| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * 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/falloc.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 <linux/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 "../internal.h" |
| #include "acl.h" |
| #include "idmap.h" |
| #endif /* CONFIG_NFSD_V4 */ |
| |
| #include "nfsd.h" |
| #include "vfs.h" |
| #include "trace.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; |
| if (path.mnt == exp->ex_path.mnt && path.dentry == dentry && |
| nfsd_mountpoint(dentry, exp) == 2) { |
| /* This is only a mountpoint in some other namespace */ |
| path_put(&path); |
| 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. |
| * We return: |
| * '1' if this dentry *must* be an export point, |
| * '2' if it might be, if there is really a mount here, and |
| * '0' if there is no chance of an export point here. |
| */ |
| int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp) |
| { |
| if (!d_inode(dentry)) |
| return 0; |
| if (exp->ex_flags & NFSEXP_V4ROOT) |
| return 1; |
| if (nfsd4_is_junction(dentry)) |
| return 1; |
| if (d_mountpoint(dentry)) |
| /* |
| * Might only be a mountpoint in a different namespace, |
| * but we need to check. |
| */ |
| return 2; |
| return 0; |
| } |
| |
| __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 = exp_get(fhp->fh_export); |
| |
| /* 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 { |
| /* |
| * In the nfsd4_open() case, this may be held across |
| * subsequent open and delegation acquisition which may |
| * need to take the child's i_mutex: |
| */ |
| fh_lock_nested(fhp, I_MUTEX_PARENT); |
| dentry = lookup_one_len(name, dparent, len); |
| host_err = PTR_ERR(dentry); |
| if (IS_ERR(dentry)) |
| goto out_nfserr; |
| if (nfsd_mountpoint(dentry, exp)) { |
| /* |
| * We don't need the i_mutex after all. It's |
| * still possible we could open this (regular |
| * files can be mountpoints too), but the |
| * i_mutex is just there to prevent renames of |
| * something that we might be about to delegate, |
| * and a mountpoint won't be renamed: |
| */ |
| fh_unlock(fhp); |
| 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 && d_really_is_negative(dentry)) |
| err = nfserr_noent; |
| out: |
| dput(dentry); |
| exp_put(exp); |
| return err; |
| } |
| |
| /* |
| * Commit metadata changes to stable storage. |
| */ |
| static int |
| commit_metadata(struct svc_fh *fhp) |
| { |
| struct inode *inode = d_inode(fhp->fh_dentry); |
| 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); |
| } |
| |
| /* |
| * Go over the attributes and take care of the small differences between |
| * NFS semantics and what Linux expects. |
| */ |
| static void |
| nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap) |
| { |
| /* 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) || (iap->ia_valid & ATTR_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); |
| } |
| } |
| } |
| |
| static __be32 |
| nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp, |
| struct iattr *iap) |
| { |
| struct inode *inode = d_inode(fhp->fh_dentry); |
| int host_err; |
| |
| if (iap->ia_size < inode->i_size) { |
| __be32 err; |
| |
| err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry, |
| NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE); |
| if (err) |
| return err; |
| } |
| |
| host_err = get_write_access(inode); |
| if (host_err) |
| goto out_nfserrno; |
| |
| host_err = locks_verify_truncate(inode, NULL, iap->ia_size); |
| if (host_err) |
| goto out_put_write_access; |
| return 0; |
| |
| out_put_write_access: |
| put_write_access(inode); |
| out_nfserrno: |
| return nfserrno(host_err); |
| } |
| |
| /* |
| * Set various file attributes. 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; |
| bool get_write_count; |
| bool size_change = (iap->ia_valid & ATTR_SIZE); |
| |
| if (iap->ia_valid & ATTR_SIZE) { |
| accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE; |
| ftype = S_IFREG; |
| } |
| |
| /* |
| * If utimes(2) and friends are called with times not NULL, we should |
| * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission |
| * will return EACCESS, when the caller's effective UID does not match |
