/* * linux/fs/nfsd/vfs.c * * File operations used by nfsd. Some of these have been ripped from * other parts of the kernel because they weren't in ksyms.c, others * are partial duplicates with added or changed functionality. * * Note that several functions dget() the dentry upon which they want * to act, most notably those that create directory entries. Response * dentry's are dput()'d if necessary in the release callback. * So if you notice code paths that apparently fail to dput() the * dentry, don't worry--they have been taken care of. * * Copyright (C) 1995-1999 Olaf Kirch */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_NFSD_V3 #include #include #endif /* CONFIG_NFSD_V3 */ #include #include #include #define NFSDDBG_FACILITY NFSDDBG_FILEOP #define NFSD_PARANOIA /* We must ignore files (but only files) which might have mandatory * locks on them because there is no way to know if the accesser has * the lock. */ #define IS_ISMNDLK(i) (S_ISREG((i)->i_mode) && MANDATORY_LOCK(i)) /* * This is a cache of readahead params that help us choose the proper * readahead strategy. Initially, we set all readahead parameters to 0 * and let the VFS handle things. * If you increase the number of cached files very much, you'll need to * add a hash table here. */ struct raparms { struct raparms *p_next; unsigned int p_count; ino_t p_ino; dev_t p_dev; unsigned long p_reada, p_ramax, p_raend, p_ralen, p_rawin; }; static struct raparms * raparml = NULL; static struct raparms * raparm_cache = NULL; /* * Look up one component of a pathname. * N.B. After this call _both_ fhp and resfh need an fh_put * * If the lookup would cross a mountpoint, and the mounted filesystem * is exported to the client with NFSEXP_CROSSMNT, then the lookup is * accepted as it stands and the mounted directory is * returned. Otherwise the covered directory is returned. * NOTE: this mountpoint crossing is not supported properly by all * clients and is explicitly disallowed for NFSv3 * NeilBrown */ int nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, int len, struct svc_fh *resfh) { struct svc_export *exp; struct dentry *dparent; struct dentry *dentry; int err; dprintk("nfsd: nfsd_lookup(fh %s, %s)\n", SVCFH_fmt(fhp), name); /* Obtain dentry and export. */ err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC); if (err) goto out; dparent = fhp->fh_dentry; exp = fhp->fh_export; err = nfserr_acces; /* Lookup the name, but don't follow links */ if (strcmp(name, ".")==0) { dentry = dget(dparent); } else if (strcmp(name, "..")==0) { /* checking mountpoint crossing is very different when stepping up */ if (dparent == exp->ex_dentry) { if (!EX_CROSSMNT(exp)) dentry = dget(dparent); /* .. == . just like at / */ else { struct svc_export *exp2 = NULL; struct dentry *dp; struct vfsmount *mnt = mntget(exp->ex_mnt); dentry = dget(dparent); while(follow_up(&mnt, &dentry)) ; dp = dget(dentry->d_parent); dput(dentry); dentry = dp; for ( ; exp2 == NULL && dp->d_parent != dp; dp=dp->d_parent) exp2 = exp_get(exp->ex_client, dp->d_inode->i_dev, dp->d_inode->i_ino); if (exp2==NULL) { dput(dentry); dentry = dget(dparent); } else { exp = exp2; } mntput(mnt); } } else dentry = dget(dparent->d_parent); } else { dentry = lookup_one(name, dparent); err = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_nfserr; /* * check if we have crossed a mount point ... */ if (d_mountpoint(dentry)) { struct svc_export *exp2 = NULL; struct vfsmount *mnt = mntget(exp->ex_mnt); struct dentry *mounts = dget(dentry); while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)) ; exp2 = exp_get(rqstp->rq_client, mounts->d_inode->i_dev, mounts->d_inode->i_ino); if (exp2 && EX_CROSSMNT(exp2)) { /* successfully crossed mount point */ exp = exp2; dput(dentry); dentry = mounts; } else dput(mounts); } } /* * Note: we compose the file handle now, but as the * dentry may be negative, it may need to be updated. */ err = fh_compose(resfh, exp, dentry); if (!err && !dentry->d_inode) err = nfserr_noent; out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Set various file attributes. * N.B. After this call fhp needs an fh_put */ int nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap) { struct dentry *dentry; struct