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 * nfserrno - Map Linux errnos to NFS errnos
54 * @errno: POSIX(-ish) error code to be mapped
56 * Returns the appropriate (net-endian) nfserr_* (or nfs_ok if errno is 0). If
57 * it's an error we don't expect, log it once and return nfserr_io.
67 { nfserr_perm, -EPERM },
68 { nfserr_noent, -ENOENT },
70 { nfserr_nxio, -ENXIO },
71 { nfserr_fbig, -E2BIG },
72 { nfserr_stale, -EBADF },
73 { nfserr_acces, -EACCES },
74 { nfserr_exist, -EEXIST },
75 { nfserr_xdev, -EXDEV },
76 { nfserr_mlink, -EMLINK },
77 { nfserr_nodev, -ENODEV },
78 { nfserr_notdir, -ENOTDIR },
79 { nfserr_isdir, -EISDIR },
80 { nfserr_inval, -EINVAL },
81 { nfserr_fbig, -EFBIG },
82 { nfserr_nospc, -ENOSPC },
83 { nfserr_rofs, -EROFS },
84 { nfserr_mlink, -EMLINK },
85 { nfserr_nametoolong, -ENAMETOOLONG },
86 { nfserr_notempty, -ENOTEMPTY },
87 { nfserr_dquot, -EDQUOT },
88 { nfserr_stale, -ESTALE },
89 { nfserr_jukebox, -ETIMEDOUT },
90 { nfserr_jukebox, -ERESTARTSYS },
91 { nfserr_jukebox, -EAGAIN },
92 { nfserr_jukebox, -EWOULDBLOCK },
93 { nfserr_jukebox, -ENOMEM },
94 { nfserr_io, -ETXTBSY },
95 { nfserr_notsupp, -EOPNOTSUPP },
96 { nfserr_toosmall, -ETOOSMALL },
97 { nfserr_serverfault, -ESERVERFAULT },
98 { nfserr_serverfault, -ENFILE },
99 { nfserr_io, -EREMOTEIO },
100 { nfserr_stale, -EOPENSTALE },
101 { nfserr_io, -EUCLEAN },
102 { nfserr_perm, -ENOKEY },
103 { nfserr_no_grace, -ENOGRACE},
107 for (i = 0; i < ARRAY_SIZE(nfs_errtbl); i++) {
108 if (nfs_errtbl[i].syserr == errno)
109 return nfs_errtbl[i].nfserr;
111 WARN_ONCE(1, "nfsd: non-standard errno: %d\n", errno);
116 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
118 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
119 * or nfs_ok having possibly changed *dpp and *expp
122 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
123 struct svc_export **expp)
125 struct svc_export *exp = *expp, *exp2 = NULL;
126 struct dentry *dentry = *dpp;
127 struct path path = {.mnt = mntget(exp->ex_path.mnt),
128 .dentry = dget(dentry)};
131 err = follow_down(&path);
134 if (path.mnt == exp->ex_path.mnt && path.dentry == dentry &&
135 nfsd_mountpoint(dentry, exp) == 2) {
136 /* This is only a mountpoint in some other namespace */
141 exp2 = rqst_exp_get_by_name(rqstp, &path);
145 * We normally allow NFS clients to continue
146 * "underneath" a mountpoint that is not exported.
147 * The exception is V4ROOT, where no traversal is ever
148 * allowed without an explicit export of the new
151 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
156 if (nfsd_v4client(rqstp) ||
157 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
158 /* successfully crossed mount point */
160 * This is subtle: path.dentry is *not* on path.mnt
161 * at this point. The only reason we are safe is that
162 * original mnt is pinned down by exp, so we should
163 * put path *before* putting exp
166 path.dentry = dentry;
176 static void follow_to_parent(struct path *path)
180 while (path->dentry == path->mnt->mnt_root && follow_up(path))
182 dp = dget_parent(path->dentry);
187 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
189 struct svc_export *exp2;
190 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
191 .dentry = dget(dparent)};
193 follow_to_parent(&path);
195 exp2 = rqst_exp_parent(rqstp, &path);
196 if (PTR_ERR(exp2) == -ENOENT) {
197 *dentryp = dget(dparent);
198 } else if (IS_ERR(exp2)) {
200 return PTR_ERR(exp2);
202 *dentryp = dget(path.dentry);
211 * For nfsd purposes, we treat V4ROOT exports as though there was an
212 * export at *every* directory.
214 * '1' if this dentry *must* be an export point,
215 * '2' if it might be, if there is really a mount here, and
216 * '0' if there is no chance of an export point here.
218 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
220 if (!d_inode(dentry))
222 if (exp->ex_flags & NFSEXP_V4ROOT)
224 if (nfsd4_is_junction(dentry))
226 if (d_mountpoint(dentry))
228 * Might only be a mountpoint in a different namespace,
229 * but we need to check.
236 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
237 const char *name, unsigned int len,
238 struct svc_export **exp_ret, struct dentry **dentry_ret)
240 struct svc_export *exp;
241 struct dentry *dparent;
242 struct dentry *dentry;
245 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
247 dparent = fhp->fh_dentry;
248 exp = exp_get(fhp->fh_export);
250 /* Lookup the name, but don't follow links */
251 if (isdotent(name, len)) {
253 dentry = dget(dparent);
254 else if (dparent != exp->ex_path.dentry)
255 dentry = dget_parent(dparent);
256 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
257 dentry = dget(dparent); /* .. == . just like at / */
259 /* checking mountpoint crossing is very different when stepping up */
260 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
265 dentry = lookup_one_len_unlocked(name, dparent, len);
266 host_err = PTR_ERR(dentry);
269 if (nfsd_mountpoint(dentry, exp)) {
270 host_err = nfsd_cross_mnt(rqstp, &dentry, &exp);
277 *dentry_ret = dentry;
283 return nfserrno(host_err);
287 * nfsd_lookup - look up a single path component for nfsd
289 * @rqstp: the request context
290 * @fhp: the file handle of the directory
291 * @name: the component name, or %NULL to look up parent
292 * @len: length of name to examine
293 * @resfh: pointer to pre-initialised filehandle to hold result.
295 * Look up one component of a pathname.
296 * N.B. After this call _both_ fhp and resfh need an fh_put
298 * If the lookup would cross a mountpoint, and the mounted filesystem
299 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
300 * accepted as it stands and the mounted directory is
301 * returned. Otherwise the covered directory is returned.
302 * NOTE: this mountpoint crossing is not supported properly by all
303 * clients and is explicitly disallowed for NFSv3
307 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
308 unsigned int len, struct svc_fh *resfh)
310 struct svc_export *exp;
311 struct dentry *dentry;
314 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
317 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
320 err = check_nfsd_access(exp, rqstp);
324 * Note: we compose the file handle now, but as the
325 * dentry may be negative, it may need to be updated.
