/* * File operations used by nfsd. Some of these have been ripped from * other parts of the kernel because they weren't exported, 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 <okir@monad.swb.de> * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp> */ #include <linux/fs.h> #include <linux/file.h> #include <linux/splice.h> #include <linux/fcntl.h> #include <linux/namei.h> #include <linux/delay.h> #include <linux/fsnotify.h> #include <linux/posix_acl_xattr.h> #include <linux/xattr.h> #include <linux/jhash.h> #include <linux/ima.h> #include <linux/slab.h> #include <asm/uaccess.h> #include <linux/exportfs.h> #include <linux/writeback.h> #include <linux/security.h> #ifdef CONFIG_NFSD_V3 #include "xdr3.h" #endif /* CONFIG_NFSD_V3 */ #ifdef CONFIG_NFSD_V4 #include "acl.h" #include "idmap.h" #endif /* CONFIG_NFSD_V4 */ #include "nfsd.h" #include "vfs.h" #define NFSDDBG_FACILITY NFSDDBG_FILEOP /* * 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; int p_set; struct file_ra_state p_ra; unsigned int p_hindex; }; struct raparm_hbucket { struct raparms *pb_head; spinlock_t pb_lock; } ____cacheline_aligned_in_smp; #define RAPARM_HASH_BITS 4 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS) #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1) static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE]; /* * Called from nfsd_lookup and encode_dirent. Check if we have crossed * a mount point. * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged, * or nfs_ok having possibly changed *dpp and *expp */ int nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp, struct svc_export **expp) { struct svc_export *exp = *expp, *exp2 = NULL; struct dentry *dentry = *dpp; struct path path = {.mnt = mntget(exp->ex_path.mnt), .dentry = dget(dentry)}; int err = 0; err = follow_down(&path); if (err < 0) goto out; exp2 = rqst_exp_get_by_name(rqstp, &path); if (IS_ERR(exp2)) { err = PTR_ERR(exp2); /* * We normally allow NFS clients to continue * "underneath" a mountpoint that is not exported. * The exception is V4ROOT, where no traversal is ever * allowed without an explicit export of the new * directory. */ if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT)) err = 0; path_put(&path); goto out; } if (nfsd_v4client(rqstp) || (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) { /* successfully crossed mount point */ /* * This is subtle: path.dentry is *not* on path.mnt * at this point. The only reason we are safe is that * original mnt is pinned down by exp, so we should * put path *before* putting exp */ *dpp = path.dentry; path.dentry = dentry; *expp = exp2; exp2 = exp; } path_put(&path); exp_put(exp2); out: return err; } static void follow_to_parent(struct path *path) { struct dentry *dp; while (path->dentry == path->mnt->mnt_root && follow_up(path)) ; dp = dget_parent(path->dentry); dput(path->dentry); path->dentry = dp; } static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp) { struct svc_export *exp2; struct path path = {.mnt = mntget((*exp)->ex_path.mnt), .dentry = dget(dparent)}; follow_to_parent(&path); exp2 = rqst_exp_parent(rqstp, &path); if (PTR_ERR(exp2) == -ENOENT) { *dentryp = dget(dparent); } else if (IS_ERR(exp2)) { path_put(&path); return PTR_ERR(exp2); } else { *dentryp = dget(path.dentry); exp_put(*exp); *exp = exp2; } path_put(&path); return 0; } /* * For nfsd purposes, we treat V4ROOT exports as though there was an * export at *every* directory. */ int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) { if (d_mountpoint(dentry)) return 1; if (nfsd4_is_junction(dentry)) return 1; if (!(exp->ex_flags & NFSEXP_V4ROOT)) return 0; return dentry->d_inode != NULL; } __be32 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, unsigned int len, struct svc_export **exp_ret, struct dentry **dentry_ret) { struct svc_export *exp; struct dentry *dparent; struct dentry *dentry; int host_err; dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name); dparent = fhp->fh_dentry; exp = fhp->fh_export; exp_get(exp); /* Lookup the name, but don't follow links */ if (isdotent(name, len)) { if (len==1) dentry = dget(dparent); else if (dparent != exp->ex_path.dentry) dentry = dget_parent(dparent); else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp)) dentry = dget(dparent); /* .. == . just like at / */ else { /* checking mountpoint crossing is very different when stepping up */ host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry); if (host_err) goto out_nfserr; } } else { fh_lock(fhp); dentry = lookup_one_len(name, dparent, len); host_err = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_nfserr; /* * check if we have crossed a mount point ... */ if (nfsd_mountpoint(dentry, exp)) { if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { dput(dentry); goto out_nfserr; } } } *dentry_ret = dentry; *exp_ret = exp; return 0; out_nfserr: exp_put(exp); return nfserrno(host_err); } /* * 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_NOHIDE, 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 <neilb@cse.unsw.edu.au> */ __be32 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name, unsigned int len, struct svc_fh *resfh) { struct svc_export *exp; struct dentry *dentry; __be32 err; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC); if (err) return err; err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry); if (err) return err; err = check_nfsd_access(exp, rqstp); if (err) goto out; /* * 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, fhp); if (!err && !dentry->d_inode) err = nfserr_noent; out: dput(dentry); exp_put(exp); return err; } static int nfsd_break_lease(struct inode *inode) { if (!S_ISREG(inode->i_mode)) return 0; return break_lease(inode, O_WRONLY | O_NONBLOCK); } /* * Commit metadata changes to stable storage. */ static int commit_metadata(struct svc_fh *fhp) { struct inode *inode = fhp->fh_dentry->d_inode; const struct export_operations *export_ops = inode->i_sb->s_export_op; if (!EX_ISSYNC(fhp->fh_export)) return 0; if (export_ops->commit_metadata) return export_ops->commit_metadata(inode); return sync_inode_metadata(inode, 1); } /* * Set various file attributes. * N.B. After this call fhp needs an fh_put */ __be32 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap, int check_guard, time_t guardtime) { struct dentry *dentry; struct inode *inode; int accmode = NFSD_MAY_SATTR; umode_t ftype = 0; __be32 err; int host_err; int size_change = 0; if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE)) accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; if (iap->ia_valid & ATTR_SIZE) ftype = S_IFREG; /* Get inode */ err = fh_verify(rqstp, fhp, ftype, accmode); if (err) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; /* Ignore any mode updates on symlinks */ if (S_ISLNK(inode->i_mode)) iap->ia_valid &= ~ATTR_MODE; if (!iap->ia_valid) goto out; /* * NFSv2 does not differentiate between "set-[ac]time-to-now" * which only requires access, and "set-[ac]time-to-X" which * requires ownership. * So if it looks like it might be "set both to the same time which * is close to now", and if inode_change_ok fails, then we * convert to "set to now" instead of "set to explicit time" * * We only call inode_change_ok as the last test as technically * it is not an interface that we should be using. It is only * valid if the filesystem does not define it's own i_op->setattr. */ #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET) #define MAX_TOUCH_TIME_ERROR (30*60) if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET && iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) { /* * Looks probable. * * Now just make sure time is in the right ballpark. * Solaris, at least, doesn't seem to care what the time * request is. We require it be within 30 minutes of now. */ time_t delta = iap->ia_atime.tv_sec - get_seconds(); if (delta < 0) delta = -delta; if (delta < MAX_TOUCH_TIME_ERROR && inode_change_ok(inode, iap) != 0) { /* * 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; } } /* * 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(rqstp, fhp->fh_export, dentry, NFSD_MAY_TRUNC|NFSD_MAY_OWNER_OVERRIDE); if (err) goto out; } host_err = get_write_access(inode); if (host_err) goto out_nfserr; size_change = 1; host_err = locks_verify_truncate(inode, NULL, iap->ia_size); if (host_err) { put_write_access(inode); goto out_nfserr; } } /* sanitize the mode change */ if (iap->ia_valid & ATTR_MODE) { iap->ia_mode &= S_IALLUGO; iap->ia_mode |= (inode->i_mode & ~S_IALLUGO); } /* Revoke setuid/setgid on chown */ if (!S_ISDIR(inode->i_mode) && (((iap->ia_valid & ATTR_UID) && !uid_eq(iap->ia_uid, inode->i_uid)) || ((iap->ia_valid & ATTR_GID) && !gid_eq(iap->ia_gid, inode->i_gid)))) { iap->ia_valid |= ATTR_KILL_PRIV; if (iap->ia_valid & ATTR_MODE) { /* we're setting mode too, just clear the s*id bits */ iap->ia_mode &= ~S_ISUID; if (iap->ia_mode & S_IXGRP) iap->ia_mode &= ~S_ISGID; } else { /* set ATTR_KILL_* bits and let VFS handle it */ iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID); } } /* Change the attributes. */ iap->ia_valid |= ATTR_CTIME; err = nfserr_notsync; if (!check_guard || guardtime == inode->i_ctime.tv_sec) { host_err = nfsd_break_lease(inode); if (host_err) goto out_nfserr; fh_lock(fhp); host_err = notify_change(dentry, iap); err = nfserrno(host_err); fh_unlock(fhp); } if (size_change) put_write_access(inode); if (!err) commit_metadata(fhp); out: return err; out_nfserr: err = nfserrno(host_err); goto out; } #if defined(CONFIG_NFSD_V2_ACL) || \ defined(CONFIG_NFSD_V3_ACL) || \ defined(CONFIG_NFSD_V4) static ssize_t nfsd_getxattr(struct dentry *dentry, char *key, void **buf) { ssize_t buflen; ssize_t ret; buflen = vfs_getxattr(dentry, key, NULL, 0); if (buflen <= 0) return buflen; *buf = kmalloc(buflen, GFP_KERNEL); if (!*buf) return -ENOMEM; ret = vfs_getxattr(dentry, key, *buf, buflen); if (ret < 0) kfree(*buf); return ret; } #endif #if defined(CONFIG_NFSD_V4) static int set_nfsv4_acl_one(struct dentry *dentry, struct posix_acl *pacl, char *key) { int len; size_t buflen; char *buf = NULL; int error = 0; buflen = posix_acl_xattr_size(pacl->a_count); buf = kmalloc(buflen, GFP_KERNEL); error = -ENOMEM; if (buf == NULL) goto out; len = posix_acl_to_xattr(&init_user_ns, pacl, buf, buflen); if (len < 0) { error = len; goto out; } error = vfs_setxattr(dentry, key, buf, len, 0); out: kfree(buf); return error; } __be32 nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfs4_acl *acl) { __be32 error; int host_error; struct dentry *dentry; struct inode *inode; struct posix_acl *pacl = NULL, *dpacl = NULL; unsigned int flags = 0; /* Get inode */ error = fh_verify(rqstp, fhp, 0, NFSD_MAY_SATTR); if (error) return error; dentry = fhp->fh_dentry; inode = dentry->d_inode; if (S_ISDIR(inode->i_mode)) flags = NFS4_ACL_DIR; host_error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); if (host_error == -EINVAL) { return nfserr_attrnotsupp; } else if (host_error < 0) goto out_nfserr; host_error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); if (host_error < 0) goto out_release; if (S_ISDIR(inode->i_mode)) host_error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); out_release: posix_acl_release(pacl); posix_acl_release(dpacl); out_nfserr: if (host_error == -EOPNOTSUPP) return nfserr_attrnotsupp; else return nfserrno(host_error); } static struct posix_acl * _get_posix_acl(struct dentry *dentry, char *key) { void *buf = NULL; struct posix_acl *pacl = NULL; int buflen; buflen = nfsd_getxattr(dentry, key, &buf); if (!buflen) buflen = -ENODATA; if (buflen <= 0) return ERR_PTR(buflen); pacl = posix_acl_from_xattr(&init_user_ns, buf, buflen); kfree(buf); return pacl; } int nfsd4_get_nfs4_acl(struct svc_rqst *rqstp, struct dentry *dentry, struct nfs4_acl **acl) { struct inode *inode = dentry->d_inode; int error = 0; struct posix_acl *pacl = NULL, *dpacl = NULL; unsigned int flags = 0; pacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_ACCESS); if (IS_ERR(pacl) && PTR_ERR(pacl) == -ENODATA) pacl = posix_acl_from_mode(inode->i_mode, GFP_KERNEL); if (IS_ERR(pacl)) { error = PTR_ERR(pacl); pacl = NULL; goto out; } if (S_ISDIR(inode->i_mode)) { dpacl = _get_posix_acl(dentry, POSIX_ACL_XATTR_DEFAULT); if (IS_ERR(dpacl) && PTR_ERR(dpacl) == -ENODATA) dpacl = NULL; else if (IS_ERR(dpacl)) { error = PTR_ERR(dpacl); dpacl = NULL; goto out; } flags = NFS4_ACL_DIR; } *acl = nfs4_acl_posix_to_nfsv4(pacl, dpacl, flags); if (IS_ERR(*acl)) { error = PTR_ERR(*acl); *acl = NULL; } out: posix_acl_release(pacl); posix_acl_release(dpacl); return error; } /* * NFS junction information is stored in an extended attribute. */ #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs" /** * nfsd4_is_junction - Test if an object could be an NFS junction * * @dentry: object to test * * Returns 1 if "dentry" appears to contain NFS junction information. * Otherwise 0 is returned. */ int nfsd4_is_junction(struct dentry *dentry) { struct inode *inode = dentry->d_inode; if (inode == NULL) return 0; if (inode->i_mode & S_IXUGO) return 0; if (!(inode->i_mode & S_ISVTX)) return 0; if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0) return 0; return 1; } #ifdef CONFIG_NFSD_V4_SECURITY_LABEL __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, struct xdr_netobj *label) { __be32 error; int host_error; struct dentry *dentry; error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR); if (error) return error; dentry = fhp->fh_dentry; mutex_lock(&dentry->d_inode->i_mutex); host_error = security_inode_setsecctx(dentry, label->data, label->len); mutex_unlock(&dentry->d_inode->i_mutex); return nfserrno(host_error); } #else __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp, struct xdr_netobj *label) { return nfserr_notsupp; } #endif #endif /* defined(CONFIG_NFSD_V4) */ #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, NFSD_MAY_READ }, { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC }, { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE }, { 0, 0 } }; static struct accessmap nfs3_diraccess[] = { { NFS3_ACCESS_READ, NFSD_MAY_READ }, { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC }, { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC}, { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE }, { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE }, { 0, 0 } }; static struct accessmap nfs3_anyaccess[] = { /* Some clients - Solaris 2.6 at least, make an access call * to the server to check for access for things like /dev/null * (which really, the server doesn't care about). So * We provide simple access checking for them, looking * mainly at mode bits, and we make sure to ignore read-only * filesystem checks */ { NFS3_ACCESS_READ, NFSD_MAY_READ }, { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC }, { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS }, { 0, 0 } }; __be32 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported) { struct accessmap *map; struct svc_export *export; struct dentry *dentry; u32 query, result = 0, sresult = 0; __be32 error; error = fh_verify(rqstp, fhp, 0, NFSD_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) { __be32 err2; sresult |= map->access; err2 = nfsd_permission(rqstp, 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; if (supported) *supported = sresult; out: return error; } #endif /* CONFIG_NFSD_V3 */ static int nfsd_open_break_lease(struct inode *inode, int access) { unsigned int mode; if (access & NFSD_MAY_NOT_BREAK_LEASE) return 0; mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY; return break_lease(inode, mode | O_NONBLOCK); } /* * Open an existing file or directory. * The may_flags argument indicates the type of open (read/write/lock) * and additional flags. * N.B. After this call fhp needs an fh_put */ __be32 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type, int may_flags, struct file **filp) { struct path path; struct inode *inode; int flags = O_RDONLY|O_LARGEFILE; __be32 err; int host_err = 0; validate_process_creds(); /* * 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. * * Arguably we should also allow the owner override for * directories, but we never have and it doesn't seem to have * caused anyone a problem. If we were to change this, note * also that our filldir callbacks would need a variant of * lookup_one_len that doesn't check permissions. */ if (type == S_IFREG) may_flags |= NFSD_MAY_OWNER_OVERRIDE; err = fh_verify(rqstp, fhp, type, may_flags); if (err) goto out; path.mnt = fhp->fh_export->ex_path.mnt; path.dentry = fhp->fh_dentry; inode = path.dentry->d_inode; /* Disallow write access to files with the append-only bit set * or any access when mandatory locking enabled */ err = nfserr_perm; if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE)) goto out; /* * 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. */ if (S_ISREG((inode)->i_mode) && mandatory_lock(inode)) goto out; if (!inode->i_fop) goto out; host_err = nfsd_open_break_lease(inode, may_flags); if (host_err) /* NOMEM or WOULDBLOCK */ goto out_nfserr; if (may_flags & NFSD_MAY_WRITE) { if (may_flags & NFSD_MAY_READ) flags = O_RDWR|O_LARGEFILE; else flags = O_WRONLY|O_LARGEFILE; } *filp = dentry_open(&path, flags, current_cred()); if (IS_ERR(*filp)) { host_err = PTR_ERR(*filp); *filp = NULL; } else { host_err = ima_file_check(*filp, may_flags); if (may_flags & NFSD_MAY_64BIT_COOKIE) (*filp)->f_mode |= FMODE_64BITHASH; else (*filp)->f_mode |= FMODE_32BITHASH; } out_nfserr: err = nfserrno(host_err); out: validate_process_creds(); return err; } /* * Close a file. */ void nfsd_close(struct file *filp) { fput(filp); } /* * 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; unsigned int hash; struct raparm_hbucket *rab; hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK; rab = &raparm_hash[hash]; spin_lock(&rab->pb_lock); for (rap = &rab->pb_head; (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; if (!frap) { spin_unlock(&rab->pb_lock); return NULL; } rap = frap; ra = *frap; ra->p_dev = dev; ra->p_ino = ino; ra->p_set = 0; ra->p_hindex = hash; found: if (rap != &rab->pb_head) { *rap = ra->p_next; ra->p_next = rab->pb_head; rab->pb_head = ra; } ra->p_count++; nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++; spin_unlock(&rab->pb_lock); return ra; } /* * Grab and keep cached pages associated with a file in the svc_rqst * so that they can be passed to the network sendmsg/sendpage routines * directly. They will be released after the sending has completed. */ static int nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, struct splice_desc *sd) { struct svc_rqst *rqstp = sd->u.data; struct page **pp = rqstp->rq_next_page; struct page *page = buf->page; size_t size; size = sd->len; if (rqstp->rq_res.page_len == 0) { get_page(page); put_page(*rqstp->rq_next_page); *(rqstp->rq_next_page++) = page; rqstp->rq_res.page_base = buf->offset; rqstp->rq_res.page_len = size; } else if (page != pp[-1]) { get_page(page); if (*rqstp->rq_next_page) put_page(*rqstp->rq_next_page); *(rqstp->rq_next_page++) = page; rqstp->rq_res.page_len += size; } else rqstp->rq_res.page_len += size; return size; } static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) { return __splice_from_pipe(pipe, sd, nfsd_splice_actor); } static __be32 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long *count) { mm_segment_t oldfs; __be32 err; int host_err; err = nfserr_perm; if (file->f_op->splice_read && rqstp->rq_splice_ok) { struct splice_desc sd = { .len = 0, .total_len = *count, .pos = offset, .u.data = rqstp, }; rqstp->rq_next_page = rqstp->rq_respages + 1; host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); } else { oldfs = get_fs(); set_fs(KERNEL_DS); host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); set_fs(oldfs); } if (host_err >= 0) { nfsdstats.io_read += host_err; *count = host_err; err = 0; fsnotify_access(file); } else err = nfserrno(host_err); return err; } static void kill_suid(struct dentry *dentry) { struct iattr ia; ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_KILL_PRIV; mutex_lock(&dentry->d_inode->i_mutex); notify_change(dentry, &ia); mutex_unlock(&dentry->d_inode->i_mutex); } /* * 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:-) * * Note: we do this only in the NFSv2 case, since v3 and higher have a * better tool (separate unstable writes and commits) for solving this * problem. */ static int wait_for_concurrent_writes(struct file *file) { struct inode *inode = file_inode(file); static ino_t last_ino; static dev_t last_dev; int err = 0; if (atomic_read(&inode->i_writecount) > 1 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) { dprintk("nfsd: write defer %d\n", task_pid_nr(current)); msleep(10); dprintk("nfsd: write resume %d\n", task_pid_nr(current)); } if (inode->i_state & I_DIRTY) { dprintk("nfsd: write sync %d\n", task_pid_nr(current)); err = vfs_fsync(file, 0); } last_ino = inode->i_ino; last_dev = inode->i_sb->s_dev; return err; } static __be32 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, int *stablep) { struct svc_export *exp; struct dentry *dentry; struct inode *inode; mm_segment_t oldfs; __be32 err = 0; int host_err; int stable = *stablep; int use_wgather; loff_t pos = offset; dentry = file->f_path.dentry; inode = dentry->d_inode; exp = fhp->fh_export; use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); if (!EX_ISSYNC(exp)) stable = 0; /* Write the data. */ oldfs = get_fs(); set_fs(KERNEL_DS); host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos); set_fs(oldfs); if (host_err < 0) goto out_nfserr; *cnt = host_err; nfsdstats.io_write += host_err; fsnotify_modify(file); /* clear setuid/setgid flag after write */ if (inode->i_mode & (S_ISUID | S_ISGID)) kill_suid(dentry); if (stable) { if (use_wgather) host_err = wait_for_concurrent_writes(file); else host_err = vfs_fsync_range(file, offset, offset+*cnt, 0); } out_nfserr: dprintk("nfsd: write complete host_err=%d\n", host_err); if (host_err >= 0) err = 0; else err = nfserrno(host_err); return err; } /* * 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 */ __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, struct kvec *vec, int vlen, unsigned long *count) { struct file *file; struct inode *inode; struct raparms *ra; __be32 err; err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); if (err) return err; inode = file_inode(file); /* Get readahead parameters */ ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino); if (ra && ra->p_set) file->f_ra = ra->p_ra; err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); /* Write back readahead params */ if (ra) { struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex]; spin_lock(&rab->pb_lock); ra->p_ra = file->f_ra; ra->p_set = 1; ra->p_count--; spin_unlock(&rab->pb_lock); } nfsd_close(file); return err; } /* As above, but use the provided file descriptor. */ __be32 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long *count) { __be32 err; if (file) { err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE); if (err) goto out; err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); } else /* Note file may still be NULL in NFSv4 special stateid case: */ err = nfsd_read(rqstp, fhp, offset, vec, vlen, count); out: return err; } /* * Write data to a file. * The stable flag requests synchronous writes. * N.B. After this call fhp needs an fh_put */ __be32 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt, int *stablep) { __be32 err = 0; if (file) { err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE); if (err) goto out; err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stablep); } else { err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); if (err) goto out; if (cnt) err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stablep); nfsd_close(file); } out: return err; } #ifdef CONFIG_NFSD_V3 /* * Commit all pending writes to stable storage. * * Note: we only guarantee that data that lies within the range specified * by the 'offset' and 'count' parameters will be synced. * * Unfortunately we cannot lock the file to make sure we return full WCC * data to the client, as locking happens lower down in the filesystem. */ __be32 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, unsigned long count) { struct file *file; loff_t end = LLONG_MAX; __be32 err = nfserr_inval; if (offset < 0) goto out; if (count != 0) { end = offset + (loff_t)count - 1; if (end < offset) goto out; } err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file); if (err) goto out; if (EX_ISSYNC(fhp->fh_export)) { int err2 = vfs_fsync_range(file, offset, end, 0); if (err2 != -EINVAL) err = nfserrno(err2); else err = nfserr_notsupp; } nfsd_close(file); out: return err; } #endif /* CONFIG_NFSD_V3 */ static __be32 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp, struct iattr *iap) { /* * Mode has already been set earlier in create: */ iap->ia_valid &= ~ATTR_MODE; /* * Setting uid/gid works only for root. Irix appears to * send along the gid on create when it tries to implement * setgid directories via NFS: */ if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID)) iap->ia_valid &= ~(ATTR_UID|ATTR_GID); if (iap->ia_valid) return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); return 0; } /* HPUX client sometimes creates a file in mode 000, and sets size to 0. * setting size to 0 may fail for some specific file systems by the permission * checking which requires WRITE permission but the mode is 000. * we ignore the resizing(to 0) on the just new created file, since the size is * 0 after file created. * * call this only after vfs_create() is called. * */ static void nfsd_check_ignore_resizing(struct iattr *iap) { if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) iap->ia_valid &= ~ATTR_SIZE; } /* * 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 */ __be32 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 = NULL; struct inode *dirp; __be32 err; __be32 err2; int host_err; err = nfserr_perm; if (!flen) goto out; err = nfserr_exist; if (isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); if (err) goto out; dentry = fhp->fh_dentry; dirp = dentry->d_inode; err = nfserr_notdir; if (!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_dentry) { host_err = fh_want_write(fhp); if (host_err) goto out_nfserr; /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ fh_lock_nested(fhp, I_MUTEX_PARENT); dchild = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(dchild); if (IS_ERR(dchild)) goto out_nfserr; err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); if (err) goto out; } else { /* called from nfsd_proc_create */ dchild = dget(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 = nfserr_io; 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; err = nfserr_inval; if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) { printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", type); goto out; } /* * Get the dir op function pointer. */ err = 0; host_err = 0; switch (type) { case S_IFREG: host_err = vfs_create(dirp, dchild, iap->ia_mode, true); if (!host_err) nfsd_check_ignore_resizing(iap); break; case S_IFDIR: host_err = vfs_mkdir(dirp, dchild, iap->ia_mode); break; case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK: host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev); break; } if (host_err < 0) goto out_nfserr; err = nfsd_create_setattr(rqstp, resfhp, iap); /* * nfsd_setattr already committed the child. Transactional filesystems * had a chance to commit changes for both parent and child * simultaneously making the following commit_metadata a noop. */ err2 = nfserrno(commit_metadata(fhp)); if (err2) err = err2; /* * Update the file handle to get the new inode info. */ if (!err) err = fh_update(resfhp); out: if (dchild && !IS_ERR(dchild)) dput(dchild); return err; out_nfserr: err = nfserrno(host_err); goto out; } #ifdef CONFIG_NFSD_V3 static inline int nfsd_create_is_exclusive(int createmode) { return createmode == NFS3_CREATE_EXCLUSIVE || createmode == NFS4_CREATE_EXCLUSIVE4_1; } /* * NFSv3 and NFSv4 version of nfsd_create */ __be32 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, char *fname, int flen, struct iattr *iap, struct svc_fh *resfhp, int createmode, u32 *verifier, bool *truncp, bool *created) { struct dentry *dentry, *dchild = NULL; struct inode *dirp; __be32 err; int host_err; __u32 v_mtime=0, v_atime=0; 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, NFSD_MAY_EXEC); 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->lookup) goto out; host_err = fh_want_write(fhp); if (host_err) goto out_nfserr; fh_lock_nested(fhp, I_MUTEX_PARENT); /* * Compose the response file handle. */ dchild = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(dchild); if (IS_ERR(dchild)) goto out_nfserr; /* If file doesn't exist, check for permissions to create one */ if (!dchild->d_inode) { err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); if (err) goto