inode *inode; int accmode = MAY_SATTR; int ftype = 0; int imode; int err; kernel_cap_t saved_cap = 0; int size_change = 0; if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) accmode |= MAY_WRITE|MAY_OWNER_OVERRIDE; if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; /* Get inode */ err = fh_verify(rqstp, fhp, ftype, accmode); if (err || !iap->ia_valid) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; err = inode_change_ok(inode, iap); /* could be a "touch" (utimes) request where the user is not the owner but does * have write permission. In this case the user should be allowed to set * both times to the current time. We could just assume any such SETATTR * is intended to set the times to "now", but we do a couple of simple tests * to increase our confidence. */ #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) #define MAX_TOUCH_TIME_ERROR (30*60) if (err && (iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && iap->ia_mtime == iap->ia_ctime ) { /* looks good. now just make sure time is in the right ballpark. * solaris, at least, doesn't seem to care what the time request is */ time_t delta = iap->ia_atime - CURRENT_TIME; if (delta<0) delta = -delta; if (delta < MAX_TOUCH_TIME_ERROR) { /* turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME * this will cause notify_change to set these times to "now" */ iap->ia_valid &= ~BOTH_TIME_SET; err = inode_change_ok(inode, iap); } } if (err) goto out_nfserr; /* The size case is special. It changes the file as well as the attributes. */ if (iap->ia_valid & ATTR_SIZE) { if (iap->ia_size < inode->i_size) { err = nfsd_permission(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); if (err) goto out; } err = get_write_access(inode); if (err) goto out_nfserr; err = locks_verify_truncate(inode, NULL, iap->ia_size); if (err) goto out_nfserr; DQUOT_INIT(inode); } imode = inode->i_mode; if (iap->ia_valid & ATTR_MODE) { iap->ia_mode &= S_IALLUGO; imode = iap->ia_mode |= (imode & ~S_IALLUGO); } /* Revoke setuid/setgid bit on chown/chgrp */ if ((iap->ia_valid & ATTR_UID) && (imode & S_ISUID) && iap->ia_uid != inode->i_uid) { iap->ia_valid |= ATTR_MODE; iap->ia_mode = imode &= ~S_ISUID; } if ((iap->ia_valid & ATTR_GID) && (imode & S_ISGID) && iap->ia_gid != inode->i_gid) { iap->ia_valid |= ATTR_MODE; iap->ia_mode = imode &= ~S_ISGID; } /* Change the attributes. */ iap->ia_valid |= ATTR_CTIME; if (current->fsuid != 0) { saved_cap = current->cap_effective; cap_clear(current->cap_effective); } #ifdef CONFIG_QUOTA /* DQUOT_TRANSFER needs both ia_uid and ia_gid defined */ if (iap->ia_valid & (ATTR_UID|ATTR_GID)) { if (! (iap->ia_valid & ATTR_UID)) iap->ia_uid = inode->i_uid; if (! (iap->ia_valid & ATTR_GID)) iap->ia_gid = inode->i_gid; iap->ia_valid |= ATTR_UID|ATTR_GID; } #endif /* CONFIG_QUOTA */ if (iap->ia_valid & ATTR_SIZE) { fh_lock(fhp); size_change = 1; } #ifdef CONFIG_QUOTA if (iap->ia_valid & (ATTR_UID|ATTR_GID)) err = DQUOT_TRANSFER(dentry, iap); else #endif err = notify_change(dentry, iap); if (size_change) { fh_unlock(fhp); put_write_access(inode); } if (current->fsuid != 0) current->cap_effective = saved_cap; if (err) goto out_nfserr; if (EX_ISSYNC(fhp->fh_export)) write_inode_now(inode); err = 0; /* Don't unlock inode; the nfssvc_release functions are supposed * to do this. */ out: return err; out_nfserr: err = nfserrno(err); goto out; } #ifdef CONFIG_NFSD_V3 /* * Check server access rights to a file system object */ struct accessmap { u32 access; int how; }; static struct accessmap nfs3_regaccess[] = { { NFS3_ACCESS_READ, MAY_READ }, { NFS3_ACCESS_EXECUTE, MAY_EXEC }, { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_TRUNC }, { NFS3_ACCESS_EXTEND, MAY_WRITE }, { 0, 0 } }; static struct accessmap nfs3_diraccess[] = { { NFS3_ACCESS_READ, MAY_READ }, { NFS3_ACCESS_LOOKUP, MAY_EXEC }, { NFS3_ACCESS_MODIFY, MAY_EXEC|MAY_WRITE|MAY_TRUNC }, { NFS3_ACCESS_EXTEND, MAY_EXEC|MAY_WRITE }, { NFS3_ACCESS_DELETE, MAY_REMOVE }, { 0, 0 } }; static struct accessmap nfs3_anyaccess[] = { /* XXX: should we try to cover read/write here for clients that * rely on us to do their access checking for special files? */ { 0, 0 } }; int nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access) { struct