p9mode2unixmode- convert plan9 mode bits to unix mode bits + * @v9ses: v9fs session information + * @stat: p9_wstat from which mode need to be derived + * @rdev: major number, minor number in case of device files. + * + */ +static umode_t p9mode2unixmode(struct v9fs_session_info *v9ses, + struct p9_wstat *stat, dev_t *rdev) +{ + int res; + u32 mode = stat->mode; + + *rdev = 0; + res = p9mode2perm(v9ses, stat); + + if ((mode & P9_DMDIR) == P9_DMDIR) + res |= S_IFDIR; + else if ((mode & P9_DMSYMLINK) && (v9fs_proto_dotu(v9ses))) + res |= S_IFLNK; + else if ((mode & P9_DMSOCKET) && (v9fs_proto_dotu(v9ses)) + && (v9ses->nodev == 0)) + res |= S_IFSOCK; + else if ((mode & P9_DMNAMEDPIPE) && (v9fs_proto_dotu(v9ses)) + && (v9ses->nodev == 0)) + res |= S_IFIFO; + else if ((mode & P9_DMDEVICE) && (v9fs_proto_dotu(v9ses)) + && (v9ses->nodev == 0)) { + char type = 0, ext[32]; + int major = -1, minor = -1; + + strlcpy(ext, stat->extension, sizeof(ext)); + sscanf(ext, "%c %i %i", &type, &major, &minor); + switch (type) { + case 'c': + res |= S_IFCHR; + break; + case 'b': + res |= S_IFBLK; + break; + default: + p9_debug(P9_DEBUG_ERROR, "Unknown special type %c %s\n", + type, stat->extension); + }; + *rdev = MKDEV(major, minor); + } else + res |= S_IFREG; + + return res; +} + +/** + * v9fs_uflags2omode- convert posix open flags to plan 9 mode bits + * @uflags: flags to convert + * @extended: if .u extensions are active + */ + +int v9fs_uflags2omode(int uflags, int extended) +{ + int ret; + + ret = 0; + switch (uflags&3) { + default: + case O_RDONLY: + ret = P9_OREAD; + break; + + case O_WRONLY: + ret = P9_OWRITE; + break; + + case O_RDWR: + ret = P9_ORDWR; + break; + } + + if (extended) { + if (uflags & O_EXCL) + ret |= P9_OEXCL; + + if (uflags & O_APPEND) + ret |= P9_OAPPEND; + } + + return ret; +} + +/** + * v9fs_blank_wstat - helper function to setup a 9P stat structure + * @wstat: structure to initialize + * + */ + +void +v9fs_blank_wstat(struct p9_wstat *wstat) +{ + wstat->type = ~0; + wstat->dev = ~0; + wstat->qid.type = ~0; + wstat->qid.version = ~0; + *((long long *)&wstat->qid.path) = ~0; + wstat->mode = ~0; + wstat->atime = ~0; + wstat->mtime = ~0; + wstat->length = ~0; + wstat->name = NULL; + wstat->uid = NULL; + wstat->gid = NULL; + wstat->muid = NULL; + wstat->n_uid = INVALID_UID; + wstat->n_gid = INVALID_GID; + wstat->n_muid = INVALID_UID; + wstat->extension = NULL; +} + +/** + * v9fs_alloc_inode - helper function to allocate an inode + * + */ +struct inode *v9fs_alloc_inode(struct super_block *sb) +{ + struct v9fs_inode *v9inode; + v9inode = (struct v9fs_inode *)kmem_cache_alloc(v9fs_inode_cache, + GFP_KERNEL); + if (!v9inode) + return NULL; +#ifdef CONFIG_9P_FSCACHE + v9inode->fscache = NULL; + mutex_init(&v9inode->fscache_lock); +#endif + v9inode->writeback_fid = NULL; + v9inode->cache_validity = 0; + mutex_init(&v9inode->v_mutex); + return &v9inode->vfs_inode; +} + +/** + * v9fs_destroy_inode - destroy an inode + * + */ + +static void v9fs_i_callback(struct rcu_head *head) +{ + struct inode *inode = container_of(head, struct inode, i_rcu); + kmem_cache_free(v9fs_inode_cache, V9FS_I(inode)); +} + +void v9fs_destroy_inode(struct inode *inode) +{ + call_rcu(&inode->i_rcu, v9fs_i_callback); +} + +int v9fs_init_inode(struct v9fs_session_info *v9ses, + struct inode *inode, umode_t mode, dev_t rdev) +{ + int err = 0; + + inode_init_owner(inode, NULL, mode); + inode->i_blocks = 0; + inode->i_rdev = rdev; + inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode); + inode->i_mapping->a_ops = &v9fs_addr_operations; + + switch (mode & S_IFMT) { + case S_IFIFO: + case S_IFBLK: + case S_IFCHR: + case S_IFSOCK: + if (v9fs_proto_dotl(v9ses)) { + inode->i_op = &v9fs_file_inode_operations_dotl; + } else if (v9fs_proto_dotu(v9ses)) { + inode->i_op = &v9fs_file_inode_operations; + } else { + p9_debug(P9_DEBUG_ERROR, + "special files without extended mode\n"); + err = -EINVAL; + goto error; + } + init_special_inode(inode, inode->i_mode, inode->i_rdev); + break; + case S_IFREG: + if (v9fs_proto_dotl(v9ses)) { + inode->i_op = &v9fs_file_inode_operations_dotl; + if (v9ses->cache == CACHE_LOOSE || + v9ses->cache == CACHE_FSCACHE) + inode->i_fop = + &v9fs_cached_file_operations_dotl; + else if (v9ses->cache == CACHE_MMAP) + inode->i_fop = &v9fs_mmap_file_operations_dotl; + else + inode->i_fop = &v9fs_file_operations_dotl; + } else { + inode->i_op = &v9fs_file_inode_operations; + if (v9ses->cache == CACHE_LOOSE || + v9ses->cache == CACHE_FSCACHE) + inode->i_fop = + &v9fs_cached_file_operations; + else if (v9ses->cache == CACHE_MMAP) + inode->i_fop = &v9fs_mmap_file_operations; + else + inode->i_fop = &v9fs_file_operations; + } + + break; + case S_IFLNK: + if (!v9fs_proto_dotu(v9ses) && !v9fs_proto_dotl(v9ses)) { + p9_debug(P9_DEBUG_ERROR, + "extended modes used with legacy protocol\n"); + err = -EINVAL; + goto error; + } + + if (v9fs_proto_dotl(v9ses)) + inode->i_op = &v9fs_symlink_inode_operations_dotl; + else + inode->i_op = &v9fs_symlink_inode_operations; + + break; + case S_IFDIR: + inc_nlink(inode); + if (v9fs_proto_dotl(v9ses)) + inode->i_op = &v9fs_dir_inode_operations_dotl; + else if (v9fs_proto_dotu(v9ses)) + inode->i_op = &v9fs_dir_inode_operations_dotu; + else + inode->i_op = &v9fs_dir_inode_operations; + + if (v9fs_proto_dotl(v9ses)) + inode->i_fop = &v9fs_dir_operations_dotl; + else + inode->i_fop = &v9fs_dir_operations; + + break; + default: + p9_debug(P9_DEBUG_ERROR, "BAD mode 0x%hx S_IFMT 0x%x\n", + mode, mode & S_IFMT); + err = -EINVAL; + goto error; + } +error: + return err; + +} + +/** + * v9fs_get_inode - helper function to setup an inode + * @sb: superblock + * @mode: mode to setup inode with + * + */ + +struct inode *v9fs_get_inode(struct super_block *sb, umode_t mode, dev_t rdev) +{ + int err; + struct inode *inode; + struct v9fs_session_info *v9ses = sb->s_fs_info; + + p9_debug(P9_DEBUG_VFS, "super block: %p mode: %ho\n", sb, mode); + + inode = new_inode(sb); + if (!inode) { + pr_warn("%s (%d): Problem allocating inode\n", + __func__, task_pid_nr(current)); + return ERR_PTR(-ENOMEM); + } + err = v9fs_init_inode(v9ses, inode, mode, rdev); + if (err) { + iput(inode); + return ERR_PTR(err); + } + return inode; +} + +/* +static struct v9fs_fid* +v9fs_clone_walk(struct v9fs_session_info *v9ses, u32 fid, struct dentry *dentry) +{ + int err; + int nfid; + struct v9fs_fid *ret; + struct v9fs_fcall *fcall; + + nfid = v9fs_get_idpool(&v9ses->fidpool); + if (nfid < 0) { + eprintk(KERN_WARNING, "no free fids available\n"); + return ERR_PTR(-ENOSPC); + } + + err = v9fs_t_walk(v9ses, fid, nfid, (char *) dentry->d_name.name, + &fcall); + + if (err < 0) { + if (fcall && fcall->id == RWALK) + goto clunk_fid; + + PRINT_FCALL_ERROR("walk error", fcall); + v9fs_put_idpool(nfid, &v9ses->fidpool); + goto error; + } + + kfree(fcall); + fcall = NULL; + ret = v9fs_fid_create(v9ses, nfid); + if (!ret) { + err = -ENOMEM; + goto clunk_fid; + } + + err = v9fs_fid_insert(ret, dentry); + if (err < 0) { + v9fs_fid_destroy(ret); + goto clunk_fid; + } + + return ret; + +clunk_fid: + v9fs_t_clunk(v9ses, nfid); + +error: + kfree(fcall); + return ERR_PTR(err); +} +*/ + + +/** + * v9fs_clear_inode - release an inode + * @inode: inode to release + * + */ +void v9fs_evict_inode(struct inode *inode) +{ + struct v9fs_inode *v9inode = V9FS_I(inode); + + truncate_inode_pages_final(&inode->i_data); + clear_inode(inode); + filemap_fdatawrite(&inode->i_data); + + v9fs_cache_inode_put_cookie(inode); + /* clunk the fid stashed in writeback_fid */ + if (v9inode->writeback_fid) { + p9_client_clunk(v9inode->writeback_fid); + v9inode->writeback_fid = NULL; + } +} + +static int v9fs_test_inode(struct inode *inode, void *data) +{ + int umode; + dev_t rdev; + struct v9fs_inode *v9inode = V9FS_I(inode); + struct p9_wstat *st = (struct p9_wstat *)data; + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(inode); + + umode = p9mode2unixmode(v9ses, st, &rdev); + /* don't match inode of different type */ + if ((inode->i_mode & S_IFMT) != (umode & S_IFMT)) + return 0; + + /* compare qid details */ + if (memcmp(&v9inode->qid.version, + &st->qid.version, sizeof(v9inode->qid.version))) + return 0; + + if (v9inode->qid.type != st->qid.type) + return 0; + + if (v9inode->qid.path != st->qid.path) + return 0; + return 1; +} + +static int v9fs_test_new_inode(struct inode *inode, void *data) +{ + return 0; +} + +static int v9fs_set_inode(struct inode *inode, void *data) +{ + struct v9fs_inode *v9inode = V9FS_I(inode); + struct p9_wstat *st = (struct p9_wstat *)data; + + memcpy(&v9inode->qid, &st->qid, sizeof(st->qid)); + return 0; +} + +static struct inode *v9fs_qid_iget(struct super_block *sb, + struct p9_qid *qid, + struct p9_wstat *st, + int new) +{ + dev_t rdev; + int retval; + umode_t umode; + unsigned long i_ino; + struct inode *inode; + struct v9fs_session_info *v9ses = sb->s_fs_info; + int (*test)(struct inode *, void *); + + if (new) + test = v9fs_test_new_inode; + else + test = v9fs_test_inode; + + i_ino = v9fs_qid2ino(qid); + inode = iget5_locked(sb, i_ino, test, v9fs_set_inode, st); + if (!inode) + return ERR_PTR(-ENOMEM); + if (!(inode->i_state & I_NEW)) + return inode; + /* + * initialize the inode with the stat info + * FIXME!! we may need support for stale inodes + * later. + */ + inode->i_ino = i_ino; + umode = p9mode2unixmode(v9ses, st, &rdev); + retval = v9fs_init_inode(v9ses, inode, umode, rdev); + if (retval) + goto error; + + v9fs_stat2inode(st, inode, sb, 0); + v9fs_cache_inode_get_cookie(inode); + unlock_new_inode(inode); + return inode; +error: + iget_failed(inode); + return ERR_PTR(retval); + +} + +struct inode * +v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid, + struct super_block *sb, int new) +{ + struct p9_wstat *st; + struct inode *inode = NULL; + + st = p9_client_stat(fid); + if (IS_ERR(st)) + return ERR_CAST(st); + + inode = v9fs_qid_iget(sb, &st->qid, st, new); + p9stat_free(st); + kfree(st); + return inode; +} + +/** + * v9fs_at_to_dotl_flags- convert Linux specific AT flags to + * plan 9 AT flag. + * @flags: flags to convert + */ +static int v9fs_at_to_dotl_flags(int flags) +{ + int rflags = 0; + if (flags & AT_REMOVEDIR) + rflags |= P9_DOTL_AT_REMOVEDIR; + return rflags; +} + +/** + * v9fs_dec_count - helper functon to drop i_nlink. + * + * If a directory had nlink <= 2 (including . and ..), then we should not drop + * the link count, which indicates the underlying exported fs doesn't maintain + * nlink accurately. e.g. + * - overlayfs sets nlink to 1 for merged dir + * - ext4 (with dir_nlink feature enabled) sets nlink to 1 if a dir has more + * than EXT4_LINK_MAX (65000) links. + * + * @inode: inode whose nlink is being dropped + */ +static void v9fs_dec_count(struct inode *inode) +{ + if (!S_ISDIR(inode->i_mode) || inode->i_nlink > 2) + drop_nlink(inode); +} + +/** + * v9fs_remove - helper function to remove files and directories + * @dir: directory inode that is being deleted + * @dentry: dentry that is being deleted + * @flags: removing a directory + * + */ + +static int v9fs_remove(struct inode *dir, struct dentry *dentry, int flags) +{ + struct inode *inode; + int retval = -EOPNOTSUPP; + struct p9_fid *v9fid, *dfid; + struct v9fs_session_info *v9ses; + + p9_debug(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %x\n", + dir, dentry, flags); + + v9ses = v9fs_inode2v9ses(dir); + inode = d_inode(dentry); + dfid = v9fs_parent_fid(dentry); + if (IS_ERR(dfid)) { + retval = PTR_ERR(dfid); + p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", retval); + return retval; + } + if (v9fs_proto_dotl(v9ses)) + retval = p9_client_unlinkat(dfid, dentry->d_name.name, + v9fs_at_to_dotl_flags(flags)); + if (retval == -EOPNOTSUPP) { + /* Try the one based on path */ + v9fid = v9fs_fid_clone(dentry); + if (IS_ERR(v9fid)) + return PTR_ERR(v9fid); + retval = p9_client_remove(v9fid); + } + if (!retval) { + /* + * directories on unlink should have zero + * link count + */ + if (flags & AT_REMOVEDIR) { + clear_nlink(inode); + v9fs_dec_count(dir); + } else + v9fs_dec_count(inode); + + v9fs_invalidate_inode_attr(inode); + v9fs_invalidate_inode_attr(dir); + } + return