1 // SPDX-License-Identifier: GPL-2.0
3 * File operations used by nfsd. Some of these have been ripped from
4 * other parts of the kernel because they weren't exported, others
5 * are partial duplicates with added or changed functionality.
7 * Note that several functions dget() the dentry upon which they want
8 * to act, most notably those that create directory entries. Response
9 * dentry's are dput()'d if necessary in the release callback.
10 * So if you notice code paths that apparently fail to dput() the
11 * dentry, don't worry--they have been taken care of.
13 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
14 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
18 #include <linux/file.h>
19 #include <linux/splice.h>
20 #include <linux/falloc.h>
21 #include <linux/fcntl.h>
22 #include <linux/namei.h>
23 #include <linux/delay.h>
24 #include <linux/fsnotify.h>
25 #include <linux/posix_acl_xattr.h>
26 #include <linux/xattr.h>
27 #include <linux/jhash.h>
28 #include <linux/ima.h>
29 #include <linux/pagemap.h>
30 #include <linux/slab.h>
31 #include <linux/uaccess.h>
32 #include <linux/exportfs.h>
33 #include <linux/writeback.h>
34 #include <linux/security.h>
39 #include "../internal.h"
43 #endif /* CONFIG_NFSD_V4 */
47 #include "filecache.h"
50 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
53 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
55 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
56 * or nfs_ok having possibly changed *dpp and *expp
59 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
60 struct svc_export **expp)
62 struct svc_export *exp = *expp, *exp2 = NULL;
63 struct dentry *dentry = *dpp;
64 struct path path = {.mnt = mntget(exp->ex_path.mnt),
65 .dentry = dget(dentry)};
68 err = follow_down(&path);
71 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
72 nfsd_mountpoint(dentry, exp) == 2) {
73 /* This is only a mountpoint in some other namespace */
78 exp2 = rqst_exp_get_by_name(rqstp, &path);
82 * We normally allow NFS clients to continue
83 * "underneath" a mountpoint that is not exported.
84 * The exception is V4ROOT, where no traversal is ever
85 * allowed without an explicit export of the new
88 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
93 if (nfsd_v4client(rqstp) ||
94 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
95 /* successfully crossed mount point */
97 * This is subtle: path.dentry is *not* on path.mnt
98 * at this point. The only reason we are safe is that
99 * original mnt is pinned down by exp, so we should
100 * put path *before* putting exp
103 path.dentry = dentry;
113 static void follow_to_parent(struct path *path)
117 while (path->dentry == path->mnt->mnt_root && follow_up(path))
119 dp = dget_parent(path->dentry);
124 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
126 struct svc_export *exp2;
127 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
128 .dentry = dget(dparent)};
130 follow_to_parent(&path);
132 exp2 = rqst_exp_parent(rqstp, &path);
133 if (PTR_ERR(exp2) == -ENOENT) {
134 *dentryp = dget(dparent);
135 } else if (IS_ERR(exp2)) {
137 return PTR_ERR(exp2);
139 *dentryp = dget(path.dentry);
148 * For nfsd purposes, we treat V4ROOT exports as though there was an
149 * export at *every* directory.
151 * '1' if this dentry *must* be an export point,
152 * '2' if it might be, if there is really a mount here, and
153 * '0' if there is no chance of an export point here.
155 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
157 if (!d_inode(dentry))
159 if (exp->ex_flags & NFSEXP_V4ROOT)
161 if (nfsd4_is_junction(dentry))
163 if (d_mountpoint(dentry))
165 * Might only be a mountpoint in a different namespace,
166 * but we need to check.
173 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
174 const char *name, unsigned int len,
175 struct svc_export **exp_ret, struct dentry **dentry_ret)
177 struct svc_export *exp;
178 struct dentry *dparent;
179 struct dentry *dentry;
182 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
184 dparent = fhp->fh_dentry;
185 exp = exp_get(fhp->fh_export);
187 /* Lookup the name, but don't follow links */
188 if (isdotent(name, len)) {
190 dentry = dget(dparent);
191 else if (dparent != exp->ex_path.dentry)
192 dentry = dget_parent(dparent);
193 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
194 dentry = dget(dparent); /* .. == . just like at / */
196 /* checking mountpoint crossing is very different when stepping up */
197 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
202 dentry = lookup_one_len_unlocked(name, dparent, len);
203 host_err = PTR_ERR(dentry);
206 if (nfsd_mountpoint(dentry, exp)) {
207 host_err = nfsd_cross_mnt(rqstp, &dentry, &exp);
214 *dentry_ret = dentry;
220 return nfserrno(host_err);
224 * nfsd_lookup - look up a single path component for nfsd
226 * @rqstp: the request context
227 * @fhp: the file handle of the directory
228 * @name: the component name, or %NULL to look up parent
229 * @len: length of name to examine
230 * @resfh: pointer to pre-initialised filehandle to hold result.
232 * Look up one component of a pathname.
233 * N.B. After this call _both_ fhp and resfh need an fh_put
235 * If the lookup would cross a mountpoint, and the mounted filesystem
236 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
237 * accepted as it stands and the mounted directory is
238 * returned. Otherwise the covered directory is returned.
239 * NOTE: this mountpoint crossing is not supported properly by all
240 * clients and is explicitly disallowed for NFSv3
244 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
245 unsigned int len, struct svc_fh *resfh)
247 struct svc_export *exp;
248 struct dentry *dentry;
251 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
254 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
257 err = check_nfsd_access(exp, rqstp);
261 * Note: we compose the file handle now, but as the
262 * dentry may be negative, it may need to be updated.