| * the owner of the file, and the caller is not privileged. In this |
| * situation, we should return EPERM(notify_change will return this). |
| */ |
| if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) { |
| accmode |= NFSD_MAY_OWNER_OVERRIDE; |
| if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET))) |
| accmode |= NFSD_MAY_WRITE; |
| } |
| |
| /* Callers that do fh_verify should do the fh_want_write: */ |
| get_write_count = !fhp->fh_dentry; |
| |
| /* Get inode */ |
| err = fh_verify(rqstp, fhp, ftype, accmode); |
| if (err) |
| return err; |
| if (get_write_count) { |
| host_err = fh_want_write(fhp); |
| if (host_err) |
| goto out; |
| } |
| |
| dentry = fhp->fh_dentry; |
| inode = d_inode(dentry); |
| |
| /* Ignore any mode updates on symlinks */ |
| if (S_ISLNK(inode->i_mode)) |
| iap->ia_valid &= ~ATTR_MODE; |
| |
| if (!iap->ia_valid) |
| return 0; |
| |
| nfsd_sanitize_attrs(inode, iap); |
| |
| if (check_guard && guardtime != inode->i_ctime.tv_sec) |
| return nfserr_notsync; |
| |
| /* |
| * The size case is special, it changes the file in addition to the |
| * attributes, and file systems don't expect it to be mixed with |
| * "random" attribute changes. We thus split out the size change |
| * into a separate call to ->setattr, and do the rest as a separate |
| * setattr call. |
| */ |
| if (size_change) { |
| err = nfsd_get_write_access(rqstp, fhp, iap); |
| if (err) |
| return err; |
| } |
| |
| fh_lock(fhp); |
| if (size_change) { |
| /* |
| * RFC5661, Section 18.30.4: |
| * Changing the size of a file with SETATTR indirectly |
| * changes the time_modify and change attributes. |
| * |
| * (and similar for the older RFCs) |
| */ |
| struct iattr size_attr = { |
| .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME, |
| .ia_size = iap->ia_size, |
| }; |
| |
| host_err = notify_change(dentry, &size_attr, NULL); |
| if (host_err) |
| goto out_unlock; |
| iap->ia_valid &= ~ATTR_SIZE; |
| |
| /* |
| * Avoid the additional setattr call below if the only other |
| * attribute that the client sends is the mtime, as we update |
| * it as part of the size change above. |
| */ |
| if ((iap->ia_valid & ~ATTR_MTIME) == 0) |
| goto out_unlock; |
| } |
| |
| iap->ia_valid |= ATTR_CTIME; |
| host_err = notify_change(dentry, iap, NULL); |
| |
| out_unlock: |
| fh_unlock(fhp); |
| if (size_change) |
| put_write_access(inode); |
| out: |
| if (!host_err) |
| host_err = commit_metadata(fhp); |
| return nfserrno(host_err); |
| } |
| |
| #if defined(CONFIG_NFSD_V4) |
| /* |
| * 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 = d_inode(dentry); |
| |
| 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; |
| |
| inode_lock(d_inode(dentry)); |
| host_error = security_inode_setsecctx(dentry, label->data, label->len); |
| inode_unlock(d_inode(dentry)); |
| 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 |
| |
| __be32 nfsd4_clone_file_range(struct file *src, u64 src_pos, struct file *dst, |
| u64 dst_pos, u64 count) |
| { |
| return nfserrno(vfs_clone_file_range(src, src_pos, dst, dst_pos, |
| count)); |
| } |
| |
| ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst, |
| u64 dst_pos, u64 count) |
| { |
| |
| /* |
| * Limit copy to 4MB to prevent indefinitely blocking an nfsd |
| * thread and client rpc slot. The choice of 4MB is somewhat |
| * arbitrary. We might instead base this on r/wsize, or make it |
| * tunable, or use a time instead of a byte limit, or implement |
| * asynchronous copy. In theory a client could also recognize a |
| * limit like this and pipeline multiple COPY requests. |
| */ |
| count = min_t(u64, count, 1 << 22); |
| return vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0); |
| } |
| |
| __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp, |
| struct file *file, loff_t offset, loff_t len, |
| int flags) |
| { |
| int error; |
| |
| if (!S_ISREG(file_inode(file)->i_mode)) |
| return nfserr_inval; |
| |
| error = vfs_fallocate(file, flags, offset, len); |
| if (!error) |
| error = commit_metadata(fhp); |
| |
| return nfserrno(error); |
| } |
| #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 (d_is_reg(dentry)) |