327 err = fh_compose(resfh, exp, dentry, fhp);
328 if (!err && d_really_is_negative(dentry))
337 * Commit metadata changes to stable storage.
340 commit_inode_metadata(struct inode *inode)
342 const struct export_operations *export_ops = inode->i_sb->s_export_op;
344 if (export_ops->commit_metadata)
345 return export_ops->commit_metadata(inode);
346 return sync_inode_metadata(inode, 1);
350 commit_metadata(struct svc_fh *fhp)
352 struct inode *inode = d_inode(fhp->fh_dentry);
354 if (!EX_ISSYNC(fhp->fh_export))
356 return commit_inode_metadata(inode);
360 * Go over the attributes and take care of the small differences between
361 * NFS semantics and what Linux expects.
364 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
366 /* Ignore mode updates on symlinks */
367 if (S_ISLNK(inode->i_mode))
368 iap->ia_valid &= ~ATTR_MODE;
370 /* sanitize the mode change */
371 if (iap->ia_valid & ATTR_MODE) {
372 iap->ia_mode &= S_IALLUGO;
373 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
376 /* Revoke setuid/setgid on chown */
377 if (!S_ISDIR(inode->i_mode) &&
378 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
379 iap->ia_valid |= ATTR_KILL_PRIV;
380 if (iap->ia_valid & ATTR_MODE) {
381 /* we're setting mode too, just clear the s*id bits */
382 iap->ia_mode &= ~S_ISUID;
383 if (iap->ia_mode & S_IXGRP)
384 iap->ia_mode &= ~S_ISGID;
386 /* set ATTR_KILL_* bits and let VFS handle it */
387 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
393 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
396 struct inode *inode = d_inode(fhp->fh_dentry);
398 if (iap->ia_size < inode->i_size) {
401 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
402 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
406 return nfserrno(get_write_access(inode));
409 static int __nfsd_setattr(struct dentry *dentry, struct iattr *iap)
413 if (iap->ia_valid & ATTR_SIZE) {
415 * RFC5661, Section 18.30.4:
416 * Changing the size of a file with SETATTR indirectly
417 * changes the time_modify and change attributes.
419 * (and similar for the older RFCs)
421 struct iattr size_attr = {
422 .ia_valid = ATTR_SIZE | ATTR_CTIME | ATTR_MTIME,
423 .ia_size = iap->ia_size,
426 if (iap->ia_size < 0)
429 host_err = notify_change(&init_user_ns, dentry, &size_attr, NULL);
432 iap->ia_valid &= ~ATTR_SIZE;
435 * Avoid the additional setattr call below if the only other
436 * attribute that the client sends is the mtime, as we update
437 * it as part of the size change above.
439 if ((iap->ia_valid & ~ATTR_MTIME) == 0)
446 iap->ia_valid |= ATTR_CTIME;
447 return notify_change(&init_user_ns, dentry, iap, NULL);
451 * nfsd_setattr - Set various file attributes.
452 * @rqstp: controlling RPC transaction
453 * @fhp: filehandle of target
454 * @attr: attributes to set
455 * @check_guard: set to 1 if guardtime is a valid timestamp
456 * @guardtime: do not act if ctime.tv_sec does not match this timestamp
458 * This call may adjust the contents of @attr (in particular, this
459 * call may change the bits in the na_iattr.ia_valid field).
461 * Returns nfs_ok on success, otherwise an NFS status code is
462 * returned. Caller must release @fhp by calling fh_put in either
466 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
467 struct nfsd_attrs *attr,
468 int check_guard, time64_t guardtime)
470 struct dentry *dentry;
472 struct iattr *iap = attr->na_iattr;
473 int accmode = NFSD_MAY_SATTR;
477 bool get_write_count;
478 bool size_change = (iap->ia_valid & ATTR_SIZE);
481 if (iap->ia_valid & ATTR_SIZE) {
482 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
487 * If utimes(2) and friends are called with times not NULL, we should
488 * not set NFSD_MAY_WRITE bit. Otherwise fh_verify->nfsd_permission
489 * will return EACCES, when the caller's effective UID does not match
490 * the owner of the file, and the caller is not privileged. In this
491 * situation, we should return EPERM(notify_change will return this).
493 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME)) {
494 accmode |= NFSD_MAY_OWNER_OVERRIDE;
495 if (!(iap->ia_valid & (ATTR_ATIME_SET | ATTR_MTIME_SET)))
496 accmode |= NFSD_MAY_WRITE;
499 /* Callers that do fh_verify should do the fh_want_write: */
500 get_write_count = !fhp->fh_dentry;
503 err = fh_verify(rqstp, fhp, ftype, accmode);
506 if (get_write_count) {
507 host_err = fh_want_write(fhp);
512 dentry = fhp->fh_dentry;
513 inode = d_inode(dentry);
515 nfsd_sanitize_attrs(inode, iap);
517 if (check_guard && guardtime != inode->i_ctime.tv_sec)
518 return nfserr_notsync;
521 * The size case is special, it changes the file in addition to the
522 * attributes, and file systems don't expect it to be mixed with
523 * "random" attribute changes. We thus split out the size change
524 * into a separate call to ->setattr, and do the rest as a separate
528 err = nfsd_get_write_access(rqstp, fhp, iap);
534 for (retries = 1;;) {
535 host_err = __nfsd_setattr(dentry, iap);
536 if (host_err != -EAGAIN || !retries--)
538 if (!nfsd_wait_for_delegreturn(rqstp, inode))
541 if (attr->na_seclabel && attr->na_seclabel->len)
542 attr->na_labelerr = security_inode_setsecctx(dentry,
543 attr->na_seclabel->data, attr->na_seclabel->len);
544 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) && attr->na_pacl)
545 attr->na_aclerr = set_posix_acl(&init_user_ns,
546 dentry, ACL_TYPE_ACCESS,
548 if (IS_ENABLED(CONFIG_FS_POSIX_ACL) &&
549 !attr->na_aclerr && attr->na_dpacl && S_ISDIR(inode->i_mode))
550 attr->na_aclerr = set_posix_acl(&init_user_ns,
551 dentry, ACL_TYPE_DEFAULT,
555 put_write_access(inode);
558 host_err = commit_metadata(fhp);
559 return nfserrno(host_err);
562 #if defined(CONFIG_NFSD_V4)
564 * NFS junction information is stored in an extended attribute.
566 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
569 * nfsd4_is_junction - Test if an object could be an NFS junction
571 * @dentry: object to test
573 * Returns 1 if "dentry" appears to contain NFS junction information.
574 * Otherwise 0 is returned.