accessmap *map; struct svc_export *export; struct dentry *dentry; u32 query, result = 0; unsigned int error; error = fh_verify(rqstp, fhp, 0, MAY_NOP); if (error) goto out; export = fhp->fh_export; dentry = fhp->fh_dentry; if (S_ISREG(dentry->d_inode->i_mode)) map = nfs3_regaccess; else if (S_ISDIR(dentry->d_inode->i_mode)) map = nfs3_diraccess; else map = nfs3_anyaccess; query = *access; for (; map->access; map++) { if (map->access & query) { unsigned int err2; err2 = nfsd_permission(export, dentry, map->how); switch (err2) { case nfs_ok: result |= map->access; break; /* the following error codes just mean the access was not allowed, * rather than an error occurred */ case nfserr_rofs: case nfserr_acces: case nfserr_perm: /* simply don't "or" in the access bit. */ break; default: error = err2; goto out; } } } *access = result; out: return error; } #endif /* * Open an existing file or directory. * The access argument indicates the type of open (read/write/lock) * N.B. After this call fhp needs an fh_put */ int nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, int access, struct file *filp) { struct dentry *dentry; struct inode *inode; int err; /* If we get here, then the client has already done an "open", and (hopefully) * checked permission - so allow OWNER_OVERRIDE in case a chmod has now revoked * permission */ err = fh_verify(rqstp, fhp, type, access | MAY_OWNER_OVERRIDE); if (err) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; /* Disallow access to files with the append-only bit set or * with mandatory locking enabled */ err = nfserr_perm; if (IS_APPEND(inode) || IS_ISMNDLK(inode)) goto out; if (!inode->i_fop) goto out; if ((access & MAY_WRITE) && (err = get_write_access(inode)) != 0) goto out_nfserr; memset(filp, 0, sizeof(*filp)); filp->f_op = inode->i_fop; atomic_set(&filp->f_count, 1); filp->f_dentry = dentry; if (access & MAY_WRITE) { filp->f_flags = O_WRONLY; filp->f_mode = FMODE_WRITE; DQUOT_INIT(inode); } else { filp->f_flags = O_RDONLY; filp->f_mode = FMODE_READ; } err = 0; if (filp->f_op && filp->f_op->open) { err = filp->f_op->open(inode, filp); if (err) { if (access & MAY_WRITE) put_write_access(inode); /* I nearly added put_filp() call here, but this filp * is really on callers stack frame. -DaveM */ atomic_dec(&filp->f_count); } } out_nfserr: if (err) err = nfserrno(err); out: return err; } /* * Close a file. */ void nfsd_close(struct file *filp) { struct dentry *dentry = filp->f_dentry; struct inode *inode = dentry->d_inode; if (!inode->i_count) printk(KERN_WARNING "nfsd: inode count == 0!\n"); if (!dentry->d_count) printk(KERN_WARNING "nfsd: wheee, %s/%s d_count == 0!\n", dentry->d_parent->d_name.name, dentry->d_name.name); if (filp->f_op && filp->f_op->release) filp->f_op->release(inode, filp); if (filp->f_mode & FMODE_WRITE) { put_write_access(inode); } } /* * Sync a file * As this calls fsync (not fdatasync) there is no need for a write_inode * after it. */ void nfsd_sync(struct file *filp) { dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); down(&filp->f_dentry->d_inode->i_sem); filp->f_op->fsync(filp, filp->f_dentry); up(&filp->f_dentry->d_inode->i_sem); } void nfsd_sync_dir(struct dentry *dp) { struct inode *inode = dp->d_inode; int (*fsync) (struct file *, struct dentry *); if (inode->i_fop && (fsync = inode->i_fop->fsync)) { fsync(NULL, dp); } } /* * Obtain the readahead parameters for the file * specified by (dev, ino). */ static inline struct raparms * nfsd_get_raparms(dev_t dev, ino_t ino) { struct raparms *ra, **rap, **frap = NULL; int depth = 0; for (rap = &raparm_cache; (ra = *rap); rap = &ra->p_next) { if (ra->p_ino == ino && ra->p_dev == dev) goto found; depth++; if (ra->p_count == 0) frap = rap; } depth = nfsdstats.ra_size*11/10; if (!frap) return NULL; rap = frap; ra = *frap; memset(ra, 0, sizeof(*ra)); ra->p_dev = dev; ra->p_ino = ino; found: if (rap != &raparm_cache) { *rap = ra->p_next; ra->p_next = raparm_cache; raparm_cache = ra; } ra->p_count++; nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; return ra; } /* * Read data from a file. count must contain the requested read count * on entry. On return, *count contains the number of bytes actually