264 err = fh_compose(resfh, exp, dentry, fhp);
265 if (!err && d_really_is_negative(dentry))
274 * Commit metadata changes to stable storage.
277 commit_inode_metadata(struct inode *inode)
279 const struct export_operations *export_ops = inode->i_sb->s_export_op;
281 if (export_ops->commit_metadata)
282 return export_ops->commit_metadata(inode);
283 return sync_inode_metadata(inode, 1);
287 commit_metadata(struct svc_fh *fhp)
289 struct inode *inode = d_inode(fhp->fh_dentry);
291 if (!EX_ISSYNC(fhp->fh_export))
293 return commit_inode_metadata(inode);
297 * Go over the attributes and take care of the small differences between
298 * NFS semantics and what Linux expects.
301 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
303 /* Ignore mode updates on symlinks */
304 if (S_ISLNK(inode->i_mode))
305 iap->ia_valid &= ~ATTR_MODE;
307 /* sanitize the mode change */
308 if (iap->ia_valid & ATTR_MODE) {
309 iap->ia_mode &= S_IALLUGO;
310 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
313 /* Revoke setuid/setgid on chown */
314 if (!S_ISDIR(inode->i_mode) &&
315 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
316 iap->ia_valid |= ATTR_KILL_PRIV;
317 if (iap->ia_valid & ATTR_MODE) {
318 /* we're setting mode too, just clear the s*id bits */
319 iap->ia_mode &= ~S_ISUID;
320 if (iap->ia_mode & S_IXGRP)
321 iap->ia_mode &= ~S_ISGID;
323 /* set ATTR_KILL_* bits and let VFS handle it */
324 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
330 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
333 struct inode *inode = d_inode(fhp->fh_dentry);
335 if (iap->ia_size < inode->i_size) {
338 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
339 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
343 return nfserrno(get_write_access(inode));
347 * Set various file attributes. After this call fhp needs an fh_put.
350 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
351 struct nfsd_attrs *attr,
352 int check_guard, time64_t guardtime)
354 struct dentry *dentry;
356 struct iattr *iap = attr->na_iattr;
357 int accmode = NFSD_MAY_SATTR;
361 bool get_write_count;
362 bool size_change = (iap->ia_valid & ATTR_SIZE);
364 if (iap->ia_valid & ATTR_SIZE) {
365 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
370 * If utimes(2) and friends are called with times not NULL, we should
371 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
372 * will return EACCES, when the caller's effective UID does not match
373 * the owner of the file, and the caller is not privileged. In this
374 * situation, we should return EPERM(notify_change will return this).
376 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
377 accmode |= NFSD_MAY_OWNER_OVERRIDE;
378 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
379 accmode |= NFSD_MAY_WRITE;
382 /* Callers that do fh_verify should do the fh_want_write: */
383 get_write_count = !fhp->fh_dentry;
386 err = fh_verify(rqstp, fhp, ftype, accmode);
389 if (get_write_count) {
390 host_err = fh_want_write(fhp);
395 dentry = fhp->fh_dentry;
396 inode = d_inode(dentry);
398 nfsd_sanitize_attrs(inode, iap);
400 if (check_guard && guardtime != inode->i_ctime.tv_sec)
401 return nfserr_notsync;
404 * The size case is special, it changes the file in addition to the
405 * attributes, and file systems don't expect it to be mixed with
406 * "random" attribute changes. We thus split out the size change
407 * into a separate call to ->setattr, and do the rest as a separate
411 err = nfsd_get_write_access(rqstp, fhp, iap);
419 * RFC5661, Section 18.30.4:
420 * Changing the size of a file with SETATTR indirectly
421 * changes the time_modify and change attributes.
423 * (and similar for the older RFCs)
425 struct iattr size_attr = {
426 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
427 .ia_size = iap->ia_size,
431 if (iap->ia_size < 0)
434 host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
437 iap->ia_valid &= ~ATTR_SIZE;
440 * Avoid the additional setattr call below if the only other
441 * attribute that the client sends is the mtime, as we update
442 * it as part of the size change above.
444 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
449 iap->ia_valid |= ATTR_CTIME;
450 host_err = notify_change(&init_user_ns, dentry, iap, NULL);
454 if (attr->na_seclabel && attr->na_seclabel->len)
455 attr->na_labelerr = security_inode_setsecctx(dentry,
456 attr->na_seclabel->data, attr->na_seclabel->len);
457 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl)
458 attr->na_aclerr = set_posix_acl(&init_user_ns,
459 inode, ACL_TYPE_ACCESS,
461 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) &&
462 !attr->na_aclerr && attr->na_dpacl && S_ISDIR(inode->i_mode))
463 attr->na_aclerr = set_posix_acl(&init_user_ns,
464 inode, ACL_TYPE_DEFAULT,
468 put_write_access(inode);
471 host_err = commit_metadata(fhp);
472 return nfserrno(host_err);
475 #if defined(CONFIG_NFSD_V4)
477 * NFS junction information is stored in an extended attribute.
479 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
482 * nfsd4_is_junction - Test if an object could be an NFS junction
484 * @dentry: object to test
486 * Returns 1 if "dentry" appears to contain NFS junction information.
487 * Otherwise 0 is returned.