| map = nfs3_regaccess; |
| else if (d_is_dir(dentry)) |
| 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; |
| struct file *file; |
| 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 = d_inode(path.dentry); |
| |
| /* 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; |
| } |
| |
| file = dentry_open(&path, flags, current_cred()); |
| if (IS_ERR(file)) { |
| host_err = PTR_ERR(file); |
| goto out_nfserr; |
| } |
| |
| host_err = ima_file_check(file, may_flags, 0); |
| if (host_err) { |
| fput(file); |
| goto out_nfserr; |
| } |
| |
| if (may_flags & NFSD_MAY_64BIT_COOKIE) |
| file->f_mode |= FMODE_64BITHASH; |
| else |
| file->f_mode |= FMODE_32BITHASH; |
| |
| *filp = file; |
| out_nfserr: |
| err = nfserrno(host_err); |
| out: |
| validate_process_creds(); |
| return err; |
| } |
| |
| struct raparms * |
| nfsd_init_raparms(struct file *file) |
| { |
| struct inode *inode = file_inode(file); |
| dev_t dev = inode->i_sb->s_dev; |
| ino_t ino = inode->i_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); |
| |
| if (ra->p_set) |
| file->f_ra = ra->p_ra; |
| return ra; |
| } |
| |
| void nfsd_put_raparams(struct file *file, struct raparms *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); |
| } |
| |
| /* |
| * 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_finish_read(struct file *file, unsigned long *count, int host_err) |
| { |
| if (host_err >= 0) { |
| nfsdstats.io_read += host_err; |
| *count = host_err; |
| fsnotify_access(file); |
| return 0; |
| } else |
| return nfserrno(host_err); |
| } |
| |
| __be32 nfsd_splice_read(struct svc_rqst *rqstp, |
| struct file *file, loff_t offset, unsigned long *count) |
| { |
| struct splice_desc sd = { |
| .len = 0, |
| .total_len = *count, |
| .pos = offset, |
| .u.data = rqstp, |
| }; |
| int host_err; |
| |
| rqstp->rq_next_page = rqstp->rq_respages + 1; |
| host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor); |
| return nfsd_finish_read(file, count, host_err); |
| } |
| |
| __be32 nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen, |
| unsigned long *count) |
| { |
| struct iov_iter iter; |
| int host_err; |
| |
| iov_iter_kvec(&iter, READ | ITER_KVEC, vec, vlen, *count); |
| host_err = vfs_iter_read(file, &iter, &offset, 0); |
| |
| return nfsd_finish_read(file, count, host_err); |
| } |
| |
| /* |
| * 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; |
| } |
| |
| __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 stable) |
| { |
| struct svc_export *exp; |
| struct iov_iter iter; |
| __be32 err = 0; |
| int host_err; |
| int use_wgather; |
| loff_t pos = offset; |
| unsigned int pflags = current->flags; |
| rwf_t flags = 0; |
| |
| if (test_bit(RQ_LOCAL, &rqstp->rq_flags)) |
| /* |
| * We want less throttling in balance_dirty_pages() |
| * and shrink_inactive_list() so that nfs to |
| * localhost doesn't cause nfsd to lock up due to all |
| * the client's dirty pages or its congested queue. |
| */ |
| current->flags |= PF_LESS_THROTTLE; |
| |
| exp = fhp->fh_export; |
| use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp); |
| |
| if (!EX_ISSYNC(exp)) |
| stable = NFS_UNSTABLE; |
| |
| if (stable && !use_wgather) |
| flags |= RWF_SYNC; |
| |
| iov_iter_kvec(&iter, WRITE | ITER_KVEC, vec, vlen, *cnt); |
| host_err = vfs_iter_write(file, &iter, &pos, flags); |
| if (host_err < 0) |
| goto out_nfserr; |
| *cnt = host_err; |
| nfsdstats.io_write += host_err; |
| fsnotify_modify(file); |
| |
| if (stable && use_wgather) |
| host_err = wait_for_concurrent_writes(file); |
| |
| out_nfserr: |
| dprintk("nfsd: write complete host_err=%d\n", host_err); |
| if (host_err >= 0) |
| err = 0; |
| else |
| err = nfserrno(host_err); |
| if (test_bit(RQ_LOCAL, &rqstp->rq_flags)) |
| current_restore_flags(pflags, PF_LESS_THROTTLE); |
| 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 raparms *ra; |
| __be32 err; |
| |
| trace_read_start(rqstp, fhp, offset, vlen); |
| err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file); |
| if (err) |
| return err; |
| |
| ra = nfsd_init_raparms(file); |
| |
| trace_read_opened(rqstp, fhp, offset, vlen); |
| |
| if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags)) |