read. * N.B. After this call fhp needs an fh_put */ int nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, char *buf, unsigned long *count) { struct raparms *ra; mm_segment_t oldfs; int err; struct file file; err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); if (err) goto out; err = nfserr_perm; if (!file.f_op->read) goto out_close; /* Get readahead parameters */ ra = nfsd_get_raparms(fhp->fh_export->ex_dev, fhp->fh_dentry->d_inode->i_ino); if (ra) { file.f_reada = ra->p_reada; file.f_ramax = ra->p_ramax; file.f_raend = ra->p_raend; file.f_ralen = ra->p_ralen; file.f_rawin = ra->p_rawin; } file.f_pos = offset; oldfs = get_fs(); set_fs(KERNEL_DS); err = file.f_op->read(&file, buf, *count, &file.f_pos); set_fs(oldfs); nfsdstats.io_read += *count; /* Write back readahead params */ if (ra != NULL) { dprintk("nfsd: raparms %ld %ld %ld %ld %ld\n", file.f_reada, file.f_ramax, file.f_raend, file.f_ralen, file.f_rawin); ra->p_reada = file.f_reada; ra->p_ramax = file.f_ramax; ra->p_raend = file.f_raend; ra->p_ralen = file.f_ralen; ra->p_rawin = file.f_rawin; ra->p_count -= 1; } if (err >= 0) { *count = err; err = 0; } else err = nfserrno(err); out_close: nfsd_close(&file); out: return err; } /* * Write data to a file. * The stable flag requests synchronous writes. * N.B. After this call fhp needs an fh_put */ int nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, char *buf, unsigned long cnt, int *stablep) { struct svc_export *exp; struct file file; struct dentry *dentry; struct inode *inode; mm_segment_t oldfs; int err = 0; int stable = *stablep; #ifdef CONFIG_QUOTA uid_t saved_euid; #endif err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file); if (err) goto out; if (!cnt) goto out_close; err = nfserr_perm; if (!file.f_op->write) goto out_close; dentry = file.f_dentry; inode = dentry->d_inode; exp = fhp->fh_export; /* * Request sync writes if * - the sync export option has been set, or * - the client requested O_SYNC behavior (NFSv3 feature). * - The file system doesn't support fsync(). * When gathered writes have been configured for this volume, * flushing the data to disk is handled separately below. */ #ifdef CONFIG_NFSD_V3 if (file.f_op->fsync == 0) {/* COMMIT3 cannot work */ stable = 2; *stablep = 2; /* FILE_SYNC */ } if (!EX_ISSYNC(exp)) stable = 0; if (stable && !EX_WGATHER(exp)) file.f_flags |= O_SYNC; #else if ((stable || (stable = EX_ISSYNC(exp))) && !EX_WGATHER(exp)) file.f_flags |= O_SYNC; #endif /* CONFIG_NFSD_V3 */ file.f_pos = offset; /* set write offset */ /* Write the data. */ oldfs = get_fs(); set_fs(KERNEL_DS); #ifdef CONFIG_QUOTA /* This is for disk quota. */ saved_euid = current->euid; current->euid = current->fsuid; err = file.f_op->write(&file, buf, cnt, &file.f_pos); current->euid = saved_euid; #else err = file.f_op->write(&file, buf, cnt, &file.f_pos); #endif nfsdstats.io_write += cnt; set_fs(oldfs); /* clear setuid/setgid flag after write */ if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) { struct iattr ia; kernel_cap_t saved_cap = 0; ia.ia_valid = ATTR_MODE; ia.ia_mode = inode->i_mode & ~(S_ISUID | S_ISGID); if (current->fsuid != 0) { saved_cap = current->cap_effective; cap_clear(current->cap_effective); } notify_change(dentry, &ia); if (current->fsuid != 0) current->cap_effective = saved_cap; } if (err >= 0 && stable) { static unsigned long last_ino = 0; static kdev_t last_dev = NODEV; /* * Gathered writes: If another process is currently * writing to the file, there's a high chance * this is another nfsd (triggered by a bulk write * from a client's biod). Rather than syncing the * file with each write request, we sleep for 10 msec. * * I don't know if this roughly approximates * C. Juszak's idea of gathered writes, but it's a * nice and simple solution (IMHO), and it seems to * work:-) */ if (EX_WGATHER(exp) && (atomic_read(&inode->i_writecount) > 1 || (last_ino == inode->i_ino && last_dev == inode->i_dev))) { #if 0 interruptible_sleep_on_timeout(&inode->i_wait, 10 * HZ / 1000); #else dprintk("nfsd: write defer %d\n", current->pid); /* FIXME: Olaf commented this out [gam3] */ schedule_timeout((HZ+99)/100); dprintk("nfsd: write resume %d\n", current->pid); #endif } if (inode->i_state & I_DIRTY) { dprintk("nfsd: write sync %d\n", current->pid); nfsd_sync(&file); } wake_up(&inode->i_wait); last_ino = inode->i_ino; last_dev = inode->i_dev; } dprintk("nfsd: write complete err=%d\n", err); if (err >= 0) err = 0; else err = nfserrno(err); out_close: nfsd_close(&file); out: return err; } #ifdef CONFIG_NFSD_V3 /* * Commit all pendig writes to stable storage. * Strictly speaking, we could sync just indicated the file region here, * but there's currently no way we can ask the VFS to do so. * * We lock the file to make sure we return full WCC data to the client. */ int nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, off_t offset, unsigned long count) { struct file file; int err; if ((err = nfsd_open(rqstp, fhp, S_IFREG, MAY_WRITE, &file)) != 0) return err; if (EX_ISSYNC(fhp->fh_export)) { if (file.f_op && file.f_op->fsync) { nfsd_sync(&file); } else { err = nfserr_notsupp; } } nfsd_close(&file); return err; } #endif /* CONFIG_NFSD_V3 */ /* * Create a file (regular, directory, device, fifo); UNIX sockets * not yet implemented. * If the response fh has been verified, the parent directory should * already be locked. Note that the parent directory is left locked. * * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp */ int nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, char *fname, int flen, struct iattr *iap, int type, dev_t rdev, struct svc_fh *resfhp) { struct dentry *dentry, *dchild; struct inode *dirp; int err; err = nfserr_perm; if (!flen) goto out; err = nfserr_exist; if (isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); if (err) goto out; dentry = fhp->fh_dentry; dirp = dentry->d_inode; err = nfserr_notdir; if(!dirp->i_op || !dirp->i_op->lookup) goto out; /* * Check whether the response file handle has been verified yet. * If it has, the parent directory should already be locked. */ if (!resfhp->fh_dverified) { /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ fh_lock(fhp); dchild = lookup_one(fname, dentry); err = PTR_ERR(dchild); if (IS_ERR(dchild)) goto out_nfserr; err = fh_compose(resfhp, fhp->fh_export, dchild); if (err) goto out; } else { /* called from nfsd_proc_create */ dchild = resfhp->fh_dentry; if (!fhp->fh_locked) { /* not actually possible */ printk(KERN_ERR "nfsd_create: parent %s/%s not locked!\n", dentry->d_parent->d_name.name, dentry->d_name.name); err = -EIO; goto out; } } /* * Make sure the child dentry is still negative ... */ err = nfserr_exist; if (dchild->d_inode) { dprintk("nfsd_create: dentry %s/%s not negative!\n", dentry->d_name.name, dchild->d_name.name); goto out; } if (!(iap->ia_valid & ATTR_MODE)) iap->ia_mode = 0; iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; /* * Get the dir op function pointer. */ err = nfserr_perm; switch (type) { case S_IFREG: err = vfs_create(dirp, dchild, iap->ia_mode); break; case S_IFDIR: err = vfs_mkdir(dirp, dchild, iap->ia_mode); break; case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK: err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); break; default: printk("nfsd: bad file type %o in nfsd_create\n", type); err = -EINVAL; } if (err < 0) goto out_nfserr; if (EX_ISSYNC(fhp->fh_export)) { nfsd_sync_dir(dentry); write_inode_now(dchild->d_inode); } /* Set file attributes. Mode has already been set and * setting uid/gid works only for root. Irix appears to * send along the gid when it tries to implement setgid * directories via NFS. */ err = 0; if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) err = nfsd_setattr(rqstp, resfhp, iap); /* * Update the file handle to get the new inode info. */ if (!err) err = fh_update(resfhp); out: return err; out_nfserr: err = nfserrno(err); goto out; } #ifdef CONFIG_NFSD_V3 /* * NFSv3 version of nfsd_create */ int nfsd_create_v3(struct svc_rqst *rqstp, struct svc_fh *fhp, char *fname, int flen, struct iattr *iap, struct svc_fh *resfhp, int createmode, u32 *verifier) { struct dentry *dentry, *dchild; struct inode *dirp; int err; err = nfserr_perm; if (!flen) goto out; err = nfserr_exist; if (isdotent(fname, flen)) goto out; if (!