489 int nfsd4_is_junction(struct dentry *dentry)
491 struct inode *inode = d_inode(dentry);
495 if (inode->i_mode & S_IXUGO)
497 if (!(inode->i_mode & S_ISVTX))
499 if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
505 static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
507 return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
510 __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
511 struct nfsd_file *nf_src, u64 src_pos,
512 struct nfsd_file *nf_dst, u64 dst_pos,
513 u64 count, bool sync)
515 struct file *src = nf_src->nf_file;
516 struct file *dst = nf_dst->nf_file;
521 since = READ_ONCE(dst->f_wb_err);
522 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
524 ret = nfserrno(cloned);
527 if (count && cloned != count) {
528 ret = nfserrno(-EINVAL);
532 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
533 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
536 status = filemap_check_wb_err(dst->f_mapping, since);
538 status = commit_inode_metadata(file_inode(src));
540 struct nfsd_net *nn = net_generic(nf_dst->nf_net,
543 trace_nfsd_clone_file_range_err(rqstp,
544 &nfsd4_get_cstate(rqstp)->save_fh,
546 &nfsd4_get_cstate(rqstp)->current_fh,
549 nfsd_reset_write_verifier(nn);
550 trace_nfsd_writeverf_reset(nn, rqstp, status);
551 ret = nfserrno(status);
558 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
559 u64 dst_pos, u64 count)
564 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
565 * thread and client rpc slot. The choice of 4MB is somewhat
566 * arbitrary. We might instead base this on r/wsize, or make it
567 * tunable, or use a time instead of a byte limit, or implement
568 * asynchronous copy. In theory a client could also recognize a
569 * limit like this and pipeline multiple COPY requests.
571 count = min_t(u64, count, 1 << 22);
572 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
574 if (ret == -EOPNOTSUPP || ret == -EXDEV)
575 ret = generic_copy_file_range(src, src_pos, dst, dst_pos,
580 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
581 struct file *file, loff_t offset, loff_t len,
586 if (!S_ISREG(file_inode(file)->i_mode))
589 error = vfs_fallocate(file, flags, offset, len);
591 error = commit_metadata(fhp);
593 return nfserrno(error);
595 #endif /* defined(CONFIG_NFSD_V4) */
598 * Check server access rights to a file system object
604 static struct accessmap nfs3_regaccess[] = {
605 { NFS3_ACCESS_READ, NFSD_MAY_READ },
606 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
607 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
608 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
610 #ifdef CONFIG_NFSD_V4
611 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
612 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
613 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
619 static struct accessmap nfs3_diraccess[] = {
620 { NFS3_ACCESS_READ, NFSD_MAY_READ },
621 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
622 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
623 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
624 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
626 #ifdef CONFIG_NFSD_V4
627 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
628 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
629 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
635 static struct accessmap nfs3_anyaccess[] = {
636 /* Some clients - Solaris 2.6 at least, make an access call
637 * to the server to check for access for things like /dev/null
638 * (which really, the server doesn't care about). So
639 * We provide simple access checking for them, looking
640 * mainly at mode bits, and we make sure to ignore read-only
643 { NFS3_ACCESS_READ, NFSD_MAY_READ },
644 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
645 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
646 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
652 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
654 struct accessmap *map;
655 struct svc_export *export;
656 struct dentry *dentry;
657 u32 query, result = 0, sresult = 0;
660 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
664 export = fhp->fh_export;
665 dentry = fhp->fh_dentry;
667 if (d_is_reg(dentry))
668 map = nfs3_regaccess;
669 else if (d_is_dir(dentry))
670 map = nfs3_diraccess;
672 map = nfs3_anyaccess;
676 for (; map->access; map++) {
677 if (map->access & query) {
680 sresult |= map->access;
682 err2 = nfsd_permission(rqstp, export, dentry, map->how);
685 result |= map->access;
688 /* the following error codes just mean the access was not allowed,
689 * rather than an error occurred */
693 /* simply don't "or" in the access bit. */
703 *supported = sresult;
709 int nfsd_open_break_lease(struct inode *inode, int access)
713 if (access & NFSD_MAY_NOT_BREAK_LEASE)
715 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
716 return break_lease(inode, mode | O_NONBLOCK);
720 * Open an existing file or directory.
721 * The may_flags argument indicates the type of open (read/write/lock)
722 * and additional flags.
723 * N.B. After this call fhp needs an fh_put
726 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
727 int may_flags, struct file **filp)
732 int flags = O_RDONLY|O_LARGEFILE;
736 path.mnt = fhp->fh_export->ex_path.mnt;
737 path.dentry = fhp->fh_dentry;
738 inode = d_inode(path.dentry);
741 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
747 host_err = nfsd_open_break_lease(inode, may_flags);
748 if (host_err) /* NOMEM or WOULDBLOCK */
751 if (may_flags & NFSD_MAY_WRITE) {
752 if (may_flags & NFSD_MAY_READ)
753 flags = O_RDWR|O_LARGEFILE;
755 flags = O_WRONLY|O_LARGEFILE;
758 file = dentry_open(&path, flags, current_cred());
760 host_err = PTR_ERR(file);
764 host_err = ima_file_check(file, may_flags);
770 if (may_flags & NFSD_MAY_64BIT_COOKIE)
771 file->f_mode |= FMODE_64BITHASH;
773 file->f_mode |= FMODE_32BITHASH;
777 err = nfserrno(host_err);
783 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
784 int may_flags, struct file **filp)
787 bool retried = false;
789 validate_process_creds();
791 * If we get here, then the client has already done an "open",
792 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
793 * in case a chmod has now revoked permission.
795 * Arguably we should also allow the owner override for
796 * directories, but we never have and it doesn't seem to have
797 * caused anyone a problem. If we were to change this, note
798 * also that our filldir callbacks would need a variant of
799 * lookup_one_len that doesn't check permissions.
802 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
804 err = fh_verify(rqstp, fhp, type, may_flags);
806 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
807 if (err == nfserr_stale && !retried) {
813 validate_process_creds();
818 * nfsd_open_verified - Open a regular file for the filecache
819 * @rqstp: RPC request
820 * @fhp: NFS filehandle of the file to open
821 * @may_flags: internal permission flags
822 * @filp: OUT: open "struct file *"
824 * Returns an nfsstat value in network byte order.
