2 * File operations used by nfsd. Some of these have been ripped from
3 * other parts of the kernel because they weren't exported, others
4 * are partial duplicates with added or changed functionality.
6 * Note that several functions dget() the dentry upon which they want
7 * to act, most notably those that create directory entries. Response
8 * dentry's are dput()'d if necessary in the release callback.
9 * So if you notice code paths that apparently fail to dput() the
10 * dentry, don't worry--they have been taken care of.
12 * Copyright (C) 1995-1999 Olaf Kirch <okir@monad.swb.de>
13 * Zerocpy NFS support (C) 2002 Hirokazu Takahashi <taka@valinux.co.jp>
17 #include <linux/file.h>
18 #include <linux/splice.h>
19 #include <linux/fcntl.h>
20 #include <linux/namei.h>
21 #include <linux/delay.h>
22 #include <linux/fsnotify.h>
23 #include <linux/posix_acl_xattr.h>
24 #include <linux/xattr.h>
25 #include <linux/jhash.h>
26 #include <linux/ima.h>
27 #include <linux/slab.h>
28 #include <asm/uaccess.h>
29 #include <linux/exportfs.h>
30 #include <linux/writeback.h>
31 #include <linux/security.h>
35 #endif /* CONFIG_NFSD_V3 */
40 #endif /* CONFIG_NFSD_V4 */
45 #define NFSDDBG_FACILITY NFSDDBG_FILEOP
49 * This is a cache of readahead params that help us choose the proper
50 * readahead strategy. Initially, we set all readahead parameters to 0
51 * and let the VFS handle things.
52 * If you increase the number of cached files very much, you'll need to
53 * add a hash table here.
56 struct raparms *p_next;
61 struct file_ra_state p_ra;
62 unsigned int p_hindex;
65 struct raparm_hbucket {
66 struct raparms *pb_head;
68 } ____cacheline_aligned_in_smp;
70 #define RAPARM_HASH_BITS 4
71 #define RAPARM_HASH_SIZE (1<<RAPARM_HASH_BITS)
72 #define RAPARM_HASH_MASK (RAPARM_HASH_SIZE-1)
73 static struct raparm_hbucket raparm_hash[RAPARM_HASH_SIZE];
76 * Called from nfsd_lookup and encode_dirent. Check if we have crossed
78 * Returns -EAGAIN or -ETIMEDOUT leaving *dpp and *expp unchanged,
79 * or nfs_ok having possibly changed *dpp and *expp
82 nfsd_cross_mnt(struct svc_rqst *rqstp, struct dentry **dpp,
83 struct svc_export **expp)
85 struct svc_export *exp = *expp, *exp2 = NULL;
86 struct dentry *dentry = *dpp;
87 struct path path = {.mnt = mntget(exp->ex_path.mnt),
88 .dentry = dget(dentry)};
91 err = follow_down(&path);
95 exp2 = rqst_exp_get_by_name(rqstp, &path);
99 * We normally allow NFS clients to continue
100 * "underneath" a mountpoint that is not exported.
101 * The exception is V4ROOT, where no traversal is ever
102 * allowed without an explicit export of the new
105 if (err == -ENOENT && !(exp->ex_flags & NFSEXP_V4ROOT))
110 if (nfsd_v4client(rqstp) ||
111 (exp->ex_flags & NFSEXP_CROSSMOUNT) || EX_NOHIDE(exp2)) {
112 /* successfully crossed mount point */
114 * This is subtle: path.dentry is *not* on path.mnt
115 * at this point. The only reason we are safe is that
116 * original mnt is pinned down by exp, so we should
117 * put path *before* putting exp
120 path.dentry = dentry;
130 static void follow_to_parent(struct path *path)
134 while (path->dentry == path->mnt->mnt_root && follow_up(path))
136 dp = dget_parent(path->dentry);
141 static int nfsd_lookup_parent(struct svc_rqst *rqstp, struct dentry *dparent, struct svc_export **exp, struct dentry **dentryp)
143 struct svc_export *exp2;
144 struct path path = {.mnt = mntget((*exp)->ex_path.mnt),
145 .dentry = dget(dparent)};
147 follow_to_parent(&path);
149 exp2 = rqst_exp_parent(rqstp, &path);
150 if (PTR_ERR(exp2) == -ENOENT) {
151 *dentryp = dget(dparent);
152 } else if (IS_ERR(exp2)) {
154 return PTR_ERR(exp2);
156 *dentryp = dget(path.dentry);
165 * For nfsd purposes, we treat V4ROOT exports as though there was an
166 * export at *every* directory.
168 int nfsd_mountpoint(struct dentry *dentry, struct svc_export *exp)
170 if (d_mountpoint(dentry))
172 if (nfsd4_is_junction(dentry))
174 if (!(exp->ex_flags & NFSEXP_V4ROOT))
176 return dentry->d_inode != NULL;
180 nfsd_lookup_dentry(struct svc_rqst *rqstp, struct svc_fh *fhp,
181 const char *name, unsigned int len,
182 struct svc_export **exp_ret, struct dentry **dentry_ret)
184 struct svc_export *exp;
185 struct dentry *dparent;
186 struct dentry *dentry;
189 dprintk("nfsd: nfsd_lookup(fh %s, %.*s)\n", SVCFH_fmt(fhp), len,name);
191 dparent = fhp->fh_dentry;
192 exp = fhp->fh_export;
195 /* Lookup the name, but don't follow links */
196 if (isdotent(name, len)) {
198 dentry = dget(dparent);
199 else if (dparent != exp->ex_path.dentry)
200 dentry = dget_parent(dparent);
201 else if (!EX_NOHIDE(exp) && !nfsd_v4client(rqstp))
202 dentry = dget(dparent); /* .. == . just like at / */
204 /* checking mountpoint crossing is very different when stepping up */
205 host_err = nfsd_lookup_parent(rqstp, dparent, &exp, &dentry);
211 * In the nfsd4_open() case, this may be held across
212 * subsequent open and delegation acquisition which may
213 * need to take the child's i_mutex:
215 fh_lock_nested(fhp, I_MUTEX_PARENT);
216 dentry = lookup_one_len(name, dparent, len);
217 host_err = PTR_ERR(dentry);
221 * check if we have crossed a mount point ...