(iap->ia_valid & ATTR_MODE)) iap->ia_mode = 0; err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); if (err) goto out; dentry = fhp->fh_dentry; dirp = dentry->d_inode; /* Get all the sanity checks out of the way before * we lock the parent. */ err = nfserr_notdir; if(!dirp->i_op || !dirp->i_op->lookup) goto out; fh_lock(fhp); /* * Compose the response file handle. */ dchild = lookup_one(fname, dentry); err = PTR_ERR(dchild); if (IS_ERR(dchild)) goto out_nfserr; err = fh_compose(resfhp, fhp->fh_export, dchild); if (err) goto out; if (dchild->d_inode) { err = 0; switch (createmode) { case NFS3_CREATE_UNCHECKED: if (! S_ISREG(dchild->d_inode->i_mode)) err = nfserr_exist; else { iap->ia_valid &= ATTR_SIZE; goto set_attr; } break; case NFS3_CREATE_EXCLUSIVE: if ( dchild->d_inode->i_mtime == verifier[0] && dchild->d_inode->i_atime == verifier[1] && dchild->d_inode->i_mode == S_IFREG && dchild->d_inode->i_size == 0 ) break; /* fallthru */ case NFS3_CREATE_GUARDED: err = nfserr_exist; } goto out; } err = vfs_create(dirp, dchild, iap->ia_mode); if (err < 0) goto out_nfserr; if (EX_ISSYNC(fhp->fh_export)) { nfsd_sync_dir(dentry); /* setattr will sync the child (or not) */ } /* * Update the filehandle to get the new inode info. */ err = fh_update(resfhp); if (err) goto out; if (createmode == NFS3_CREATE_EXCLUSIVE) { /* Cram the verifier into atime/mtime */ iap->ia_valid = ATTR_MTIME|ATTR_ATIME|ATTR_MTIME_SET|ATTR_ATIME_SET; iap->ia_mtime = verifier[0]; iap->ia_atime = verifier[1]; } /* Set file attributes. Mode has already been set and * setting uid/gid works only for root. Irix appears to * send along the gid when it tries to implement setgid * directories via NFS. Clear out all that cruft. */ set_attr: if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) err = nfsd_setattr(rqstp, resfhp, iap); out: fh_unlock(fhp); return err; out_nfserr: err = nfserrno(err); goto out; } #endif /* CONFIG_NFSD_V3 */ /* * Read a symlink. On entry, *lenp must contain the maximum path length that * fits into the buffer. On return, it contains the true length. * N.B. After this call fhp needs an fh_put */ int nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) { struct dentry *dentry; struct inode *inode; mm_segment_t oldfs; int err; err = fh_verify(rqstp, fhp, S_IFLNK, MAY_NOP); if (err) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; err = nfserr_inval; if (!inode->i_op || !inode->i_op->readlink) goto out; UPDATE_ATIME(inode); /* N.B. Why does this call need a get_fs()?? * Remove the set_fs and watch the fireworks:-) --okir */ oldfs = get_fs(); set_fs(KERNEL_DS); err = inode->i_op->readlink(dentry, buf, *lenp); set_fs(oldfs); if (err < 0) goto out_nfserr; *lenp = err; err = 0; out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Create a symlink and look up its inode * N.B. After this call _both_ fhp and resfhp need an fh_put */ int nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *fname, int flen, char *path, int plen, struct svc_fh *resfhp, struct iattr *iap) { struct dentry *dentry, *dnew; int err, cerr; err = nfserr_noent; if (!flen || !plen) goto out; err = nfserr_exist; if (isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, MAY_CREATE); if (err) goto out; fh_lock(fhp); dentry = fhp->fh_dentry; dnew = lookup_one(fname, dentry); err = PTR_ERR(dnew); if (IS_ERR(dnew)) goto out_nfserr; err = vfs_symlink(dentry->d_inode, dnew, path); if (!err) { if (EX_ISSYNC(fhp->fh_export)) nfsd_sync_dir(dentry); if (iap) { iap->ia_valid &= ATTR_MODE /* ~(ATTR_MODE|ATTR_UID|ATTR_GID)*/; if (iap->ia_valid) { iap->ia_valid |= ATTR_CTIME; iap->ia_mode = (iap->ia_mode&S_IALLUGO) | S_IFLNK; err = notify_change(dnew, iap); if (!err && EX_ISSYNC(fhp->fh_export)) write_inode_now(dentry->d_inode); } } } else err = nfserrno(err); fh_unlock(fhp); /* Compose the fh so the dentry will be freed ... */ cerr = fh_compose(resfhp, fhp->fh_export, dnew); if (err==0) err = cerr; out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Create a hardlink * N.B. After this call _both_ ffhp and tfhp need an fh_put */ int nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int len, struct svc_fh *tfhp) { struct dentry *ddir, *dnew, *dold; struct inode *dirp, *dest; int err; err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_CREATE); if (err) goto out; err = fh_verify(rqstp, tfhp, -S_IFDIR, MAY_NOP); if (err) goto