827 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
832 validate_process_creds();
833 err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
834 validate_process_creds();
839 * Grab and keep cached pages associated with a file in the svc_rqst
840 * so that they can be passed to the network sendmsg/sendpage routines
841 * directly. They will be released after the sending has completed.
844 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
845 struct splice_desc *sd)
847 struct svc_rqst *rqstp = sd->u.data;
848 struct page *page = buf->page; // may be a compound one
849 unsigned offset = buf->offset;
851 page += offset / PAGE_SIZE;
852 for (int i = sd->len; i > 0; i -= PAGE_SIZE)
853 svc_rqst_replace_page(rqstp, page++);
854 if (rqstp->rq_res.page_len == 0) // first call
855 rqstp->rq_res.page_base = offset % PAGE_SIZE;
856 rqstp->rq_res.page_len += sd->len;
860 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
861 struct splice_desc *sd)
863 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
866 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
869 if (expected != 0 && len == 0)
871 if (offset+len >= i_size_read(file_inode(file)))
876 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
877 struct file *file, loff_t offset,
878 unsigned long *count, u32 *eof, ssize_t host_err)
881 nfsd_stats_io_read_add(fhp->fh_export, host_err);
882 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
884 fsnotify_access(file);
885 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
888 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
889 return nfserrno(host_err);
893 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
894 struct file *file, loff_t offset, unsigned long *count,
897 struct splice_desc sd = {
905 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
906 rqstp->rq_next_page = rqstp->rq_respages + 1;
907 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
908 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
911 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
912 struct file *file, loff_t offset,
913 struct kvec *vec, int vlen, unsigned long *count,
916 struct iov_iter iter;
917 loff_t ppos = offset;
920 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
921 iov_iter_kvec(&iter, READ, vec, vlen, *count);
922 host_err = vfs_iter_read(file, &iter, &ppos, 0);
923 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
927 * Gathered writes: If another process is currently writing to the file,
928 * there's a high chance this is another nfsd (triggered by a bulk write
929 * from a client's biod). Rather than syncing the file with each write
930 * request, we sleep for 10 msec.
932 * I don't know if this roughly approximates C. Juszak's idea of
933 * gathered writes, but it's a nice and simple solution (IMHO), and it
936 * Note: we do this only in the NFSv2 case, since v3 and higher have a
937 * better tool (separate unstable writes and commits) for solving this
940 static int wait_for_concurrent_writes(struct file *file)
942 struct inode *inode = file_inode(file);
943 static ino_t last_ino;
944 static dev_t last_dev;
947 if (atomic_read(&inode->i_writecount) > 1
948 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
949 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
951 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
954 if (inode->i_state & I_DIRTY) {
955 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
956 err = vfs_fsync(file, 0);
958 last_ino = inode->i_ino;
959 last_dev = inode->i_sb->s_dev;
964 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
965 loff_t offset, struct kvec *vec, int vlen,
966 unsigned long *cnt, int stable,
969 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
970 struct file *file = nf->nf_file;
971 struct super_block *sb = file_inode(file)->i_sb;
972 struct svc_export *exp;
973 struct iov_iter iter;
979 unsigned long exp_op_flags = 0;
980 unsigned int pflags = current->flags;
982 bool restore_flags = false;
984 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
987 exp_op_flags = sb->s_export_op->flags;
989 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
990 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
992 * We want throttling in balance_dirty_pages()
993 * and shrink_inactive_list() to only consider
994 * the backingdev we are writing to, so that nfs to
995 * localhost doesn't cause nfsd to lock up due to all
996 * the client's dirty pages or its congested queue.
998 current->flags |= PF_LOCAL_THROTTLE;
999 restore_flags = true;
1002 exp = fhp->fh_export;
1003 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1005 if (!EX_ISSYNC(exp))
1006 stable = NFS_UNSTABLE;
1008 if (stable && !use_wgather)
1011 iov_iter_kvec(&iter, WRITE, vec, vlen, *cnt);
1012 since = READ_ONCE(file->f_wb_err);
1014 nfsd_copy_write_verifier(verf, nn);
1015 host_err = vfs_iter_write(file, &iter, &pos, flags);
1017 nfsd_reset_write_verifier(nn);
1018 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1022 nfsd_stats_io_write_add(exp, *cnt);
1023 fsnotify_modify(file);
1024 host_err = filemap_check_wb_err(file->f_mapping, since);
1028 if (stable && use_wgather) {
1029 host_err = wait_for_concurrent_writes(file);
1031 nfsd_reset_write_verifier(nn);
1032 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1037 if (host_err >= 0) {
1038 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1041 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1042 nfserr = nfserrno(host_err);
1045 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1050 * Read data from a file. count must contain the requested read count
1051 * on entry. On return, *count contains the number of bytes actually read.
1052 * N.B. After this call fhp needs an fh_put
1054 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1055 loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
1058 struct nfsd_file *nf;
1062 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1063 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_READ, &nf);
1068 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1069 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1071 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
1075 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1081 * Write data to a file.
1082 * The stable flag requests synchronous writes.
1083 * N.B. After this call fhp needs an fh_put
1086 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1087 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1090 struct nfsd_file *nf;
1093 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1095 err = nfsd_file_acquire(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1099 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1100 vlen, cnt, stable, verf);
1103 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1108 * nfsd_commit - Commit pending writes to stable storage
1109 * @rqstp: RPC request being processed
1110 * @fhp: NFS filehandle
1111 * @offset: raw offset from beginning of file
1112 * @count: raw count of bytes to sync
1113 * @verf: filled in with the server's current write verifier
1115 * Note: we guarantee that data that lies within the range specified
1116 * by the 'offset' and 'count' parameters will be synced. The server
1117 * is permitted to sync data that lies outside this range at the
1120 * Unfortunately we cannot lock the file to make sure we return full WCC
1121 * data to the client, as locking happens lower down in the filesystem.