| err = nfsd_splice_read(rqstp, file, offset, count); |
| else |
| err = nfsd_readv(file, offset, vec, vlen, count); |
| |
| trace_read_io_done(rqstp, fhp, offset, vlen); |
| |
| if (ra) |
| nfsd_put_raparams(file, ra); |
| fput(file); |
| |
| trace_read_done(rqstp, fhp, offset, vlen); |
| |
| 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, loff_t offset, |
| struct kvec *vec, int vlen, unsigned long *cnt, int stable) |
| { |
| struct file *file = NULL; |
| __be32 err = 0; |
| |
| trace_write_start(rqstp, fhp, offset, vlen); |
| |
| err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file); |
| if (err) |
| goto out; |
| |
| trace_write_opened(rqstp, fhp, offset, vlen); |
| err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt, stable); |
| trace_write_io_done(rqstp, fhp, offset, vlen); |
| fput(file); |
| out: |
| trace_write_done(rqstp, fhp, offset, vlen); |
| 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; |
| } |
| |
| fput(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); |
| /* Callers expect file metadata to be committed here */ |
| return nfserrno(commit_metadata(resfhp)); |
| } |
| |
| /* 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; |
| } |
| |
| /* The parent directory should already be locked: */ |
| __be32 |
| nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp, |
| char *fname, int flen, struct iattr *iap, |
| int type, dev_t rdev, struct svc_fh *resfhp) |
| { |
| struct dentry *dentry, *dchild; |
| struct inode *dirp; |
| __be32 err; |
| __be32 err2; |
| int host_err; |
| |
| dentry = fhp->fh_dentry; |
| dirp = d_inode(dentry); |
| |
| dchild = dget(resfhp->fh_dentry); |
| if (!fhp->fh_locked) { |
| WARN_ONCE(1, "nfsd_create: parent %pd2 not locked!\n", |
| dentry); |
| err = nfserr_io; |
| goto out; |
| } |
| |
| err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE); |
| if (err) |
| goto out; |
| |
| if (!(iap->ia_valid & ATTR_MODE)) |
| iap->ia_mode = 0; |
| iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type; |
| |
| if (!IS_POSIXACL(dirp)) |
| iap->ia_mode &= ~current_umask(); |
| |
| 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; |
| default: |
| printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n", |
| type); |
| host_err = -EINVAL; |
| } |
| if (host_err < 0) |
| goto out_nfserr; |
| |
| err = nfsd_create_setattr(rqstp, resfhp, iap); |
| |
| /* |
| * nfsd_create_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: |
| dput(dchild); |
| return err; |
| |
| out_nfserr: |
| err = nfserrno(host_err); |
| goto out; |
| } |
| |
| /* |
| * Create a filesystem object (regular, directory, special). |
| * 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; |
| int host_err; |
| |
| if (isdotent(fname, flen)) |
| return nfserr_exist; |
| |
| err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP); |
| if (err) |
| return err; |
| |
| dentry = fhp->fh_dentry; |
| dirp = d_inode(dentry); |
| |
| host_err = fh_want_write(fhp); |
| if (host_err) |
| return nfserrno(host_err); |
| |
| fh_lock_nested(fhp, I_MUTEX_PARENT); |
| dchild = lookup_one_len(fname, dentry, flen); |
| host_err = PTR_ERR(dchild); |
| if (IS_ERR(dchild)) |
| return nfserrno(host_err); |
| err = fh_compose(resfhp, fhp->fh_export, dchild, fhp); |
| /* |
| * We unconditionally drop our ref to dchild as fh_compose will have |
| * already grabbed its own ref for it. |
| */ |
| dput(dchild); |
| if (err) |
| return err; |
| return nfsd_create_locked(rqstp, fhp, fname, flen, iap, type, |
| rdev, resfhp); |
| } |
| |
| #ifdef CONFIG_NFSD_V3 |
| |
| /* |
| * 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 = d_inode(dentry); |
| |
| 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 (d_really_is_negative(dchild)) { |
| 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 (d_really_is_positive(dchild)) { |
| err = 0; |
| |
| switch (createmode) { |
| case NFS3_CREATE_UNCHECKED: |
| if (! d_is_reg(dchild)) |
| 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 ( d_inode(dchild)->i_mtime.tv_sec == v_mtime |
| && d_inode(dchild)->i_atime.tv_sec == v_atime |
| && d_inode(dchild)->i_size == 0 ) { |
| if (created) |
| *created = 1; |
