/* * 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 * */ #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 <net/9p/9p.h> #include <net/9p/client.h> #include "v9fs.h" #include "v9fs_vfs.h" #include "fid.h" #include "cache.h" static const struct inode_operations v9fs_dir_inode_operations; static const struct inode_operations v9fs_dir_inode_operations_ext; 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 int unixmode2p9mode(struct v9fs_session_info *v9ses, int mode) { int res; res = mode & 0777; if (S_ISDIR(mode)) res |= P9_DMDIR; if (v9fs_extended(v9ses)) { if (S_ISLNK(mode)) res |= P9_DMSYMLINK; 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; if ((mode & P9_DMLINK)) res |= P9_DMLINK; } return res; } /** * p9mode2unixmode- convert plan9 mode bits to unix mode bits * @v9ses: v9fs session information * @mode: mode to convert * */ static int p9mode2unixmode(struct v9fs_session_info *v9ses, int mode) { int res; res = mode & 0777; if ((mode & P9_DMDIR) == P9_DMDIR) res |= S_IFDIR; else if ((mode & P9_DMSYMLINK) && (v9fs_extended(v9ses))) res |= S_IFLNK; else if ((mode & P9_DMSOCKET) && (v9fs_extended(v9ses)) && (v9ses->nodev == 0)) res |= S_IFSOCK; else if ((mode & P9_DMNAMEDPIPE) && (v9fs_extended(v9ses)) && (v9ses->nodev == 0)) res |= S_IFIFO; else if ((mode & P9_DMDEVICE) && (v9fs_extended(v9ses)) && (v9ses->nodev == 0)) res |= S_IFBLK; else res |= S_IFREG; if (v9fs_extended(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; } /** * 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 (uflags & O_TRUNC) ret |= P9_OTRUNC; 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 * */ static 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 = ~0; wstat->n_gid = ~0; wstat->n_muid = ~0; wstat->extension = NULL; } #ifdef CONFIG_9P_FSCACHE /** * v9fs_alloc_inode - helper function to allocate an inode * This callback is executed before setting up the inode so that we * can associate a vcookie with each inode. * */ struct inode *v9fs_alloc_inode(struct super_block *sb) { struct v9fs_cookie *vcookie; vcookie = (struct v9fs_cookie *)kmem_cache_alloc(vcookie_cache, GFP_KERNEL); if (!vcookie) return NULL; vcookie->fscache = NULL; vcookie->qid = NULL; spin_lock_init(&vcookie->lock); return &vcookie->inode; } /** * v9fs_destroy_inode - destroy an inode * */ void v9fs_destroy_inode(struct inode *inode) { kmem_cache_free(vcookie_cache, v9fs_inode2cookie(inode)); } #endif /** * 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, int mode) { int err; struct inode *inode; struct v9fs_session_info *v9ses = sb->s_fs_info; P9_DPRINTK(P9_DEBUG_VFS, "super block: %p mode: %o\n", sb, mode); inode = new_inode(sb); if (!inode) { P9_EPRINTK(KERN_WARNING, "Problem allocating inode\n"); return ERR_PTR(-ENOMEM); } inode->i_mode = mode; inode->i_uid = current_fsuid(); inode->i_gid = current_fsgid(); inode->i_blocks = 0; inode->i_rdev = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; 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_extended(v9ses)) { P9_DPRINTK(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: inode->i_op = &v9fs_file_inode_operations; inode->i_fop = &v9fs_file_operations; break; case S_IFLNK: if (!v9fs_extended(v9ses)) { P9_DPRINTK(P9_DEBUG_ERROR, "extended modes used w/o 9P2000.u\n"); err = -EINVAL; goto error; } inode->i_op = &v9fs_symlink_inode_operations; break; case S_IFDIR: inc_nlink(inode); if (v9fs_extended(v9ses)) inode->i_op = &v9fs_dir_inode_operations_ext; else inode->i_op = &v9fs_dir_inode_operations; inode->i_fop = &v9fs_dir_operations; break; default: P9_DPRINTK(P9_DEBUG_ERROR, "BAD