1124 * An nfsstat value in network byte order.
1127 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, u64 offset,
1128 u32 count, __be32 *verf)
1132 struct nfsd_net *nn;
1133 struct nfsd_file *nf;
1136 err = nfsd_file_acquire(rqstp, fhp,
1137 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &nf);
1142 * Convert the client-provided (offset, count) range to a
1143 * (start, end) range. If the client-provided range falls
1144 * outside the maximum file size of the underlying FS,
1145 * clamp the sync range appropriately.
1149 maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
1150 if (offset < maxbytes) {
1152 if (count && (offset + count - 1 < maxbytes))
1153 end = offset + count - 1;
1156 nn = net_generic(nf->nf_net, nfsd_net_id);
1157 if (EX_ISSYNC(fhp->fh_export)) {
1158 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
1161 err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
1164 nfsd_copy_write_verifier(verf, nn);
1165 err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
1167 err = nfserrno(err2);
1170 err = nfserr_notsupp;
1173 nfsd_reset_write_verifier(nn);
1174 trace_nfsd_writeverf_reset(nn, rqstp, err2);
1175 err = nfserrno(err2);
1178 nfsd_copy_write_verifier(verf, nn);
1186 * nfsd_create_setattr - Set a created file's attributes
1187 * @rqstp: RPC transaction being executed
1188 * @fhp: NFS filehandle of parent directory
1189 * @resfhp: NFS filehandle of new object
1190 * @attrs: requested attributes of new object
1192 * Returns nfs_ok on success, or an nfsstat in network byte order.
1195 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
1196 struct svc_fh *resfhp, struct nfsd_attrs *attrs)
1198 struct iattr *iap = attrs->na_iattr;
1202 * Mode has already been set by file creation.
1204 iap->ia_valid &= ~ATTR_MODE;
1207 * Setting uid/gid works only for root. Irix appears to
1208 * send along the gid on create when it tries to implement
1209 * setgid directories via NFS:
1211 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1212 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1215 * Callers expect new file metadata to be committed even
1216 * if the attributes have not changed.
1219 status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0);
1221 status = nfserrno(commit_metadata(resfhp));
1224 * Transactional filesystems had a chance to commit changes
1225 * for both parent and child simultaneously making the
1226 * following commit_metadata a noop in many cases.
1229 status = nfserrno(commit_metadata(fhp));
1232 * Update the new filehandle to pick up the new attributes.
1235 status = fh_update(resfhp);
1240 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1241 * setting size to 0 may fail for some specific file systems by the permission
1242 * checking which requires WRITE permission but the mode is 000.
1243 * we ignore the resizing(to 0) on the just new created file, since the size is
1244 * 0 after file created.
1246 * call this only after vfs_create() is called.
1249 nfsd_check_ignore_resizing(struct iattr *iap)
1251 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1252 iap->ia_valid &= ~ATTR_SIZE;
1255 /* The parent directory should already be locked: */
1257 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1258 char *fname, int flen, struct nfsd_attrs *attrs,
1259 int type, dev_t rdev, struct svc_fh *resfhp)
1261 struct dentry *dentry, *dchild;
1263 struct iattr *iap = attrs->na_iattr;
1267 dentry = fhp->fh_dentry;
1268 dirp = d_inode(dentry);
1270 dchild = dget(resfhp->fh_dentry);
1271 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1275 if (!(iap->ia_valid & ATTR_MODE))
1277 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1279 if (!IS_POSIXACL(dirp))
1280 iap->ia_mode &= ~current_umask();
1286 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1288 nfsd_check_ignore_resizing(iap);
1291 host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
1292 if (!host_err && unlikely(d_unhashed(dchild))) {
1294 d = lookup_one_len(dchild->d_name.name,
1296 dchild->d_name.len);
1298 host_err = PTR_ERR(d);
1301 if (unlikely(d_is_negative(d))) {
1303 err = nfserr_serverfault;
1306 dput(resfhp->fh_dentry);
1307 resfhp->fh_dentry = dget(d);
1308 err = fh_update(resfhp);
1319 host_err = vfs_mknod(&init_user_ns, dirp, dchild,
1320 iap->ia_mode, rdev);
1323 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1330 err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1337 err = nfserrno(host_err);
1342 * Create a filesystem object (regular, directory, special).
1343 * Note that the parent directory is left locked.
1345 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1348 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1349 char *fname, int flen, struct nfsd_attrs *attrs,
1350 int type, dev_t rdev, struct svc_fh *resfhp)
1352 struct dentry *dentry, *dchild = NULL;
1356 if (isdotent(fname, flen))
1357 return nfserr_exist;
1359 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1363 dentry = fhp->fh_dentry;
1365 host_err = fh_want_write(fhp);
1367 return nfserrno(host_err);
1369 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1370 dchild = lookup_one_len(fname, dentry, flen);
1371 host_err = PTR_ERR(dchild);
1372 if (IS_ERR(dchild)) {
1373 err = nfserrno(host_err);
1376 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1378 * We unconditionally drop our ref to dchild as fh_compose will have
1379 * already grabbed its own ref for it.
