#define MSNFS /* HACK HACK */ /* * 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 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/string.h> #include <linux/time.h> #include <linux/errno.h> #include <linux/fs.h> #include <linux/file.h> #include <linux/mount.h> #include <linux/major.h> #include <linux/ext2_fs.h> #include <linux/proc_fs.h> #include <linux/stat.h> #include <linux/fcntl.h> #include <linux/net.h> #include <linux/unistd.h> #include <linux/slab.h> #include <linux/pagemap.h> #include <linux/in.h> #include <linux/module.h> #include <linux/namei.h> #include <linux/vfs.h> #include <linux/delay.h> #include <linux/sunrpc/svc.h> #include <linux/nfsd/nfsd.h> #ifdef CONFIG_NFSD_V3 #include <linux/nfs3.h> #include <linux/nfsd/xdr3.h> #endif /* CONFIG_NFSD_V3 */ #include <linux/nfsd/nfsfh.h> #include <linux/quotaops.h> #include <linux/fsnotify.h> #include <linux/posix_acl.h> #include <linux/posix_acl_xattr.h> #include <linux/xattr.h> #ifdef CONFIG_NFSD_V4 #include <linux/nfs4.h> #include <linux/nfs4_acl.h> #include <linux/nfsd_idmap.h> #include <linux/security.h> #endif /* CONFIG_NFSD_V4 */ #include <linux/jhash.h> #include <asm/uaccess.h> #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; 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; static struct raparms * raparml; #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 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 vfsmount *mnt = mntget(exp->ex_mnt); struct dentry *mounts = dget(dentry); int err = nfs_ok; while (follow_down(&mnt,&mounts)&&d_mountpoint(mounts)); exp2 = exp_get_by_name(exp->ex_client, mnt, mounts, &rqstp->rq_chandle); if (IS_ERR(exp2)) { err = PTR_ERR(exp2); dput(mounts); mntput(mnt); goto out; } if (exp2 && ((exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2))) { /* successfully crossed mount point */ exp_put(exp); *expp = exp2; dput(dentry); *dpp = mounts; } else { if (exp2) exp_put(exp2); dput(mounts); } mntput(mnt); out: return 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> */ 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), len,name); /* Obtain dentry and export. */ err = fh_verify(rqstp, fhp, S_IFDIR, MAY_EXEC); if (err) return err; dparent = fhp->fh_dentry; exp = fhp->fh_export; exp_get(exp); err = nfserr_acces; /* Lookup the name, but don't follow links */ if (isdotent(name, len)) { if (len==1) dentry = dget(dparent); else if (dparent != exp->ex_dentry) { dentry = dget_parent(dparent); } else if (!EX_NOHIDE(exp)) dentry = dget(dparent); /* .. == . just like at / */ else { /* checking mountpoint crossing is very different when stepping up */ struct svc_export *exp2 = NULL; struct dentry *dp; struct vfsmount *mnt = mntget(exp->ex_mnt); dentry = dget(dparent); while(dentry == mnt->mnt_root && follow_up(&mnt, &dentry)) ; dp = dget_parent(dentry); dput(dentry); dentry = dp; exp2 = exp_parent(exp->ex_client, mnt, dentry, &rqstp->rq_chandle); if (IS_ERR(exp2)) { err = PTR_ERR(exp2); dput(dentry); mntput(mnt); goto out_nfserr; } if (!exp2) { dput(dentry); dentry = dget(dparent); } else { exp_put(exp); exp = exp2; } mntput(mnt); } } else { fh_lock(fhp); dentry = lookup_one_len(name, dparent, len); err = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_nfserr; /* * check if we have crossed a mount point ... */ if (d_mountpoint(dentry)) { if ((err = nfsd_cross_mnt(rqstp, &dentry, &exp))) { dput(dentry); goto out_nfserr; } } } /* * 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; dput(dentry); out: exp_put(exp); 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, int check_guard, time_t guardtime) { struct dentry *dentry; struct inode *inode; int accmode = MAY_SATTR; int ftype = 0; int imode; int err; 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) 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(fhp->fh_export, dentry, MAY_TRUNC|MAY_OWNER_OVERRIDE); if (err) goto out; } /* * If we are changing the size of the file, then * we need to break all leases. */ err = break_lease(inode, FMODE_WRITE | O_NONBLOCK); if (err == -EWOULDBLOCK) err = -ETIMEDOUT; if (err) /* ENOMEM or EWOULDBLOCK */ goto out_nfserr; err = get_write_access(inode); if (err) goto out_nfserr; size_change = 1; err = locks_verify_truncate(inode, NULL, iap->ia_size); if (err) { put_write_access(inode); 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) && iap->ia_uid != inode->i_uid) iap->ia_valid |= ATTR_KILL_SUID; if ((iap->ia_valid & ATTR_GID) && iap->ia_gid != inode->i_gid) iap->ia_valid |= ATTR_KILL_SGID; /* Change the attributes. */ iap->ia_valid |= ATTR_CTIME; err = nfserr_notsync; if (!check_guard || guardtime == inode->i_ctime.tv_sec) { fh_lock(fhp); err = notify_change(dentry, iap); err = nfserrno(err); fh_unlock(fhp); } if (size_change) put_write_access(inode); if (!err) if (EX_ISSYNC(fhp->fh_export)) write_inode_now(inode, 1); out: return err; out_nfserr: err = nfserrno(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; buflen = vfs_getxattr(dentry, key, NULL, 0); if (buflen <= 0) return buflen; *buf = kmalloc(buflen, GFP_KERNEL); if (!