576 int nfsd4_is_junction(struct dentry *dentry)
578 struct inode *inode = d_inode(dentry);
582 if (inode->i_mode & S_IXUGO)
584 if (!(inode->i_mode & S_ISVTX))
586 if (vfs_getxattr(&init_user_ns, dentry, NFSD_JUNCTION_XATTR_NAME,
592 static struct nfsd4_compound_state *nfsd4_get_cstate(struct svc_rqst *rqstp)
594 return &((struct nfsd4_compoundres *)rqstp->rq_resp)->cstate;
597 __be32 nfsd4_clone_file_range(struct svc_rqst *rqstp,
598 struct nfsd_file *nf_src, u64 src_pos,
599 struct nfsd_file *nf_dst, u64 dst_pos,
600 u64 count, bool sync)
602 struct file *src = nf_src->nf_file;
603 struct file *dst = nf_dst->nf_file;
608 since = READ_ONCE(dst->f_wb_err);
609 cloned = vfs_clone_file_range(src, src_pos, dst, dst_pos, count, 0);
611 ret = nfserrno(cloned);
614 if (count && cloned != count) {
615 ret = nfserrno(-EINVAL);
619 loff_t dst_end = count ? dst_pos + count - 1 : LLONG_MAX;
620 int status = vfs_fsync_range(dst, dst_pos, dst_end, 0);
623 status = filemap_check_wb_err(dst->f_mapping, since);
625 status = commit_inode_metadata(file_inode(src));
627 struct nfsd_net *nn = net_generic(nf_dst->nf_net,
630 trace_nfsd_clone_file_range_err(rqstp,
631 &nfsd4_get_cstate(rqstp)->save_fh,
633 &nfsd4_get_cstate(rqstp)->current_fh,
636 nfsd_reset_write_verifier(nn);
637 trace_nfsd_writeverf_reset(nn, rqstp, status);
638 ret = nfserrno(status);
645 ssize_t nfsd_copy_file_range(struct file *src, u64 src_pos, struct file *dst,
646 u64 dst_pos, u64 count)
651 * Limit copy to 4MB to prevent indefinitely blocking an nfsd
652 * thread and client rpc slot. The choice of 4MB is somewhat
653 * arbitrary. We might instead base this on r/wsize, or make it
654 * tunable, or use a time instead of a byte limit, or implement
655 * asynchronous copy. In theory a client could also recognize a
656 * limit like this and pipeline multiple COPY requests.
658 count = min_t(u64, count, 1 << 22);
659 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count, 0);
661 if (ret == -EOPNOTSUPP || ret == -EXDEV)
662 ret = vfs_copy_file_range(src, src_pos, dst, dst_pos, count,
667 __be32 nfsd4_vfs_fallocate(struct svc_rqst *rqstp, struct svc_fh *fhp,
668 struct file *file, loff_t offset, loff_t len,
673 if (!S_ISREG(file_inode(file)->i_mode))
676 error = vfs_fallocate(file, flags, offset, len);
678 error = commit_metadata(fhp);
680 return nfserrno(error);
682 #endif /* defined(CONFIG_NFSD_V4) */
685 * Check server access rights to a file system object
691 static struct accessmap nfs3_regaccess[] = {
692 { NFS3_ACCESS_READ, NFSD_MAY_READ },
693 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
694 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
695 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
697 #ifdef CONFIG_NFSD_V4
698 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
699 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
700 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
706 static struct accessmap nfs3_diraccess[] = {
707 { NFS3_ACCESS_READ, NFSD_MAY_READ },
708 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
709 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
710 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
711 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
713 #ifdef CONFIG_NFSD_V4
714 { NFS4_ACCESS_XAREAD, NFSD_MAY_READ },
715 { NFS4_ACCESS_XAWRITE, NFSD_MAY_WRITE },
716 { NFS4_ACCESS_XALIST, NFSD_MAY_READ },
722 static struct accessmap nfs3_anyaccess[] = {
723 /* Some clients - Solaris 2.6 at least, make an access call
724 * to the server to check for access for things like /dev/null
725 * (which really, the server doesn't care about). So
726 * We provide simple access checking for them, looking
727 * mainly at mode bits, and we make sure to ignore read-only
730 { NFS3_ACCESS_READ, NFSD_MAY_READ },
731 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
732 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
733 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
739 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
741 struct accessmap *map;
742 struct svc_export *export;
743 struct dentry *dentry;
744 u32 query, result = 0, sresult = 0;
747 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
751 export = fhp->fh_export;
752 dentry = fhp->fh_dentry;
754 if (d_is_reg(dentry))
755 map = nfs3_regaccess;
756 else if (d_is_dir(dentry))
757 map = nfs3_diraccess;
759 map = nfs3_anyaccess;
763 for (; map->access; map++) {
764 if (map->access & query) {
767 sresult |= map->access;
769 err2 = nfsd_permission(rqstp, export, dentry, map->how);
772 result |= map->access;
775 /* the following error codes just mean the access was not allowed,
776 * rather than an error occurred */
780 /* simply don't "or" in the access bit. */
790 *supported = sresult;
796 int nfsd_open_break_lease(struct inode *inode, int access)
800 if (access & NFSD_MAY_NOT_BREAK_LEASE)
802 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
803 return break_lease(inode, mode | O_NONBLOCK);
807 * Open an existing file or directory.
808 * The may_flags argument indicates the type of open (read/write/lock)
809 * and additional flags.
810 * N.B. After this call fhp needs an fh_put
813 __nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
814 int may_flags, struct file **filp)
819 int flags = O_RDONLY|O_LARGEFILE;
823 path.mnt = fhp->fh_export->ex_path.mnt;
824 path.dentry = fhp->fh_dentry;
825 inode = d_inode(path.dentry);
828 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
834 host_err = nfsd_open_break_lease(inode, may_flags);
835 if (host_err) /* NOMEM or WOULDBLOCK */
838 if (may_flags & NFSD_MAY_WRITE) {
839 if (may_flags & NFSD_MAY_READ)
840 flags = O_RDWR|O_LARGEFILE;
842 flags = O_WRONLY|O_LARGEFILE;
845 file = dentry_open(&path, flags, current_cred());
847 host_err = PTR_ERR(file);
851 host_err = ima_file_check(file, may_flags);
857 if (may_flags & NFSD_MAY_64BIT_COOKIE)
858 file->f_mode |= FMODE_64BITHASH;
860 file->f_mode |= FMODE_32BITHASH;
864 err = nfserrno(host_err);
870 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
871 int may_flags, struct file **filp)
874 bool retried = false;
876 validate_process_creds();
878 * If we get here, then the client has already done an "open",
879 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
880 * in case a chmod has now revoked permission.
882 * Arguably we should also allow the owner override for
883 * directories, but we never have and it doesn't seem to have
884 * caused anyone a problem. If we were to change this, note
885 * also that our filldir callbacks would need a variant of
886 * lookup_one_len that doesn't check permissions.