223 if (nfsd_mountpoint(dentry, exp)) {
224 if ((host_err = nfsd_cross_mnt(rqstp, &dentry, &exp))) {
230 *dentry_ret = dentry;
236 return nfserrno(host_err);
240 * Look up one component of a pathname.
241 * N.B. After this call _both_ fhp and resfh need an fh_put
243 * If the lookup would cross a mountpoint, and the mounted filesystem
244 * is exported to the client with NFSEXP_NOHIDE, then the lookup is
245 * accepted as it stands and the mounted directory is
246 * returned. Otherwise the covered directory is returned.
247 * NOTE: this mountpoint crossing is not supported properly by all
248 * clients and is explicitly disallowed for NFSv3
249 * NeilBrown <neilb@cse.unsw.edu.au>
252 nfsd_lookup(struct svc_rqst *rqstp, struct svc_fh *fhp, const char *name,
253 unsigned int len, struct svc_fh *resfh)
255 struct svc_export *exp;
256 struct dentry *dentry;
259 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
262 err = nfsd_lookup_dentry(rqstp, fhp, name, len, &exp, &dentry);
265 err = check_nfsd_access(exp, rqstp);
269 * Note: we compose the file handle now, but as the
270 * dentry may be negative, it may need to be updated.
272 err = fh_compose(resfh, exp, dentry, fhp);
273 if (!err && !dentry->d_inode)
282 * Commit metadata changes to stable storage.
285 commit_metadata(struct svc_fh *fhp)
287 struct inode *inode = fhp->fh_dentry->d_inode;
288 const struct export_operations *export_ops = inode->i_sb->s_export_op;
290 if (!EX_ISSYNC(fhp->fh_export))
293 if (export_ops->commit_metadata)
294 return export_ops->commit_metadata(inode);
295 return sync_inode_metadata(inode, 1);
299 * Go over the attributes and take care of the small differences between
300 * NFS semantics and what Linux expects.
303 nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
306 * NFSv2 does not differentiate between "set-[ac]time-to-now"
307 * which only requires access, and "set-[ac]time-to-X" which
308 * requires ownership.
309 * So if it looks like it might be "set both to the same time which
310 * is close to now", and if inode_change_ok fails, then we
311 * convert to "set to now" instead of "set to explicit time"
313 * We only call inode_change_ok as the last test as technically
314 * it is not an interface that we should be using.
316 #define BOTH_TIME_SET (ATTR_ATIME_SET | ATTR_MTIME_SET)
317 #define MAX_TOUCH_TIME_ERROR (30*60)
318 if ((iap->ia_valid & BOTH_TIME_SET) == BOTH_TIME_SET &&
319 iap->ia_mtime.tv_sec == iap->ia_atime.tv_sec) {
323 * Now just make sure time is in the right ballpark.
324 * Solaris, at least, doesn't seem to care what the time
325 * request is. We require it be within 30 minutes of now.
327 time_t delta = iap->ia_atime.tv_sec - get_seconds();
330 if (delta < MAX_TOUCH_TIME_ERROR &&
331 inode_change_ok(inode, iap) != 0) {
333 * Turn off ATTR_[AM]TIME_SET but leave ATTR_[AM]TIME.
334 * This will cause notify_change to set these times
337 iap->ia_valid &= ~BOTH_TIME_SET;
341 /* sanitize the mode change */
342 if (iap->ia_valid & ATTR_MODE) {
343 iap->ia_mode &= S_IALLUGO;
344 iap->ia_mode |= (inode->i_mode & ~S_IALLUGO);
347 /* Revoke setuid/setgid on chown */
348 if (!S_ISDIR(inode->i_mode) &&
349 ((iap->ia_valid & ATTR_UID) || (iap->ia_valid & ATTR_GID))) {
350 iap->ia_valid |= ATTR_KILL_PRIV;
351 if (iap->ia_valid & ATTR_MODE) {
352 /* we're setting mode too, just clear the s*id bits */
353 iap->ia_mode &= ~S_ISUID;
354 if (iap->ia_mode & S_IXGRP)
355 iap->ia_mode &= ~S_ISGID;
357 /* set ATTR_KILL_* bits and let VFS handle it */
358 iap->ia_valid |= (ATTR_KILL_SUID | ATTR_KILL_SGID);
364 nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
367 struct inode *inode = fhp->fh_dentry->d_inode;
370 if (iap->ia_size < inode->i_size) {
373 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
374 NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
379 host_err = get_write_access(inode);
383 host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
385 goto out_put_write_access;
388 out_put_write_access:
389 put_write_access(inode);
391 return nfserrno(host_err);
395 * Set various file attributes. After this call fhp needs an fh_put.
