Patrick Welche <prlw1@cam.ac.uk>
[netbsd-mini2440.git] / external / cddl / osnet / dist / uts / common / fs / gfs.c
blob4d24df60f75b1f92f3d870925504465a3698d002
1 /*
2 * CDDL HEADER START
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
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21 /* Portions Copyright 2007 Shivakumar GN */
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
27 #pragma ident "%Z%%M% %I% %E% SMI"
29 #include <sys/types.h>
30 #include <sys/cmn_err.h>
31 #include <sys/debug.h>
32 #include <sys/dirent.h>
33 #include <sys/kmem.h>
34 #include <sys/mman.h>
35 #include <sys/mutex.h>
36 #include <sys/sysmacros.h>
37 #include <sys/systm.h>
38 #include <sys/sunddi.h>
39 #include <sys/uio.h>
40 #include <sys/vmsystm.h>
41 #include <sys/vfs.h>
42 #include <sys/vnode.h>
44 #include <vm/as.h>
45 #include <vm/seg_vn.h>
47 #include <sys/gfs.h>
50 * Generic pseudo-filesystem routines.
52 * There are significant similarities between the implementation of certain file
53 * system entry points across different filesystems. While one could attempt to
54 * "choke up on the bat" and incorporate common functionality into a VOP
55 * preamble or postamble, such an approach is limited in the benefit it can
56 * provide. In this file we instead define a toolkit of routines which can be
57 * called from a filesystem (with in-kernel pseudo-filesystems being the focus
58 * of the exercise) in a more component-like fashion.
60 * There are three basic classes of routines:
62 * 1) Lowlevel support routines
64 * These routines are designed to play a support role for existing
65 * pseudo-filesystems (such as procfs). They simplify common tasks,
66 * without forcing the filesystem to hand over management to GFS. The
67 * routines covered are:
69 * gfs_readdir_init()
70 * gfs_readdir_emit()
71 * gfs_readdir_emitn()
72 * gfs_readdir_pred()
73 * gfs_readdir_fini()
74 * gfs_lookup_dot()
76 * 2) Complete GFS management
78 * These routines take a more active role in management of the
79 * pseudo-filesystem. They handle the relationship between vnode private
80 * data and VFS data, as well as the relationship between vnodes in the
81 * directory hierarchy.
83 * In order to use these interfaces, the first member of every private
84 * v_data must be a gfs_file_t or a gfs_dir_t. This hands over all control
85 * to GFS.
87 * gfs_file_create()
88 * gfs_dir_create()
89 * gfs_root_create()
91 * gfs_file_inactive()
92 * gfs_dir_inactive()
93 * gfs_dir_lookup()
94 * gfs_dir_readdir()
96 * gfs_vop_inactive()
97 * gfs_vop_lookup()
98 * gfs_vop_readdir()
99 * gfs_vop_map()
101 * 3) Single File pseudo-filesystems
103 * This routine creates a rooted file to be overlayed ontop of another
104 * file in the physical filespace.
106 * Note that the parent is NULL (actually the vfs), but there is nothing
107 * technically keeping such a file from utilizing the "Complete GFS
108 * management" set of routines.
110 * gfs_root_create_file()
114 * gfs_make_opsvec: take an array of vnode type definitions and create
115 * their vnodeops_t structures
117 * This routine takes an array of gfs_opsvec_t's. It could
118 * alternatively take an array of gfs_opsvec_t*'s, which would allow
119 * vnode types to be completely defined in files external to the caller
120 * of gfs_make_opsvec(). As it stands, much more sharing takes place --
121 * both the caller and the vnode type provider need to access gfsv_ops
122 * and gfsv_template, and the caller also needs to know gfsv_name.
125 gfs_make_opsvec(gfs_opsvec_t *vec)
127 int error, i;
129 for (i = 0; ; i++) {
130 if (vec[i].gfsv_name == NULL)
131 return (0);
132 error = vn_make_ops(vec[i].gfsv_name, vec[i].gfsv_template,
133 vec[i].gfsv_ops);
134 if (error)
135 break;
138 cmn_err(CE_WARN, "gfs_make_opsvec: bad vnode ops template for '%s'",
139 vec[i].gfsv_name);
140 for (i--; i >= 0; i--) {
141 vn_freevnodeops(*vec[i].gfsv_ops);
142 *vec[i].gfsv_ops = NULL;
144 return (error);
148 * Low level directory routines
150 * These routines provide some simple abstractions for reading directories.
151 * They are designed to be used by existing pseudo filesystems (namely procfs)
152 * that already have a complicated management infrastructure.
156 * gfs_get_parent_ino: used to obtain a parent inode number and the
157 * inode number of the given vnode in preparation for calling gfs_readdir_init.
160 gfs_get_parent_ino(vnode_t *dvp, cred_t *cr, caller_context_t *ct,
161 ino64_t *pino, ino64_t *ino)
163 vnode_t *parent;
164 gfs_dir_t *dp = dvp->v_data;
165 int error;
167 *ino = dp->gfsd_file.gfs_ino;
168 parent = dp->gfsd_file.gfs_parent;
170 if (parent == NULL) {
171 *pino = *ino; /* root of filesystem */
172 } else if (dvp->v_flag & V_XATTRDIR) {
173 vattr_t va;
175 va.va_mask = AT_NODEID;
176 error = VOP_GETATTR(parent, &va, 0, cr, ct);
177 if (error)
178 return (error);
179 *pino = va.va_nodeid;
180 } else {
181 *pino = ((gfs_file_t *)(parent->v_data))->gfs_ino;
184 return (0);
188 * gfs_readdir_init: initiate a generic readdir
189 * st - a pointer to an uninitialized gfs_readdir_state_t structure
190 * name_max - the directory's maximum file name length
191 * ureclen - the exported file-space record length (1 for non-legacy FSs)
192 * uiop - the uiop passed to readdir
193 * parent - the parent directory's inode
194 * self - this directory's inode
195 * flags - flags from VOP_READDIR
197 * Returns 0 or a non-zero errno.
199 * Typical VOP_READDIR usage of gfs_readdir_*:
201 * if ((error = gfs_readdir_init(...)) != 0)
202 * return (error);
203 * eof = 0;
204 * while ((error = gfs_readdir_pred(..., &voffset)) != 0) {
205 * if (!consumer_entry_at(voffset))
206 * voffset = consumer_next_entry(voffset);
207 * if (consumer_eof(voffset)) {
208 * eof = 1
209 * break;
211 * if ((error = gfs_readdir_emit(..., voffset,
212 * consumer_ino(voffset), consumer_name(voffset))) != 0)
213 * break;
215 * return (gfs_readdir_fini(..., error, eofp, eof));
217 * As you can see, a zero result from gfs_readdir_pred() or
218 * gfs_readdir_emit() indicates that processing should continue,
219 * whereas a non-zero result indicates that the loop should terminate.
220 * Most consumers need do nothing more than let gfs_readdir_fini()
221 * determine what the cause of failure was and return the appropriate
222 * value.
225 gfs_readdir_init(gfs_readdir_state_t *st, int name_max, int ureclen,
226 uio_t *uiop, ino64_t parent, ino64_t self, int flags)
228 size_t dirent_size;
230 if (uiop->uio_loffset < 0 || uiop->uio_resid <= 0 ||
231 (uiop->uio_loffset % ureclen) != 0)
232 return (EINVAL);
234 st->grd_ureclen = ureclen;
235 st->grd_oresid = uiop->uio_resid;
236 st->grd_namlen = name_max;
237 if (flags & V_RDDIR_ENTFLAGS)
238 dirent_size = EDIRENT_RECLEN(st->grd_namlen);
239 else
240 dirent_size = DIRENT64_RECLEN(st->grd_namlen);
241 st->grd_dirent = kmem_zalloc(dirent_size, KM_SLEEP);
242 st->grd_parent = parent;
243 st->grd_self = self;
244 st->grd_flags = flags;
246 return (0);
250 * gfs_readdir_emit_int: internal routine to emit directory entry
252 * st - the current readdir state, which must have d_ino/ed_ino
253 * and d_name/ed_name set
254 * uiop - caller-supplied uio pointer
255 * next - the offset of the next entry
257 static int
258 gfs_readdir_emit_int(gfs_readdir_state_t *st, uio_t *uiop, offset_t next)
260 int reclen;
261 dirent64_t *dp;
262 edirent_t *edp;
264 if (st->grd_flags & V_RDDIR_ENTFLAGS) {
265 edp = st->grd_dirent;
266 reclen = EDIRENT_RECLEN(strlen(edp->ed_name));
267 } else {
268 dp = st->grd_dirent;
269 reclen = DIRENT64_RECLEN(strlen(dp->d_name));
272 if (reclen > uiop->uio_resid) {
274 * Error if no entries were returned yet
276 if (uiop->uio_resid == st->grd_oresid)
277 return (EINVAL);
278 return (-1);
281 if (st->grd_flags & V_RDDIR_ENTFLAGS) {
282 edp->ed_off = next;
283 edp->ed_reclen = (ushort_t)reclen;
284 } else {
285 dp->d_off = next;
286 dp->d_reclen = (ushort_t)reclen;
289 if (uiomove((caddr_t)st->grd_dirent, reclen, UIO_READ, uiop))
290 return (EFAULT);
292 uiop->uio_loffset = next;
294 return (0);
298 * gfs_readdir_emit: emit a directory entry
299 * voff - the virtual offset (obtained from gfs_readdir_pred)
300 * ino - the entry's inode
301 * name - the entry's name
302 * eflags - value for ed_eflags (if processing edirent_t)
304 * Returns a 0 on success, a non-zero errno on failure, or -1 if the
305 * readdir loop should terminate. A non-zero result (either errno or
306 * -1) from this function is typically passed directly to
307 * gfs_readdir_fini().
310 gfs_readdir_emit(gfs_readdir_state_t *st, uio_t *uiop, offset_t voff,
311 ino64_t ino, const char *name, int eflags)
313 offset_t off = (voff + 2) * st->grd_ureclen;
315 if (st->grd_flags & V_RDDIR_ENTFLAGS) {
316 edirent_t *edp = st->grd_dirent;
318 edp->ed_ino = ino;
319 (void) strncpy(edp->ed_name, name, st->grd_namlen);
320 edp->ed_eflags = eflags;
321 } else {
322 dirent64_t *dp = st->grd_dirent;
324 dp->d_ino = ino;
325 (void) strncpy(dp->d_name, name, st->grd_namlen);
329 * Inter-entry offsets are invalid, so we assume a record size of
330 * grd_ureclen and explicitly set the offset appropriately.
332 return (gfs_readdir_emit_int(st, uiop, off + st->grd_ureclen));
336 * gfs_readdir_emitn: like gfs_readdir_emit(), but takes an integer
337 * instead of a string for the entry's name.
340 gfs_readdir_emitn(gfs_readdir_state_t *st, uio_t *uiop, offset_t voff,
341 ino64_t ino, unsigned long num)
343 char buf[40];
345 numtos(num, buf);
346 return (gfs_readdir_emit(st, uiop, voff, ino, buf, 0));
350 * gfs_readdir_pred: readdir loop predicate
351 * voffp - a pointer in which the next virtual offset should be stored
353 * Returns a 0 on success, a non-zero errno on failure, or -1 if the
354 * readdir loop should terminate. A non-zero result (either errno or
355 * -1) from this function is typically passed directly to
356 * gfs_readdir_fini().
359 gfs_readdir_pred(gfs_readdir_state_t *st, uio_t *uiop, offset_t *voffp)
361 offset_t off, voff;
362 int error;
364 top:
365 if (uiop->uio_resid <= 0)
366 return (-1);
368 off = uiop->uio_loffset / st->grd_ureclen;
369 voff = off - 2;
370 if (off == 0) {
371 if ((error = gfs_readdir_emit(st, uiop, voff, st->grd_self,
372 ".", 0)) == 0)
373 goto top;
374 } else if (off == 1) {
375 if ((error = gfs_readdir_emit(st, uiop, voff, st->grd_parent,
376 "..", 0)) == 0)
377 goto top;
378 } else {
379 *voffp = voff;
380 return (0);
383 return (error);
387 * gfs_readdir_fini: generic readdir cleanup
388 * error - if positive, an error to return
389 * eofp - the eofp passed to readdir
390 * eof - the eof value
392 * Returns a 0 on success, a non-zero errno on failure. This result
393 * should be returned from readdir.
396 gfs_readdir_fini(gfs_readdir_state_t *st, int error, int *eofp, int eof)
398 size_t dirent_size;
400 if (st->grd_flags & V_RDDIR_ENTFLAGS)
401 dirent_size = EDIRENT_RECLEN(st->grd_namlen);
402 else
403 dirent_size = DIRENT64_RECLEN(st->grd_namlen);
404 kmem_free(st->grd_dirent, dirent_size);
405 if (error > 0)
406 return (error);
407 if (eofp)
408 *eofp = eof;
409 return (0);
413 * gfs_lookup_dot
415 * Performs a basic check for "." and ".." directory entries.
418 gfs_lookup_dot(vnode_t **vpp, vnode_t *dvp, vnode_t *pvp, const char *nm)
420 if (*nm == '\0' || strcmp(nm, ".") == 0) {
421 VN_HOLD(dvp);
422 *vpp = dvp;
423 return (0);
424 } else if (strcmp(nm, "..") == 0) {
425 if (pvp == NULL) {
426 ASSERT(dvp->v_flag & VROOT);
427 VN_HOLD(dvp);
428 *vpp = dvp;
429 } else {
430 VN_HOLD(pvp);
431 *vpp = pvp;
433 return (0);
436 return (-1);
440 * gfs_file_create(): create a new GFS file
442 * size - size of private data structure (v_data)
443 * pvp - parent vnode (GFS directory)
444 * ops - vnode operations vector
446 * In order to use this interface, the parent vnode must have been created by
447 * gfs_dir_create(), and the private data stored in v_data must have a
448 * 'gfs_file_t' as its first field.
450 * Given these constraints, this routine will automatically:
452 * - Allocate v_data for the vnode
453 * - Initialize necessary fields in the vnode
454 * - Hold the parent
456 vnode_t *
457 gfs_file_create(size_t size, vnode_t *pvp, vnodeops_t *ops)
459 gfs_file_t *fp;
460 vnode_t *vp;
463 * Allocate vnode and internal data structure
465 fp = kmem_zalloc(size, KM_SLEEP);
466 vp = vn_alloc(KM_SLEEP);
469 * Set up various pointers
471 fp->gfs_vnode = vp;
472 fp->gfs_parent = pvp;
473 vp->v_data = fp;
474 fp->gfs_size = size;
475 fp->gfs_type = GFS_FILE;
478 * Initialize vnode and hold parent.
480 vn_setops(vp, ops);
481 if (pvp) {
482 VN_SET_VFS_TYPE_DEV(vp, pvp->v_vfsp, VREG, 0);
483 VN_HOLD(pvp);
486 return (vp);
490 * gfs_dir_create: creates a new directory in the parent
492 * size - size of private data structure (v_data)
493 * pvp - parent vnode (GFS directory)
494 * ops - vnode operations vector
495 * entries - NULL-terminated list of static entries (if any)
496 * maxlen - maximum length of a directory entry
497 * readdir_cb - readdir callback (see gfs_dir_readdir)
498 * inode_cb - inode callback (see gfs_dir_readdir)
499 * lookup_cb - lookup callback (see gfs_dir_lookup)
501 * In order to use this function, the first member of the private vnode
502 * structure (v_data) must be a gfs_dir_t. For each directory, there are
503 * static entries, defined when the structure is initialized, and dynamic
504 * entries, retrieved through callbacks.
506 * If a directory has static entries, then it must supply a inode callback,
507 * which will compute the inode number based on the parent and the index.
508 * For a directory with dynamic entries, the caller must supply a readdir
509 * callback and a lookup callback. If a static lookup fails, we fall back to
510 * the supplied lookup callback, if any.
512 * This function also performs the same initialization as gfs_file_create().
514 vnode_t *
515 gfs_dir_create(size_t struct_size, vnode_t *pvp, vnodeops_t *ops,
516 gfs_dirent_t *entries, gfs_inode_cb inode_cb, int maxlen,
517 gfs_readdir_cb readdir_cb, gfs_lookup_cb lookup_cb)
519 vnode_t *vp;
520 gfs_dir_t *dp;
521 gfs_dirent_t *de;
523 vp = gfs_file_create(struct_size, pvp, ops);
524 vp->v_type = VDIR;
526 dp = vp->v_data;
527 dp->gfsd_file.gfs_type = GFS_DIR;
528 dp->gfsd_maxlen = maxlen;
530 if (entries != NULL) {
531 for (de = entries; de->gfse_name != NULL; de++)
532 dp->gfsd_nstatic++;
534 dp->gfsd_static = kmem_alloc(
535 dp->gfsd_nstatic * sizeof (gfs_dirent_t), KM_SLEEP);
536 bcopy(entries, dp->gfsd_static,
537 dp->gfsd_nstatic * sizeof (gfs_dirent_t));
540 dp->gfsd_readdir = readdir_cb;
541 dp->gfsd_lookup = lookup_cb;
542 dp->gfsd_inode = inode_cb;
544 mutex_init(&dp->gfsd_lock, NULL, MUTEX_DEFAULT, NULL);
546 return (vp);
550 * gfs_root_create(): create a root vnode for a GFS filesystem
552 * Similar to gfs_dir_create(), this creates a root vnode for a filesystem. The
553 * only difference is that it takes a vfs_t instead of a vnode_t as its parent.
555 vnode_t *
556 gfs_root_create(size_t size, vfs_t *vfsp, vnodeops_t *ops, ino64_t ino,
557 gfs_dirent_t *entries, gfs_inode_cb inode_cb, int maxlen,
558 gfs_readdir_cb readdir_cb, gfs_lookup_cb lookup_cb)
560 vnode_t *vp = gfs_dir_create(size, NULL, ops, entries, inode_cb,
561 maxlen, readdir_cb, lookup_cb);
563 /* Manually set the inode */
564 ((gfs_file_t *)vp->v_data)->gfs_ino = ino;
566 VFS_HOLD(vfsp);
567 VN_SET_VFS_TYPE_DEV(vp, vfsp, VDIR, 0);
568 vp->v_flag |= VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT;
570 return (vp);
574 * gfs_root_create_file(): create a root vnode for a GFS file as a filesystem
576 * Similar to gfs_root_create(), this creates a root vnode for a file to
577 * be the pseudo-filesystem.
579 vnode_t *
580 gfs_root_create_file(size_t size, vfs_t *vfsp, vnodeops_t *ops, ino64_t ino)
582 vnode_t *vp = gfs_file_create(size, NULL, ops);
584 ((gfs_file_t *)vp->v_data)->gfs_ino = ino;
586 VFS_HOLD(vfsp);
587 VN_SET_VFS_TYPE_DEV(vp, vfsp, VREG, 0);
588 vp->v_flag |= VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT;
590 return (vp);
594 * gfs_file_inactive()
596 * Called from the VOP_INACTIVE() routine. If necessary, this routine will
597 * remove the given vnode from the parent directory and clean up any references
598 * in the VFS layer.
600 * If the vnode was not removed (due to a race with vget), then NULL is
601 * returned. Otherwise, a pointer to the private data is returned.
603 void *
604 gfs_file_inactive(vnode_t *vp)
606 int i;
607 gfs_dirent_t *ge = NULL;
608 gfs_file_t *fp = vp->v_data;
609 gfs_dir_t *dp = NULL;
610 void *data;
612 if (fp->gfs_parent == NULL || (vp->v_flag & V_XATTRDIR))
613 goto found;
615 dp = fp->gfs_parent->v_data;
618 * First, see if this vnode is cached in the parent.
620 gfs_dir_lock(dp);
623 * Find it in the set of static entries.
625 for (i = 0; i < dp->gfsd_nstatic; i++) {
626 ge = &dp->gfsd_static[i];
628 if (ge->gfse_vnode == vp)
629 goto found;
633 * If 'ge' is NULL, then it is a dynamic entry.
635 ge = NULL;
637 found:
638 if (vp->v_flag & V_XATTRDIR) {
639 mutex_enter(&fp->gfs_parent->v_lock);
641 mutex_enter(&vp->v_lock);
642 if (vp->v_count == 1) {
644 * Really remove this vnode
646 data = vp->v_data;
647 if (ge != NULL) {
649 * If this was a statically cached entry, simply set the
650 * cached vnode to NULL.
652 ge->gfse_vnode = NULL;
654 if (vp->v_flag & V_XATTRDIR) {
655 fp->gfs_parent->v_xattrdir = NULL;
656 mutex_exit(&fp->gfs_parent->v_lock);
658 mutex_exit(&vp->v_lock);
661 * Free vnode and release parent
663 if (fp->gfs_parent) {
664 if (dp) {
665 gfs_dir_unlock(dp);
667 VN_RELE(fp->gfs_parent);
668 } else {
669 ASSERT(vp->v_vfsp != NULL);
670 VFS_RELE(vp->v_vfsp);
672 vn_free(vp);
673 } else {
674 vp->v_count--;
675 data = NULL;
676 mutex_exit(&vp->v_lock);
677 if (vp->v_flag & V_XATTRDIR) {
678 mutex_exit(&fp->gfs_parent->v_lock);
680 if (dp)
681 gfs_dir_unlock(dp);
684 return (data);
688 * gfs_dir_inactive()
690 * Same as above, but for directories.
692 void *
693 gfs_dir_inactive(vnode_t *vp)
695 gfs_dir_t *dp;
697 ASSERT(vp->v_type == VDIR);
699 if ((dp = gfs_file_inactive(vp)) != NULL) {
700 mutex_destroy(&dp->gfsd_lock);
701 if (dp->gfsd_nstatic)
702 kmem_free(dp->gfsd_static,
703 dp->gfsd_nstatic * sizeof (gfs_dirent_t));
706 return (dp);
710 * gfs_dir_lookup_dynamic()
712 * This routine looks up the provided name amongst the dynamic entries
713 * in the gfs directory and returns the corresponding vnode, if found.
715 * The gfs directory is expected to be locked by the caller prior to
716 * calling this function. The directory will be unlocked during the
717 * execution of this function, but will be locked upon return from the
718 * function. This function returns 0 on success, non-zero on error.
720 * The dynamic lookups are performed by invoking the lookup
721 * callback, which is passed to this function as the first argument.
722 * The arguments to the callback are:
724 * int gfs_lookup_cb(vnode_t *pvp, const char *nm, vnode_t **vpp, cred_t *cr,
725 * int flags, int *deflgs, pathname_t *rpnp);
727 * pvp - parent vnode
728 * nm - name of entry
729 * vpp - pointer to resulting vnode
730 * cr - pointer to cred
731 * flags - flags value from lookup request
732 * ignored here; currently only used to request
733 * insensitive lookups
734 * direntflgs - output parameter, directory entry flags
735 * ignored here; currently only used to indicate a lookup
736 * has more than one possible match when case is not considered
737 * realpnp - output parameter, real pathname
738 * ignored here; when lookup was performed case-insensitively,
739 * this field contains the "real" name of the file.
741 * Returns 0 on success, non-zero on error.
743 static int
744 gfs_dir_lookup_dynamic(gfs_lookup_cb callback, gfs_dir_t *dp,
745 const char *nm, vnode_t *dvp, vnode_t **vpp, cred_t *cr, int flags,
746 int *direntflags, pathname_t *realpnp)
748 gfs_file_t *fp;
749 ino64_t ino;
750 int ret;
752 ASSERT(GFS_DIR_LOCKED(dp));
755 * Drop the directory lock, as the lookup routine
756 * will need to allocate memory, or otherwise deadlock on this
757 * directory.
759 gfs_dir_unlock(dp);
760 ret = callback(dvp, nm, vpp, &ino, cr, flags, direntflags, realpnp);
761 gfs_dir_lock(dp);
764 * The callback for extended attributes returns a vnode
765 * with v_data from an underlying fs.
767 if (ret == 0 && !IS_XATTRDIR(dvp)) {
768 fp = (gfs_file_t *)((*vpp)->v_data);
769 fp->gfs_index = -1;
770 fp->gfs_ino = ino;
773 return (ret);
777 * gfs_dir_lookup_static()
779 * This routine looks up the provided name amongst the static entries
780 * in the gfs directory and returns the corresponding vnode, if found.
781 * The first argument to the function is a pointer to the comparison
782 * function this function should use to decide if names are a match.
784 * If a match is found, and GFS_CACHE_VNODE is set and the vnode
785 * exists, we simply return the existing vnode. Otherwise, we call
786 * the static entry's callback routine, caching the result if
787 * necessary. If the idx pointer argument is non-NULL, we use it to
788 * return the index of the matching static entry.
790 * The gfs directory is expected to be locked by the caller prior to calling
791 * this function. The directory may be unlocked during the execution of
792 * this function, but will be locked upon return from the function.
794 * This function returns 0 if a match is found, ENOENT if not.
796 static int
797 gfs_dir_lookup_static(int (*compare)(const char *, const char *),
798 gfs_dir_t *dp, const char *nm, vnode_t *dvp, int *idx,
799 vnode_t **vpp, pathname_t *rpnp)
801 gfs_dirent_t *ge;
802 vnode_t *vp = NULL;
803 int i;
805 ASSERT(GFS_DIR_LOCKED(dp));
808 * Search static entries.
810 for (i = 0; i < dp->gfsd_nstatic; i++) {
811 ge = &dp->gfsd_static[i];
813 if (compare(ge->gfse_name, nm) == 0) {
814 if (rpnp)
815 (void) strlcpy(rpnp->pn_buf, ge->gfse_name,
816 rpnp->pn_bufsize);
818 if (ge->gfse_vnode) {
819 ASSERT(ge->gfse_flags & GFS_CACHE_VNODE);
820 vp = ge->gfse_vnode;
821 VN_HOLD(vp);
822 break;
826 * We drop the directory lock, as the constructor will
827 * need to do KM_SLEEP allocations. If we return from
828 * the constructor only to find that a parallel
829 * operation has completed, and GFS_CACHE_VNODE is set
830 * for this entry, we discard the result in favor of
831 * the cached vnode.
833 gfs_dir_unlock(dp);
834 vp = ge->gfse_ctor(dvp);
835 gfs_dir_lock(dp);
837 ((gfs_file_t *)vp->v_data)->gfs_index = i;
839 /* Set the inode according to the callback. */
840 ((gfs_file_t *)vp->v_data)->gfs_ino =
841 dp->gfsd_inode(dvp, i);
843 if (ge->gfse_flags & GFS_CACHE_VNODE) {
844 if (ge->gfse_vnode == NULL) {
845 ge->gfse_vnode = vp;
846 } else {
848 * A parallel constructor beat us to it;
849 * return existing vnode. We have to be
850 * careful because we can't release the
851 * current vnode while holding the
852 * directory lock; its inactive routine
853 * will try to lock this directory.
855 vnode_t *oldvp = vp;
856 vp = ge->gfse_vnode;
857 VN_HOLD(vp);
859 gfs_dir_unlock(dp);
860 VN_RELE(oldvp);
861 gfs_dir_lock(dp);
864 break;
868 if (vp == NULL)
869 return (ENOENT);
870 else if (idx)
871 *idx = i;
872 *vpp = vp;
873 return (0);
877 * gfs_dir_lookup()
879 * Looks up the given name in the directory and returns the corresponding
880 * vnode, if found.
882 * First, we search statically defined entries, if any, with a call to
883 * gfs_dir_lookup_static(). If no static entry is found, and we have
884 * a callback function we try a dynamic lookup via gfs_dir_lookup_dynamic().
886 * This function returns 0 on success, non-zero on error.
889 gfs_dir_lookup(vnode_t *dvp, const char *nm, vnode_t **vpp, cred_t *cr,
890 int flags, int *direntflags, pathname_t *realpnp)
892 gfs_dir_t *dp = dvp->v_data;
893 boolean_t casecheck;
894 vnode_t *dynvp = NULL;
895 vnode_t *vp = NULL;
896 int (*compare)(const char *, const char *);
897 int error, idx;
899 ASSERT(dvp->v_type == VDIR);
901 if (gfs_lookup_dot(vpp, dvp, dp->gfsd_file.gfs_parent, nm) == 0)
902 return (0);
904 casecheck = (flags & FIGNORECASE) != 0 && direntflags != NULL;
905 if (vfs_has_feature(dvp->v_vfsp, VFSFT_NOCASESENSITIVE) ||
906 (flags & FIGNORECASE))
907 compare = strcasecmp;
908 else
909 compare = strcmp;
911 gfs_dir_lock(dp);
913 error = gfs_dir_lookup_static(compare, dp, nm, dvp, &idx, &vp, realpnp);
915 if (vp && casecheck) {
916 gfs_dirent_t *ge;
917 int i;
919 for (i = idx + 1; i < dp->gfsd_nstatic; i++) {
920 ge = &dp->gfsd_static[i];
922 if (strcasecmp(ge->gfse_name, nm) == 0) {
923 *direntflags |= ED_CASE_CONFLICT;
924 goto out;
929 if ((error || casecheck) && dp->gfsd_lookup)
930 error = gfs_dir_lookup_dynamic(dp->gfsd_lookup, dp, nm, dvp,
931 &dynvp, cr, flags, direntflags, vp ? NULL : realpnp);
933 if (vp && dynvp) {
934 /* static and dynamic entries are case-insensitive conflict */
935 ASSERT(casecheck);
936 *direntflags |= ED_CASE_CONFLICT;
937 VN_RELE(dynvp);
938 } else if (vp == NULL) {
939 vp = dynvp;
940 } else if (error == ENOENT) {
941 error = 0;
942 } else if (error) {
943 VN_RELE(vp);
944 vp = NULL;
947 out:
948 gfs_dir_unlock(dp);
950 *vpp = vp;
951 return (error);
955 * gfs_dir_readdir: does a readdir() on the given directory
957 * dvp - directory vnode
958 * uiop - uio structure
959 * eofp - eof pointer
960 * data - arbitrary data passed to readdir callback
962 * This routine does all the readdir() dirty work. Even so, the caller must
963 * supply two callbacks in order to get full compatibility.
965 * If the directory contains static entries, an inode callback must be
966 * specified. This avoids having to create every vnode and call VOP_GETATTR()
967 * when reading the directory. This function has the following arguments:
969 * ino_t gfs_inode_cb(vnode_t *vp, int index);
971 * vp - vnode for the directory
972 * index - index in original gfs_dirent_t array
974 * Returns the inode number for the given entry.
976 * For directories with dynamic entries, a readdir callback must be provided.
977 * This is significantly more complex, thanks to the particulars of
978 * VOP_READDIR().
980 * int gfs_readdir_cb(vnode_t *vp, void *dp, int *eofp,
981 * offset_t *off, offset_t *nextoff, void *data, int flags)
983 * vp - directory vnode
984 * dp - directory entry, sized according to maxlen given to
985 * gfs_dir_create(). callback must fill in d_name and
986 * d_ino (if a dirent64_t), or ed_name, ed_ino, and ed_eflags
987 * (if an edirent_t). edirent_t is used if V_RDDIR_ENTFLAGS
988 * is set in 'flags'.
989 * eofp - callback must set to 1 when EOF has been reached
990 * off - on entry, the last offset read from the directory. Callback
991 * must set to the offset of the current entry, typically left
992 * untouched.
993 * nextoff - callback must set to offset of next entry. Typically
994 * (off + 1)
995 * data - caller-supplied data
996 * flags - VOP_READDIR flags
998 * Return 0 on success, or error on failure.
1001 gfs_dir_readdir(vnode_t *dvp, uio_t *uiop, int *eofp, void *data, cred_t *cr,
1002 caller_context_t *ct, int flags)
1004 gfs_readdir_state_t gstate;
1005 int error, eof = 0;
1006 ino64_t ino, pino;
1007 offset_t off, next;
1008 gfs_dir_t *dp = dvp->v_data;
1010 error = gfs_get_parent_ino(dvp, cr, ct, &pino, &ino);
1011 if (error)
1012 return (error);
1014 if ((error = gfs_readdir_init(&gstate, dp->gfsd_maxlen, 1, uiop,
1015 pino, ino, flags)) != 0)
1016 return (error);
1018 while ((error = gfs_readdir_pred(&gstate, uiop, &off)) == 0 &&
1019 !eof) {
1021 if (off >= 0 && off < dp->gfsd_nstatic) {
1022 ino = dp->gfsd_inode(dvp, off);
1024 if ((error = gfs_readdir_emit(&gstate, uiop,
1025 off, ino, dp->gfsd_static[off].gfse_name, 0))
1026 != 0)
1027 break;
1029 } else if (dp->gfsd_readdir) {
1030 off -= dp->gfsd_nstatic;
1032 if ((error = dp->gfsd_readdir(dvp,
1033 gstate.grd_dirent, &eof, &off, &next,
1034 data, flags)) != 0 || eof)
1035 break;
1037 off += dp->gfsd_nstatic + 2;
1038 next += dp->gfsd_nstatic + 2;
1040 if ((error = gfs_readdir_emit_int(&gstate, uiop,
1041 next)) != 0)
1042 break;
1043 } else {
1045 * Offset is beyond the end of the static entries, and
1046 * we have no dynamic entries. Set EOF.
1048 eof = 1;
1052 return (gfs_readdir_fini(&gstate, error, eofp, eof));
1057 * gfs_vop_lookup: VOP_LOOKUP() entry point
1059 * For use directly in vnode ops table. Given a GFS directory, calls
1060 * gfs_dir_lookup() as necessary.
1062 /* ARGSUSED */
1064 gfs_vop_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp,
1065 int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct,
1066 int *direntflags, pathname_t *realpnp)
1068 return (gfs_dir_lookup(dvp, nm, vpp, cr, flags, direntflags, realpnp));
1072 * gfs_vop_readdir: VOP_READDIR() entry point
1074 * For use directly in vnode ops table. Given a GFS directory, calls
1075 * gfs_dir_readdir() as necessary.
1077 /* ARGSUSED */
1079 gfs_vop_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
1080 caller_context_t *ct, int flags)
1082 return (gfs_dir_readdir(vp, uiop, eofp, NULL, cr, ct, flags));
1087 * gfs_vop_map: VOP_MAP() entry point
1089 * Convenient routine for handling pseudo-files that wish to allow mmap() calls.
1090 * This function only works for readonly files, and uses the read function for
1091 * the vnode to fill in the data. The mapped data is immediately faulted in and
1092 * filled with the necessary data during this call; there are no getpage() or
1093 * putpage() routines.
1095 /* ARGSUSED */
1097 gfs_vop_map(vnode_t *vp, offset_t off, struct as *as, caddr_t *addrp,
1098 size_t len, uchar_t prot, uchar_t maxprot, uint_t flags, cred_t *cred,
1099 caller_context_t *ct)
1101 int rv;
1102 ssize_t resid = len;
1105 * Check for bad parameters
1107 #ifdef _ILP32
1108 if (len > MAXOFF_T)
1109 return (ENOMEM);
1110 #endif
1111 if (vp->v_flag & VNOMAP)
1112 return (ENOTSUP);
1113 if (off > MAXOFF_T)
1114 return (EFBIG);
1115 if ((long)off < 0 || (long)(off + len) < 0)
1116 return (EINVAL);
1117 if (vp->v_type != VREG)
1118 return (ENODEV);
1119 if ((prot & (PROT_EXEC | PROT_WRITE)) != 0)
1120 return (EACCES);
1123 * Find appropriate address if needed, otherwise clear address range.
1125 as_rangelock(as);
1126 rv = choose_addr(as, addrp, len, off, ADDR_VACALIGN, flags);
1127 if (rv != 0) {
1128 as_rangeunlock(as);
1129 return (rv);
1133 * Create mapping
1135 rv = as_map(as, *addrp, len, segvn_create, zfod_argsp);
1136 as_rangeunlock(as);
1137 if (rv != 0)
1138 return (rv);
1141 * Fill with data from read()
1143 rv = vn_rdwr(UIO_READ, vp, *addrp, len, off, UIO_USERSPACE,
1144 0, (rlim64_t)0, cred, &resid);
1146 if (rv == 0 && resid != 0)
1147 rv = ENXIO;
1149 if (rv != 0) {
1150 as_rangelock(as);
1151 (void) as_unmap(as, *addrp, len);
1152 as_rangeunlock(as);
1155 return (rv);
1159 * gfs_vop_inactive: VOP_INACTIVE() entry point
1161 * Given a vnode that is a GFS file or directory, call gfs_file_inactive() or
1162 * gfs_dir_inactive() as necessary, and kmem_free()s associated private data.
1164 /* ARGSUSED */
1165 void
1166 gfs_vop_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
1168 gfs_file_t *fp = vp->v_data;
1169 void *data;
1171 if (fp->gfs_type == GFS_DIR)
1172 data = gfs_dir_inactive(vp);
1173 else
1174 data = gfs_file_inactive(vp);
1176 if (data != NULL)
1177 kmem_free(data, fp->gfs_size);