889 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
891 err = fh_verify(rqstp, fhp, type, may_flags);
893 err = __nfsd_open(rqstp, fhp, type, may_flags, filp);
894 if (err == nfserr_stale && !retried) {
900 validate_process_creds();
905 * nfsd_open_verified - Open a regular file for the filecache
906 * @rqstp: RPC request
907 * @fhp: NFS filehandle of the file to open
908 * @may_flags: internal permission flags
909 * @filp: OUT: open "struct file *"
911 * Returns an nfsstat value in network byte order.
914 nfsd_open_verified(struct svc_rqst *rqstp, struct svc_fh *fhp, int may_flags,
919 validate_process_creds();
920 err = __nfsd_open(rqstp, fhp, S_IFREG, may_flags, filp);
921 validate_process_creds();
926 * Grab and keep cached pages associated with a file in the svc_rqst
927 * so that they can be passed to the network sendmsg/sendpage routines
928 * directly. They will be released after the sending has completed.
931 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
932 struct splice_desc *sd)
934 struct svc_rqst *rqstp = sd->u.data;
935 struct page *page = buf->page; // may be a compound one
936 unsigned offset = buf->offset;
937 struct page *last_page;
939 last_page = page + (offset + sd->len - 1) / PAGE_SIZE;
940 for (page += offset / PAGE_SIZE; page <= last_page; page++)
941 svc_rqst_replace_page(rqstp, page);
942 if (rqstp->rq_res.page_len == 0) // first call
943 rqstp->rq_res.page_base = offset % PAGE_SIZE;
944 rqstp->rq_res.page_len += sd->len;
948 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
949 struct splice_desc *sd)
951 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
954 static u32 nfsd_eof_on_read(struct file *file, loff_t offset, ssize_t len,
957 if (expected != 0 && len == 0)
959 if (offset+len >= i_size_read(file_inode(file)))
964 static __be32 nfsd_finish_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
965 struct file *file, loff_t offset,
966 unsigned long *count, u32 *eof, ssize_t host_err)
969 nfsd_stats_io_read_add(fhp->fh_export, host_err);
970 *eof = nfsd_eof_on_read(file, offset, host_err, *count);
972 fsnotify_access(file);
973 trace_nfsd_read_io_done(rqstp, fhp, offset, *count);
976 trace_nfsd_read_err(rqstp, fhp, offset, host_err);
977 return nfserrno(host_err);
981 __be32 nfsd_splice_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
982 struct file *file, loff_t offset, unsigned long *count,
985 struct splice_desc sd = {
993 trace_nfsd_read_splice(rqstp, fhp, offset, *count);
994 rqstp->rq_next_page = rqstp->rq_respages + 1;
995 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
996 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
999 __be32 nfsd_readv(struct svc_rqst *rqstp, struct svc_fh *fhp,
1000 struct file *file, loff_t offset,
1001 struct kvec *vec, int vlen, unsigned long *count,
1004 struct iov_iter iter;
1005 loff_t ppos = offset;
1008 trace_nfsd_read_vector(rqstp, fhp, offset, *count);
1009 iov_iter_kvec(&iter, ITER_DEST, vec, vlen, *count);
1010 host_err = vfs_iter_read(file, &iter, &ppos, 0);
1011 return nfsd_finish_read(rqstp, fhp, file, offset, count, eof, host_err);
1015 * Gathered writes: If another process is currently writing to the file,
1016 * there's a high chance this is another nfsd (triggered by a bulk write
1017 * from a client's biod). Rather than syncing the file with each write
1018 * request, we sleep for 10 msec.
1020 * I don't know if this roughly approximates C. Juszak's idea of
1021 * gathered writes, but it's a nice and simple solution (IMHO), and it
1024 * Note: we do this only in the NFSv2 case, since v3 and higher have a
1025 * better tool (separate unstable writes and commits) for solving this
1028 static int wait_for_concurrent_writes(struct file *file)
1030 struct inode *inode = file_inode(file);
1031 static ino_t last_ino;
1032 static dev_t last_dev;
1035 if (atomic_read(&inode->i_writecount) > 1
1036 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
1037 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
1039 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
1042 if (inode->i_state & I_DIRTY) {
1043 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
1044 err = vfs_fsync(file, 0);
1046 last_ino = inode->i_ino;
1047 last_dev = inode->i_sb->s_dev;
1052 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
1053 loff_t offset, struct kvec *vec, int vlen,
1054 unsigned long *cnt, int stable,
1057 struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1058 struct file *file = nf->nf_file;
1059 struct super_block *sb = file_inode(file)->i_sb;
1060 struct svc_export *exp;
1061 struct iov_iter iter;
1066 loff_t pos = offset;
1067 unsigned long exp_op_flags = 0;
1068 unsigned int pflags = current->flags;
1070 bool restore_flags = false;
1072 trace_nfsd_write_opened(rqstp, fhp, offset, *cnt);
1074 if (sb->s_export_op)
1075 exp_op_flags = sb->s_export_op->flags;
1077 if (test_bit(RQ_LOCAL, &rqstp->rq_flags) &&
1078 !(exp_op_flags & EXPORT_OP_REMOTE_FS)) {
1080 * We want throttling in balance_dirty_pages()
1081 * and shrink_inactive_list() to only consider
1082 * the backingdev we are writing to, so that nfs to
1083 * localhost doesn't cause nfsd to lock up due to all
1084 * the client's dirty pages or its congested queue.
1086 current->flags |= PF_LOCAL_THROTTLE;
1087 restore_flags = true;
1090 exp = fhp->fh_export;
1091 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
1093 if (!EX_ISSYNC(exp))
1094 stable = NFS_UNSTABLE;
1096 if (stable && !use_wgather)
1099 iov_iter_kvec(&iter, ITER_SOURCE, vec, vlen, *cnt);
1100 since = READ_ONCE(file->f_wb_err);
1102 nfsd_copy_write_verifier(verf, nn);
1103 host_err = vfs_iter_write(file, &iter, &pos, flags);
1105 nfsd_reset_write_verifier(nn);
1106 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1110 nfsd_stats_io_write_add(exp, *cnt);
1111 fsnotify_modify(file);
1112 host_err = filemap_check_wb_err(file->f_mapping, since);
1116 if (stable && use_wgather) {
1117 host_err = wait_for_concurrent_writes(file);
1119 nfsd_reset_write_verifier(nn);
1120 trace_nfsd_writeverf_reset(nn, rqstp, host_err);
1125 if (host_err >= 0) {
1126 trace_nfsd_write_io_done(rqstp, fhp, offset, *cnt);
1129 trace_nfsd_write_err(rqstp, fhp, offset, host_err);
1130 nfserr = nfserrno(host_err);
1133 current_restore_flags(pflags, PF_LOCAL_THROTTLE);
1138 * Read data from a file. count must contain the requested read count
1139 * on entry. On return, *count contains the number of bytes actually read.