out; } err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); if (err) goto out; if (nfsd_create_is_exclusive(createmode)) { /* solaris7 gets confused (bugid 4218508) if these have * the high bit set, so just clear the high bits. If this is * ever changed to use different attrs for storing the * verifier, then do_open_lookup() will also need to be fixed * accordingly. */ v_mtime = verifier[0]&0x7fffffff; v_atime = verifier[1]&0x7fffffff; } if (dchild->d_inode) { err = 0; switch (createmode) { case NFS3_CREATE_UNCHECKED: if (! S_ISREG(dchild->d_inode->i_mode)) goto out; else if (truncp) { /* in nfsv4, we need to treat this case a little * differently. we don't want to truncate the * file now; this would be wrong if the OPEN * fails for some other reason. furthermore, * if the size is nonzero, we should ignore it * according to spec! */ *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size; } else { iap->ia_valid &= ATTR_SIZE; goto set_attr; } break; case NFS3_CREATE_EXCLUSIVE: if ( dchild->d_inode->i_mtime.tv_sec == v_mtime && dchild->d_inode->i_atime.tv_sec == v_atime && dchild->d_inode->i_size == 0 ) { if (created) *created = 1; break; } case NFS4_CREATE_EXCLUSIVE4_1: if ( dchild->d_inode->i_mtime.tv_sec == v_mtime && dchild->d_inode->i_atime.tv_sec == v_atime && dchild->d_inode->i_size == 0 ) { if (created) *created = 1; goto set_attr; } /* fallthru */ case NFS3_CREATE_GUARDED: err = nfserr_exist; } fh_drop_write(fhp); goto out; } host_err = vfs_create(dirp, dchild, iap->ia_mode, true); if (host_err < 0) { fh_drop_write(fhp); goto out_nfserr; } if (created) *created = 1; nfsd_check_ignore_resizing(iap); if (nfsd_create_is_exclusive(createmode)) { /* Cram the verifier into atime/mtime */ iap->ia_valid = ATTR_MTIME|ATTR_ATIME | ATTR_MTIME_SET|ATTR_ATIME_SET; /* XXX someone who knows this better please fix it for nsec */ iap->ia_mtime.tv_sec = v_mtime; iap->ia_atime.tv_sec = v_atime; iap->ia_mtime.tv_nsec = 0; iap->ia_atime.tv_nsec = 0; } set_attr: err = nfsd_create_setattr(rqstp, resfhp, iap); /* * nfsd_setattr already committed the child (and possibly also the parent). */ if (!err) err = nfserrno(commit_metadata(fhp)); /* * Update the filehandle to get the new inode info. */ if (!err) err = fh_update(resfhp); out: fh_unlock(fhp); if (dchild && !IS_ERR(dchild)) dput(dchild); fh_drop_write(fhp); return err; out_nfserr: err = nfserrno(host_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 */ __be32 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp) { struct inode *inode; mm_segment_t oldfs; __be32 err; int host_err; struct path path; err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); if (err) goto out; path.mnt = fhp->fh_export->ex_path.mnt; path.dentry = fhp->fh_dentry; inode = path.dentry->d_inode; err = nfserr_inval; if (!inode->i_op->readlink) goto out; touch_atime(&path); /* 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); host_err = inode->i_op->readlink(path.dentry, (char __user *)buf, *lenp); set_fs(oldfs); if (host_err < 0) goto out_nfserr; *lenp = host_err; err = 0; out: return err; out_nfserr: err = nfserrno(host_err); goto out; } /* * Create a symlink and look up its inode * N.B. After this call _both_ fhp and resfhp need an fh_put */ __be32 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; __be32 err, cerr; int host_err; err = nfserr_noent; if (!flen || !plen) goto out; err = nfserr_exist; if (isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE); if (err) goto out; host_err = fh_want_write(fhp); if (host_err) goto out_nfserr; fh_lock(fhp); dentry = fhp->fh_dentry; dnew = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(dnew); if (IS_ERR(dnew)) goto out_nfserr; if (unlikely(path[plen] != 0)) { char *path_alloced = kmalloc(plen+1, GFP_KERNEL); if (path_alloced == NULL) host_err = -ENOMEM; else { strncpy(path_alloced, path, plen); path_alloced[plen] = 0; host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced); kfree(path_alloced); } } else host_err = vfs_symlink(dentry->d_inode, dnew, path); err = nfserrno(host_err); if (!err) err = nfserrno(commit_metadata(fhp)); fh_unlock(fhp); fh_drop_write(fhp); cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); dput(dnew); if (err==0) err = cerr; out: return err; out_nfserr: err = nfserrno(host_err); goto out; } /* * Create a hardlink * N.B. After this call _both_ ffhp and tfhp need an fh_put */ __be32 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *name, int len, struct svc_fh *tfhp) { struct dentry *ddir, *dnew, *dold; struct inode *dirp; __be32 err; int host_err; err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE); if (err) goto out; err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP); if (err) goto out; err = nfserr_isdir; if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode)) goto out; err = nfserr_perm; if (!len) goto out; err = nfserr_exist; if (isdotent(name, len)) goto out; host_err = fh_want_write(tfhp); if (host_err) { err = nfserrno(host_err); goto out; } fh_lock_nested(ffhp, I_MUTEX_PARENT); ddir = ffhp->fh_dentry; dirp = ddir->d_inode; dnew = lookup_one_len(name, ddir, len); host_err = PTR_ERR(dnew); if (IS_ERR(dnew)) goto out_nfserr; dold = tfhp->fh_dentry; err = nfserr_noent; if (!dold->d_inode) goto out_dput; host_err = nfsd_break_lease(dold->d_inode); if (host_err) { err = nfserrno(host_err); goto out_dput; } host_err = vfs_link(dold, dirp, dnew); if (!host_err) { err = nfserrno(commit_metadata(ffhp)); if (!err) err = nfserrno(commit_metadata(tfhp)); } else { if (host_err == -EXDEV && rqstp->rq_vers == 2) err = nfserr_acces; else err = nfserrno(host_err); } out_dput: dput(dnew); out_unlock: fh_unlock(ffhp); fh_drop_write(tfhp); out: return err; out_nfserr: err = nfserrno(host_err); goto out_unlock; } /* * Rename a file * N.B. After