*buf) return -ENOMEM; return vfs_getxattr(dentry, key, *buf, buflen); } #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(pacl, buf, buflen); if (len < 0) { error = len; goto out; } error = vfs_setxattr(dentry, key, buf, len, 0); out: kfree(buf); return error; } int nfsd4_set_nfs4_acl(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfs4_acl *acl) { int 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 /* S_IFREG */, MAY_SATTR); if (error) goto out; dentry = fhp->fh_dentry; inode = dentry->d_inode; if (S_ISDIR(inode->i_mode)) flags = NFS4_ACL_DIR; error = nfs4_acl_nfsv4_to_posix(acl, &pacl, &dpacl, flags); if (error == -EINVAL) { error = nfserr_attrnotsupp; goto out; } else if (error < 0) goto out_nfserr; error = set_nfsv4_acl_one(dentry, pacl, POSIX_ACL_XATTR_ACCESS); if (error < 0) goto out_nfserr; if (S_ISDIR(inode->i_mode)) { error = set_nfsv4_acl_one(dentry, dpacl, POSIX_ACL_XATTR_DEFAULT); if (error < 0) goto out_nfserr; } error = nfs_ok; out: posix_acl_release(pacl); posix_acl_release(dpacl); return (error); out_nfserr: error = nfserrno(error); goto out; } 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(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; } #endif /* defined(CONFIG_NFS_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, 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[] = { /* 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, MAY_READ }, { NFS3_ACCESS_EXECUTE, MAY_EXEC }, { NFS3_ACCESS_MODIFY, MAY_WRITE|MAY_LOCAL_ACCESS }, { NFS3_ACCESS_EXTEND, MAY_WRITE|MAY_LOCAL_ACCESS }, { 0, 0 } }; int 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; 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; sresult |= map->access; 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; if (supported) *supported = sresult; out: return error; } #endif /* CONFIG_NFSD_V3 */ /* * 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 flags = O_RDONLY|O_LARGEFILE, 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 write access to files with the append-only bit set * or any access when mandatory locking enabled */ err = nfserr_perm; if (IS_APPEND(inode) && (access & MAY_WRITE)) goto out; if (IS_ISMNDLK(inode)) goto out; if (!inode->i_fop) goto out; /* * Check to see if there are any leases on this file. * This may block while leases are broken. */ err = break_lease(inode, O_NONBLOCK | ((access & MAY_WRITE) ? FMODE_WRITE : 0)); if (err == -EWOULDBLOCK) err = -ETIMEDOUT; if (err) /* NOMEM or WOULDBLOCK */ goto out_nfserr; if (access & MAY_WRITE) { if (access & MAY_READ) flags = O_RDWR|O_LARGEFILE; else flags = O_WRONLY|O_LARGEFILE; DQUOT_INIT(inode); } *filp = dentry_open(dget(dentry), mntget(fhp->fh_export->ex_mnt), flags); if (IS_ERR(*filp)) err = PTR_ERR(*filp); out_nfserr: if (err) err = nfserrno(err); out: return err; } /* * Close a file. */ void nfsd_close(struct file *filp) { fput(filp); } /* * Sync a file * As this calls fsync (not fdatasync) there is no need for a write_inode * after it. */ static inline int nfsd_dosync(struct file *filp, struct dentry *dp, const struct file_operations *fop) { struct inode *inode = dp->d_inode; int (*fsync) (struct file *, struct dentry *, int); int err; err = filemap_fdatawrite(inode->i_mapping); if (err == 0 && fop && (fsync = fop->fsync)) err = fsync(filp, dp, 0); if (err == 0) err = filemap_fdatawait(inode->i_mapping); return err; } static int nfsd_sync(struct file *filp) { int err; struct inode *inode = filp->f_dentry->d_inode; dprintk("nfsd: sync file %s\n", filp->f_dentry->d_name.name); mutex_lock(&inode->i_mutex); err=nfsd_dosync(filp, filp->f_dentry, filp->f_op); mutex_unlock(&inode->i_mutex); return err; } int nfsd_sync_dir(struct dentry *dp) { return nfsd_dosync(NULL, dp, dp->d_inode->i_fop); } /* * 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*11/10; 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 assosiated with a file in the svc_rqst * so that they can be passed to the netowork sendmsg/sendpage routines * directrly. They will be released after the sending has completed. */ static int nfsd_read_actor(read_descriptor_t *desc, struct page *page, unsigned long offset , unsigned long size) { unsigned long count = desc->count; struct svc_rqst *rqstp = desc->arg.data; struct page **pp = rqstp->rq_respages + rqstp->rq_resused; if (size > count) size = count; if (rqstp->rq_res.page_len == 0) { get_page(page); put_page(*pp); *pp = page; rqstp->rq_resused++; rqstp->rq_res.page_base = offset; rqstp->rq_res.page_len = size; } else if (page != pp[-1]) { get_page(page); put_page(*pp); *pp = page; rqstp->rq_resused++; rqstp->rq_res.page_len += size; } else rqstp->rq_res.page_len += size; desc->count = count - size; desc->written += size; return size; } static int 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) { struct inode *inode; struct raparms *ra; mm_segment_t oldfs; int err; err = nfserr_perm; inode = file->f_dentry->d_inode; #ifdef MSNFS if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && (!lock_may_read(inode, offset, *count))) goto out; #endif /* 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; if (file->f_op->sendfile && rqstp->rq_sendfile_ok) { rqstp->rq_resused = 1; err = file->f_op->sendfile(file, &offset, *count, nfsd_read_actor, rqstp); } else { oldfs = get_fs(); set_fs(KERNEL_DS); err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset); set_fs(oldfs); } /* 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); } if (err >= 0) { nfsdstats.io_read += err; *count = err; err = 0; fsnotify_access(file->f_dentry); } else err = nfserrno(err); out: return err; } static void kill_suid(struct dentry *dentry) { struct iattr ia; ia.ia_valid = ATTR_KILL_SUID | ATTR_KILL_SGID; mutex_lock(&dentry->d_inode->i_mutex); notify_change(dentry, &ia); mutex_unlock(&dentry->d_inode->i_mutex); } static int 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; int err = 0; int stable = *stablep; #ifdef MSNFS err = nfserr_perm; if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && (!lock_may_write(file->f_dentry->d_inode, offset, cnt))) goto out; #endif 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. */ 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; /* Write the data. */ oldfs = get_fs(); set_fs(KERNEL_DS); err = vfs_writev(file, (struct iovec __user *)vec, vlen, &offset); set_fs(oldfs); if (err >= 0) { nfsdstats.io_write += cnt; fsnotify_modify(file->f_dentry); } /* clear setuid/setgid flag after write */ if (err >= 0 && (inode->i_mode & (S_ISUID | S_ISGID))) kill_suid(dentry); if (err >= 0 && stable) { static ino_t last_ino; static dev_t last_dev; /* * 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)) { 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", current->pid); msleep(10); dprintk("nfsd: write resume %d\n", current->pid); } if (inode->i_state & I_DIRTY) { dprintk("nfsd: write sync %d\n", current->pid); err=nfsd_sync(file); } #if 0 wake_up(&inode->i_wait); #endif } last_ino = inode->i_ino; last_dev = inode->i_sb->s_dev; } dprintk("nfsd: write complete err=%d\n", err); if (err >= 0) err = 0; else err = nfserrno(err); out: 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 */ int nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long *count) { int err; if (file) { err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, MAY_READ|MAY_OWNER_OVERRIDE); if (err) goto out; err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); } else { err = nfsd_open(rqstp, fhp, S_IFREG, MAY_READ, &file); if (err) goto out; err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count); 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, struct file *file, loff_t offset, struct kvec *vec, int vlen, unsigned long cnt, int *stablep) { int err = 0; if (file) { err = nfsd_permission(fhp->fh_export, fhp->fh_dentry, MAY_WRITE|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, 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. * Strictly speaking, we could sync just the indicated file region here, * but there's currently no way we can ask the VFS to do so. * * 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. */ int nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset, unsigned long count) { struct file *file; int err; if ((u64)count > ~(u64)offset) return nfserr_inval; 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) { err = nfserrno(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 = NULL; 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_dentry) { /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */ fh_lock_nested(fhp, I_MUTEX_PARENT); dchild = lookup_one_len(fname, dentry, flen); 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; /* * Get the dir op function pointer. */ err = nfserr_perm; switch (type) { case S_IFREG: err = vfs_create(dirp, dchild, iap->ia_mode, NULL); 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)) { err = nfserrno(nfsd_sync_dir(dentry)); write_inode_now(dchild->d_inode, 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. */ if ((iap->ia_valid &= ~(ATTR_UID|ATTR_GID|ATTR_MODE)) != 0) { int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); 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(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, int *truncp) { struct dentry *dentry, *dchild = NULL; struct inode *dirp; int err; __u32 v_mtime=0, v_atime=0; int v_mode=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, 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_nested(fhp, I_MUTEX_PARENT); /* * Compose the response file handle. */ dchild = lookup_one_len(fname, dentry, flen); err = PTR_ERR(dchild); if (IS_ERR(dchild)) goto out_nfserr; err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); if (err) goto out; if (createmode == NFS3_CREATE_EXCLUSIVE) { /* while the verifier would fit in mtime+atime, * solaris7 gets confused (bugid 4218508) if these have * the high bit set, so we use the mode as well */ v_mtime = verifier[0]&0x7fffffff; v_atime = verifier[1]&0x7fffffff; v_mode = S_IFREG | ((verifier[0]&0x80000000) >> (32-7)) /* u+x */ | ((verifier[1]&0x80000000) >> (32-9)) /* u+r */ ; } if (dchild->d_inode) { err = 0; switch (createmode) { case NFS3_CREATE_UNCHECKED: if (! S_ISREG(dchild->d_inode->i_mode)) err = nfserr_exist; 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_mode == v_mode && 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, NULL); if (err < 0) goto out_nfserr; if (EX_ISSYNC(fhp->fh_export)) { err = nfserrno(nfsd_sync_dir(dentry)); /* setattr will sync the child (or not) */ } if (createmode == NFS3_CREATE_EXCLUSIVE) { /* Cram the verifier into atime/mtime/mode */ iap->ia_valid = ATTR_MTIME|ATTR_ATIME | ATTR_MTIME_SET|ATTR_ATIME_SET | ATTR_MODE; /* 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; iap->ia_mode = v_mode; } /* Set file attributes. * Mode has already been set but we might need to reset it * for CREATE_EXCLUSIVE * 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)) != 0) { int err2 = nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0); if (err2) err = err2; } /* * 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); 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; touch_atime(fhp->fh_export->ex_mnt, dentry); /* 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; umode_t mode; 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_len(fname, dentry, flen); err = PTR_ERR(dnew); if (IS_ERR(dnew)) goto out_nfserr; mode = S_IALLUGO; /* Only the MODE ATTRibute is even vaguely meaningful */ if (iap && (iap->ia_valid & ATTR_MODE)) mode = iap->ia_mode & S_IALLUGO; if (unlikely(path[plen] != 0)) { char *path_alloced = kmalloc(plen+1, GFP_KERNEL); if (path_alloced == NULL) err = -ENOMEM; else { strncpy(path_alloced, path, plen); path_alloced[plen] = 0; err = vfs_symlink(dentry->d_inode, dnew, path_alloced, mode); kfree(path_alloced); } } else err = vfs_symlink(dentry->d_inode, dnew, path, mode); if (!err) if (EX_ISSYNC(fhp->fh_export)) err = nfsd_sync_dir(dentry); if (err) err = nfserrno(err); fh_unlock(fhp); cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); dput(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 *name, 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(name, len)) goto out; fh_lock_nested(ffhp, I_MUTEX_PARENT); ddir = ffhp->fh_dentry; dirp = ddir->d_inode; dnew = lookup_one_len(name, ddir, len); 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)) { err = nfserrno(nfsd_sync_dir(ddir)); write_inode_now(dest, 1); } } else { if (err == -EXDEV && rqstp->rq_vers == 2) err = nfserr_acces; else err = nfserrno(err); } dput(dnew); out_unlock: fh_unlock(ffhp); out: return err; out_nfserr: err = nfserrno(err); goto out_unlock; } /* * 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, *trap; 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 (ffhp->fh_export != tfhp->fh_export) goto out; err = nfserr_perm; if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) 