1140 * N.B. After this call fhp needs an fh_put
1142 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1143 loff_t offset, struct kvec *vec, int vlen, unsigned long *count,
1146 struct nfsd_file *nf;
1150 trace_nfsd_read_start(rqstp, fhp, offset, *count);
1151 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_READ, &nf);
1156 if (file->f_op->splice_read && test_bit(RQ_SPLICE_OK, &rqstp->rq_flags))
1157 err = nfsd_splice_read(rqstp, fhp, file, offset, count, eof);
1159 err = nfsd_readv(rqstp, fhp, file, offset, vec, vlen, count, eof);
1163 trace_nfsd_read_done(rqstp, fhp, offset, *count);
1169 * Write data to a file.
1170 * The stable flag requests synchronous writes.
1171 * N.B. After this call fhp needs an fh_put
1174 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t offset,
1175 struct kvec *vec, int vlen, unsigned long *cnt, int stable,
1178 struct nfsd_file *nf;
1181 trace_nfsd_write_start(rqstp, fhp, offset, *cnt);
1183 err = nfsd_file_acquire_gc(rqstp, fhp, NFSD_MAY_WRITE, &nf);
1187 err = nfsd_vfs_write(rqstp, fhp, nf, offset, vec,
1188 vlen, cnt, stable, verf);
1191 trace_nfsd_write_done(rqstp, fhp, offset, *cnt);
1196 * nfsd_commit - Commit pending writes to stable storage
1197 * @rqstp: RPC request being processed
1198 * @fhp: NFS filehandle
1200 * @offset: raw offset from beginning of file
1201 * @count: raw count of bytes to sync
1202 * @verf: filled in with the server's current write verifier
1204 * Note: we guarantee that data that lies within the range specified
1205 * by the 'offset' and 'count' parameters will be synced. The server
1206 * is permitted to sync data that lies outside this range at the
1209 * Unfortunately we cannot lock the file to make sure we return full WCC
1210 * data to the client, as locking happens lower down in the filesystem.
1213 * An nfsstat value in network byte order.
1216 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp, struct nfsd_file *nf,
1217 u64 offset, u32 count, __be32 *verf)
1219 __be32 err = nfs_ok;
1222 struct nfsd_net *nn;
1225 * Convert the client-provided (offset, count) range to a
1226 * (start, end) range. If the client-provided range falls
1227 * outside the maximum file size of the underlying FS,
1228 * clamp the sync range appropriately.
1232 maxbytes = (u64)fhp->fh_dentry->d_sb->s_maxbytes;
1233 if (offset < maxbytes) {
1235 if (count && (offset + count - 1 < maxbytes))
1236 end = offset + count - 1;
1239 nn = net_generic(nf->nf_net, nfsd_net_id);
1240 if (EX_ISSYNC(fhp->fh_export)) {
1241 errseq_t since = READ_ONCE(nf->nf_file->f_wb_err);
1244 err2 = vfs_fsync_range(nf->nf_file, start, end, 0);
1247 nfsd_copy_write_verifier(verf, nn);
1248 err2 = filemap_check_wb_err(nf->nf_file->f_mapping,
1250 err = nfserrno(err2);
1253 err = nfserr_notsupp;
1256 nfsd_reset_write_verifier(nn);
1257 trace_nfsd_writeverf_reset(nn, rqstp, err2);
1258 err = nfserrno(err2);
1261 nfsd_copy_write_verifier(verf, nn);
1267 * nfsd_create_setattr - Set a created file's attributes
1268 * @rqstp: RPC transaction being executed
1269 * @fhp: NFS filehandle of parent directory
1270 * @resfhp: NFS filehandle of new object
1271 * @attrs: requested attributes of new object
1273 * Returns nfs_ok on success, or an nfsstat in network byte order.
1276 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp,
1277 struct svc_fh *resfhp, struct nfsd_attrs *attrs)
1279 struct iattr *iap = attrs->na_iattr;
1283 * Mode has already been set by file creation.
1285 iap->ia_valid &= ~ATTR_MODE;
1288 * Setting uid/gid works only for root. Irix appears to
1289 * send along the gid on create when it tries to implement
1290 * setgid directories via NFS:
1292 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1293 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1296 * Callers expect new file metadata to be committed even
1297 * if the attributes have not changed.
1300 status = nfsd_setattr(rqstp, resfhp, attrs, 0, (time64_t)0);
1302 status = nfserrno(commit_metadata(resfhp));
1305 * Transactional filesystems had a chance to commit changes
1306 * for both parent and child simultaneously making the
1307 * following commit_metadata a noop in many cases.
1310 status = nfserrno(commit_metadata(fhp));
1313 * Update the new filehandle to pick up the new attributes.
1316 status = fh_update(resfhp);
1321 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1322 * setting size to 0 may fail for some specific file systems by the permission
1323 * checking which requires WRITE permission but the mode is 000.
1324 * we ignore the resizing(to 0) on the just new created file, since the size is
1325 * 0 after file created.
1327 * call this only after vfs_create() is called.
1330 nfsd_check_ignore_resizing(struct iattr *iap)
1332 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1333 iap->ia_valid &= ~ATTR_SIZE;
1336 /* The parent directory should already be locked: */
1338 nfsd_create_locked(struct svc_rqst *rqstp, struct svc_fh *fhp,
1339 struct nfsd_attrs *attrs,
1340 int type, dev_t rdev, struct svc_fh *resfhp)
1342 struct dentry *dentry, *dchild;
1344 struct iattr *iap = attrs->na_iattr;
1348 dentry = fhp->fh_dentry;
1349 dirp = d_inode(dentry);
1351 dchild = dget(resfhp->fh_dentry);
1352 err = nfsd_permission(rqstp, fhp->fh_export, dentry, NFSD_MAY_CREATE);
1356 if (!(iap->ia_valid & ATTR_MODE))
1358 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1360 if (!IS_POSIXACL(dirp))
1361 iap->ia_mode &= ~current_umask();
1366 host_err = vfs_create(&init_user_ns, dirp, dchild, iap->ia_mode, true);
1368 nfsd_check_ignore_resizing(iap);
1371 host_err = vfs_mkdir(&init_user_ns, dirp, dchild, iap->ia_mode);
1372 if (!host_err && unlikely(d_unhashed(dchild))) {
1374 d = lookup_one_len(dchild->d_name.name,
1376 dchild->d_name.len);
1378 host_err = PTR_ERR(d);
1381 if (unlikely(d_is_negative(d))) {
1383 err = nfserr_serverfault;
1386 dput(resfhp->fh_dentry);
1387 resfhp->fh_dentry = dget(d);
1388 err = fh_update(resfhp);
1399 host_err = vfs_mknod(&init_user_ns, dirp, dchild,
1400 iap->ia_mode, rdev);
1403 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1410 err = nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1417 err = nfserrno(host_err);
1422 * Create a filesystem object (regular, directory, special).