retval; +} + +/** + * v9fs_create - Create a file + * @v9ses: session information + * @dir: directory that dentry is being created in + * @dentry: dentry that is being created + * @extension: 9p2000.u extension string to support devices, etc. + * @perm: create permissions + * @mode: open mode + * + */ +static struct p9_fid * +v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, + struct dentry *dentry, char *extension, u32 perm, u8 mode) +{ + int err; + const unsigned char *name; + struct p9_fid *dfid, *ofid, *fid; + struct inode *inode; + + p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); + + err = 0; + ofid = NULL; + fid = NULL; + name = dentry->d_name.name; + dfid = v9fs_parent_fid(dentry); + if (IS_ERR(dfid)) { + err = PTR_ERR(dfid); + p9_debug(P9_DEBUG_VFS, "fid lookup failed %d\n", err); + return ERR_PTR(err); + } + + /* clone a fid to use for creation */ + ofid = clone_fid(dfid); + if (IS_ERR(ofid)) { + err = PTR_ERR(ofid); + p9_debug(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); + return ERR_PTR(err); + } + + err = p9_client_fcreate(ofid, name, perm, mode, extension); + if (err < 0) { + p9_debug(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); + goto error; + } + + if (!(perm & P9_DMLINK)) { + /* now walk from the parent so we can get unopened fid */ + fid = p9_client_walk(dfid, 1, &name, 1); + if (IS_ERR(fid)) { + err = PTR_ERR(fid); + p9_debug(P9_DEBUG_VFS, + "p9_client_walk failed %d\n", err); + fid = NULL; + goto error; + } + /* + * instantiate inode and assign the unopened fid to the dentry + */ + inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + p9_debug(P9_DEBUG_VFS, + "inode creation failed %d\n", err); + goto error; + } + v9fs_fid_add(dentry, fid); + d_instantiate(dentry, inode); + } + return ofid; +error: + if (ofid) + p9_client_clunk(ofid); + + if (fid) + p9_client_clunk(fid); + + return ERR_PTR(err); +} + +/** + * v9fs_vfs_create - VFS hook to create a regular file + * + * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open(). This is only called + * for mknod(2). + * + * @dir: directory inode that is being created + * @dentry: dentry that is being deleted + * @mode: create permissions + * + */ + +static int +v9fs_vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, + bool excl) +{ + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); + u32 perm = unixmode2p9mode(v9ses, mode); + struct p9_fid *fid; + + /* P9_OEXCL? */ + fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_ORDWR); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + v9fs_invalidate_inode_attr(dir); + p9_client_clunk(fid); + + return 0; +} + +/** + * v9fs_vfs_mkdir - VFS mkdir hook to create a directory + * @dir: inode that is being unlinked + * @dentry: dentry that is being unlinked + * @mode: mode for new directory + * + */ + +static int v9fs_vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + int err; + u32 perm; + struct p9_fid *fid; + struct v9fs_session_info *v9ses; + + p9_debug(P9_DEBUG_VFS, "name %pd\n", dentry); + err = 0; + v9ses = v9fs_inode2v9ses(dir); + perm = unixmode2p9mode(v9ses, mode | S_IFDIR); + fid = v9fs_create(v9ses, dir, dentry, NULL, perm, P9_OREAD); + if (IS_ERR(fid)) { + err = PTR_ERR(fid); + fid = NULL; + } else { + inc_nlink(dir); + v9fs_invalidate_inode_attr(dir); + } + + if (fid) + p9_client_clunk(fid); + + return err; +} + +/** + * v9fs_vfs_lookup - VFS lookup hook to "walk" to a new inode + * @dir: inode that is being walked from + * @dentry: dentry that is being walked to? + * @flags: lookup flags (unused) + * + */ + +struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, + unsigned int flags) +{ + struct dentry *res; + struct v9fs_session_info *v9ses; + struct p9_fid *dfid, *fid; + struct inode *inode; + const unsigned char *name; + + p9_debug(P9_DEBUG_VFS, "dir: %p dentry: (%pd) %p flags: %x\n", + dir, dentry, dentry, flags); + + if (dentry->d_name.len > NAME_MAX) + return ERR_PTR(-ENAMETOOLONG); + + v9ses = v9fs_inode2v9ses(dir); + /* We can walk d_parent because we hold the dir->i_mutex */ + dfid = v9fs_parent_fid(dentry); + if (IS_ERR(dfid)) + return ERR_CAST(dfid); + + /* + * Make sure we don't use a wrong inode due to parallel + * unlink. For cached mode create calls request for new + * inode. But with cache disabled, lookup should do this. + */ + name = dentry->d_name.name; + fid = p9_client_walk(dfid, 1, &name, 1); + if (fid == ERR_PTR(-ENOENT)) + inode = NULL; + else if (IS_ERR(fid)) + inode = ERR_CAST(fid); + else if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) + inode = v9fs_get_inode_from_fid(v9ses, fid, dir->i_sb); + else + inode = v9fs_get_new_inode_from_fid(v9ses, fid, dir->i_sb); + /* + * If we had a rename on the server and a parallel lookup + * for the new name, then make sure we instantiate with + * the new name. ie look up for a/b, while on server somebody + * moved b under k and client parallely did a lookup for + * k/b. + */ + res = d_splice_alias(inode, dentry); + if (!IS_ERR(fid)) { + if (!res) + v9fs_fid_add(dentry, fid); + else if (!IS_ERR(res)) + v9fs_fid_add(res, fid); + else + p9_client_clunk(fid); + } + return res; +} + +static int +v9fs_vfs_atomic_open(struct inode *dir, struct dentry *dentry, + struct file *file, unsigned flags, umode_t mode) +{ + int err; + u32 perm; + struct v9fs_inode *v9inode; + struct v9fs_session_info *v9ses; + struct p9_fid *fid, *inode_fid; + struct dentry *res = NULL; + + if (d_in_lookup(dentry)) { + res = v9fs_vfs_lookup(dir, dentry, 0); + if (IS_ERR(res)) + return PTR_ERR(res); + + if (res) + dentry = res; + } + + /* Only creates */ + if (!(flags & O_CREAT) || d_really_is_positive(dentry)) + return finish_no_open(file, res); + + err = 0; + + v9ses = v9fs_inode2v9ses(dir); + perm = unixmode2p9mode(v9ses, mode); + fid = v9fs_create(v9ses, dir, dentry, NULL, perm, + v9fs_uflags2omode(flags, + v9fs_proto_dotu(v9ses))); + if (IS_ERR(fid)) { + err = PTR_ERR(fid); + fid = NULL; + goto error; + } + + v9fs_invalidate_inode_attr(dir); + v9inode = V9FS_I(d_inode(dentry)); + mutex_lock(&v9inode->v_mutex); + if ((v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) && + !v9inode->writeback_fid && + ((flags & O_ACCMODE) != O_RDONLY)) { + /* + * clone a fid and add it to writeback_fid + * we do it during open time instead of + * page dirty time via write_begin/page_mkwrite + * because we want write after unlink usecase + * to work. + */ + inode_fid = v9fs_writeback_fid(dentry); + if (IS_ERR(inode_fid)) { + err = PTR_ERR(inode_fid); + mutex_unlock(&v9inode->v_mutex); + goto error; + } + v9inode->writeback_fid = (void *) inode_fid; + } + mutex_unlock(&v9inode->v_mutex); + err = finish_open(file, dentry, generic_file_open); + if (err) + goto error; + + file->private_data = fid; + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) + v9fs_cache_inode_set_cookie(d_inode(dentry), file); + + file->f_mode |= FMODE_CREATED; +out: + dput(res); + return err; + +error: + if (fid) + p9_client_clunk(fid); + goto out; +} + +/** + * v9fs_vfs_unlink - VFS unlink hook to delete an inode + * @i: inode that is being unlinked + * @d: dentry that is being unlinked + * + */ + +int v9fs_vfs_unlink(struct inode *i, struct dentry *d) +{ + return v9fs_remove(i, d, 0); +} + +/** + * v9fs_vfs_rmdir - VFS unlink hook to delete a directory + * @i: inode that is being unlinked + * @d: dentry that is being unlinked + * + */ + +int v9fs_vfs_rmdir(struct inode *i, struct dentry *d) +{ + return v9fs_remove(i, d, AT_REMOVEDIR); +} + +/** + * v9fs_vfs_rename - VFS hook to rename an inode + * @old_dir: old dir inode + * @old_dentry: old dentry + * @new_dir: new dir inode + * @new_dentry: new dentry + * + */ + +int +v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + int retval; + struct inode *old_inode; + struct inode *new_inode; + struct v9fs_session_info *v9ses; + struct p9_fid *oldfid; + struct p9_fid *olddirfid; + struct p9_fid *newdirfid; + struct p9_wstat wstat; + + if (flags) + return -EINVAL; + + p9_debug(P9_DEBUG_VFS, "\n"); + retval = 0; + old_inode = d_inode(old_dentry); + new_inode = d_inode(new_dentry); + v9ses = v9fs_inode2v9ses(old_inode); + oldfid = v9fs_fid_lookup(old_dentry); + if (IS_ERR(oldfid)) + return PTR_ERR(oldfid); + + olddirfid = clone_fid(v9fs_parent_fid(old_dentry)); + if (IS_ERR(olddirfid)) { + retval = PTR_ERR(olddirfid); + goto done; + } + + newdirfid = clone_fid(v9fs_parent_fid(new_dentry)); + if (IS_ERR(newdirfid)) { + retval = PTR_ERR(newdirfid); + goto clunk_olddir; + } + + down_write(&v9ses->rename_sem); + if (v9fs_proto_dotl(v9ses)) { + retval = p9_client_renameat(olddirfid, old_dentry->d_name.name, + newdirfid, new_dentry->d_name.name); + if (retval == -EOPNOTSUPP) + retval = p9_client_rename(oldfid, newdirfid, + new_dentry->d_name.name); + if (retval != -EOPNOTSUPP) + goto clunk_newdir; + } + if (old_dentry->d_parent != new_dentry->d_parent) { + /* + * 9P .u can only handle file rename in the same directory + */ + + p9_debug(P9_DEBUG_ERROR, "old dir and new dir are different\n"); + retval = -EXDEV; + goto clunk_newdir; + } + v9fs_blank_wstat(&wstat); + wstat.muid = v9ses->uname; + wstat.name = new_dentry->d_name.name; + retval = p9_client_wstat(oldfid, &wstat); + +clunk_newdir: + if (!retval) { + if (new_inode) { + if (S_ISDIR(new_inode->i_mode)) + clear_nlink(new_inode); + else + v9fs_dec_count(new_inode); + } + if (S_ISDIR(old_inode->i_mode)) { + if (!new_inode) + inc_nlink(new_dir); + v9fs_dec_count(old_dir); + } + v9fs_invalidate_inode_attr(old_inode); + v9fs_invalidate_inode_attr(old_dir); + v9fs_invalidate_inode_attr(new_dir); + + /* successful rename */ + d_move(old_dentry, new_dentry); + } + up_write(&v9ses->rename_sem); + p9_client_clunk(newdirfid); + +clunk_olddir: + p9_client_clunk(olddirfid); + +done: + return retval; +} + +/** + * v9fs_vfs_getattr - retrieve file metadata + * @path: Object to query + * @stat: metadata structure to populate + * @request_mask: Mask of STATX_xxx flags indicating the caller's interests + * @flags: AT_STATX_xxx setting + * + */ + +static int +v9fs_vfs_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int flags) +{ + struct dentry *dentry = path->dentry; + struct v9fs_session_info *v9ses; + struct p9_fid *fid; + struct p9_wstat *st; + + p9_debug(P9_DEBUG_VFS, "dentry: %p\n", dentry); + v9ses = v9fs_dentry2v9ses(dentry); + if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) { + generic_fillattr(d_inode(dentry), stat); + return 0; + } + fid = v9fs_fid_lookup(dentry); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + st = p9_client_stat(fid); + if (IS_ERR(st)) + return PTR_ERR(st); + + v9fs_stat2inode(st, d_inode(dentry), dentry->d_sb, 0); + generic_fillattr(d_inode(dentry), stat); + + p9stat_free(st); + kfree(st); + return 0; +} + +/** + * v9fs_vfs_setattr - set file metadata + * @dentry: file whose metadata to set + * @iattr: metadata assignment structure + * + */ + +static int v9fs_vfs_setattr(struct dentry *dentry, struct iattr *iattr) +{ + int retval; + struct v9fs_session_info *v9ses; + struct p9_fid *fid; + struct p9_wstat wstat; + + p9_debug(P9_DEBUG_VFS, "\n"); + retval = setattr_prepare(dentry, iattr); + if (retval) + return retval; + + retval = -EPERM; + v9ses = v9fs_dentry2v9ses(dentry); + fid = v9fs_fid_lookup(dentry); + if(IS_ERR(fid)) + return PTR_ERR(fid); + + v9fs_blank_wstat(&wstat); + if (iattr->ia_valid & ATTR_MODE) + wstat.mode = unixmode2p9mode(v9ses, iattr->ia_mode); + + if (iattr->ia_valid & ATTR_MTIME) + wstat.mtime = iattr->ia_mtime.tv_sec; + + if (iattr->ia_valid & ATTR_ATIME) + wstat.atime = iattr->ia_atime.tv_sec; + + if (iattr->ia_valid & ATTR_SIZE) + wstat.length = iattr->ia_size; + + if (v9fs_proto_dotu(v9ses)) { + if (iattr->ia_valid & ATTR_UID) + wstat.n_uid = iattr->ia_uid; + + if (iattr->ia_valid & ATTR_GID) + wstat.n_gid = iattr->ia_gid; + } + + /* Write all dirty data */ + if (d_is_reg(dentry)) + filemap_write_and_wait(d_inode(dentry)->i_mapping); + + retval = p9_client_wstat(fid, &wstat); + if (retval < 0) + return retval; + + if ((iattr->ia_valid & ATTR_SIZE) && + iattr->ia_size != i_size_read(d_inode(dentry))) + truncate_setsize(d_inode(dentry), iattr->ia_size); + + v9fs_invalidate_inode_attr(d_inode(dentry)); + + setattr_copy(d_inode(dentry), iattr); + mark_inode_dirty(d_inode(dentry)); + return 0; +} + +/** + * v9fs_stat2inode - populate an inode structure with mistat info + * @stat: Plan 9 metadata (mistat) structure + * @inode: inode to populate + * @sb: superblock of filesystem + * @flags: control flags (e.g. V9FS_STAT2INODE_KEEP_ISIZE) + * + */ + +void +v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, + struct super_block *sb, unsigned int flags) +{ + umode_t mode; + char ext[32]; + char tag_name[14]; + unsigned int i_nlink; + struct v9fs_session_info *v9ses = sb->s_fs_info; + struct v9fs_inode *v9inode = V9FS_I(inode); + + set_nlink(inode, 1); + + inode->i_atime.tv_sec = stat->atime; + inode->i_mtime.tv_sec = stat->mtime; + inode->i_ctime.tv_sec = stat->mtime; + + inode->i_uid = v9ses->dfltuid; + inode->i_gid = v9ses->dfltgid; + + if (v9fs_proto_dotu(v9ses)) { + inode->i_uid = stat->n_uid; + inode->i_gid = stat->n_gid; + } + if ((S_ISREG(inode->i_mode)) || (S_ISDIR(inode->i_mode))) { + if (v9fs_proto_dotu(v9ses) && (stat->extension[0] != '\0')) { + /* + * Hadlink support got added later to + * to the .u extension. So there can be + * server out there that doesn't support + * this even with .u extension. So check + * for non NULL stat->extension + */ + strlcpy(ext, stat->extension, sizeof(ext)); + /* HARDLINKCOUNT %u */ + sscanf(ext, "%13s %u", tag_name, &i_nlink); + if (!strncmp(tag_name, "HARDLINKCOUNT", 13)) + set_nlink(inode, i_nlink); + } + } + mode = p9mode2perm(v9ses, stat); + mode |= inode->i_mode & ~S_IALLUGO; + inode->i_mode = mode; + + if (!(flags & V9FS_STAT2INODE_KEEP_ISIZE)) + v9fs_i_size_write(inode, stat->length); + /* not real number of blocks, but 512 byte ones ... */ + inode->i_blocks = (stat->length + 512 - 1) >> 9; + v9inode->cache_validity &= ~V9FS_INO_INVALID_ATTR; +} + +/** + * v9fs_qid2ino - convert qid into inode number + * @qid: qid to hash + * + * BUG: potential for inode number collisions? + */ + +ino_t v9fs_qid2ino(struct p9_qid *qid) +{ + u64 path = qid->path + 2; + ino_t i = 0; + + if (sizeof(ino_t) == sizeof(path)) + memcpy(&i, &path, sizeof(ino_t)); + else + i = (ino_t) (path ^ (path >> 32)); + + return i; +} + +/** + * v9fs_vfs_get_link - follow a symlink path + * @dentry: dentry for symlink + * @inode: inode for symlink + * @done: delayed call for when we are done with the return value + */ + +static const char *v9fs_vfs_get_link(struct dentry *dentry, + struct inode *inode, + struct delayed_call *done) +{ + struct v9fs_session_info *v9ses; + struct p9_fid *fid; + struct p9_wstat *st; + char *res; + + if (!dentry) + return ERR_PTR(-ECHILD); + + v9ses = v9fs_dentry2v9ses(dentry); + fid = v9fs_fid_lookup(dentry); + p9_debug(P9_DEBUG_VFS, "%pd\n", dentry); + + if (IS_ERR(fid)) + return ERR_CAST(fid); + + if (!v9fs_proto_dotu(v9ses)) + return ERR_PTR(-EBADF); + + st = p9_client_stat(fid); + if (IS_ERR(st)) + return ERR_CAST(st); + + if (!(st->mode & P9_DMSYMLINK)) { + p9stat_free(st); + kfree(st); + return ERR_PTR(-EINVAL); + } + res = st->extension; + st->extension = NULL; + if (strlen(res) >= PATH_MAX) + res[PATH_MAX - 1] = '\0'; + + p9stat_free(st); + kfree(st); + set_delayed_call(done, kfree_link, res); + return res; +} + +/** + * v9fs_vfs_mkspecial - create a special file + * @dir: inode to create special file in + * @dentry: dentry to create + * @perm: mode to create special file + * @extension: 9p2000.u format extension string representing special file + * + */ + +static int v9fs_vfs_mkspecial(struct inode *dir, struct dentry *dentry, + u32 perm, const char *extension) +{ + struct p9_fid *fid; + struct v9fs_session_info *v9ses; + + v9ses = v9fs_inode2v9ses(dir); + if (!v9fs_proto_dotu(v9ses)) { + p9_debug(P9_DEBUG_ERROR, "not extended\n"); + return -EPERM; + } + + fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm, + P9_OREAD); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + v9fs_invalidate_inode_attr(dir); + p9_client_clunk(fid); + return 