1384 fh_fill_pre_attrs(fhp);
1385 err = nfsd_create_locked(rqstp, fhp, fname, flen, attrs, type,
1387 fh_fill_post_attrs(fhp);
1389 inode_unlock(dentry->d_inode);
1394 * Read a symlink. On entry, *lenp must contain the maximum path length that
1395 * fits into the buffer. On return, it contains the true length.
1396 * N.B. After this call fhp needs an fh_put
1399 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1404 DEFINE_DELAYED_CALL(done);
1407 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1411 path.mnt = fhp->fh_export->ex_path.mnt;
1412 path.dentry = fhp->fh_dentry;
1414 if (unlikely(!d_is_symlink(path.dentry)))
1415 return nfserr_inval;
1419 link = vfs_get_link(path.dentry, &done);
1421 return nfserrno(PTR_ERR(link));
1426 memcpy(buf, link, *lenp);
1427 do_delayed_call(&done);
1432 * nfsd_symlink - Create a symlink and look up its inode
1433 * @rqstp: RPC transaction being executed
1434 * @fhp: NFS filehandle of parent directory
1435 * @fname: filename of the new symlink
1436 * @flen: length of @fname
1437 * @path: content of the new symlink (NUL-terminated)
1438 * @attrs: requested attributes of new object
1439 * @resfhp: NFS filehandle of new object
1441 * N.B. After this call _both_ fhp and resfhp need an fh_put
1443 * Returns nfs_ok on success, or an nfsstat in network byte order.
1446 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1447 char *fname, int flen,
1448 char *path, struct nfsd_attrs *attrs,
1449 struct svc_fh *resfhp)
1451 struct dentry *dentry, *dnew;
1456 if (!flen || path[0] == '\0')
1459 if (isdotent(fname, flen))
1462 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1466 host_err = fh_want_write(fhp);
1468 err = nfserrno(host_err);
1472 dentry = fhp->fh_dentry;
1473 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1474 dnew = lookup_one_len(fname, dentry, flen);
1476 err = nfserrno(PTR_ERR(dnew));
1477 inode_unlock(dentry->d_inode);
1478 goto out_drop_write;
1480 fh_fill_pre_attrs(fhp);
1481 host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
1482 err = nfserrno(host_err);
1483 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1485 nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1486 fh_fill_post_attrs(fhp);
1487 inode_unlock(dentry->d_inode);
1489 err = nfserrno(commit_metadata(fhp));
1491 if (err==0) err = cerr;
1500 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1503 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1504 char *name, int len, struct svc_fh *tfhp)
1506 struct dentry *ddir, *dnew, *dold;
1511 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1514 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1518 if (d_is_dir(tfhp->fh_dentry))
1524 if (isdotent(name, len))
1527 host_err = fh_want_write(tfhp);
1529 err = nfserrno(host_err);
1533 ddir = ffhp->fh_dentry;
1534 dirp = d_inode(ddir);
1535 inode_lock_nested(dirp, I_MUTEX_PARENT);
1537 dnew = lookup_one_len(name, ddir, len);
1539 err = nfserrno(PTR_ERR(dnew));
1543 dold = tfhp->fh_dentry;
1546 if (d_really_is_negative(dold))
1548 fh_fill_pre_attrs(ffhp);
1549 host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
1550 fh_fill_post_attrs(ffhp);
1553 err = nfserrno(commit_metadata(ffhp));
1555 err = nfserrno(commit_metadata(tfhp));
1557 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1560 err = nfserrno(host_err);
1564 fh_drop_write(tfhp);
1572 goto out_drop_write;
1576 nfsd_close_cached_files(struct dentry *dentry)
1578 struct inode *inode = d_inode(dentry);
1580 if (inode && S_ISREG(inode->i_mode))
1581 nfsd_file_close_inode_sync(inode);
1585 nfsd_has_cached_files(struct dentry *dentry)
1588 struct inode *inode = d_inode(dentry);
1590 if (inode && S_ISREG(inode->i_mode))
1591 ret = nfsd_file_is_cached(inode);
1597 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1600 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1601 struct svc_fh *tfhp, char *tname, int tlen)
1603 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1604 struct inode *fdir, *tdir;
1607 bool close_cached = false;
1609 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1612 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1616 fdentry = ffhp->fh_dentry;
1617 fdir = d_inode(fdentry);
1619 tdentry = tfhp->fh_dentry;
1620 tdir = d_inode(tdentry);
1623 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1627 host_err = fh_want_write(ffhp);
1629 err = nfserrno(host_err);
1633 trap = lock_rename(tdentry, fdentry);
1634 fh_fill_pre_attrs(ffhp);
1635 fh_fill_pre_attrs(tfhp);
1637 odentry = lookup_one_len(fname, fdentry, flen);
1638 host_err = PTR_ERR(odentry);
1639 if (IS_ERR(odentry))
1643 if (d_really_is_negative(odentry))
1646 if (odentry == trap)
1649 ndentry = lookup_one_len(tname, tdentry, tlen);
1650 host_err = PTR_ERR(ndentry);
1651 if (IS_ERR(ndentry))
1653 host_err = -ENOTEMPTY;
1654 if (ndentry == trap)
1658 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1660 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1663 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
1664 nfsd_has_cached_files(ndentry)) {
1665 close_cached = true;
1668 struct renamedata rd = {
1669 .old_mnt_userns = &init_user_ns,
1671 .old_dentry = odentry,
1672 .new_mnt_userns = &init_user_ns,
1674 .new_dentry = ndentry,
1676 host_err = vfs_rename(&rd);
1678 host_err = commit_metadata(tfhp);
1680 host_err = commit_metadata(ffhp);
1688 err = nfserrno(host_err);
1690 if (!close_cached) {
1691 fh_fill_post_attrs(ffhp);
1692 fh_fill_post_attrs(tfhp);
1694 unlock_rename(tdentry, fdentry);
1695 fh_drop_write(ffhp);
1698 * If the target dentry has cached open files, then we need to try to
1699 * close them prior to doing the rename. Flushing delayed fput
1700 * shouldn't be done with locks held however, so we delay it until this
1701 * point and then reattempt the whole shebang.