1423 * Note that the parent directory is left locked.
1425 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1428 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1429 char *fname, int flen, struct nfsd_attrs *attrs,
1430 int type, dev_t rdev, struct svc_fh *resfhp)
1432 struct dentry *dentry, *dchild = NULL;
1436 if (isdotent(fname, flen))
1437 return nfserr_exist;
1439 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_NOP);
1443 dentry = fhp->fh_dentry;
1445 host_err = fh_want_write(fhp);
1447 return nfserrno(host_err);
1449 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1450 dchild = lookup_one_len(fname, dentry, flen);
1451 host_err = PTR_ERR(dchild);
1452 if (IS_ERR(dchild)) {
1453 err = nfserrno(host_err);
1456 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1458 * We unconditionally drop our ref to dchild as fh_compose will have
1459 * already grabbed its own ref for it.
1464 fh_fill_pre_attrs(fhp);
1465 err = nfsd_create_locked(rqstp, fhp, attrs, type, rdev, resfhp);
1466 fh_fill_post_attrs(fhp);
1468 inode_unlock(dentry->d_inode);
1473 * Read a symlink. On entry, *lenp must contain the maximum path length that
1474 * fits into the buffer. On return, it contains the true length.
1475 * N.B. After this call fhp needs an fh_put
1478 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1483 DEFINE_DELAYED_CALL(done);
1486 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1490 path.mnt = fhp->fh_export->ex_path.mnt;
1491 path.dentry = fhp->fh_dentry;
1493 if (unlikely(!d_is_symlink(path.dentry)))
1494 return nfserr_inval;
1498 link = vfs_get_link(path.dentry, &done);
1500 return nfserrno(PTR_ERR(link));
1505 memcpy(buf, link, *lenp);
1506 do_delayed_call(&done);
1511 * nfsd_symlink - Create a symlink and look up its inode
1512 * @rqstp: RPC transaction being executed
1513 * @fhp: NFS filehandle of parent directory
1514 * @fname: filename of the new symlink
1515 * @flen: length of @fname
1516 * @path: content of the new symlink (NUL-terminated)
1517 * @attrs: requested attributes of new object
1518 * @resfhp: NFS filehandle of new object
1520 * N.B. After this call _both_ fhp and resfhp need an fh_put
1522 * Returns nfs_ok on success, or an nfsstat in network byte order.
1525 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1526 char *fname, int flen,
1527 char *path, struct nfsd_attrs *attrs,
1528 struct svc_fh *resfhp)
1530 struct dentry *dentry, *dnew;
1535 if (!flen || path[0] == '\0')
1538 if (isdotent(fname, flen))
1541 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1545 host_err = fh_want_write(fhp);
1547 err = nfserrno(host_err);
1551 dentry = fhp->fh_dentry;
1552 inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT);
1553 dnew = lookup_one_len(fname, dentry, flen);
1555 err = nfserrno(PTR_ERR(dnew));
1556 inode_unlock(dentry->d_inode);
1557 goto out_drop_write;
1559 fh_fill_pre_attrs(fhp);
1560 host_err = vfs_symlink(&init_user_ns, d_inode(dentry), dnew, path);
1561 err = nfserrno(host_err);
1562 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1564 nfsd_create_setattr(rqstp, fhp, resfhp, attrs);
1565 fh_fill_post_attrs(fhp);
1566 inode_unlock(dentry->d_inode);
1568 err = nfserrno(commit_metadata(fhp));
1570 if (err==0) err = cerr;
1579 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1582 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1583 char *name, int len, struct svc_fh *tfhp)
1585 struct dentry *ddir, *dnew, *dold;
1590 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1593 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1597 if (d_is_dir(tfhp->fh_dentry))
1603 if (isdotent(name, len))
1606 host_err = fh_want_write(tfhp);
1608 err = nfserrno(host_err);
1612 ddir = ffhp->fh_dentry;
1613 dirp = d_inode(ddir);
1614 inode_lock_nested(dirp, I_MUTEX_PARENT);
1616 dnew = lookup_one_len(name, ddir, len);
1618 err = nfserrno(PTR_ERR(dnew));
1622 dold = tfhp->fh_dentry;
1625 if (d_really_is_negative(dold))
1627 fh_fill_pre_attrs(ffhp);
1628 host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL);
1629 fh_fill_post_attrs(ffhp);
1632 err = nfserrno(commit_metadata(ffhp));
1634 err = nfserrno(commit_metadata(tfhp));
1636 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1639 err = nfserrno(host_err);
1643 fh_drop_write(tfhp);
1651 goto out_drop_write;
1655 nfsd_close_cached_files(struct dentry *dentry)
1657 struct inode *inode = d_inode(dentry);
1659 if (inode && S_ISREG(inode->i_mode))
1660 nfsd_file_close_inode_sync(inode);
1664 nfsd_has_cached_files(struct dentry *dentry)
1667 struct inode *inode = d_inode(dentry);
1669 if (inode && S_ISREG(inode->i_mode))
1670 ret = nfsd_file_is_cached(inode);
1676 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1679 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1680 struct svc_fh *tfhp, char *tname, int tlen)
1682 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1683 struct inode *fdir, *tdir;
1686 bool close_cached = false;
1688 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1691 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1695 fdentry = ffhp->fh_dentry;
1696 fdir = d_inode(fdentry);
1698 tdentry = tfhp->fh_dentry;
1699 tdir = d_inode(tdentry);
1702 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1706 host_err = fh_want_write(ffhp);
1708 err = nfserrno(host_err);
1712 trap = lock_rename(tdentry, fdentry);
1713 fh_fill_pre_attrs(ffhp);
1714 fh_fill_pre_attrs(tfhp);
1716 odentry = lookup_one_len(fname, fdentry, flen);
1717 host_err = PTR_ERR(odentry);
1718 if (IS_ERR(odentry))
1722 if (d_really_is_negative(odentry))
1725 if (odentry == trap)
1728 ndentry = lookup_one_len(tname, tdentry, tlen);
1729 host_err = PTR_ERR(ndentry);
1730 if (IS_ERR(ndentry))
1732 host_err = -ENOTEMPTY;
1733 if (ndentry == trap)
1737 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1739 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1742 if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) &&
1743 nfsd_has_cached_files(ndentry)) {
1744 close_cached = true;
1747 struct renamedata rd = {
1748 .old_mnt_userns = &init_user_ns,
1750 .old_dentry = odentry,
1751 .new_mnt_userns = &init_user_ns,
1753 .new_dentry = ndentry,
1757 for (retries = 1;;) {
1758 host_err = vfs_rename(&rd);
1759 if (host_err != -EAGAIN || !retries--)
1761 if (!nfsd_wait_for_delegreturn(rqstp, d_inode(odentry)))
1765 host_err = commit_metadata(tfhp);
1767 host_err = commit_metadata(ffhp);
1775 err = nfserrno(host_err);
1777 if (!close_cached) {
1778 fh_fill_post_attrs(ffhp);
1779 fh_fill_post_attrs(tfhp);
1781 unlock_rename(tdentry, fdentry);
1782 fh_drop_write(ffhp);
1785 * If the target dentry has cached open files, then we need to try to
1786 * close them prior to doing the rename. Flushing delayed fput
1787 * shouldn't be done with locks held however, so we delay it until this
1788 * point and then reattempt the whole shebang.