out; err = nfserr_perm; if (!len) goto out; err = nfserr_exist; if (isdotent(fname, len)) goto out; fh_lock(ffhp); ddir = ffhp->fh_dentry; dirp = ddir->d_inode; dnew = lookup_one(fname, ddir); err = PTR_ERR(dnew); if (IS_ERR(dnew)) goto out_nfserr; dold = tfhp->fh_dentry; dest = dold->d_inode; err = vfs_link(dold, dirp, dnew); if (!err) { if (EX_ISSYNC(ffhp->fh_export)) { nfsd_sync_dir(ddir); write_inode_now(dest); } } else { if (err == -EXDEV && rqstp->rq_vers == 2) err = nfserr_acces; else err = nfserrno(err); } fh_unlock(ffhp); dput(dnew); out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Rename a file * N.B. After this call _both_ ffhp and tfhp need an fh_put */ int nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, struct svc_fh *tfhp, char *tname, int tlen) { struct dentry *fdentry, *tdentry, *odentry, *ndentry; struct inode *fdir, *tdir; int err; err = fh_verify(rqstp, ffhp, S_IFDIR, MAY_REMOVE); if (err) goto out; err = fh_verify(rqstp, tfhp, S_IFDIR, MAY_CREATE); if (err) goto out; fdentry = ffhp->fh_dentry; fdir = fdentry->d_inode; tdentry = tfhp->fh_dentry; tdir = tdentry->d_inode; err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; if (fdir->i_dev != tdir->i_dev) goto out; err = nfserr_perm; if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) goto out; double_down(&tdir->i_sem, &fdir->i_sem); odentry = lookup_one(fname, fdentry); err = PTR_ERR(odentry); if (IS_ERR(odentry)) goto out_nfserr; err = -ENOENT; if (!odentry->d_inode) goto out_dput_old; ndentry = lookup_one(tname, tdentry); err = PTR_ERR(ndentry); if (IS_ERR(ndentry)) goto out_dput_old; #ifdef CONFIG_NFSD_V3 /* Fill in the pre-op attr for the wcc data for both * tdir and fdir */ fill_pre_wcc(ffhp); fill_pre_wcc(tfhp); #endif /* CONFIG_NFSD_V3 */ err = vfs_rename(fdir, odentry, tdir, ndentry); if (!err && EX_ISSYNC(tfhp->fh_export)) { nfsd_sync_dir(tdentry); nfsd_sync_dir(fdentry); } #ifdef CONFIG_NFSD_V3 /* Fill in the post-op attr for the wcc data for both * tdir and fdir */ fill_post_wcc(ffhp); fill_post_wcc(tfhp); #endif /* CONFIG_NFSD_V3 */ double_up(&tdir->i_sem, &fdir->i_sem); dput(ndentry); out_dput_old: dput(odentry); if (err) goto out_nfserr; out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Unlink a file or directory * N.B. After this call fhp needs an fh_put */ int nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, char *fname, int flen) { struct dentry *dentry, *rdentry; struct inode *dirp; int err; err = nfserr_acces; if (!flen || isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, MAY_REMOVE); if (err) goto out; fh_lock(fhp); dentry = fhp->fh_dentry; dirp = dentry->d_inode; rdentry = lookup_one(fname, dentry); err = PTR_ERR(rdentry); if (IS_ERR(rdentry)) goto out_nfserr; if (!rdentry->d_inode) { dput(rdentry); err = nfserr_noent; goto out; } if (type != S_IFDIR) { /* It's UNLINK */ err = vfs_unlink(dirp, rdentry); } else { /* It's RMDIR */ err = vfs_rmdir(dirp, rdentry); } fh_unlock(fhp); dput(rdentry); if (err) goto out_nfserr; if (EX_ISSYNC(fhp->fh_export)) { down(&dentry->d_inode->i_sem); nfsd_sync_dir(dentry); up(&dentry->d_inode->i_sem); } out: return err; out_nfserr: err = nfserrno(err); goto out; } /* * Read entries from a directory. * The verifier is an NFSv3 thing we ignore for now. */ int nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, encode_dent_fn func, u32 *buffer, int *countp, u32 *verf) { struct inode *inode; u32 *p; int oldlen, eof, err; struct file file; struct readdir_cd cd; err = 0; if (offset > ~(u32) 0) goto out; err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); if (err) goto out; err = nfserr_notdir; if (!file.f_op->readdir) goto out_close; file.f_pos = offset; /* Set up the readdir context */ memset(&cd, 0, sizeof(cd)); cd.rqstp = rqstp; cd.buffer = buffer; cd.buflen = *countp; /* count of words */ cd.dirfh = fhp; /* * Read the directory entries. This silly loop is necessary because * readdir() is not guaranteed to fill up the entire buffer, but * may choose to do less. */ inode = file.f_dentry->d_inode; down(&inode->i_sem); while (1) { oldlen = cd.buflen; /* dprintk("nfsd: f_op->readdir(%x/%ld @ %d) buflen = %d (%d)\n", file.f_inode->i_dev, file.f_inode->i_ino, (int) file.f_pos, (int) oldlen, (int) cd.buflen); */ err = file.f_op->readdir(&file, &cd, (filldir_t) func); if (err < 0) goto out_nfserr; if (oldlen == cd.buflen) break; if (cd.eob) break; } up(&inode->i_sem); /* If we didn't fill the buffer completely, we're at EOF */ eof = !cd.eob; if (cd.offset) { #ifdef CONFIG_NFSD_V3 if (rqstp->rq_vers == 3) (void)xdr_encode_hyper(cd.offset, file.f_pos); else #endif /* CONFIG_NFSD_V3 */ *cd.offset = htonl(file.f_pos); } p = cd.buffer; *p++ = 0; /* no more entries */ *p++ = htonl(eof); /* end of directory */ *countp = (caddr_t) p - (caddr_t) buffer; dprintk("nfsd: readdir result %d bytes, eof %d offset %d\n", *countp, eof, cd.offset? ntohl(*cd.offset) : -1); err = 0; out_close: nfsd_close(&file); out: return err; out_nfserr: up(&inode->i_sem); err = nfserrno(err); goto out_close; } /* * Get file system stats * N.B. After this call fhp needs an fh_put */ int nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct statfs *stat) { int err = fh_verify(rqstp, fhp, 0, MAY_NOP); if (!err && vfs_statfs(fhp->fh_dentry->d_inode->i_sb,stat)) err = nfserr_io; return err; } /* * Check for a user's access permissions to this inode. */ int nfsd_permission(struct svc_export *exp, struct dentry *dentry, int acc) { struct inode *inode = dentry->d_inode; int err; kernel_cap_t saved_cap = 0; if (acc == MAY_NOP) return 0; #if 0 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n", acc, (acc & MAY_READ)? " read" : "", (acc & MAY_WRITE)? " write" : "", (acc & MAY_EXEC)? " exec" : "", (acc & MAY_SATTR)? " sattr" : "", (acc & MAY_TRUNC)? " trunc" : "", (acc & MAY_LOCK)? " lock" : "", (acc & MAY_OWNER_OVERRIDE)? " owneroverride" : "", inode->i_mode, IS_IMMUTABLE(inode)? " immut" : "", IS_APPEND(inode)? " append" : "", IS_RDONLY(inode)? " ro" : ""); dprintk(" owner %d/%d user %d/%d\n", inode->i_uid, inode->i_gid, current->fsuid, current->fsgid); #endif if (acc & (MAY_WRITE | MAY_SATTR | MAY_TRUNC)) { if (EX_RDONLY(exp) || IS_RDONLY(inode)) return nfserr_rofs; if (/* (acc & MAY_WRITE) && */ IS_IMMUTABLE(inode)) return nfserr_perm; } if ((acc & MAY_TRUNC) && IS_APPEND(inode)) return nfserr_perm; if (acc & MAY_LOCK) { /* If we cannot rely on authentication in NLM requests, * just allow locks, otherwise require read permission, or * ownership */ if (exp->ex_flags & NFSEXP_NOAUTHNLM) return 0; else acc = MAY_READ | MAY_OWNER_OVERRIDE; } /* * The file owner always gets access permission for accesses that * would normally be checked at open time. This is to make * file access work even when the client has done a fchmod(fd, 0). * * However, `cp foo bar' should fail nevertheless when bar is * readonly. A sensible way to do this might be to reject all * attempts to truncate a read-only file, because a creat() call * always implies file truncation. * ... but this isn't really fair. A process may reasonably call * ftruncate on an open file descriptor on a file with perm 000. * We must trust the client to do permission checking - using "ACCESS" * with NFSv3. */ if ((acc & MAY_OWNER_OVERRIDE) && inode->i_uid == current->fsuid) return 0; if (current->fsuid != 0) { saved_cap = current->cap_effective; cap_clear(current->cap_effective); } err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC)); /* Allow read access to binaries even when mode 111 */ if (err == -EACCES && S_ISREG(inode->i_mode) && acc == MAY_READ) err = permission(inode, MAY_EXEC); if (current->fsuid != 0) current->cap_effective = saved_cap; return err? nfserrno(err) : 0; } void nfsd_racache_shutdown(void) { if (!raparm_cache) return; dprintk("nfsd: freeing readahead buffers.\n"); kfree(raparml); raparm_cache = raparml = NULL; } /* * Initialize readahead param cache */ int nfsd_racache_init(int cache_size) { int i; if (raparm_cache) return 0; raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); if (raparml != NULL) { dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); memset(raparml, 0, sizeof(struct raparms) * cache_size); for (i = 0; i < cache_size - 1; i++) { raparml[i].p_next = raparml + i + 1; } raparm_cache = raparml; } else { printk(KERN_WARNING "nfsd: Could not allocate memory read-ahead cache.\n"); return -ENOMEM; } nfsdstats.ra_size = cache_size; return 0; }