1704 close_cached = false;
1705 nfsd_close_cached_files(ndentry);
1714 * Unlink a file or directory
1715 * N.B. After this call fhp needs an fh_put
1718 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1719 char *fname, int flen)
1721 struct dentry *dentry, *rdentry;
1723 struct inode *rinode;
1728 if (!flen || isdotent(fname, flen))
1730 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1734 host_err = fh_want_write(fhp);
1738 dentry = fhp->fh_dentry;
1739 dirp = d_inode(dentry);
1740 inode_lock_nested(dirp, I_MUTEX_PARENT);
1742 rdentry = lookup_one_len(fname, dentry, flen);
1743 host_err = PTR_ERR(rdentry);
1744 if (IS_ERR(rdentry))
1747 if (d_really_is_negative(rdentry)) {
1752 rinode = d_inode(rdentry);
1756 type = d_inode(rdentry)->i_mode & S_IFMT;
1758 fh_fill_pre_attrs(fhp);
1759 if (type != S_IFDIR) {
1760 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
1761 nfsd_close_cached_files(rdentry);
1762 host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
1764 host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
1766 fh_fill_post_attrs(fhp);
1770 host_err = commit_metadata(fhp);
1772 iput(rinode); /* truncate the inode here */
1777 if (host_err == -EBUSY) {
1778 /* name is mounted-on. There is no perfect
1781 if (nfsd_v4client(rqstp))
1782 err = nfserr_file_open;
1786 err = nfserrno(host_err);
1792 goto out_drop_write;
1796 * We do this buffering because we must not call back into the file
1797 * system's ->lookup() method from the filldir callback. That may well
1798 * deadlock a number of file systems.
1800 * This is based heavily on the implementation of same in XFS.
1802 struct buffered_dirent {
1806 unsigned int d_type;
1810 struct readdir_data {
1811 struct dir_context ctx;
1817 static int nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1818 int namlen, loff_t offset, u64 ino,
1819 unsigned int d_type)
1821 struct readdir_data *buf =
1822 container_of(ctx, struct readdir_data, ctx);
1823 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1824 unsigned int reclen;
1826 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1827 if (buf->used + reclen > PAGE_SIZE) {
1832 de->namlen = namlen;
1833 de->offset = offset;
1835 de->d_type = d_type;
1836 memcpy(de->name, name, namlen);
1837 buf->used += reclen;
1842 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
1843 nfsd_filldir_t func, struct readdir_cd *cdp,
1846 struct buffered_dirent *de;
1850 struct readdir_data buf = {
1851 .ctx.actor = nfsd_buffered_filldir,
1852 .dirent = (void *)__get_free_page(GFP_KERNEL)
1856 return nfserrno(-ENOMEM);
1861 unsigned int reclen;
1863 cdp->err = nfserr_eof; /* will be cleared on successful read */
1867 host_err = iterate_dir(file, &buf.ctx);
1879 de = (struct buffered_dirent *)buf.dirent;
1881 offset = de->offset;
1883 if (func(cdp, de->name, de->namlen, de->offset,
1884 de->ino, de->d_type))
1887 if (cdp->err != nfs_ok)
1890 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
1892 reclen = ALIGN(sizeof(*de) + de->namlen,
1895 de = (struct buffered_dirent *)((char *)de + reclen);
1897 if (size > 0) /* We bailed out early */
1900 offset = vfs_llseek(file, 0, SEEK_CUR);
1903 free_page((unsigned long)(buf.dirent));
1906 return nfserrno(host_err);
1913 * Read entries from a directory.
1914 * The NFSv3/4 verifier we ignore for now.
1917 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1918 struct readdir_cd *cdp, nfsd_filldir_t func)
1922 loff_t offset = *offsetp;
1923 int may_flags = NFSD_MAY_READ;
1925 /* NFSv2 only supports 32 bit cookies */
1926 if (rqstp->rq_vers > 2)
1927 may_flags |= NFSD_MAY_64BIT_COOKIE;
1929 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
1933 offset = vfs_llseek(file, offset, SEEK_SET);
1935 err = nfserrno((int)offset);
1939 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
1941 if (err == nfserr_eof || err == nfserr_toosmall)
1942 err = nfs_ok; /* can still be found in ->err */
1950 * Get file system stats
1951 * N.B. After this call fhp needs an fh_put
1954 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
1958 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
1960 struct path path = {
1961 .mnt = fhp->fh_export->ex_path.mnt,
1962 .dentry = fhp->fh_dentry,
1964 if (vfs_statfs(&path, stat))
1970 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1972 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1975 #ifdef CONFIG_NFSD_V4
1977 * Helper function to translate error numbers. In the case of xattr operations,
1978 * some error codes need to be translated outside of the standard translations.
1980 * ENODATA needs to be translated to nfserr_noxattr.
1981 * E2BIG to nfserr_xattr2big.
1983 * Additionally, vfs_listxattr can return -ERANGE. This means that the
1984 * file has too many extended attributes to retrieve inside an
1985 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
1986 * filesystems will allow the adding of extended attributes until they hit
1987 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
1988 * So, at that point, the attributes are present and valid, but can't
1989 * be retrieved using listxattr, since the upper level xattr code enforces
1990 * the XATTR_LIST_MAX limit.