1791 close_cached = false;
1792 nfsd_close_cached_files(ndentry);
1801 * Unlink a file or directory
1802 * N.B. After this call fhp needs an fh_put
1805 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1806 char *fname, int flen)
1808 struct dentry *dentry, *rdentry;
1810 struct inode *rinode;
1815 if (!flen || isdotent(fname, flen))
1817 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1821 host_err = fh_want_write(fhp);
1825 dentry = fhp->fh_dentry;
1826 dirp = d_inode(dentry);
1827 inode_lock_nested(dirp, I_MUTEX_PARENT);
1829 rdentry = lookup_one_len(fname, dentry, flen);
1830 host_err = PTR_ERR(rdentry);
1831 if (IS_ERR(rdentry))
1834 if (d_really_is_negative(rdentry)) {
1839 rinode = d_inode(rdentry);
1843 type = d_inode(rdentry)->i_mode & S_IFMT;
1845 fh_fill_pre_attrs(fhp);
1846 if (type != S_IFDIR) {
1849 if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK)
1850 nfsd_close_cached_files(rdentry);
1852 for (retries = 1;;) {
1853 host_err = vfs_unlink(&init_user_ns, dirp, rdentry, NULL);
1854 if (host_err != -EAGAIN || !retries--)
1856 if (!nfsd_wait_for_delegreturn(rqstp, rinode))
1860 host_err = vfs_rmdir(&init_user_ns, dirp, rdentry);
1862 fh_fill_post_attrs(fhp);
1866 host_err = commit_metadata(fhp);
1868 iput(rinode); /* truncate the inode here */
1873 if (host_err == -EBUSY) {
1874 /* name is mounted-on. There is no perfect
1877 if (nfsd_v4client(rqstp))
1878 err = nfserr_file_open;
1882 err = nfserrno(host_err);
1888 goto out_drop_write;
1892 * We do this buffering because we must not call back into the file
1893 * system's ->lookup() method from the filldir callback. That may well
1894 * deadlock a number of file systems.
1896 * This is based heavily on the implementation of same in XFS.
1898 struct buffered_dirent {
1902 unsigned int d_type;
1906 struct readdir_data {
1907 struct dir_context ctx;
1913 static bool nfsd_buffered_filldir(struct dir_context *ctx, const char *name,
1914 int namlen, loff_t offset, u64 ino,
1915 unsigned int d_type)
1917 struct readdir_data *buf =
1918 container_of(ctx, struct readdir_data, ctx);
1919 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1920 unsigned int reclen;
1922 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1923 if (buf->used + reclen > PAGE_SIZE) {
1928 de->namlen = namlen;
1929 de->offset = offset;
1931 de->d_type = d_type;
1932 memcpy(de->name, name, namlen);
1933 buf->used += reclen;
1938 static __be32 nfsd_buffered_readdir(struct file *file, struct svc_fh *fhp,
1939 nfsd_filldir_t func, struct readdir_cd *cdp,
1942 struct buffered_dirent *de;
1946 struct readdir_data buf = {
1947 .ctx.actor = nfsd_buffered_filldir,
1948 .dirent = (void *)__get_free_page(GFP_KERNEL)
1952 return nfserrno(-ENOMEM);
1957 unsigned int reclen;
1959 cdp->err = nfserr_eof; /* will be cleared on successful read */
1963 host_err = iterate_dir(file, &buf.ctx);
1975 de = (struct buffered_dirent *)buf.dirent;
1977 offset = de->offset;
1979 if (func(cdp, de->name, de->namlen, de->offset,
1980 de->ino, de->d_type))
1983 if (cdp->err != nfs_ok)
1986 trace_nfsd_dirent(fhp, de->ino, de->name, de->namlen);
1988 reclen = ALIGN(sizeof(*de) + de->namlen,
1991 de = (struct buffered_dirent *)((char *)de + reclen);
1993 if (size > 0) /* We bailed out early */
1996 offset = vfs_llseek(file, 0, SEEK_CUR);
1999 free_page((unsigned long)(buf.dirent));
2002 return nfserrno(host_err);
2009 * Read entries from a directory.
2010 * The NFSv3/4 verifier we ignore for now.
2013 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
2014 struct readdir_cd *cdp, nfsd_filldir_t func)
2018 loff_t offset = *offsetp;
2019 int may_flags = NFSD_MAY_READ;
2021 /* NFSv2 only supports 32 bit cookies */
2022 if (rqstp->rq_vers > 2)
2023 may_flags |= NFSD_MAY_64BIT_COOKIE;
2025 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
2029 offset = vfs_llseek(file, offset, SEEK_SET);
2031 err = nfserrno((int)offset);
2035 err = nfsd_buffered_readdir(file, fhp, func, cdp, offsetp);
2037 if (err == nfserr_eof || err == nfserr_toosmall)
2038 err = nfs_ok; /* can still be found in ->err */
2046 * Get file system stats
2047 * N.B. After this call fhp needs an fh_put
2050 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
2054 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
2056 struct path path = {
2057 .mnt = fhp->fh_export->ex_path.mnt,
2058 .dentry = fhp->fh_dentry,
2060 if (vfs_statfs(&path, stat))
2066 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
2068 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
2071 #ifdef CONFIG_NFSD_V4
2073 * Helper function to translate error numbers. In the case of xattr operations,
2074 * some error codes need to be translated outside of the standard translations.
2076 * ENODATA needs to be translated to nfserr_noxattr.
2077 * E2BIG to nfserr_xattr2big.
2079 * Additionally, vfs_listxattr can return -ERANGE. This means that the
2080 * file has too many extended attributes to retrieve inside an
2081 * XATTR_LIST_MAX sized buffer. This is a bug in the xattr implementation:
2082 * filesystems will allow the adding of extended attributes until they hit
2083 * their own internal limit. This limit may be larger than XATTR_LIST_MAX.