398 nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
399 int check_guard, time_t guardtime)
401 struct dentry *dentry;
403 int accmode = NFSD_MAY_SATTR;
407 bool get_write_count;
410 if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
411 accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
412 if (iap->ia_valid & ATTR_SIZE)
415 /* Callers that do fh_verify should do the fh_want_write: */
416 get_write_count = !fhp->fh_dentry;
419 err = fh_verify(rqstp, fhp, ftype, accmode);
422 if (get_write_count) {
423 host_err = fh_want_write(fhp);
425 return nfserrno(host_err);
428 dentry = fhp->fh_dentry;
429 inode = dentry->d_inode;
431 /* Ignore any mode updates on symlinks */
432 if (S_ISLNK(inode->i_mode))
433 iap->ia_valid &= ~ATTR_MODE;
438 nfsd_sanitize_attrs(inode, iap);
441 * The size case is special, it changes the file in addition to the
444 if (iap->ia_valid & ATTR_SIZE) {
445 err = nfsd_get_write_access(rqstp, fhp, iap);
451 iap->ia_valid |= ATTR_CTIME;
453 if (check_guard && guardtime != inode->i_ctime.tv_sec) {
454 err = nfserr_notsync;
455 goto out_put_write_access;
459 host_err = notify_change(dentry, iap, NULL);
461 err = nfserrno(host_err);
463 out_put_write_access:
465 put_write_access(inode);
467 commit_metadata(fhp);
472 #if defined(CONFIG_NFSD_V4)
474 * NFS junction information is stored in an extended attribute.
476 #define NFSD_JUNCTION_XATTR_NAME XATTR_TRUSTED_PREFIX "junction.nfs"
479 * nfsd4_is_junction - Test if an object could be an NFS junction
481 * @dentry: object to test
483 * Returns 1 if "dentry" appears to contain NFS junction information.
484 * Otherwise 0 is returned.
486 int nfsd4_is_junction(struct dentry *dentry)
488 struct inode *inode = dentry->d_inode;
492 if (inode->i_mode & S_IXUGO)
494 if (!(inode->i_mode & S_ISVTX))
496 if (vfs_getxattr(dentry, NFSD_JUNCTION_XATTR_NAME, NULL, 0) <= 0)
500 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
501 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
502 struct xdr_netobj *label)
506 struct dentry *dentry;
508 error = fh_verify(rqstp, fhp, 0 /* S_IFREG */, NFSD_MAY_SATTR);
512 dentry = fhp->fh_dentry;
514 mutex_lock(&dentry->d_inode->i_mutex);
515 host_error = security_inode_setsecctx(dentry, label->data, label->len);
516 mutex_unlock(&dentry->d_inode->i_mutex);
517 return nfserrno(host_error);
520 __be32 nfsd4_set_nfs4_label(struct svc_rqst *rqstp, struct svc_fh *fhp,
521 struct xdr_netobj *label)
523 return nfserr_notsupp;
527 #endif /* defined(CONFIG_NFSD_V4) */
529 #ifdef CONFIG_NFSD_V3
531 * Check server access rights to a file system object
537 static struct accessmap nfs3_regaccess[] = {
538 { NFS3_ACCESS_READ, NFSD_MAY_READ },
539 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
540 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_TRUNC },
541 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE },
546 static struct accessmap nfs3_diraccess[] = {
547 { NFS3_ACCESS_READ, NFSD_MAY_READ },
548 { NFS3_ACCESS_LOOKUP, NFSD_MAY_EXEC },
549 { NFS3_ACCESS_MODIFY, NFSD_MAY_EXEC|NFSD_MAY_WRITE|NFSD_MAY_TRUNC},
550 { NFS3_ACCESS_EXTEND, NFSD_MAY_EXEC|NFSD_MAY_WRITE },
551 { NFS3_ACCESS_DELETE, NFSD_MAY_REMOVE },
556 static struct accessmap nfs3_anyaccess[] = {
557 /* Some clients - Solaris 2.6 at least, make an access call
558 * to the server to check for access for things like /dev/null
559 * (which really, the server doesn't care about). So
560 * We provide simple access checking for them, looking
561 * mainly at mode bits, and we make sure to ignore read-only
564 { NFS3_ACCESS_READ, NFSD_MAY_READ },
565 { NFS3_ACCESS_EXECUTE, NFSD_MAY_EXEC },
566 { NFS3_ACCESS_MODIFY, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
567 { NFS3_ACCESS_EXTEND, NFSD_MAY_WRITE|NFSD_MAY_LOCAL_ACCESS },
573 nfsd_access(struct svc_rqst *rqstp, struct svc_fh *fhp, u32 *access, u32 *supported)
575 struct accessmap *map;
576 struct svc_export *export;
577 struct dentry *dentry;
578 u32 query, result = 0, sresult = 0;
581 error = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP);
585 export = fhp->fh_export;
586 dentry = fhp->fh_dentry;
588 if (S_ISREG(dentry->d_inode->i_mode))
589 map = nfs3_regaccess;
590 else if (S_ISDIR(dentry->d_inode->i_mode))
591 map = nfs3_diraccess;
593 map = nfs3_anyaccess;
597 for (; map->access; map++) {
598 if (map->access & query) {
601 sresult |= map->access;
603 err2 = nfsd_permission(rqstp, export, dentry, map->how);
606 result |= map->access;
609 /* the following error codes just mean the access was not allowed,
610 * rather than an error occurred */
614 /* simply don't "or" in the access bit. */
624 *supported = sresult;
629 #endif /* CONFIG_NFSD_V3 */
631 static int nfsd_open_break_lease(struct inode *inode, int access)
635 if (access & NFSD_MAY_NOT_BREAK_LEASE)
637 mode = (access & NFSD_MAY_WRITE) ? O_WRONLY : O_RDONLY;
638 return break_lease(inode, mode | O_NONBLOCK);
642 * Open an existing file or directory.
643 * The may_flags argument indicates the type of open (read/write/lock)
644 * and additional flags.
645 * N.B. After this call fhp needs an fh_put
648 nfsd_open(struct svc_rqst *rqstp, struct svc_fh *fhp, umode_t type,
649 int may_flags, struct file **filp)
653 int flags = O_RDONLY|O_LARGEFILE;
657 validate_process_creds();
660 * If we get here, then the client has already done an "open",
661 * and (hopefully) checked permission - so allow OWNER_OVERRIDE
662 * in case a chmod has now revoked permission.
664 * Arguably we should also allow the owner override for
665 * directories, but we never have and it doesn't seem to have
666 * caused anyone a problem. If we were to change this, note
667 * also that our filldir callbacks would need a variant of
668 * lookup_one_len that doesn't check permissions.
671 may_flags |= NFSD_MAY_OWNER_OVERRIDE;
672 err = fh_verify(rqstp, fhp, type, may_flags);
676 path.mnt = fhp->fh_export->ex_path.mnt;
677 path.dentry = fhp->fh_dentry;
678 inode = path.dentry->d_inode;
680 /* Disallow write access to files with the append-only bit set
681 * or any access when mandatory locking enabled
684 if (IS_APPEND(inode) && (may_flags & NFSD_MAY_WRITE))
687 * We must ignore files (but only files) which might have mandatory
688 * locks on them because there is no way to know if the accesser has
691 if (S_ISREG((inode)->i_mode) && mandatory_lock(inode))
697 host_err = nfsd_open_break_lease(inode, may_flags);
698 if (host_err) /* NOMEM or WOULDBLOCK */
701 if (may_flags & NFSD_MAY_WRITE) {
702 if (may_flags & NFSD_MAY_READ)
703 flags = O_RDWR|O_LARGEFILE;
705 flags = O_WRONLY|O_LARGEFILE;
707 *filp = dentry_open(&path, flags, current_cred());
709 host_err = PTR_ERR(*filp);
712 host_err = ima_file_check(*filp, may_flags);
714 if (may_flags & NFSD_MAY_64BIT_COOKIE)
715 (*filp)->f_mode |= FMODE_64BITHASH;
717 (*filp)->f_mode |= FMODE_32BITHASH;
721 err = nfserrno(host_err);
723 validate_process_creds();
731 nfsd_close(struct file *filp)
737 * Obtain the readahead parameters for the file
738 * specified by (dev, ino).
741 static inline struct raparms *
742 nfsd_get_raparms(dev_t dev, ino_t ino)
744 struct raparms *ra, **rap, **frap = NULL;
747 struct raparm_hbucket *rab;
749 hash = jhash_2words(dev, ino, 0xfeedbeef) & RAPARM_HASH_MASK;
750 rab = &raparm_hash[hash];
752 spin_lock(&rab->pb_lock);
753 for (rap = &rab->pb_head; (ra = *rap); rap = &ra->p_next) {
754 if (ra->p_ino == ino && ra->p_dev == dev)
757 if (ra->p_count == 0)
760 depth = nfsdstats.ra_size;
762 spin_unlock(&rab->pb_lock);
772 if (rap != &rab->pb_head) {
774 ra->p_next = rab->pb_head;
778 nfsdstats.ra_depth[depth*10/nfsdstats.ra_size]++;
779 spin_unlock(&rab->pb_lock);
784 * Grab and keep cached pages associated with a file in the svc_rqst
785 * so that they can be passed to the network sendmsg/sendpage routines
786 * directly. They will be released after the sending has completed.
789 nfsd_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf,
790 struct splice_desc *sd)
792 struct svc_rqst *rqstp = sd->u.data;
793 struct page **pp = rqstp->rq_next_page;
794 struct page *page = buf->page;
799 if (rqstp->rq_res.page_len == 0) {
801 put_page(*rqstp->rq_next_page);
802 *(rqstp->rq_next_page++) = page;
803 rqstp->rq_res.page_base = buf->offset;
804 rqstp->rq_res.page_len = size;
805 } else if (page != pp[-1]) {
807 if (*rqstp->rq_next_page)
808 put_page(*rqstp->rq_next_page);
809 *(rqstp->rq_next_page++) = page;
810 rqstp->rq_res.page_len += size;
812 rqstp->rq_res.page_len += size;
817 static int nfsd_direct_splice_actor(struct pipe_inode_info *pipe,
818 struct splice_desc *sd)
820 return __splice_from_pipe(pipe, sd, nfsd_splice_actor);
823 __be32 nfsd_finish_read(struct file *file, unsigned long *count, int host_err)
826 nfsdstats.io_read += host_err;
828 fsnotify_access(file);
831 return nfserrno(host_err);
834 int nfsd_splice_read(struct svc_rqst *rqstp,
835 struct file *file, loff_t offset, unsigned long *count)
837 struct splice_desc sd = {
845 rqstp->rq_next_page = rqstp->rq_respages + 1;
846 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
847 return nfsd_finish_read(file, count, host_err);
850 int nfsd_readv(struct file *file, loff_t offset, struct kvec *vec, int vlen,
851 unsigned long *count)
858 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
860 return nfsd_finish_read(file, count, host_err);
864 nfsd_vfs_read(struct svc_rqst *rqstp, struct file *file,
865 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
867 if (file->f_op->splice_read && rqstp->rq_splice_ok)
868 return nfsd_splice_read(rqstp, file, offset, count);
870 return nfsd_readv(file, offset, vec, vlen, count);
874 * Gathered writes: If another process is currently writing to the file,
875 * there's a high chance this is another nfsd (triggered by a bulk write
876 * from a client's biod). Rather than syncing the file with each write
877 * request, we sleep for 10 msec.
879 * I don't know if this roughly approximates C. Juszak's idea of
880 * gathered writes, but it's a nice and simple solution (IMHO), and it
883 * Note: we do this only in the NFSv2 case, since v3 and higher have a
884 * better tool (separate unstable writes and commits) for solving this
887 static int wait_for_concurrent_writes(struct file *file)
889 struct inode *inode = file_inode(file);
890 static ino_t last_ino;
891 static dev_t last_dev;
894 if (atomic_read(&inode->i_writecount) > 1
895 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
896 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
898 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
901 if (inode->i_state & I_DIRTY) {
902 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
903 err = vfs_fsync(file, 0);
905 last_ino = inode->i_ino;
906 last_dev = inode->i_sb->s_dev;
911 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
912 loff_t offset, struct kvec *vec, int vlen,
913 unsigned long *cnt, int *stablep)
915 struct svc_export *exp;
916 struct dentry *dentry;
921 int stable = *stablep;
924 unsigned int pflags = current->flags;
928 * We want less throttling in balance_dirty_pages()
929 * and shrink_inactive_list() so that nfs to
930 * localhost doesn't cause nfsd to lock up due to all
931 * the client's dirty pages or its congested queue.
933 current->flags |= PF_LESS_THROTTLE;
935 dentry = file->f_path.dentry;
936 inode = dentry->d_inode;
937 exp = fhp->fh_export;
939 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
944 /* Write the data. */
945 oldfs = get_fs(); set_fs(KERNEL_DS);
946 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos);
951 nfsdstats.io_write += host_err;
952 fsnotify_modify(file);
956 host_err = wait_for_concurrent_writes(file);
958 host_err = vfs_fsync_range(file, offset, offset+*cnt, 0);
962 dprintk("nfsd: write complete host_err=%d\n", host_err);
966 err = nfserrno(host_err);
968 tsk_restore_flags(current, pflags, PF_LESS_THROTTLE);
972 __be32 nfsd_get_tmp_read_open(struct svc_rqst *rqstp, struct svc_fh *fhp,
973 struct file **file, struct raparms **ra)
978 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, file);
982 inode = file_inode(*file);
984 /* Get readahead parameters */
985 *ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
987 if (*ra && (*ra)->p_set)
988 (*file)->f_ra = (*ra)->p_ra;
992 void nfsd_put_tmp_read_open(struct file *file, struct raparms *ra)
994 /* Write back readahead params */
996 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
997 spin_lock(&rab->pb_lock);
998 ra->p_ra = file->f_ra;
1001 spin_unlock(&rab->pb_lock);
1007 * Read data from a file. count must contain the requested read count
1008 * on entry. On return, *count contains the number of bytes actually read.
1009 * N.B. After this call fhp needs an fh_put
1011 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
1012 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
1018 err = nfsd_get_tmp_read_open(rqstp, fhp, &file, &ra);
1022 err = nfsd_vfs_read(rqstp, file, offset, vec, vlen, count);
1024 nfsd_put_tmp_read_open(file, ra);
1029 /* As above, but use the provided file descriptor. */
1031 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1032 loff_t offset, struct kvec *vec, int vlen,
1033 unsigned long *count)
1038 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1039 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1042 err = nfsd_vfs_read(rqstp, file, offset, vec, vlen, count);
1043 } else /* Note file may still be NULL in NFSv4 special stateid case: */
1044 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count);
1050 * Write data to a file.
1051 * The stable flag requests synchronous writes.
1052 * N.B. After this call fhp needs an fh_put
1055 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1056 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1062 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1063 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1066 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1069 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1074 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1082 #ifdef CONFIG_NFSD_V3
1084 * Commit all pending writes to stable storage.
1086 * Note: we only guarantee that data that lies within the range specified
1087 * by the 'offset' and 'count' parameters will be synced.
1089 * Unfortunately we cannot lock the file to make sure we return full WCC
1090 * data to the client, as locking happens lower down in the filesystem.
1093 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1094 loff_t offset, unsigned long count)
1097 loff_t end = LLONG_MAX;
1098 __be32 err = nfserr_inval;
1103 end = offset + (loff_t)count - 1;
1108 err = nfsd_open(rqstp, fhp, S_IFREG,
1109 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1112 if (EX_ISSYNC(fhp->fh_export)) {
1113 int err2 = vfs_fsync_range(file, offset, end, 0);
1115 if (err2 != -EINVAL)
1116 err = nfserrno(err2);
1118 err = nfserr_notsupp;
1125 #endif /* CONFIG_NFSD_V3 */
1128 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1132 * Mode has already been set earlier in create:
1134 iap->ia_valid &= ~ATTR_MODE;
1136 * Setting uid/gid works only for root. Irix appears to
1137 * send along the gid on create when it tries to implement
1138 * setgid directories via NFS:
1140 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1141 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1143 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1147 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1148 * setting size to 0 may fail for some specific file systems by the permission
1149 * checking which requires WRITE permission but the mode is 000.
1150 * we ignore the resizing(to 0) on the just new created file, since the size is
1151 * 0 after file created.
1153 * call this only after vfs_create() is called.
1156 nfsd_check_ignore_resizing(struct iattr *iap)
1158 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1159 iap->ia_valid &= ~ATTR_SIZE;
1163 * Create a file (regular, directory, device, fifo); UNIX sockets
1164 * not yet implemented.
1165 * If the response fh has been verified, the parent directory should
1166 * already be locked. Note that the parent directory is left locked.
1168 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1171 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1172 char *fname, int flen, struct iattr *iap,
1173 int type, dev_t rdev, struct svc_fh *resfhp)
1175 struct dentry *dentry, *dchild = NULL;
1185 if (isdotent(fname, flen))
1188 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1192 dentry = fhp->fh_dentry;
1193 dirp = dentry->d_inode;
1195 err = nfserr_notdir;
1196 if (!dirp->i_op->lookup)
1199 * Check whether the response file handle has been verified yet.
1200 * If it has, the parent directory should already be locked.
1202 if (!resfhp->fh_dentry) {
1203 host_err = fh_want_write(fhp);
1207 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1208 fh_lock_nested(fhp, I_MUTEX_PARENT);
1209 dchild = lookup_one_len(fname, dentry, flen);
1210 host_err = PTR_ERR(dchild);
1213 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1217 /* called from nfsd_proc_create */
1218 dchild = dget(resfhp->fh_dentry);
1219 if (!fhp->fh_locked) {
1220 /* not actually possible */
1222 "nfsd_create: parent %pd2 not locked!\n",
1229 * Make sure the child dentry is still negative ...
1232 if (dchild->d_inode) {
1233 dprintk("nfsd_create: dentry %pd/%pd not negative!\n",
1238 if (!(iap->ia_valid & ATTR_MODE))
1240 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1243 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1244 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1250 * Get the dir op function pointer.
1256 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1258 nfsd_check_ignore_resizing(iap);
1261 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1267 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1273 err = nfsd_create_setattr(rqstp, resfhp, iap);
1276 * nfsd_setattr already committed the child. Transactional filesystems
1277 * had a chance to commit changes for both parent and child
1278 * simultaneously making the following commit_metadata a noop.
1280 err2 = nfserrno(commit_metadata(fhp));
1284 * Update the file handle to get the new inode info.
1287 err = fh_update(resfhp);
1289 if (dchild && !IS_ERR(dchild))
1294 err = nfserrno(host_err);
1298 #ifdef CONFIG_NFSD_V3
1300 static inline int nfsd_create_is_exclusive(int createmode)
1302 return createmode == NFS3_CREATE_EXCLUSIVE
1303 || createmode == NFS4_CREATE_EXCLUSIVE4_1;
1307 * NFSv3 and NFSv4 version of nfsd_create
1310 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1311 char *fname, int flen, struct iattr *iap,
1312 struct svc_fh *resfhp, int createmode, u32 *verifier,
1313 bool *truncp, bool *created)
1315 struct dentry *dentry, *dchild = NULL;
1319 __u32 v_mtime=0, v_atime=0;
1325 if (isdotent(fname, flen))
1327 if (!(iap->ia_valid & ATTR_MODE))
1329 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1333 dentry = fhp->fh_dentry;
1334 dirp = dentry->d_inode;
1336 /* Get all the sanity checks out of the way before
1337 * we lock the parent. */
1338 err = nfserr_notdir;
1339 if (!dirp->i_op->lookup)
1342 host_err = fh_want_write(fhp);
1346 fh_lock_nested(fhp, I_MUTEX_PARENT);
1349 * Compose the response file handle.
1351 dchild = lookup_one_len(fname, dentry, flen);
1352 host_err = PTR_ERR(dchild);
1356 /* If file doesn't exist, check for permissions to create one */
1357 if (!dchild->d_inode) {
1358 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1363 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1367 if (nfsd_create_is_exclusive(createmode)) {
1368 /* solaris7 gets confused (bugid 4218508) if these have
1369 * the high bit set, so just clear the high bits. If this is
1370 * ever changed to use different attrs for storing the
1371 * verifier, then do_open_lookup() will also need to be fixed
1374 v_mtime = verifier[0]&0x7fffffff;
1375 v_atime = verifier[1]&0x7fffffff;
1378 if (dchild->d_inode) {
1381 switch (createmode) {
1382 case NFS3_CREATE_UNCHECKED:
1383 if (! S_ISREG(dchild->d_inode->i_mode))
1386 /* in nfsv4, we need to treat this case a little
1387 * differently. we don't want to truncate the
1388 * file now; this would be wrong if the OPEN
1389 * fails for some other reason. furthermore,
1390 * if the size is nonzero, we should ignore it
1391 * according to spec!
1393 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1396 iap->ia_valid &= ATTR_SIZE;
1400 case NFS3_CREATE_EXCLUSIVE:
1401 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1402 && dchild->d_inode->i_atime.tv_sec == v_atime
1403 && dchild->d_inode->i_size == 0 ) {
1408 case NFS4_CREATE_EXCLUSIVE4_1:
1409 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1410 && dchild->d_inode->i_atime.tv_sec == v_atime
1411 && dchild->d_inode->i_size == 0 ) {
1417 case NFS3_CREATE_GUARDED:
1424 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1432 nfsd_check_ignore_resizing(iap);
1434 if (nfsd_create_is_exclusive(createmode)) {
1435 /* Cram the verifier into atime/mtime */
1436 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1437 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1438 /* XXX someone who knows this better please fix it for nsec */
1439 iap->ia_mtime.tv_sec = v_mtime;
1440 iap->ia_atime.tv_sec = v_atime;
1441 iap->ia_mtime.tv_nsec = 0;
1442 iap->ia_atime.tv_nsec = 0;
1446 err = nfsd_create_setattr(rqstp, resfhp, iap);
1449 * nfsd_setattr already committed the child (and possibly also the parent).
1452 err = nfserrno(commit_metadata(fhp));
1455 * Update the filehandle to get the new inode info.
1458 err = fh_update(resfhp);
1462 if (dchild && !IS_ERR(dchild))
1468 err = nfserrno(host_err);
1471 #endif /* CONFIG_NFSD_V3 */
1474 * Read a symlink. On entry, *lenp must contain the maximum path length that
1475 * fits into the buffer. On return, it contains the true length.
1476 * N.B. After this call fhp needs an fh_put
1479 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1481 struct inode *inode;
1487 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1491 path.mnt = fhp->fh_export->ex_path.mnt;
1492 path.dentry = fhp->fh_dentry;
1493 inode = path.dentry->d_inode;
1496 if (!inode->i_op->readlink)
1500 /* N.B. Why does this call need a get_fs()??
1501 * Remove the set_fs and watch the fireworks:-) --okir
1504 oldfs = get_fs(); set_fs(KERNEL_DS);
1505 host_err = inode->i_op->readlink(path.dentry, (char __user *)buf, *lenp);
1516 err = nfserrno(host_err);
1521 * Create a symlink and look up its inode
1522 * N.B. After this call _both_ fhp and resfhp need an fh_put
1525 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1526 char *fname, int flen,
1527 char *path, int plen,
1528 struct svc_fh *resfhp,
1531 struct dentry *dentry, *dnew;
1539 if (isdotent(fname, flen))
1542 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1546 host_err = fh_want_write(fhp);
1551 dentry = fhp->fh_dentry;
1552 dnew = lookup_one_len(fname, dentry, flen);
1553 host_err = PTR_ERR(dnew);
1557 if (unlikely(path[plen] != 0)) {
1558 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1559 if (path_alloced == NULL)
1562 strncpy(path_alloced, path, plen);
1563 path_alloced[plen] = 0;
1564 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1565 kfree(path_alloced);
1568 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1569 err = nfserrno(host_err);
1571 err = nfserrno(commit_metadata(fhp));
1576 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1578 if (err==0) err = cerr;
1583 err = nfserrno(host_err);
1589 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1592 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1593 char *name, int len, struct svc_fh *tfhp)
1595 struct dentry *ddir, *dnew, *dold;
1600 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1603 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1607 if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode))
1613 if (isdotent(name, len))
1616 host_err = fh_want_write(tfhp);
1618 err = nfserrno(host_err);
1622 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1623 ddir = ffhp->fh_dentry;
1624 dirp = ddir->d_inode;
1626 dnew = lookup_one_len(name, ddir, len);
1627 host_err = PTR_ERR(dnew);
1631 dold = tfhp->fh_dentry;
1636 host_err = vfs_link(dold, dirp, dnew, NULL);
1638 err = nfserrno(commit_metadata(ffhp));
1640 err = nfserrno(commit_metadata(tfhp));
1642 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1645 err = nfserrno(host_err);
1651 fh_drop_write(tfhp);
1656 err = nfserrno(host_err);
1662 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1665 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1666 struct svc_fh *tfhp, char *tname, int tlen)
1668 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1669 struct inode *fdir, *tdir;
1673 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1676 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1680 fdentry = ffhp->fh_dentry;
1681 fdir = fdentry->d_inode;
1683 tdentry = tfhp->fh_dentry;
1684 tdir = tdentry->d_inode;
1687 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1690 host_err = fh_want_write(ffhp);
1692 err = nfserrno(host_err);
1696 /* cannot use fh_lock as we need deadlock protective ordering
1697 * so do it by hand */
1698 trap = lock_rename(tdentry, fdentry);
1699 ffhp->fh_locked = tfhp->fh_locked = 1;
1703 odentry = lookup_one_len(fname, fdentry, flen);
1704 host_err = PTR_ERR(odentry);
1705 if (IS_ERR(odentry))
1709 if (!odentry->d_inode)
1712 if (odentry == trap)
1715 ndentry = lookup_one_len(tname, tdentry, tlen);
1716 host_err = PTR_ERR(ndentry);
1717 if (IS_ERR(ndentry))
1719 host_err = -ENOTEMPTY;
1720 if (ndentry == trap)
1724 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1726 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1729 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
1731 host_err = commit_metadata(tfhp);
1733 host_err = commit_metadata(ffhp);
1740 err = nfserrno(host_err);
1742 * We cannot rely on fh_unlock on the two filehandles,
1743 * as that would do the wrong thing if the two directories
1744 * were the same, so again we do it by hand.
1746 fill_post_wcc(ffhp);
1747 fill_post_wcc(tfhp);
1748 unlock_rename(tdentry, fdentry);
1749 ffhp->fh_locked = tfhp->fh_locked = 0;
1750 fh_drop_write(ffhp);
1757 * Unlink a file or directory
1758 * N.B. After this call fhp needs an fh_put
1761 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1762 char *fname, int flen)
1764 struct dentry *dentry, *rdentry;
1770 if (!flen || isdotent(fname, flen))
1772 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1776 host_err = fh_want_write(fhp);
1780 fh_lock_nested(fhp, I_MUTEX_PARENT);
1781 dentry = fhp->fh_dentry;
1782 dirp = dentry->d_inode;
1784 rdentry = lookup_one_len(fname, dentry, flen);
1785 host_err = PTR_ERR(rdentry);
1786 if (IS_ERR(rdentry))
1789 if (!rdentry->d_inode) {
1796 type = rdentry->d_inode->i_mode & S_IFMT;
1798 if (type != S_IFDIR)
1799 host_err = vfs_unlink(dirp, rdentry, NULL);
1801 host_err = vfs_rmdir(dirp, rdentry);
1803 host_err = commit_metadata(fhp);
1807 err = nfserrno(host_err);
1813 * We do this buffering because we must not call back into the file
1814 * system's ->lookup() method from the filldir callback. That may well
1815 * deadlock a number of file systems.
1817 * This is based heavily on the implementation of same in XFS.
1819 struct buffered_dirent {
1823 unsigned int d_type;
1827 struct readdir_data {
1828 struct dir_context ctx;
1834 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1835 loff_t offset, u64 ino, unsigned int d_type)
1837 struct readdir_data *buf = __buf;
1838 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1839 unsigned int reclen;
1841 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1842 if (buf->used + reclen > PAGE_SIZE) {
1847 de->namlen = namlen;
1848 de->offset = offset;
1850 de->d_type = d_type;
1851 memcpy(de->name, name, namlen);
1852 buf->used += reclen;
1857 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1858 struct readdir_cd *cdp, loff_t *offsetp)
1860 struct buffered_dirent *de;
1864 struct readdir_data buf = {
1865 .ctx.actor = nfsd_buffered_filldir,
1866 .dirent = (void *)__get_free_page(GFP_KERNEL)
1870 return nfserrno(-ENOMEM);
1875 struct inode *dir_inode = file_inode(file);
1876 unsigned int reclen;
1878 cdp->err = nfserr_eof; /* will be cleared on successful read */
1882 host_err = iterate_dir(file, &buf.ctx);
1895 * Various filldir functions may end up calling back into
1896 * lookup_one_len() and the file system's ->lookup() method.
1897 * These expect i_mutex to be held, as it would within readdir.
1899 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1903 de = (struct buffered_dirent *)buf.dirent;
1905 offset = de->offset;
1907 if (func(cdp, de->name, de->namlen, de->offset,
1908 de->ino, de->d_type))
1911 if (cdp->err != nfs_ok)
1914 reclen = ALIGN(sizeof(*de) + de->namlen,
1917 de = (struct buffered_dirent *)((char *)de + reclen);
1919 mutex_unlock(&dir_inode->i_mutex);
1920 if (size > 0) /* We bailed out early */
1923 offset = vfs_llseek(file, 0, SEEK_CUR);
1926 free_page((unsigned long)(buf.dirent));
1929 return nfserrno(host_err);
1936 * Read entries from a directory.
1937 * The NFSv3/4 verifier we ignore for now.
1940 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1941 struct readdir_cd *cdp, filldir_t func)
1945 loff_t offset = *offsetp;
1946 int may_flags = NFSD_MAY_READ;
1948 /* NFSv2 only supports 32 bit cookies */
1949 if (rqstp->rq_vers > 2)
1950 may_flags |= NFSD_MAY_64BIT_COOKIE;
1952 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
1956 offset = vfs_llseek(file, offset, SEEK_SET);
1958 err = nfserrno((int)offset);
1962 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
1964 if (err == nfserr_eof || err == nfserr_toosmall)
1965 err = nfs_ok; /* can still be found in ->err */
1973 * Get file system stats
1974 * N.B. After this call fhp needs an fh_put
1977 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
1981 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
1983 struct path path = {
1984 .mnt = fhp->fh_export->ex_path.mnt,
1985 .dentry = fhp->fh_dentry,
1987 if (vfs_statfs(&path, stat))
1993 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1995 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1999 * Check for a user's access permissions to this inode.
2002 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
2003 struct dentry *dentry, int acc)
2005 struct inode *inode = dentry->d_inode;
2008 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
2011 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
2013 (acc & NFSD_MAY_READ)? " read" : "",
2014 (acc & NFSD_MAY_WRITE)? " write" : "",
2015 (acc & NFSD_MAY_EXEC)? " exec" : "",
2016 (acc & NFSD_MAY_SATTR)? " sattr" : "",
2017 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
2018 (acc & NFSD_MAY_LOCK)? " lock" : "",
2019 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
2021 IS_IMMUTABLE(inode)? " immut" : "",
2022 IS_APPEND(inode)? " append" : "",
2023 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
2024 dprintk(" owner %d/%d user %d/%d\n",
2025 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
2028 /* Normally we reject any write/sattr etc access on a read-only file
2029 * system. But if it is IRIX doing check on write-access for a
2030 * device special file, we ignore rofs.
2032 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
2033 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
2034 if (exp_rdonly(rqstp, exp) ||
2035 __mnt_is_readonly(exp->ex_path.mnt))
2037 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
2040 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2043 if (acc & NFSD_MAY_LOCK) {
2044 /* If we cannot rely on authentication in NLM requests,
2045 * just allow locks, otherwise require read permission, or
2048 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2051 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2054 * The file owner always gets access permission for accesses that
2055 * would normally be checked at open time. This is to make
2056 * file access work even when the client has done a fchmod(fd, 0).
2058 * However, `cp foo bar' should fail nevertheless when bar is
2059 * readonly. A sensible way to do this might be to reject all
2060 * attempts to truncate a read-only file, because a creat() call
2061 * always implies file truncation.
2062 * ... but this isn't really fair. A process may reasonably call
2063 * ftruncate on an open file descriptor on a file with perm 000.
2064 * We must trust the client to do permission checking - using "ACCESS"
2067 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2068 uid_eq(inode->i_uid, current_fsuid()))
2071 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2072 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2074 /* Allow read access to binaries even when mode 111 */
2075 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2076 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2077 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2078 err = inode_permission(inode, MAY_EXEC);
2080 return err? nfserrno(err) : 0;
2084 nfsd_racache_shutdown(void)
2086 struct raparms *raparm, *last_raparm;
2089 dprintk("nfsd: freeing readahead buffers.\n");
2091 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2092 raparm = raparm_hash[i].pb_head;
2094 last_raparm = raparm;
2095 raparm = raparm->p_next;
2098 raparm_hash[i].pb_head = NULL;
2102 * Initialize readahead param cache
2105 nfsd_racache_init(int cache_size)
2110 struct raparms **raparm = NULL;
2113 if (raparm_hash[0].pb_head)
2115 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2118 cache_size = nperbucket * RAPARM_HASH_SIZE;
2120 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2122 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2123 spin_lock_init(&raparm_hash[i].pb_lock);
2125 raparm = &raparm_hash[i].pb_head;
2126 for (j = 0; j < nperbucket; j++) {
2127 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2130 raparm = &(*raparm)->p_next;
2135 nfsdstats.ra_size = cache_size;
2139 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2140 nfsd_racache_shutdown();