1992 * This bug means that we need to deal with listxattr returning -ERANGE. The
1993 * best mapping is to return TOOSMALL.
1996 nfsd_xattr_errno(int err)
2000 return nfserr_noxattr;
2002 return nfserr_xattr2big;
2004 return nfserr_toosmall;
2006 return nfserrno(err);
2010 * Retrieve the specified user extended attribute. To avoid always
2011 * having to allocate the maximum size (since we are not getting
2012 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2013 * lock on i_rwsem to prevent the extended attribute from changing
2014 * size while we're doing this.
2017 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2018 void **bufp, int *lenp)
2023 struct inode *inode;
2024 struct dentry *dentry;
2026 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2031 dentry = fhp->fh_dentry;
2032 inode = d_inode(dentry);
2034 inode_lock_shared(inode);
2036 len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
2039 * Zero-length attribute, just return.
2048 err = nfsd_xattr_errno(len);
2053 err = nfserr_toosmall;
2057 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2059 err = nfserr_jukebox;
2063 len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
2067 err = nfsd_xattr_errno(len);
2074 inode_unlock_shared(inode);
2080 * Retrieve the xattr names. Since we can't know how many are
2081 * user extended attributes, we must get all attributes here,
2082 * and have the XDR encode filter out the "user." ones.
2084 * While this could always just allocate an XATTR_LIST_MAX
2085 * buffer, that's a waste, so do a probe + allocate. To
2086 * avoid any changes between the probe and allocate, wrap
2087 * this in inode_lock.
2090 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2096 struct inode *inode;
2097 struct dentry *dentry;
2099 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2103 dentry = fhp->fh_dentry;
2104 inode = d_inode(dentry);
2107 inode_lock_shared(inode);
2109 len = vfs_listxattr(dentry, NULL, 0);
2111 err = nfsd_xattr_errno(len);
2115 if (len > XATTR_LIST_MAX) {
2116 err = nfserr_xattr2big;
2121 * We're holding i_rwsem - use GFP_NOFS.
2123 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2125 err = nfserr_jukebox;
2129 len = vfs_listxattr(dentry, buf, len);
2132 err = nfsd_xattr_errno(len);
2141 inode_unlock_shared(inode);
2147 * nfsd_removexattr - Remove an extended attribute
2148 * @rqstp: RPC transaction being executed
2149 * @fhp: NFS filehandle of object with xattr to remove
2150 * @name: name of xattr to remove (NUL-terminate)
2152 * Pass in a NULL pointer for delegated_inode, and let the client deal
2153 * with NFS4ERR_DELAY (same as with e.g. setattr and remove).
2155 * Returns nfs_ok on success, or an nfsstat in network byte order.
2158 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2163 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2167 ret = fh_want_write(fhp);
2169 return nfserrno(ret);
2171 inode_lock(fhp->fh_dentry->d_inode);
2172 fh_fill_pre_attrs(fhp);
2174 ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
2177 fh_fill_post_attrs(fhp);
2178 inode_unlock(fhp->fh_dentry->d_inode);
2181 return nfsd_xattr_errno(ret);
2185 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2186 void *buf, u32 len, u32 flags)
2191 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2195 ret = fh_want_write(fhp);
2197 return nfserrno(ret);
2198 inode_lock(fhp->fh_dentry->d_inode);
2199 fh_fill_pre_attrs(fhp);
2201 ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
2203 fh_fill_post_attrs(fhp);
2204 inode_unlock(fhp->fh_dentry->d_inode);
2207 return nfsd_xattr_errno(ret);
2212 * Check for a user's access permissions to this inode.
2215 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2216 struct dentry *dentry, int acc)
2218 struct inode *inode = d_inode(dentry);
2221 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2224 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2226 (acc & NFSD_MAY_READ)? " read" : "",
2227 (acc & NFSD_MAY_WRITE)? " write" : "",
2228 (acc & NFSD_MAY_EXEC)? " exec" : "",
2229 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2230 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2231 (acc & NFSD_MAY_LOCK)? " lock" : "",
2232 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2234 IS_IMMUTABLE(inode)? " immut" : "",
2235 IS_APPEND(inode)? " append" : "",
2236 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2237 dprintk(" owner %d/%d user %d/%d\n",
2238 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2241 /* Normally we reject any write/sattr etc access on a read-only file
2242 * system. But if it is IRIX doing check on write-access for a
2243 * device special file, we ignore rofs.
2245 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2246 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2247 if (exp_rdonly(rqstp, exp) ||
2248 __mnt_is_readonly(exp->ex_path.mnt))
2250 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2253 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2256 if (acc & NFSD_MAY_LOCK) {
2257 /* If we cannot rely on authentication in NLM requests,
2258 * just allow locks, otherwise require read permission, or
2261 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2264 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2267 * The file owner always gets access permission for accesses that
2268 * would normally be checked at open time. This is to make
2269 * file access work even when the client has done a fchmod(fd, 0).
2271 * However, `cp foo bar' should fail nevertheless when bar is
2272 * readonly. A sensible way to do this might be to reject all
2273 * attempts to truncate a read-only file, because a creat() call
2274 * always implies file truncation.
2275 * ... but this isn't really fair. A process may reasonably call
2276 * ftruncate on an open file descriptor on a file with perm 000.
2277 * We must trust the client to do permission checking - using "ACCESS"
2280 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2281 uid_eq(inode->i_uid, current_fsuid()))
2284 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2285 err = inode_permission(&init_user_ns, inode,
2286 acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
2288 /* Allow read access to binaries even when mode 111 */
2289 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2290 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2291 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2292 err = inode_permission(&init_user_ns, inode, MAY_EXEC);
2294 return err? nfserrno(err) : 0;