2084 * So, at that point, the attributes are present and valid, but can't
2085 * be retrieved using listxattr, since the upper level xattr code enforces
2086 * the XATTR_LIST_MAX limit.
2088 * This bug means that we need to deal with listxattr returning -ERANGE. The
2089 * best mapping is to return TOOSMALL.
2092 nfsd_xattr_errno(int err)
2096 return nfserr_noxattr;
2098 return nfserr_xattr2big;
2100 return nfserr_toosmall;
2102 return nfserrno(err);
2106 * Retrieve the specified user extended attribute. To avoid always
2107 * having to allocate the maximum size (since we are not getting
2108 * a maximum size from the RPC), do a probe + alloc. Hold a reader
2109 * lock on i_rwsem to prevent the extended attribute from changing
2110 * size while we're doing this.
2113 nfsd_getxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2114 void **bufp, int *lenp)
2119 struct inode *inode;
2120 struct dentry *dentry;
2122 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2127 dentry = fhp->fh_dentry;
2128 inode = d_inode(dentry);
2130 inode_lock_shared(inode);
2132 len = vfs_getxattr(&init_user_ns, dentry, name, NULL, 0);
2135 * Zero-length attribute, just return.
2144 err = nfsd_xattr_errno(len);
2149 err = nfserr_toosmall;
2153 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2155 err = nfserr_jukebox;
2159 len = vfs_getxattr(&init_user_ns, dentry, name, buf, len);
2163 err = nfsd_xattr_errno(len);
2170 inode_unlock_shared(inode);
2176 * Retrieve the xattr names. Since we can't know how many are
2177 * user extended attributes, we must get all attributes here,
2178 * and have the XDR encode filter out the "user." ones.
2180 * While this could always just allocate an XATTR_LIST_MAX
2181 * buffer, that's a waste, so do a probe + allocate. To
2182 * avoid any changes between the probe and allocate, wrap
2183 * this in inode_lock.
2186 nfsd_listxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char **bufp,
2192 struct inode *inode;
2193 struct dentry *dentry;
2195 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_READ);
2199 dentry = fhp->fh_dentry;
2200 inode = d_inode(dentry);
2203 inode_lock_shared(inode);
2205 len = vfs_listxattr(dentry, NULL, 0);
2207 err = nfsd_xattr_errno(len);
2211 if (len > XATTR_LIST_MAX) {
2212 err = nfserr_xattr2big;
2217 * We're holding i_rwsem - use GFP_NOFS.
2219 buf = kvmalloc(len, GFP_KERNEL | GFP_NOFS);
2221 err = nfserr_jukebox;
2225 len = vfs_listxattr(dentry, buf, len);
2228 err = nfsd_xattr_errno(len);
2237 inode_unlock_shared(inode);
2243 * nfsd_removexattr - Remove an extended attribute
2244 * @rqstp: RPC transaction being executed
2245 * @fhp: NFS filehandle of object with xattr to remove
2246 * @name: name of xattr to remove (NUL-terminate)
2248 * Pass in a NULL pointer for delegated_inode, and let the client deal
2249 * with NFS4ERR_DELAY (same as with e.g. setattr and remove).
2251 * Returns nfs_ok on success, or an nfsstat in network byte order.
2254 nfsd_removexattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name)
2259 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2263 ret = fh_want_write(fhp);
2265 return nfserrno(ret);
2267 inode_lock(fhp->fh_dentry->d_inode);
2268 fh_fill_pre_attrs(fhp);
2270 ret = __vfs_removexattr_locked(&init_user_ns, fhp->fh_dentry,
2273 fh_fill_post_attrs(fhp);
2274 inode_unlock(fhp->fh_dentry->d_inode);
2277 return nfsd_xattr_errno(ret);
2281 nfsd_setxattr(struct svc_rqst *rqstp, struct svc_fh *fhp, char *name,
2282 void *buf, u32 len, u32 flags)
2287 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_WRITE);
2291 ret = fh_want_write(fhp);
2293 return nfserrno(ret);
2294 inode_lock(fhp->fh_dentry->d_inode);
2295 fh_fill_pre_attrs(fhp);
2297 ret = __vfs_setxattr_locked(&init_user_ns, fhp->fh_dentry, name, buf,
2299 fh_fill_post_attrs(fhp);
2300 inode_unlock(fhp->fh_dentry->d_inode);
2303 return nfsd_xattr_errno(ret);
2308 * Check for a user's access permissions to this inode.
2311 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2312 struct dentry *dentry, int acc)
2314 struct inode *inode = d_inode(dentry);
2317 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2320 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2322 (acc & NFSD_MAY_READ)? " read" : "",
2323 (acc & NFSD_MAY_WRITE)? " write" : "",
2324 (acc & NFSD_MAY_EXEC)? " exec" : "",
2325 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2326 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2327 (acc & NFSD_MAY_LOCK)? " lock" : "",
2328 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2330 IS_IMMUTABLE(inode)? " immut" : "",
2331 IS_APPEND(inode)? " append" : "",
2332 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2333 dprintk(" owner %d/%d user %d/%d\n",
2334 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2337 /* Normally we reject any write/sattr etc access on a read-only file
2338 * system. But if it is IRIX doing check on write-access for a
2339 * device special file, we ignore rofs.
2341 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2342 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2343 if (exp_rdonly(rqstp, exp) ||
2344 __mnt_is_readonly(exp->ex_path.mnt))
2346 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2349 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2352 if (acc & NFSD_MAY_LOCK) {
2353 /* If we cannot rely on authentication in NLM requests,
2354 * just allow locks, otherwise require read permission, or
2357 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2360 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2363 * The file owner always gets access permission for accesses that
2364 * would normally be checked at open time. This is to make
2365 * file access work even when the client has done a fchmod(fd, 0).
2367 * However, `cp foo bar' should fail nevertheless when bar is
2368 * readonly. A sensible way to do this might be to reject all
2369 * attempts to truncate a read-only file, because a creat() call
2370 * always implies file truncation.
2371 * ... but this isn't really fair. A process may reasonably call
2372 * ftruncate on an open file descriptor on a file with perm 000.
2373 * We must trust the client to do permission checking - using "ACCESS"
2376 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2377 uid_eq(inode->i_uid, current_fsuid()))
2380 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2381 err = inode_permission(&init_user_ns, inode,
2382 acc & (MAY_READ | MAY_WRITE | MAY_EXEC));
2384 /* Allow read access to binaries even when mode 111 */
2385 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2386 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2387 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2388 err = inode_permission(&init_user_ns, inode, MAY_EXEC);
2390 return err? nfserrno(err) : 0;