| break; |
| } |
| case NFS4_CREATE_EXCLUSIVE4_1: |
| if ( d_inode(dchild)->i_mtime.tv_sec == v_mtime |
| && d_inode(dchild)->i_atime.tv_sec == v_atime |
| && d_inode(dchild)->i_size == 0 ) { |
| if (created) |
| *created = 1; |
| goto set_attr; |
| } |
| /* fallthru */ |
| case NFS3_CREATE_GUARDED: |
| err = nfserr_exist; |
| } |
| fh_drop_write(fhp); |
| goto out; |
| } |
| |
| if (!IS_POSIXACL(dirp)) |
| iap->ia_mode &= ~current_umask(); |
| |
| 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_create_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) |
| { |
| __be32 err; |
| const char *link; |
| struct path path; |
| DEFINE_DELAYED_CALL(done); |
| int len; |
| |
| err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP); |
| if (unlikely(err)) |
| return err; |
| |
| path.mnt = fhp->fh_export->ex_path.mnt; |
| path.dentry = fhp->fh_dentry; |
| |
| if (unlikely(!d_is_symlink(path.dentry))) |
| return nfserr_inval; |
| |
| touch_atime(&path); |
| |
| link = vfs_get_link(path.dentry, &done); |
| if (IS_ERR(link)) |
| return nfserrno(PTR_ERR(link)); |
| |
| len = strlen(link); |
| if (len < *lenp) |
| *lenp = len; |
| memcpy(buf, link, *lenp); |
| do_delayed_call(&done); |
| return 0; |
| } |
| |
| /* |
| * 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, |
| struct svc_fh *resfhp) |
| { |
| struct dentry *dentry, *dnew; |
| __be32 err, cerr; |
| int host_err; |
| |
| err = nfserr_noent; |
| if (!flen || path[0] == '\0') |
| 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; |
| |
| host_err = vfs_symlink(d_inode(dentry), 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 (d_is_dir(tfhp->fh_dentry)) |
| 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 = d_inode(ddir); |
| |
| 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 (d_really_is_negative(dold)) |
| goto out_dput; |
| host_err = vfs_link(dold, dirp, dnew, NULL); |
| 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 = d_inode(fdentry); |
| |
| tdentry = tfhp->fh_dentry; |
| tdir = d_inode(tdentry); |
| |
| err = nfserr_perm; |
| if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen)) |
| goto out; |
| |
| err = (rqstp->rq_vers == 2) ? nfserr_acces : nfserr_xdev; |
| if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt) |
| goto out; |
| if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) |
| 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 = true; |
| 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 (d_really_is_negative(odentry)) |
| 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 = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0); |
| 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 rely 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 = false; |
| 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 = d_inode(dentry); |
| |
| rdentry = lookup_one_len(fname, dentry, flen); |
| host_err = PTR_ERR(rdentry); |
| if (IS_ERR(rdentry)) |
| goto out_nfserr; |
| |
| if (d_really_is_negative(rdentry)) { |
| dput(rdentry); |
| err = nfserr_noent; |
| goto out; |
| } |
| |
| if (!type) |
| type = d_inode(rdentry)->i_mode & S_IFMT; |
| |
| if (type != S_IFDIR) |
| host_err = vfs_unlink(dirp, rdentry, NULL); |
| else |
| host_err = vfs_rmdir(dirp, rdentry); |
| if (!host_err) |
| host_err = commit_metadata(fhp); |
| 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(struct dir_context *ctx, const char *name, |
| int namlen, loff_t offset, u64 ino, |
| unsigned int d_type) |
| { |
| struct readdir_data *buf = |
| container_of(ctx, struct readdir_data, ctx); |
| 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, nfsd_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) { |
| 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; |
| |
| 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); |
| } |
| 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, nfsd_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: |
| fput(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 = d_inode(dentry); |
| 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); |
| nperbucket = max(2, nperbucket); |
| 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; |
| } |