mode 0x%x S_IFMT 0x%x\n", mode, mode & S_IFMT); err = -EINVAL; goto error; } return inode; error: iput(inode); return ERR_PTR(err); } /* 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_clear_inode(struct inode *inode) { filemap_fdatawrite(inode->i_mapping); #ifdef CONFIG_9P_FSCACHE v9fs_cache_inode_put_cookie(inode); #endif } /** * v9fs_inode_from_fid - populate an inode by issuing a attribute request * @v9ses: session information * @fid: fid to issue attribute request for * @sb: superblock on which to create inode * */ static struct inode * v9fs_inode_from_fid(struct v9fs_session_info *v9ses, struct p9_fid *fid, struct super_block *sb) { int err, umode; struct inode *ret; struct p9_wstat *st; ret = NULL; st = p9_client_stat(fid); if (IS_ERR(st)) return ERR_CAST(st); umode = p9mode2unixmode(v9ses, st->mode); ret = v9fs_get_inode(sb, umode); if (IS_ERR(ret)) { err = PTR_ERR(ret); goto error; } v9fs_stat2inode(st, ret, sb); ret->i_ino = v9fs_qid2ino(&st->qid); #ifdef CONFIG_9P_FSCACHE v9fs_vcookie_set_qid(ret, &st->qid); v9fs_cache_inode_get_cookie(ret); #endif p9stat_free(st); kfree(st); return ret; error: p9stat_free(st); kfree(st); return ERR_PTR(err); } /** * v9fs_remove - helper function to remove files and directories * @dir: directory inode that is being deleted * @file: dentry that is being deleted * @rmdir: removing a directory * */ static int v9fs_remove(struct inode *dir, struct dentry *file, int rmdir) { struct inode *file_inode; struct v9fs_session_info *v9ses; struct p9_fid *v9fid; P9_DPRINTK(P9_DEBUG_VFS, "inode: %p dentry: %p rmdir: %d\n", dir, file, rmdir); file_inode = file->d_inode; v9ses = v9fs_inode2v9ses(file_inode); v9fid = v9fs_fid_clone(file); if (IS_ERR(v9fid)) return PTR_ERR(v9fid); return p9_client_remove(v9fid); } static int v9fs_open_created(struct inode *inode, struct file *file) { return 0; } /** * 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; char *name; struct p9_fid *dfid, *ofid, *fid; struct inode *inode; P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name); err = 0; ofid = NULL; fid = NULL; name = (char *) dentry->d_name.name; dfid = v9fs_fid_clone(dentry->d_parent); if (IS_ERR(dfid)) { err = PTR_ERR(dfid); P9_DPRINTK(P9_DEBUG_VFS, "fid clone failed %d\n", err); dfid = NULL; goto error; } /* clone a fid to use for creation */ ofid = p9_client_walk(dfid, 0, NULL, 1); if (IS_ERR(ofid)) { err = PTR_ERR(ofid); P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); ofid = NULL; goto error; } err = p9_client_fcreate(ofid, name, perm, mode, extension); if (err < 0) { P9_DPRINTK(P9_DEBUG_VFS, "p9_client_fcreate failed %d\n", err); goto error; } /* now walk from the parent so we can get unopened fid */ fid = p9_client_walk(dfid, 1, &name, 0); if (IS_ERR(fid)) { err = PTR_ERR(fid); P9_DPRINTK(P9_DEBUG_VFS, "p9_client_walk failed %d\n", err); fid = NULL; goto error; } else dfid = NULL; /* instantiate inode and assign the unopened fid to the dentry */ inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb); if (IS_ERR(inode)) { err = PTR_ERR(inode); P9_DPRINTK(P9_DEBUG_VFS, "inode creation failed %d\n", err); goto error; } if (v9ses->cache) dentry->d_op = &v9fs_cached_dentry_operations; else dentry->d_op = &v9fs_dentry_operations; d_instantiate(dentry, inode); err = v9fs_fid_add(dentry, fid); if (err < 0) goto error; return ofid; error: if (dfid) p9_client_clunk(dfid); if (ofid) p9_client_clunk(ofid); if (fid) p9_client_clunk(fid); return ERR_PTR(err); } /** * v9fs_vfs_create - VFS hook to create files * @dir: directory inode that is being created * @dentry: dentry that is being deleted * @mode: create permissions * @nd: path information * */ static int v9fs_vfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { int err; u32 perm; int flags; struct v9fs_session_info *v9ses; struct p9_fid *fid; struct file *filp; err = 0; fid = NULL; v9ses = v9fs_inode2v9ses(dir); perm = unixmode2p9mode(v9ses, mode); if (nd && nd->flags & LOOKUP_OPEN) flags = nd->intent.open.flags - 1; else flags = O_RDWR; fid = v9fs_create(v9ses, dir, dentry, NULL, perm, v9fs_uflags2omode(flags, v9fs_extended(v9ses))); if (IS_ERR(fid)) { err = PTR_ERR(fid); fid = NULL; goto error; } /* if we are opening a file, assign the open fid to the file */ if (nd && nd->flags & LOOKUP_OPEN) { filp = lookup_instantiate_filp(nd, dentry, v9fs_open_created); if (IS_ERR(filp)) { err = PTR_ERR(filp); goto error; } filp->private_data = fid; } else p9_client_clunk(fid); return 0; error: if (fid) p9_client_clunk(fid); return err; } /** * 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, int mode) { int err; u32 perm; struct v9fs_session_info *v9ses; struct p9_fid *fid; P9_DPRINTK(P9_DEBUG_VFS, "name %s\n", dentry->d_name.name); 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; } 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? * @nameidata: path data * */ static struct dentry *v9fs_vfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nameidata) { struct super_block *sb; struct v9fs_session_info *v9ses; struct p9_fid *dfid, *fid; struct inode *inode; char *name; int result = 0; P9_DPRINTK(P9_DEBUG_VFS, "dir: %p dentry: (%s) %p nameidata: %p\n", dir, dentry->d_name.name, dentry, nameidata); sb = dir->i_sb; v9ses = v9fs_inode2v9ses(dir); dfid = v9fs_fid_lookup(dentry->d_parent); if (IS_ERR(dfid)) return ERR_CAST(dfid); name = (char *) dentry->d_name.name; fid = p9_client_walk(dfid, 1, &name, 1); if (IS_ERR(fid)) { result = PTR_ERR(fid); if (result == -ENOENT) { d_add(dentry, NULL); return NULL; } return ERR_PTR(result); } inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb); if (IS_ERR(inode)) { result = PTR_ERR(inode); inode = NULL; goto error; } result = v9fs_fid_add(dentry, fid); if (result < 0) goto error; if ((fid->qid.version) && (v9ses->cache)) dentry->d_op = &v9fs_cached_dentry_operations; else dentry->d_op = &v9fs_dentry_operations; d_add(dentry, inode); return NULL; error: p9_client_clunk(fid); return ERR_PTR(result); } /** * v9fs_vfs_unlink - VFS unlink hook to delete an inode * @i: inode that is being unlinked * @d: dentry that is being unlinked * */ static 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 * */ static int v9fs_vfs_rmdir(struct inode *i, struct dentry *d) { return v9fs_remove(i, d, 1); } /** * 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 * */ static int v9fs_vfs_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct inode *old_inode; struct v9fs_session_info *v9ses; struct p9_fid *oldfid; struct p9_fid *olddirfid; struct p9_fid *newdirfid; struct p9_wstat wstat; int retval; P9_DPRINTK(P9_DEBUG_VFS, "\n"); retval = 0; old_inode = old_dentry->d_inode; v9ses = v9fs_inode2v9ses(old_inode); oldfid = v9fs_fid_lookup(old_dentry); if (IS_ERR(oldfid)) return PTR_ERR(oldfid); olddirfid = v9fs_fid_clone(old_dentry->d_parent); if (IS_ERR(olddirfid)) { retval = PTR_ERR(olddirfid); goto done; } newdirfid = v9fs_fid_clone(new_dentry->d_parent); if (IS_ERR(newdirfid)) { retval = PTR_ERR(newdirfid); goto clunk_olddir; } /* 9P can only handle file rename in the same directory */ if (memcmp(&olddirfid->qid, &newdirfid->qid, sizeof(newdirfid->qid))) { P9_DPRINTK(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 = (char *) new_dentry->d_name.name; retval = p9_client_wstat(oldfid, &wstat); clunk_newdir: p9_client_clunk(newdirfid); clunk_olddir: p9_client_clunk(olddirfid); done: return retval; } /** * v9fs_vfs_getattr - retrieve file metadata * @mnt: mount information * @dentry: file to get attributes on * @stat: metadata structure to populate * */ static int v9fs_vfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { int err; struct v9fs_session_info *v9ses; struct p9_fid *fid; struct p9_wstat *st; P9_DPRINTK(P9_DEBUG_VFS, "dentry: %p\n", dentry); err = -EPERM; v9ses = v9fs_inode2v9ses(dentry->d_inode); if (v9ses->cache == CACHE_LOOSE || v9ses->cache == CACHE_FSCACHE) return simple_getattr(mnt, dentry, stat); 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, dentry->d_inode, dentry->d_inode->i_sb); generic_fillattr(dentry->d_inode, stat); 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_DPRINTK(P9_DEBUG_VFS, "\n"); retval = -EPERM; v9ses = v9fs_inode2v9ses(dentry->d_inode); 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_extended(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; } retval = p9_client_wstat(fid, &wstat); if (retval >= 0) retval = inode_setattr(dentry->d_inode, iattr); return retval; } /** * v9fs_stat2inode - populate an inode structure with mistat info * @stat: Plan 9 metadata (mistat) structure * @inode: inode to populate * @sb: superblock of filesystem * */ void v9fs_stat2inode(struct p9_wstat *stat, struct inode *inode, struct super_block *sb) { char ext[32]; struct v9fs_session_info *v9ses = sb->s_fs_info; inode->i_nlink = 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_extended(v9ses)) { inode->i_uid = stat->n_uid; inode->i_gid = stat->n_gid; } inode->i_mode = p9mode2unixmode(v9ses, stat->mode); if ((S_ISBLK(inode->i_mode)) || (S_ISCHR(inode->i_mode))) { char type = 0; int major = -1; int minor = -1; strncpy(ext, stat->extension, sizeof(ext)); sscanf(ext, "%c %u %u", &type, &major, &minor); switch (type) { case 'c': inode->i_mode &= ~S_IFBLK; inode->i_mode |= S_IFCHR; break; case 'b': break; default: P9_DPRINTK(P9_DEBUG_ERROR, "Unknown special type %c %s\n", type, stat->extension); }; inode->i_rdev = MKDEV(major, minor); init_special_inode(inode, inode->i_mode, inode->i_rdev); } else inode->i_rdev = 0; i_size_write(inode, stat->length); /* not real number of blocks, but 512 byte ones ... */ inode->i_blocks = (i_size_read(inode) + 512 - 1) >> 9; } /** * 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_readlink - read a symlink's location (internal version) * @dentry: dentry for symlink * @buffer: buffer to load symlink location into * @buflen: length of buffer * */ static int v9fs_readlink(struct dentry *dentry, char *buffer, int buflen) { int retval; struct v9fs_session_info *v9ses; struct p9_fid *fid; struct p9_wstat *st; P9_DPRINTK(P9_DEBUG_VFS, " %s\n", dentry->d_name.name); retval = -EPERM; v9ses = v9fs_inode2v9ses(dentry->d_inode); fid = v9fs_fid_lookup(dentry); if (IS_ERR(fid)) return PTR_ERR(fid); if (!v9fs_extended(v9ses)) return -EBADF; st = p9_client_stat(fid); if (IS_ERR(st)) return PTR_ERR(st); if (!(st->mode & P9_DMSYMLINK)) { retval = -EINVAL; goto done; } /* copy extension buffer into buffer */ strncpy(buffer, st->extension, buflen); P9_DPRINTK(P9_DEBUG_VFS, "%s -> %s (%s)\n", dentry->d_name.name, st->extension, buffer); retval = buflen; done: kfree(st); return retval; } /** * v9fs_vfs_readlink - read a symlink's location * @dentry: dentry for symlink * @buffer: buffer to load symlink location into * @buflen: length of buffer * */ static int v9fs_vfs_readlink(struct dentry *dentry, char __user * buffer, int buflen) { int retval; int ret; char *link = __getname(); if (unlikely(!link)) return -ENOMEM; if (buflen > PATH_MAX) buflen = PATH_MAX; P9_DPRINTK(P9_DEBUG_VFS, " dentry: %s (%p)\n", dentry->d_name.name, dentry); retval = v9fs_readlink(dentry, link, buflen); if (retval > 0) { if ((ret = copy_to_user(buffer, link, retval)) != 0) { P9_DPRINTK(P9_DEBUG_ERROR, "problem copying to user: %d\n", ret); retval = ret; } } __putname(link); return retval; } /** * v9fs_vfs_follow_link - follow a symlink path * @dentry: dentry for symlink * @nd: nameidata * */ static void *v9fs_vfs_follow_link(struct dentry *dentry, struct nameidata *nd) { int len = 0; char *link = __getname(); P9_DPRINTK(P9_DEBUG_VFS, "%s n", dentry->d_name.name); if (!link) link = ERR_PTR(-ENOMEM); else { len = v9fs_readlink(dentry, link, PATH_MAX); if (len < 0) { __putname(link); link = ERR_PTR(len); } else link[len] = 0; } nd_set_link(nd, link); return NULL; } /** * v9fs_vfs_put_link - release a symlink path * @dentry: dentry for symlink * @nd: nameidata * @p: unused * */ static void v9fs_vfs_put_link(struct dentry *dentry, struct nameidata *nd, void *p) { char *s = nd_get_link(nd); P9_DPRINTK(P9_DEBUG_VFS, " %s %s\n", dentry->d_name.name, IS_ERR(s) ? "<error>" : s); if (!IS_ERR(s)) __putname(s); } /** * v9fs_vfs_mkspecial - create a special file * @dir: inode to create special file in * @dentry: dentry to create * @mode: 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, int mode, const char *extension) { u32 perm; struct v9fs_session_info *v9ses; struct p9_fid *fid; v9ses = v9fs_inode2v9ses(dir); if (!v9fs_extended(v9ses)) { P9_DPRINTK(P9_DEBUG_ERROR, "not extended\n"); return -EPERM; } perm = unixmode2p9mode(v9ses, mode); fid = v9fs_create(v9ses, dir, dentry, (char *) extension, perm, P9_OREAD); if (IS_ERR(fid)) return PTR_ERR(fid); 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_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name, symname); return v9fs_vfs_mkspecial(dir, dentry, S_IFLNK, symname); } /** * 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; struct p9_fid *oldfid; char *name; P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s,%s\n", dir->i_ino, dentry->d_name.name, old_dentry->d_name.name); oldfid = v9fs_fid_clone(old_dentry); if (IS_ERR(oldfid)) return PTR_ERR(oldfid); name = __getname(); if (unlikely(!name)) { retval = -ENOMEM; goto clunk_fid; } sprintf(name, "%d\n", oldfid->fid); retval = v9fs_vfs_mkspecial(dir, dentry, P9_DMLINK, name); __putname(name); clunk_fid: 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, int mode, dev_t rdev) { int retval; char *name; P9_DPRINTK(P9_DEBUG_VFS, " %lu,%s mode: %x MAJOR: %u MINOR: %u\n", dir->i_ino, dentry->d_name.name, mode, MAJOR(rdev), MINOR(rdev)); if (!new_valid_dev(rdev)) return -EINVAL; name = __getname(); if (!name) return -ENOMEM; /* 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 if (S_ISFIFO(mode)) *name = 0; else { __putname(name); return -EINVAL; } retval = v9fs_vfs_mkspecial(dir, dentry, mode, name); __putname(name); return retval; } static const struct inode_operations v9fs_dir_inode_operations_ext = { .create = v9fs_vfs_create, .lookup = v9fs_vfs_lookup, .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, .readlink = v9fs_vfs_readlink, .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, .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 = { .readlink = v9fs_vfs_readlink, .follow_link = v9fs_vfs_follow_link, .put_link = v9fs_vfs_put_link, .getattr = v9fs_vfs_getattr, .setattr = v9fs_vfs_setattr, };