0; +} + +/** + * v9fs_vfs_symlink - helper function to create symlinks + * @dir: directory inode containing symlink + * @dentry: dentry for symlink + * @symname: symlink data + * + * See Also: 9P2000.u RFC for more information + * + */ + +static int +v9fs_vfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) +{ + p9_debug(P9_DEBUG_VFS, " %lu,%pd,%s\n", + dir->i_ino, dentry, symname); + + return v9fs_vfs_mkspecial(dir, dentry, P9_DMSYMLINK, symname); +} + +#define U32_MAX_DIGITS 10 + +/** + * v9fs_vfs_link - create a hardlink + * @old_dentry: dentry for file to link to + * @dir: inode destination for new link + * @dentry: dentry for link + * + */ + +static int +v9fs_vfs_link(struct dentry *old_dentry, struct inode *dir, + struct dentry *dentry) +{ + int retval; + char name[1 + U32_MAX_DIGITS + 2]; /* sign + number + \n + \0 */ + struct p9_fid *oldfid; + + p9_debug(P9_DEBUG_VFS, " %lu,%pd,%pd\n", + dir->i_ino, dentry, old_dentry); + + oldfid = v9fs_fid_clone(old_dentry); + if (IS_ERR(oldfid)) + return PTR_ERR(oldfid); + + sprintf(name, "%d\n", oldfid->fid); + retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name); + if (!retval) { + v9fs_refresh_inode(oldfid, d_inode(old_dentry)); + v9fs_invalidate_inode_attr(dir); + } + p9_client_clunk(oldfid); + return retval; +} + +/** + * v9fs_vfs_mknod - create a special file + * @dir: inode destination for new link + * @dentry: dentry for file + * @mode: mode for creation + * @rdev: device associated with special file + * + */ + +static int +v9fs_vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t rdev) +{ + struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir); + int retval; + char name[2 + U32_MAX_DIGITS + 1 + U32_MAX_DIGITS + 1]; + u32 perm; + + p9_debug(P9_DEBUG_VFS, " %lu,%pd mode: %hx MAJOR: %u MINOR: %u\n", + dir->i_ino, dentry, mode, + MAJOR(rdev), MINOR(rdev)); + + /* build extension */ + if (S_ISBLK(mode)) + sprintf(name, "b %u %u", MAJOR(rdev), MINOR(rdev)); + else if (S_ISCHR(mode)) + sprintf(name, "c %u %u", MAJOR(rdev), MINOR(rdev)); + else + *name = 0; + + perm = unixmode2p9mode(v9ses, mode); + retval = v9fs_vfs_mkspecial(dir, dentry, perm, name); + + return retval; +} + +int v9fs_refresh_inode(struct p9_fid *fid, struct inode *inode) +{ + int umode; + dev_t rdev; + struct p9_wstat *st; + struct v9fs_session_info *v9ses; + unsigned int flags; + + v9ses = v9fs_inode2v9ses(inode); + st = p9_client_stat(fid); + if (IS_ERR(st)) + return PTR_ERR(st); + /* + * Don't update inode if the file type is different + */ + umode = p9mode2unixmode(v9ses, st, &rdev); + if ((inode->i_mode & S_IFMT) != (umode & S_IFMT)) + goto out; + + /* + * We don't want to refresh inode->i_size, + * because we may have cached data + */ + flags = (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) ? + V9FS_STAT2INODE_KEEP_ISIZE : 0; + v9fs_stat2inode(st, inode, inode->i_sb, flags); +out: + p9stat_free(st); + kfree(st); + return 0; +} + +static const struct inode_operations v9fs_dir_inode_operations_dotu = { + .create = v9fs_vfs_create, + .lookup = v9fs_vfs_lookup, + .atomic_open = v9fs_vfs_atomic_open, + .symlink = v9fs_vfs_symlink, + .link = v9fs_vfs_link, + .unlink = v9fs_vfs_unlink, + .mkdir = v9fs_vfs_mkdir, + .rmdir = v9fs_vfs_rmdir, + .mknod = v9fs_vfs_mknod, + .rename = v9fs_vfs_rename, + .getattr = v9fs_vfs_getattr, + .setattr = v9fs_vfs_setattr, +}; + +static const struct inode_operations v9fs_dir_inode_operations = { + .create = v9fs_vfs_create, + .lookup = v9fs_vfs_lookup, + .atomic_open = v9fs_vfs_atomic_open, + .unlink = v9fs_vfs_unlink, + .mkdir = v9fs_vfs_mkdir, + .rmdir = v9fs_vfs_rmdir, + .mknod = v9fs_vfs_mknod, + .rename = v9fs_vfs_rename, + .getattr = v9fs_vfs_getattr, + .setattr = v9fs_vfs_setattr, +}; + +static const struct inode_operations v9fs_file_inode_operations = { + .getattr = v9fs_vfs_getattr, + .setattr = v9fs_vfs_setattr, +}; + +static const struct inode_operations v9fs_symlink_inode_operations = { + .get_link = v9fs_vfs_get_link, + .getattr = v9fs_vfs_getattr, + .setattr = v9fs_vfs_setattr, +}; + |