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); err = PTR_ERR(odentry); if (IS_ERR(odentry)) goto out_nfserr; err = -ENOENT; if (!odentry->d_inode) goto out_dput_old; err = -EINVAL; if (odentry == trap) goto out_dput_old; ndentry = lookup_one_len(tname, tdentry, tlen); err = PTR_ERR(ndentry); if (IS_ERR(ndentry)) goto out_dput_old; err = -ENOTEMPTY; if (ndentry == trap) goto out_dput_new; #ifdef MSNFS if ((ffhp->fh_export->ex_flags & NFSEXP_MSNFS) && ((atomic_read(&odentry->d_count) > 1) || (atomic_read(&ndentry->d_count) > 1))) { err = -EPERM; } else #endif err = vfs_rename(fdir, odentry, tdir, ndentry); if (!err && EX_ISSYNC(tfhp->fh_export)) { err = nfsd_sync_dir(tdentry); if (!err) err = nfsd_sync_dir(fdentry); } out_dput_new: dput(ndentry); out_dput_old: dput(odentry); out_nfserr: if (err) err = nfserrno(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; out: return err; } /* * 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_nested(fhp, I_MUTEX_PARENT); dentry = fhp->fh_dentry; dirp = dentry->d_inode; rdentry = lookup_one_len(fname, dentry, flen); 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; if (type != S_IFDIR) { /* It's UNLINK */ #ifdef MSNFS if ((fhp->fh_export->ex_flags & NFSEXP_MSNFS) && (atomic_read(&rdentry->d_count) > 1)) { err = -EPERM; } else #endif err = vfs_unlink(dirp, rdentry); } else { /* It's RMDIR */ err = vfs_rmdir(dirp, rdentry); } dput(rdentry); if (err == 0 && EX_ISSYNC(fhp->fh_export)) err = nfsd_sync_dir(dentry); out_nfserr: err = nfserrno(err); out: return err; } /* * Read entries from a directory. * The NFSv3/4 verifier we ignore for now. */ int nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp, struct readdir_cd *cdp, encode_dent_fn func) { int err; struct file *file; loff_t offset = *offsetp; err = nfsd_open(rqstp, fhp, S_IFDIR, MAY_READ, &file); if (err) goto out; offset = vfs_llseek(file, offset, 0); if (offset < 0) { err = nfserrno((int)offset); goto out_close; } /* * 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. */ do { cdp->err = nfserr_eof; /* will be cleared on successful read */ err = vfs_readdir(file, (filldir_t) func, cdp); } while (err >=0 && cdp->err == nfs_ok); if (err) err = nfserrno(err); else err = cdp->err; *offsetp = vfs_llseek(file, 0, 1); 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 */ int nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat) { int err = fh_verify(rqstp, fhp, 0, MAY_NOP); if (!err && vfs_statfs(fhp->fh_dentry,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; 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 /* 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 & MAY_LOCAL_ACCESS)) 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; err = permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC), NULL); /* Allow read access to binaries even when mode 111 */ if (err == -EACCES && S_ISREG(inode->i_mode) && acc == (MAY_READ | MAY_OWNER_OVERRIDE)) err = permission(inode, MAY_EXEC, NULL); return err? nfserrno(err) : 0; } void nfsd_racache_shutdown(void) { if (!raparml) return; dprintk("nfsd: freeing readahead buffers.\n"); kfree(raparml); raparml = NULL; } /* * Initialize readahead param cache */ int nfsd_racache_init(int cache_size) { int i; int j = 0; int nperbucket; if (raparml) return 0; if (cache_size < 2*RAPARM_HASH_SIZE) cache_size = 2*RAPARM_HASH_SIZE; raparml = kmalloc(sizeof(struct raparms) * cache_size, GFP_KERNEL); if (raparml != NULL) { dprintk("nfsd: allocating %d readahead buffers.\n", cache_size); for (i = 0 ; i < RAPARM_HASH_SIZE ; i++) { raparm_hash[i].pb_head = NULL; spin_lock_init(&raparm_hash[i].pb_lock); } nperbucket = cache_size >> RAPARM_HASH_BITS; memset(raparml, 0, sizeof(struct raparms) * cache_size); for (i = 0; i < cache_size - 1; i++) { if (i % nperbucket == 0) raparm_hash[j++].pb_head = raparml + i; if (i % nperbucket < nperbucket-1) raparml[i].p_next = raparml + i + 1; } } else { printk(KERN_WARNING "nfsd: Could not allocate memory read-ahead cache.\n"); return -ENOMEM; } nfsdstats.ra_size = cache_size; return 0; } #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(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 || !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(acl, value, size); if (error < 0) goto getout; size = error; } else size = 0; 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; } } getout: kfree(value); return error; } #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */