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);
824 nfsd_vfs_read(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
825 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
833 if (file->f_op->splice_read && rqstp->rq_splice_ok) {
834 struct splice_desc sd = {
841 rqstp->rq_next_page = rqstp->rq_respages + 1;
842 host_err = splice_direct_to_actor(file, &sd, nfsd_direct_splice_actor);
846 host_err = vfs_readv(file, (struct iovec __user *)vec, vlen, &offset);
851 nfsdstats.io_read += host_err;
854 fsnotify_access(file);
856 err = nfserrno(host_err);
861 * Gathered writes: If another process is currently writing to the file,
862 * there's a high chance this is another nfsd (triggered by a bulk write
863 * from a client's biod). Rather than syncing the file with each write
864 * request, we sleep for 10 msec.
866 * I don't know if this roughly approximates C. Juszak's idea of
867 * gathered writes, but it's a nice and simple solution (IMHO), and it
870 * Note: we do this only in the NFSv2 case, since v3 and higher have a
871 * better tool (separate unstable writes and commits) for solving this
874 static int wait_for_concurrent_writes(struct file *file)
876 struct inode *inode = file_inode(file);
877 static ino_t last_ino;
878 static dev_t last_dev;
881 if (atomic_read(&inode->i_writecount) > 1
882 || (last_ino == inode->i_ino && last_dev == inode->i_sb->s_dev)) {
883 dprintk("nfsd: write defer %d\n", task_pid_nr(current));
885 dprintk("nfsd: write resume %d\n", task_pid_nr(current));
888 if (inode->i_state & I_DIRTY) {
889 dprintk("nfsd: write sync %d\n", task_pid_nr(current));
890 err = vfs_fsync(file, 0);
892 last_ino = inode->i_ino;
893 last_dev = inode->i_sb->s_dev;
898 nfsd_vfs_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
899 loff_t offset, struct kvec *vec, int vlen,
900 unsigned long *cnt, int *stablep)
902 struct svc_export *exp;
903 struct dentry *dentry;
908 int stable = *stablep;
912 dentry = file->f_path.dentry;
913 inode = dentry->d_inode;
914 exp = fhp->fh_export;
916 use_wgather = (rqstp->rq_vers == 2) && EX_WGATHER(exp);
921 /* Write the data. */
922 oldfs = get_fs(); set_fs(KERNEL_DS);
923 host_err = vfs_writev(file, (struct iovec __user *)vec, vlen, &pos);
928 nfsdstats.io_write += host_err;
929 fsnotify_modify(file);
933 host_err = wait_for_concurrent_writes(file);
935 host_err = vfs_fsync_range(file, offset, offset+*cnt, 0);
939 dprintk("nfsd: write complete host_err=%d\n", host_err);
943 err = nfserrno(host_err);
948 * Read data from a file. count must contain the requested read count
949 * on entry. On return, *count contains the number of bytes actually read.
950 * N.B. After this call fhp needs an fh_put
952 __be32 nfsd_read(struct svc_rqst *rqstp, struct svc_fh *fhp,
953 loff_t offset, struct kvec *vec, int vlen, unsigned long *count)
960 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
964 inode = file_inode(file);
966 /* Get readahead parameters */
967 ra = nfsd_get_raparms(inode->i_sb->s_dev, inode->i_ino);
970 file->f_ra = ra->p_ra;
972 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
974 /* Write back readahead params */
976 struct raparm_hbucket *rab = &raparm_hash[ra->p_hindex];
977 spin_lock(&rab->pb_lock);
978 ra->p_ra = file->f_ra;
981 spin_unlock(&rab->pb_lock);
988 /* As above, but use the provided file descriptor. */
990 nfsd_read_file(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
991 loff_t offset, struct kvec *vec, int vlen,
992 unsigned long *count)
997 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
998 NFSD_MAY_READ|NFSD_MAY_OWNER_OVERRIDE);
1001 err = nfsd_vfs_read(rqstp, fhp, file, offset, vec, vlen, count);
1002 } else /* Note file may still be NULL in NFSv4 special stateid case: */
1003 err = nfsd_read(rqstp, fhp, offset, vec, vlen, count);
1009 * Write data to a file.
1010 * The stable flag requests synchronous writes.
1011 * N.B. After this call fhp needs an fh_put
1014 nfsd_write(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file *file,
1015 loff_t offset, struct kvec *vec, int vlen, unsigned long *cnt,
1021 err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
1022 NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE);
1025 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen, cnt,
1028 err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_WRITE, &file);
1033 err = nfsd_vfs_write(rqstp, fhp, file, offset, vec, vlen,
1041 #ifdef CONFIG_NFSD_V3
1043 * Commit all pending writes to stable storage.
1045 * Note: we only guarantee that data that lies within the range specified
1046 * by the 'offset' and 'count' parameters will be synced.
1048 * Unfortunately we cannot lock the file to make sure we return full WCC
1049 * data to the client, as locking happens lower down in the filesystem.
1052 nfsd_commit(struct svc_rqst *rqstp, struct svc_fh *fhp,
1053 loff_t offset, unsigned long count)
1056 loff_t end = LLONG_MAX;
1057 __be32 err = nfserr_inval;
1062 end = offset + (loff_t)count - 1;
1067 err = nfsd_open(rqstp, fhp, S_IFREG,
1068 NFSD_MAY_WRITE|NFSD_MAY_NOT_BREAK_LEASE, &file);
1071 if (EX_ISSYNC(fhp->fh_export)) {
1072 int err2 = vfs_fsync_range(file, offset, end, 0);
1074 if (err2 != -EINVAL)
1075 err = nfserrno(err2);
1077 err = nfserr_notsupp;
1084 #endif /* CONFIG_NFSD_V3 */
1087 nfsd_create_setattr(struct svc_rqst *rqstp, struct svc_fh *resfhp,
1091 * Mode has already been set earlier in create:
1093 iap->ia_valid &= ~ATTR_MODE;
1095 * Setting uid/gid works only for root. Irix appears to
1096 * send along the gid on create when it tries to implement
1097 * setgid directories via NFS:
1099 if (!uid_eq(current_fsuid(), GLOBAL_ROOT_UID))
1100 iap->ia_valid &= ~(ATTR_UID|ATTR_GID);
1102 return nfsd_setattr(rqstp, resfhp, iap, 0, (time_t)0);
1106 /* HPUX client sometimes creates a file in mode 000, and sets size to 0.
1107 * setting size to 0 may fail for some specific file systems by the permission
1108 * checking which requires WRITE permission but the mode is 000.
1109 * we ignore the resizing(to 0) on the just new created file, since the size is
1110 * 0 after file created.
1112 * call this only after vfs_create() is called.
1115 nfsd_check_ignore_resizing(struct iattr *iap)
1117 if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0))
1118 iap->ia_valid &= ~ATTR_SIZE;
1122 * Create a file (regular, directory, device, fifo); UNIX sockets
1123 * not yet implemented.
1124 * If the response fh has been verified, the parent directory should
1125 * already be locked. Note that the parent directory is left locked.
1127 * N.B. Every call to nfsd_create needs an fh_put for _both_ fhp and resfhp
1130 nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1131 char *fname, int flen, struct iattr *iap,
1132 int type, dev_t rdev, struct svc_fh *resfhp)
1134 struct dentry *dentry, *dchild = NULL;
1144 if (isdotent(fname, flen))
1147 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1151 dentry = fhp->fh_dentry;
1152 dirp = dentry->d_inode;
1154 err = nfserr_notdir;
1155 if (!dirp->i_op->lookup)
1158 * Check whether the response file handle has been verified yet.
1159 * If it has, the parent directory should already be locked.
1161 if (!resfhp->fh_dentry) {
1162 host_err = fh_want_write(fhp);
1166 /* called from nfsd_proc_mkdir, or possibly nfsd3_proc_create */
1167 fh_lock_nested(fhp, I_MUTEX_PARENT);
1168 dchild = lookup_one_len(fname, dentry, flen);
1169 host_err = PTR_ERR(dchild);
1172 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1176 /* called from nfsd_proc_create */
1177 dchild = dget(resfhp->fh_dentry);
1178 if (!fhp->fh_locked) {
1179 /* not actually possible */
1181 "nfsd_create: parent %pd2 not locked!\n",
1188 * Make sure the child dentry is still negative ...
1191 if (dchild->d_inode) {
1192 dprintk("nfsd_create: dentry %pd/%pd not negative!\n",
1197 if (!(iap->ia_valid & ATTR_MODE))
1199 iap->ia_mode = (iap->ia_mode & S_IALLUGO) | type;
1202 if (!S_ISREG(type) && !S_ISDIR(type) && !special_file(type)) {
1203 printk(KERN_WARNING "nfsd: bad file type %o in nfsd_create\n",
1209 * Get the dir op function pointer.
1215 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1217 nfsd_check_ignore_resizing(iap);
1220 host_err = vfs_mkdir(dirp, dchild, iap->ia_mode);
1226 host_err = vfs_mknod(dirp, dchild, iap->ia_mode, rdev);
1232 err = nfsd_create_setattr(rqstp, resfhp, iap);
1235 * nfsd_setattr already committed the child. Transactional filesystems
1236 * had a chance to commit changes for both parent and child
1237 * simultaneously making the following commit_metadata a noop.
1239 err2 = nfserrno(commit_metadata(fhp));
1243 * Update the file handle to get the new inode info.
1246 err = fh_update(resfhp);
1248 if (dchild && !IS_ERR(dchild))
1253 err = nfserrno(host_err);
1257 #ifdef CONFIG_NFSD_V3
1259 static inline int nfsd_create_is_exclusive(int createmode)
1261 return createmode == NFS3_CREATE_EXCLUSIVE
1262 || createmode == NFS4_CREATE_EXCLUSIVE4_1;
1266 * NFSv3 and NFSv4 version of nfsd_create
1269 do_nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp,
1270 char *fname, int flen, struct iattr *iap,
1271 struct svc_fh *resfhp, int createmode, u32 *verifier,
1272 bool *truncp, bool *created)
1274 struct dentry *dentry, *dchild = NULL;
1278 __u32 v_mtime=0, v_atime=0;
1284 if (isdotent(fname, flen))
1286 if (!(iap->ia_valid & ATTR_MODE))
1288 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_EXEC);
1292 dentry = fhp->fh_dentry;
1293 dirp = dentry->d_inode;
1295 /* Get all the sanity checks out of the way before
1296 * we lock the parent. */
1297 err = nfserr_notdir;
1298 if (!dirp->i_op->lookup)
1301 host_err = fh_want_write(fhp);
1305 fh_lock_nested(fhp, I_MUTEX_PARENT);
1308 * Compose the response file handle.
1310 dchild = lookup_one_len(fname, dentry, flen);
1311 host_err = PTR_ERR(dchild);
1315 /* If file doesn't exist, check for permissions to create one */
1316 if (!dchild->d_inode) {
1317 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1322 err = fh_compose(resfhp, fhp->fh_export, dchild, fhp);
1326 if (nfsd_create_is_exclusive(createmode)) {
1327 /* solaris7 gets confused (bugid 4218508) if these have
1328 * the high bit set, so just clear the high bits. If this is
1329 * ever changed to use different attrs for storing the
1330 * verifier, then do_open_lookup() will also need to be fixed
1333 v_mtime = verifier[0]&0x7fffffff;
1334 v_atime = verifier[1]&0x7fffffff;
1337 if (dchild->d_inode) {
1340 switch (createmode) {
1341 case NFS3_CREATE_UNCHECKED:
1342 if (! S_ISREG(dchild->d_inode->i_mode))
1345 /* in nfsv4, we need to treat this case a little
1346 * differently. we don't want to truncate the
1347 * file now; this would be wrong if the OPEN
1348 * fails for some other reason. furthermore,
1349 * if the size is nonzero, we should ignore it
1350 * according to spec!
1352 *truncp = (iap->ia_valid & ATTR_SIZE) && !iap->ia_size;
1355 iap->ia_valid &= ATTR_SIZE;
1359 case NFS3_CREATE_EXCLUSIVE:
1360 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1361 && dchild->d_inode->i_atime.tv_sec == v_atime
1362 && dchild->d_inode->i_size == 0 ) {
1367 case NFS4_CREATE_EXCLUSIVE4_1:
1368 if ( dchild->d_inode->i_mtime.tv_sec == v_mtime
1369 && dchild->d_inode->i_atime.tv_sec == v_atime
1370 && dchild->d_inode->i_size == 0 ) {
1376 case NFS3_CREATE_GUARDED:
1383 host_err = vfs_create(dirp, dchild, iap->ia_mode, true);
1391 nfsd_check_ignore_resizing(iap);
1393 if (nfsd_create_is_exclusive(createmode)) {
1394 /* Cram the verifier into atime/mtime */
1395 iap->ia_valid = ATTR_MTIME|ATTR_ATIME
1396 | ATTR_MTIME_SET|ATTR_ATIME_SET;
1397 /* XXX someone who knows this better please fix it for nsec */
1398 iap->ia_mtime.tv_sec = v_mtime;
1399 iap->ia_atime.tv_sec = v_atime;
1400 iap->ia_mtime.tv_nsec = 0;
1401 iap->ia_atime.tv_nsec = 0;
1405 err = nfsd_create_setattr(rqstp, resfhp, iap);
1408 * nfsd_setattr already committed the child (and possibly also the parent).
1411 err = nfserrno(commit_metadata(fhp));
1414 * Update the filehandle to get the new inode info.
1417 err = fh_update(resfhp);
1421 if (dchild && !IS_ERR(dchild))
1427 err = nfserrno(host_err);
1430 #endif /* CONFIG_NFSD_V3 */
1433 * Read a symlink. On entry, *lenp must contain the maximum path length that
1434 * fits into the buffer. On return, it contains the true length.
1435 * N.B. After this call fhp needs an fh_put
1438 nfsd_readlink(struct svc_rqst *rqstp, struct svc_fh *fhp, char *buf, int *lenp)
1440 struct inode *inode;
1446 err = fh_verify(rqstp, fhp, S_IFLNK, NFSD_MAY_NOP);
1450 path.mnt = fhp->fh_export->ex_path.mnt;
1451 path.dentry = fhp->fh_dentry;
1452 inode = path.dentry->d_inode;
1455 if (!inode->i_op->readlink)
1459 /* N.B. Why does this call need a get_fs()??
1460 * Remove the set_fs and watch the fireworks:-) --okir
1463 oldfs = get_fs(); set_fs(KERNEL_DS);
1464 host_err = inode->i_op->readlink(path.dentry, (char __user *)buf, *lenp);
1475 err = nfserrno(host_err);
1480 * Create a symlink and look up its inode
1481 * N.B. After this call _both_ fhp and resfhp need an fh_put
1484 nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp,
1485 char *fname, int flen,
1486 char *path, int plen,
1487 struct svc_fh *resfhp,
1490 struct dentry *dentry, *dnew;
1498 if (isdotent(fname, flen))
1501 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_CREATE);
1505 host_err = fh_want_write(fhp);
1510 dentry = fhp->fh_dentry;
1511 dnew = lookup_one_len(fname, dentry, flen);
1512 host_err = PTR_ERR(dnew);
1516 if (unlikely(path[plen] != 0)) {
1517 char *path_alloced = kmalloc(plen+1, GFP_KERNEL);
1518 if (path_alloced == NULL)
1521 strncpy(path_alloced, path, plen);
1522 path_alloced[plen] = 0;
1523 host_err = vfs_symlink(dentry->d_inode, dnew, path_alloced);
1524 kfree(path_alloced);
1527 host_err = vfs_symlink(dentry->d_inode, dnew, path);
1528 err = nfserrno(host_err);
1530 err = nfserrno(commit_metadata(fhp));
1535 cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp);
1537 if (err==0) err = cerr;
1542 err = nfserrno(host_err);
1548 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1551 nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp,
1552 char *name, int len, struct svc_fh *tfhp)
1554 struct dentry *ddir, *dnew, *dold;
1559 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_CREATE);
1562 err = fh_verify(rqstp, tfhp, 0, NFSD_MAY_NOP);
1566 if (S_ISDIR(tfhp->fh_dentry->d_inode->i_mode))
1572 if (isdotent(name, len))
1575 host_err = fh_want_write(tfhp);
1577 err = nfserrno(host_err);
1581 fh_lock_nested(ffhp, I_MUTEX_PARENT);
1582 ddir = ffhp->fh_dentry;
1583 dirp = ddir->d_inode;
1585 dnew = lookup_one_len(name, ddir, len);
1586 host_err = PTR_ERR(dnew);
1590 dold = tfhp->fh_dentry;
1595 host_err = vfs_link(dold, dirp, dnew, NULL);
1597 err = nfserrno(commit_metadata(ffhp));
1599 err = nfserrno(commit_metadata(tfhp));
1601 if (host_err == -EXDEV && rqstp->rq_vers == 2)
1604 err = nfserrno(host_err);
1610 fh_drop_write(tfhp);
1615 err = nfserrno(host_err);
1621 * N.B. After this call _both_ ffhp and tfhp need an fh_put
1624 nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
1625 struct svc_fh *tfhp, char *tname, int tlen)
1627 struct dentry *fdentry, *tdentry, *odentry, *ndentry, *trap;
1628 struct inode *fdir, *tdir;
1632 err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE);
1635 err = fh_verify(rqstp, tfhp, S_IFDIR, NFSD_MAY_CREATE);
1639 fdentry = ffhp->fh_dentry;
1640 fdir = fdentry->d_inode;
1642 tdentry = tfhp->fh_dentry;
1643 tdir = tdentry->d_inode;
1646 if (!flen || isdotent(fname, flen) || !tlen || isdotent(tname, tlen))
1649 host_err = fh_want_write(ffhp);
1651 err = nfserrno(host_err);
1655 /* cannot use fh_lock as we need deadlock protective ordering
1656 * so do it by hand */
1657 trap = lock_rename(tdentry, fdentry);
1658 ffhp->fh_locked = tfhp->fh_locked = 1;
1662 odentry = lookup_one_len(fname, fdentry, flen);
1663 host_err = PTR_ERR(odentry);
1664 if (IS_ERR(odentry))
1668 if (!odentry->d_inode)
1671 if (odentry == trap)
1674 ndentry = lookup_one_len(tname, tdentry, tlen);
1675 host_err = PTR_ERR(ndentry);
1676 if (IS_ERR(ndentry))
1678 host_err = -ENOTEMPTY;
1679 if (ndentry == trap)
1683 if (ffhp->fh_export->ex_path.mnt != tfhp->fh_export->ex_path.mnt)
1685 if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry)
1688 host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0);
1690 host_err = commit_metadata(tfhp);
1692 host_err = commit_metadata(ffhp);
1699 err = nfserrno(host_err);
1701 * We cannot rely on fh_unlock on the two filehandles,
1702 * as that would do the wrong thing if the two directories
1703 * were the same, so again we do it by hand.
1705 fill_post_wcc(ffhp);
1706 fill_post_wcc(tfhp);
1707 unlock_rename(tdentry, fdentry);
1708 ffhp->fh_locked = tfhp->fh_locked = 0;
1709 fh_drop_write(ffhp);
1716 * Unlink a file or directory
1717 * N.B. After this call fhp needs an fh_put
1720 nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type,
1721 char *fname, int flen)
1723 struct dentry *dentry, *rdentry;
1729 if (!flen || isdotent(fname, flen))
1731 err = fh_verify(rqstp, fhp, S_IFDIR, NFSD_MAY_REMOVE);
1735 host_err = fh_want_write(fhp);
1739 fh_lock_nested(fhp, I_MUTEX_PARENT);
1740 dentry = fhp->fh_dentry;
1741 dirp = dentry->d_inode;
1743 rdentry = lookup_one_len(fname, dentry, flen);
1744 host_err = PTR_ERR(rdentry);
1745 if (IS_ERR(rdentry))
1748 if (!rdentry->d_inode) {
1755 type = rdentry->d_inode->i_mode & S_IFMT;
1757 if (type != S_IFDIR)
1758 host_err = vfs_unlink(dirp, rdentry, NULL);
1760 host_err = vfs_rmdir(dirp, rdentry);
1762 host_err = commit_metadata(fhp);
1766 err = nfserrno(host_err);
1772 * We do this buffering because we must not call back into the file
1773 * system's ->lookup() method from the filldir callback. That may well
1774 * deadlock a number of file systems.
1776 * This is based heavily on the implementation of same in XFS.
1778 struct buffered_dirent {
1782 unsigned int d_type;
1786 struct readdir_data {
1787 struct dir_context ctx;
1793 static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
1794 loff_t offset, u64 ino, unsigned int d_type)
1796 struct readdir_data *buf = __buf;
1797 struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
1798 unsigned int reclen;
1800 reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
1801 if (buf->used + reclen > PAGE_SIZE) {
1806 de->namlen = namlen;
1807 de->offset = offset;
1809 de->d_type = d_type;
1810 memcpy(de->name, name, namlen);
1811 buf->used += reclen;
1816 static __be32 nfsd_buffered_readdir(struct file *file, filldir_t func,
1817 struct readdir_cd *cdp, loff_t *offsetp)
1819 struct buffered_dirent *de;
1823 struct readdir_data buf = {
1824 .ctx.actor = nfsd_buffered_filldir,
1825 .dirent = (void *)__get_free_page(GFP_KERNEL)
1829 return nfserrno(-ENOMEM);
1834 struct inode *dir_inode = file_inode(file);
1835 unsigned int reclen;
1837 cdp->err = nfserr_eof; /* will be cleared on successful read */
1841 host_err = iterate_dir(file, &buf.ctx);
1854 * Various filldir functions may end up calling back into
1855 * lookup_one_len() and the file system's ->lookup() method.
1856 * These expect i_mutex to be held, as it would within readdir.
1858 host_err = mutex_lock_killable(&dir_inode->i_mutex);
1862 de = (struct buffered_dirent *)buf.dirent;
1864 offset = de->offset;
1866 if (func(cdp, de->name, de->namlen, de->offset,
1867 de->ino, de->d_type))
1870 if (cdp->err != nfs_ok)
1873 reclen = ALIGN(sizeof(*de) + de->namlen,
1876 de = (struct buffered_dirent *)((char *)de + reclen);
1878 mutex_unlock(&dir_inode->i_mutex);
1879 if (size > 0) /* We bailed out early */
1882 offset = vfs_llseek(file, 0, SEEK_CUR);
1885 free_page((unsigned long)(buf.dirent));
1888 return nfserrno(host_err);
1895 * Read entries from a directory.
1896 * The NFSv3/4 verifier we ignore for now.
1899 nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
1900 struct readdir_cd *cdp, filldir_t func)
1904 loff_t offset = *offsetp;
1905 int may_flags = NFSD_MAY_READ;
1907 /* NFSv2 only supports 32 bit cookies */
1908 if (rqstp->rq_vers > 2)
1909 may_flags |= NFSD_MAY_64BIT_COOKIE;
1911 err = nfsd_open(rqstp, fhp, S_IFDIR, may_flags, &file);
1915 offset = vfs_llseek(file, offset, SEEK_SET);
1917 err = nfserrno((int)offset);
1921 err = nfsd_buffered_readdir(file, func, cdp, offsetp);
1923 if (err == nfserr_eof || err == nfserr_toosmall)
1924 err = nfs_ok; /* can still be found in ->err */
1932 * Get file system stats
1933 * N.B. After this call fhp needs an fh_put
1936 nfsd_statfs(struct svc_rqst *rqstp, struct svc_fh *fhp, struct kstatfs *stat, int access)
1940 err = fh_verify(rqstp, fhp, 0, NFSD_MAY_NOP | access);
1942 struct path path = {
1943 .mnt = fhp->fh_export->ex_path.mnt,
1944 .dentry = fhp->fh_dentry,
1946 if (vfs_statfs(&path, stat))
1952 static int exp_rdonly(struct svc_rqst *rqstp, struct svc_export *exp)
1954 return nfsexp_flags(rqstp, exp) & NFSEXP_READONLY;
1958 * Check for a user's access permissions to this inode.
1961 nfsd_permission(struct svc_rqst *rqstp, struct svc_export *exp,
1962 struct dentry *dentry, int acc)
1964 struct inode *inode = dentry->d_inode;
1967 if ((acc & NFSD_MAY_MASK) == NFSD_MAY_NOP)
1970 dprintk("nfsd: permission 0x%x%s%s%s%s%s%s%s mode 0%o%s%s%s\n",
1972 (acc & NFSD_MAY_READ)? " read" : "",
1973 (acc & NFSD_MAY_WRITE)? " write" : "",
1974 (acc & NFSD_MAY_EXEC)? " exec" : "",
1975 (acc & NFSD_MAY_SATTR)? " sattr" : "",
1976 (acc & NFSD_MAY_TRUNC)? " trunc" : "",
1977 (acc & NFSD_MAY_LOCK)? " lock" : "",
1978 (acc & NFSD_MAY_OWNER_OVERRIDE)? " owneroverride" : "",
1980 IS_IMMUTABLE(inode)? " immut" : "",
1981 IS_APPEND(inode)? " append" : "",
1982 __mnt_is_readonly(exp->ex_path.mnt)? " ro" : "");
1983 dprintk(" owner %d/%d user %d/%d\n",
1984 inode->i_uid, inode->i_gid, current_fsuid(), current_fsgid());
1987 /* Normally we reject any write/sattr etc access on a read-only file
1988 * system. But if it is IRIX doing check on write-access for a
1989 * device special file, we ignore rofs.
1991 if (!(acc & NFSD_MAY_LOCAL_ACCESS))
1992 if (acc & (NFSD_MAY_WRITE | NFSD_MAY_SATTR | NFSD_MAY_TRUNC)) {
1993 if (exp_rdonly(rqstp, exp) ||
1994 __mnt_is_readonly(exp->ex_path.mnt))
1996 if (/* (acc & NFSD_MAY_WRITE) && */ IS_IMMUTABLE(inode))
1999 if ((acc & NFSD_MAY_TRUNC) && IS_APPEND(inode))
2002 if (acc & NFSD_MAY_LOCK) {
2003 /* If we cannot rely on authentication in NLM requests,
2004 * just allow locks, otherwise require read permission, or
2007 if (exp->ex_flags & NFSEXP_NOAUTHNLM)
2010 acc = NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE;
2013 * The file owner always gets access permission for accesses that
2014 * would normally be checked at open time. This is to make
2015 * file access work even when the client has done a fchmod(fd, 0).
2017 * However, `cp foo bar' should fail nevertheless when bar is
2018 * readonly. A sensible way to do this might be to reject all
2019 * attempts to truncate a read-only file, because a creat() call
2020 * always implies file truncation.
2021 * ... but this isn't really fair. A process may reasonably call
2022 * ftruncate on an open file descriptor on a file with perm 000.
2023 * We must trust the client to do permission checking - using "ACCESS"
2026 if ((acc & NFSD_MAY_OWNER_OVERRIDE) &&
2027 uid_eq(inode->i_uid, current_fsuid()))
2030 /* This assumes NFSD_MAY_{READ,WRITE,EXEC} == MAY_{READ,WRITE,EXEC} */
2031 err = inode_permission(inode, acc & (MAY_READ|MAY_WRITE|MAY_EXEC));
2033 /* Allow read access to binaries even when mode 111 */
2034 if (err == -EACCES && S_ISREG(inode->i_mode) &&
2035 (acc == (NFSD_MAY_READ | NFSD_MAY_OWNER_OVERRIDE) ||
2036 acc == (NFSD_MAY_READ | NFSD_MAY_READ_IF_EXEC)))
2037 err = inode_permission(inode, MAY_EXEC);
2039 return err? nfserrno(err) : 0;
2043 nfsd_racache_shutdown(void)
2045 struct raparms *raparm, *last_raparm;
2048 dprintk("nfsd: freeing readahead buffers.\n");
2050 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2051 raparm = raparm_hash[i].pb_head;
2053 last_raparm = raparm;
2054 raparm = raparm->p_next;
2057 raparm_hash[i].pb_head = NULL;
2061 * Initialize readahead param cache
2064 nfsd_racache_init(int cache_size)
2069 struct raparms **raparm = NULL;
2072 if (raparm_hash[0].pb_head)
2074 nperbucket = DIV_ROUND_UP(cache_size, RAPARM_HASH_SIZE);
2077 cache_size = nperbucket * RAPARM_HASH_SIZE;
2079 dprintk("nfsd: allocating %d readahead buffers.\n", cache_size);
2081 for (i = 0; i < RAPARM_HASH_SIZE; i++) {
2082 spin_lock_init(&raparm_hash[i].pb_lock);
2084 raparm = &raparm_hash[i].pb_head;
2085 for (j = 0; j < nperbucket; j++) {
2086 *raparm = kzalloc(sizeof(struct raparms), GFP_KERNEL);
2089 raparm = &(*raparm)->p_next;
2094 nfsdstats.ra_size = cache_size;
2098 dprintk("nfsd: kmalloc failed, freeing readahead buffers\n");
2099 nfsd_racache_shutdown();