this call _both_ ffhp and tfhp need an fh_put */ __be32 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, *trap; struct inode *fdir, *tdir; __be32 err; int host_err; err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); if (err) goto out; err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE); if (err) goto out; fdentry = ffhp->fh_dentry; fdir = fdentry->d_inode; tdentry = tfhp->fh_dentry; tdir = tdentry->d_inode; err = nfserr_perm; if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) goto out; host_err = fh_want_write(ffhp); if (host_err) { err = nfserrno(host_err); goto out; } /* cannot use fh_lock as we need deadlock protective ordering * so do it by hand */ trap = lock_rename(tdentry, fdentry); ffhp->fh_locked = tfhp->fh_locked = 1; fill_pre_wcc(ffhp); fill_pre_wcc(tfhp); odentry = lookup_one_len(fname, fdentry, flen); host_err = PTR_ERR(odentry); if (IS_ERR(odentry)) goto out_nfserr; host_err = -ENOENT; if (!odentry->d_inode) goto out_dput_old; host_err = -EINVAL; if (odentry == trap) goto out_dput_old; ndentry = lookup_one_len(tname, tdentry, tlen); host_err = PTR_ERR(ndentry); if (IS_ERR(ndentry)) goto out_dput_old; host_err = -ENOTEMPTY; if (ndentry == trap) goto out_dput_new; host_err = -EXDEV; if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) goto out_dput_new; if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) goto out_dput_new; host_err = nfsd_break_lease(odentry->d_inode); if (host_err) goto out_dput_new; if (ndentry->d_inode) { host_err = nfsd_break_lease(ndentry->d_inode); if (host_err) goto out_dput_new; } host_err = vfs_rename(fdir, odentry, tdir, ndentry); if (!host_err) { host_err = commit_metadata(tfhp); if (!host_err) host_err = commit_metadata(ffhp); } out_dput_new: dput(ndentry); out_dput_old: dput(odentry); out_nfserr: err = nfserrno(host_err); /* we cannot reply on fh_unlock on the two filehandles, * as that would do the wrong thing if the two directories * were the same, so again we do it by hand */ fill_post_wcc(ffhp); fill_post_wcc(tfhp); unlock_rename(tdentry, fdentry); ffhp->fh_locked = tfhp->fh_locked = 0; fh_drop_write(ffhp); out: return err; } /* * Unlink a file or directory * N.B. After this call fhp needs an fh_put */ __be32 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, char *fname, int flen) { struct dentry *dentry, *rdentry; struct inode *dirp; __be32 err; int host_err; err = nfserr_acces; if (!flen || isdotent(fname, flen)) goto out; err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE); if (err) goto out; host_err = fh_want_write(fhp); if (host_err) goto out_nfserr; fh_lock_nested(fhp, I_MUTEX_PARENT); dentry = fhp->fh_dentry; dirp = dentry->d_inode; rdentry = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(rdentry); if (IS_ERR(rdentry)) goto out_nfserr; if (!rdentry->d_inode) { dput(rdentry); err = nfserr_noent; goto out; } if (!type) type = rdentry->d_inode->i_mode & S_IFMT; host_err = nfsd_break_lease(rdentry->d_inode); if (host_err) goto out_put; if (type != S_IFDIR) host_err = vfs_unlink(dirp, rdentry); else host_err = vfs_rmdir(dirp, rdentry); if (!host_err) host_err = commit_metadata(fhp); out_put: dput(rdentry); out_nfserr: err = nfserrno(host_err); out: return err; } /* * We do this buffering because we must not call back into the file * system's ->lookup() method from the filldir callback. That may well * deadlock a number of file systems. * * This is based heavily on the implementation of same in XFS. */ struct buffered_dirent { u64 ino; loff_t offset; int namlen; unsigned int d_type; char name[]; }; struct readdir_data { struct dir_context ctx; char *dirent; size_t used; int full; }; static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) { struct readdir_data *buf = __buf; struct buffered_dirent *de = (void *)(buf->dirent + buf->used); unsigned int reclen; reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64)); if (buf->used + reclen > PAGE_SIZE) { buf->full = 1; return -EINVAL; } de->namlen = namlen; de->offset = offset; de->ino = ino; de->d_type = d_type; memcpy(de->name, name, namlen); buf->used += reclen; return 0; } static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func, struct readdir_cd *cdp, loff_t *offsetp) { struct buffered_dirent *de; int host_err; int size; loff_t offset; struct readdir_data buf = { .ctx.actor = nfsd_buffered_filldir, .dirent = (void *)__get_free_page(GFP_KERNEL) }; if (!buf.dirent) return nfserrno(-ENOMEM); offset = *offsetp; while (1) { struct inode *dir_inode = file_inode(file); unsigned int reclen; cdp->err = nfserr_eof; /* will be cleared on successful read */ buf.used = 0; buf.full = 0; host_err = iterate_dir(file, &buf.ctx); if (buf.full) host_err = 0; if (host_err < 0) break; size = buf.used; if (!size) break; /* * Various filldir functions may end up calling back into * lookup_one_len() and the file system's ->lookup() method. * These expect i_mutex to be held, as it would within readdir. */ host_err = mutex_lock_killable(&dir_inode->i_mutex); if (host_err) break; de = (struct buffered_dirent *)buf.dirent; while (size > 0) { offset = de->offset; if (func(cdp, de->name, de->namlen, de->offset, de->ino, de->d_type)) break; if (cdp->err != nfs_ok) break; reclen = ALIGN(sizeof(*de) + de->namlen, sizeof(u64)); size -= reclen; de = (struct buffered_dirent *)((char *)de + reclen); } mutex_unlock(&dir_inode->i_mutex); if (size > 0) /* We bailed out early */ break; offset = vfs_llseek(file, 0, SEEK_CUR); } free_page((unsigned long)(buf.dirent)); if (host_err) return nfserrno(host_err); *offsetp = offset; return cdp->err; } /* * Read entries from a directory. * The NFSv3/4 verifier we ignore for now. */ __be32 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, struct readdir_cd *cdp, filldir_t func) { __be32 err; struct file *file; loff_t offset = *offsetp; int may_flags = NFSD_MAY_READ; /* NFSv2 only supports 32 bit cookies */ if (rqstp->rq_vers > 2) may_flags |= NFSD_MAY_64BIT_COOKIE; err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file); if (err) goto out; offset = vfs_llseek(file, offset, SEEK_SET); if (offset < 0) { err = nfserrno((int)offset); goto out_close; } err = nfsd_buffered_readdir(file, func, cdp, offsetp); if (err == nfserr_eof || err == nfserr_toosmall) err = nfs_ok; /* can still be found in ->err */ out_close: nfsd_close(file); out: return err; } /* * Get file system stats * N.B. After this call fhp needs an fh_put */ __be32 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access) { __be32 err; err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access); if (!err) { struct path path = { .mnt = fhp->fh_export->ex_path.mnt, .dentry = fhp->fh_dentry, }; if (vfs_statfs(&path, stat)) err = nfserr_io; } return err; } static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp) { return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY; } /* * Check for a user's access permissions to this inode. */ __be32 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp, struct dentry *dentry, int acc) { struct inode *inode = dentry->d_inode; int err; if ((acc & NFSD_MAY_MASK) == NFSD_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 & NFSD_MAY_READ)? " read" : "", (acc & NFSD_MAY_WRITE)? " write" : "", (acc & NFSD_MAY_EXEC)? " exec" : "", (acc & NFSD_MAY_SATTR)? " sattr" : "", (acc & NFSD_MAY_TRUNC)? " trunc" : "", (acc & NFSD_MAY_LOCK)? " lock" : "", (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "", inode->i_mode, IS_IMMUTABLE(inode)? " immut" : "", IS_APPEND(inode)? " append" : "", __mnt_is_readonly(exp->ex_path.mnt)? " ro" : ""); dprintk(" owner %d/%d user %d/%d\n", inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid()); #endif /* Normally we reject any write/sattr etc access on a read-only file * system. But if it is IRIX doing check on write-access for a * device special file, we ignore rofs. */ if (!(acc & NFSD_MAY_LOCAL_ACCESS)) if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) { if (exp_rdonly(rqstp, exp) || __mnt_is_readonly(exp->ex_path.mnt)) return nfserr_rofs; if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode)) return nfserr_perm; } if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode)) return nfserr_perm; if (acc & NFSD_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 = NFSD_MAY_READ | NFSD_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 & NFSD_MAY_OWNER_OVERRIDE) && uid_eq(inode->i_uid, current_fsuid())) return 0; /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */ err = inode_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 == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) || acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC))) err = inode_permission(inode, MAY_EXEC); return err? nfserrno(err) : 0; } void nfsd_racache_shutdown(void) { struct raparms *raparm, *last_raparm; unsigned int i; dprintk("nfsd: freeing readahead buffers.\n"); for (i = 0; i < RAPARM_HASH_SIZE; i++) { raparm = raparm_hash[i].pb_head; while(raparm) { last_raparm = raparm; raparm = raparm->p_next; kfree(last_raparm); } raparm_hash[i].pb_head = NULL; } } /* * Initialize readahead param cache */ int nfsd_racache_init(int cache_size) { int i; int j = 0; int nperbucket; struct raparms **raparm = NULL; if (raparm_hash[0].pb_head) return 0; nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE); if (nperbucket < 2) nperbucket = 2; cache_size = nperbucket * RAPARM_HASH_SIZE; dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); for (i = 0; i < RAPARM_HASH_SIZE; i++) { spin_lock_init(&raparm_hash[i].pb_lock); raparm = &raparm_hash[i].pb_head; for (j = 0; j < nperbucket; j++) { *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL); if (!*raparm) goto out_nomem; raparm = &(*raparm)->p_next; } *raparm = NULL; } nfsdstats.ra_size = cache_size; return 0; out_nomem: dprintk("nfsd: kmalloc failed, freeing readahead buffers\n"); nfsd_racache_shutdown(); return -ENOMEM; } #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) struct posix_acl * nfsd_get_posix_acl(struct svc_fh *fhp, int type) { struct inode *inode = fhp->fh_dentry->d_inode; char *name; void *value = NULL; ssize_t size; struct posix_acl *acl; if (!IS_POSIXACL(inode)) return ERR_PTR(-EOPNOTSUPP); switch (type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; break; default: return ERR_PTR(-EOPNOTSUPP); } size = nfsd_getxattr(fhp->fh_dentry, name, &value); if (size < 0) return ERR_PTR(size); acl = posix_acl_from_xattr(&init_user_ns, value, size); kfree(value); return acl; } int nfsd_set_posix_acl(struct svc_fh *fhp, int type, struct posix_acl *acl) { struct inode *inode = fhp->fh_dentry->d_inode; char *name; void *value = NULL; size_t size; int error; if (!IS_POSIXACL(inode) || !inode->i_op->setxattr || !inode->i_op->removexattr) return -EOPNOTSUPP; switch(type) { case ACL_TYPE_ACCESS: name = POSIX_ACL_XATTR_ACCESS; break; case ACL_TYPE_DEFAULT: name = POSIX_ACL_XATTR_DEFAULT; break; default: return -EOPNOTSUPP; } if (acl && acl->a_count) { size = posix_acl_xattr_size(acl->a_count); value = kmalloc(size, GFP_KERNEL); if (!value) return -ENOMEM; error = posix_acl_to_xattr(&init_user_ns, acl, value, size); if (error < 0) goto getout; size = error; } else size = 0; error = fh_want_write(fhp); if (error) goto getout; if (size) error = vfs_setxattr(fhp->fh_dentry, name, value, size, 0); else { if (!S_ISDIR(inode->i_mode) && type == ACL_TYPE_DEFAULT) error = 0; else { error = vfs_removexattr(fhp->fh_dentry, name); if (error == -ENODATA) error = 0; } } fh_drop_write(fhp); getout: kfree(value); return error; } #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */