1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4  * All Rights Reserved.
5  */
6 
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_mount.h"
14 #include "xfs_inode.h"
15 #include "xfs_trans.h"
16 #include "xfs_inode_item.h"
17 #include "xfs_btree.h"
18 #include "xfs_bmap_btree.h"
19 #include "xfs_bmap.h"
20 #include "xfs_error.h"
21 #include "xfs_trace.h"
22 #include "xfs_da_format.h"
23 #include "xfs_da_btree.h"
24 #include "xfs_dir2_priv.h"
25 #include "xfs_attr_leaf.h"
26 #include "xfs_types.h"
27 #include "xfs_errortag.h"
28 
29 struct kmem_cache *xfs_ifork_cache;
30 
31 void
xfs_init_local_fork(struct xfs_inode * ip,int whichfork,const void * data,int64_t size)32 xfs_init_local_fork(
33 	struct xfs_inode	*ip,
34 	int			whichfork,
35 	const void		*data,
36 	int64_t			size)
37 {
38 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
39 	int			mem_size = size;
40 	bool			zero_terminate;
41 
42 	/*
43 	 * If we are using the local fork to store a symlink body we need to
44 	 * zero-terminate it so that we can pass it back to the VFS directly.
45 	 * Overallocate the in-memory fork by one for that and add a zero
46 	 * to terminate it below.
47 	 */
48 	zero_terminate = S_ISLNK(VFS_I(ip)->i_mode);
49 	if (zero_terminate)
50 		mem_size++;
51 
52 	if (size) {
53 		ifp->if_u1.if_data = kmem_alloc(mem_size, KM_NOFS);
54 		memcpy(ifp->if_u1.if_data, data, size);
55 		if (zero_terminate)
56 			ifp->if_u1.if_data[size] = '\0';
57 	} else {
58 		ifp->if_u1.if_data = NULL;
59 	}
60 
61 	ifp->if_bytes = size;
62 }
63 
64 /*
65  * The file is in-lined in the on-disk inode.
66  */
67 STATIC int
xfs_iformat_local(struct xfs_inode * ip,struct xfs_dinode * dip,int whichfork,int size)68 xfs_iformat_local(
69 	struct xfs_inode	*ip,
70 	struct xfs_dinode	*dip,
71 	int			whichfork,
72 	int			size)
73 {
74 	/*
75 	 * If the size is unreasonable, then something
76 	 * is wrong and we just bail out rather than crash in
77 	 * kmem_alloc() or memcpy() below.
78 	 */
79 	if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
80 		xfs_warn(ip->i_mount,
81 	"corrupt inode %llu (bad size %d for local fork, size = %zd).",
82 			(unsigned long long) ip->i_ino, size,
83 			XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
84 		xfs_inode_verifier_error(ip, -EFSCORRUPTED,
85 				"xfs_iformat_local", dip, sizeof(*dip),
86 				__this_address);
87 		return -EFSCORRUPTED;
88 	}
89 
90 	xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
91 	return 0;
92 }
93 
94 /*
95  * The file consists of a set of extents all of which fit into the on-disk
96  * inode.
97  */
98 STATIC int
xfs_iformat_extents(struct xfs_inode * ip,struct xfs_dinode * dip,int whichfork)99 xfs_iformat_extents(
100 	struct xfs_inode	*ip,
101 	struct xfs_dinode	*dip,
102 	int			whichfork)
103 {
104 	struct xfs_mount	*mp = ip->i_mount;
105 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
106 	int			state = xfs_bmap_fork_to_state(whichfork);
107 	xfs_extnum_t		nex = xfs_dfork_nextents(dip, whichfork);
108 	int			size = nex * sizeof(xfs_bmbt_rec_t);
109 	struct xfs_iext_cursor	icur;
110 	struct xfs_bmbt_rec	*dp;
111 	struct xfs_bmbt_irec	new;
112 	int			i;
113 
114 	/*
115 	 * If the number of extents is unreasonable, then something is wrong and
116 	 * we just bail out rather than crash in kmem_alloc() or memcpy() below.
117 	 */
118 	if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
119 		xfs_warn(ip->i_mount, "corrupt inode %llu ((a)extents = %llu).",
120 			ip->i_ino, nex);
121 		xfs_inode_verifier_error(ip, -EFSCORRUPTED,
122 				"xfs_iformat_extents(1)", dip, sizeof(*dip),
123 				__this_address);
124 		return -EFSCORRUPTED;
125 	}
126 
127 	ifp->if_bytes = 0;
128 	ifp->if_u1.if_root = NULL;
129 	ifp->if_height = 0;
130 	if (size) {
131 		dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);
132 
133 		xfs_iext_first(ifp, &icur);
134 		for (i = 0; i < nex; i++, dp++) {
135 			xfs_failaddr_t	fa;
136 
137 			xfs_bmbt_disk_get_all(dp, &new);
138 			fa = xfs_bmap_validate_extent(ip, whichfork, &new);
139 			if (fa) {
140 				xfs_inode_verifier_error(ip, -EFSCORRUPTED,
141 						"xfs_iformat_extents(2)",
142 						dp, sizeof(*dp), fa);
143 				return xfs_bmap_complain_bad_rec(ip, whichfork,
144 						fa, &new);
145 			}
146 
147 			xfs_iext_insert(ip, &icur, &new, state);
148 			trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
149 			xfs_iext_next(ifp, &icur);
150 		}
151 	}
152 	return 0;
153 }
154 
155 /*
156  * The file has too many extents to fit into
157  * the inode, so they are in B-tree format.
158  * Allocate a buffer for the root of the B-tree
159  * and copy the root into it.  The i_extents
160  * field will remain NULL until all of the
161  * extents are read in (when they are needed).
162  */
163 STATIC int
xfs_iformat_btree(struct xfs_inode * ip,struct xfs_dinode * dip,int whichfork)164 xfs_iformat_btree(
165 	struct xfs_inode	*ip,
166 	struct xfs_dinode	*dip,
167 	int			whichfork)
168 {
169 	struct xfs_mount	*mp = ip->i_mount;
170 	xfs_bmdr_block_t	*dfp;
171 	struct xfs_ifork	*ifp;
172 	/* REFERENCED */
173 	int			nrecs;
174 	int			size;
175 	int			level;
176 
177 	ifp = xfs_ifork_ptr(ip, whichfork);
178 	dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork);
179 	size = XFS_BMAP_BROOT_SPACE(mp, dfp);
180 	nrecs = be16_to_cpu(dfp->bb_numrecs);
181 	level = be16_to_cpu(dfp->bb_level);
182 
183 	/*
184 	 * blow out if -- fork has less extents than can fit in
185 	 * fork (fork shouldn't be a btree format), root btree
186 	 * block has more records than can fit into the fork,
187 	 * or the number of extents is greater than the number of
188 	 * blocks.
189 	 */
190 	if (unlikely(ifp->if_nextents <= XFS_IFORK_MAXEXT(ip, whichfork) ||
191 		     nrecs == 0 ||
192 		     XFS_BMDR_SPACE_CALC(nrecs) >
193 					XFS_DFORK_SIZE(dip, mp, whichfork) ||
194 		     ifp->if_nextents > ip->i_nblocks) ||
195 		     level == 0 || level > XFS_BM_MAXLEVELS(mp, whichfork)) {
196 		xfs_warn(mp, "corrupt inode %llu (btree).",
197 					(unsigned long long) ip->i_ino);
198 		xfs_inode_verifier_error(ip, -EFSCORRUPTED,
199 				"xfs_iformat_btree", dfp, size,
200 				__this_address);
201 		return -EFSCORRUPTED;
202 	}
203 
204 	ifp->if_broot_bytes = size;
205 	ifp->if_broot = kmem_alloc(size, KM_NOFS);
206 	ASSERT(ifp->if_broot != NULL);
207 	/*
208 	 * Copy and convert from the on-disk structure
209 	 * to the in-memory structure.
210 	 */
211 	xfs_bmdr_to_bmbt(ip, dfp, XFS_DFORK_SIZE(dip, ip->i_mount, whichfork),
212 			 ifp->if_broot, size);
213 
214 	ifp->if_bytes = 0;
215 	ifp->if_u1.if_root = NULL;
216 	ifp->if_height = 0;
217 	return 0;
218 }
219 
220 int
xfs_iformat_data_fork(struct xfs_inode * ip,struct xfs_dinode * dip)221 xfs_iformat_data_fork(
222 	struct xfs_inode	*ip,
223 	struct xfs_dinode	*dip)
224 {
225 	struct inode		*inode = VFS_I(ip);
226 	int			error;
227 
228 	/*
229 	 * Initialize the extent count early, as the per-format routines may
230 	 * depend on it.  Use release semantics to set needextents /after/ we
231 	 * set the format. This ensures that we can use acquire semantics on
232 	 * needextents in xfs_need_iread_extents() and be guaranteed to see a
233 	 * valid format value after that load.
234 	 */
235 	ip->i_df.if_format = dip->di_format;
236 	ip->i_df.if_nextents = xfs_dfork_data_extents(dip);
237 	smp_store_release(&ip->i_df.if_needextents,
238 			   ip->i_df.if_format == XFS_DINODE_FMT_BTREE ? 1 : 0);
239 
240 	switch (inode->i_mode & S_IFMT) {
241 	case S_IFIFO:
242 	case S_IFCHR:
243 	case S_IFBLK:
244 	case S_IFSOCK:
245 		ip->i_disk_size = 0;
246 		inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
247 		return 0;
248 	case S_IFREG:
249 	case S_IFLNK:
250 	case S_IFDIR:
251 		switch (ip->i_df.if_format) {
252 		case XFS_DINODE_FMT_LOCAL:
253 			error = xfs_iformat_local(ip, dip, XFS_DATA_FORK,
254 					be64_to_cpu(dip->di_size));
255 			if (!error)
256 				error = xfs_ifork_verify_local_data(ip);
257 			return error;
258 		case XFS_DINODE_FMT_EXTENTS:
259 			return xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
260 		case XFS_DINODE_FMT_BTREE:
261 			return xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
262 		default:
263 			xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__,
264 					dip, sizeof(*dip), __this_address);
265 			return -EFSCORRUPTED;
266 		}
267 		break;
268 	default:
269 		xfs_inode_verifier_error(ip, -EFSCORRUPTED, __func__, dip,
270 				sizeof(*dip), __this_address);
271 		return -EFSCORRUPTED;
272 	}
273 }
274 
275 static uint16_t
xfs_dfork_attr_shortform_size(struct xfs_dinode * dip)276 xfs_dfork_attr_shortform_size(
277 	struct xfs_dinode		*dip)
278 {
279 	struct xfs_attr_shortform	*atp =
280 		(struct xfs_attr_shortform *)XFS_DFORK_APTR(dip);
281 
282 	return be16_to_cpu(atp->hdr.totsize);
283 }
284 
285 void
xfs_ifork_init_attr(struct xfs_inode * ip,enum xfs_dinode_fmt format,xfs_extnum_t nextents)286 xfs_ifork_init_attr(
287 	struct xfs_inode	*ip,
288 	enum xfs_dinode_fmt	format,
289 	xfs_extnum_t		nextents)
290 {
291 	/*
292 	 * Initialize the extent count early, as the per-format routines may
293 	 * depend on it.  Use release semantics to set needextents /after/ we
294 	 * set the format. This ensures that we can use acquire semantics on
295 	 * needextents in xfs_need_iread_extents() and be guaranteed to see a
296 	 * valid format value after that load.
297 	 */
298 	ip->i_af.if_format = format;
299 	ip->i_af.if_nextents = nextents;
300 	smp_store_release(&ip->i_af.if_needextents,
301 			   ip->i_af.if_format == XFS_DINODE_FMT_BTREE ? 1 : 0);
302 }
303 
304 void
xfs_ifork_zap_attr(struct xfs_inode * ip)305 xfs_ifork_zap_attr(
306 	struct xfs_inode	*ip)
307 {
308 	xfs_idestroy_fork(&ip->i_af);
309 	memset(&ip->i_af, 0, sizeof(struct xfs_ifork));
310 	ip->i_af.if_format = XFS_DINODE_FMT_EXTENTS;
311 }
312 
313 int
xfs_iformat_attr_fork(struct xfs_inode * ip,struct xfs_dinode * dip)314 xfs_iformat_attr_fork(
315 	struct xfs_inode	*ip,
316 	struct xfs_dinode	*dip)
317 {
318 	xfs_extnum_t		naextents = xfs_dfork_attr_extents(dip);
319 	int			error = 0;
320 
321 	/*
322 	 * Initialize the extent count early, as the per-format routines may
323 	 * depend on it.
324 	 */
325 	xfs_ifork_init_attr(ip, dip->di_aformat, naextents);
326 
327 	switch (ip->i_af.if_format) {
328 	case XFS_DINODE_FMT_LOCAL:
329 		error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK,
330 				xfs_dfork_attr_shortform_size(dip));
331 		if (!error)
332 			error = xfs_ifork_verify_local_attr(ip);
333 		break;
334 	case XFS_DINODE_FMT_EXTENTS:
335 		error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
336 		break;
337 	case XFS_DINODE_FMT_BTREE:
338 		error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
339 		break;
340 	default:
341 		xfs_inode_verifier_error(ip, error, __func__, dip,
342 				sizeof(*dip), __this_address);
343 		error = -EFSCORRUPTED;
344 		break;
345 	}
346 
347 	if (error)
348 		xfs_ifork_zap_attr(ip);
349 	return error;
350 }
351 
352 /*
353  * Reallocate the space for if_broot based on the number of records
354  * being added or deleted as indicated in rec_diff.  Move the records
355  * and pointers in if_broot to fit the new size.  When shrinking this
356  * will eliminate holes between the records and pointers created by
357  * the caller.  When growing this will create holes to be filled in
358  * by the caller.
359  *
360  * The caller must not request to add more records than would fit in
361  * the on-disk inode root.  If the if_broot is currently NULL, then
362  * if we are adding records, one will be allocated.  The caller must also
363  * not request that the number of records go below zero, although
364  * it can go to zero.
365  *
366  * ip -- the inode whose if_broot area is changing
367  * ext_diff -- the change in the number of records, positive or negative,
368  *	 requested for the if_broot array.
369  */
370 void
xfs_iroot_realloc(xfs_inode_t * ip,int rec_diff,int whichfork)371 xfs_iroot_realloc(
372 	xfs_inode_t		*ip,
373 	int			rec_diff,
374 	int			whichfork)
375 {
376 	struct xfs_mount	*mp = ip->i_mount;
377 	int			cur_max;
378 	struct xfs_ifork	*ifp;
379 	struct xfs_btree_block	*new_broot;
380 	int			new_max;
381 	size_t			new_size;
382 	char			*np;
383 	char			*op;
384 
385 	/*
386 	 * Handle the degenerate case quietly.
387 	 */
388 	if (rec_diff == 0) {
389 		return;
390 	}
391 
392 	ifp = xfs_ifork_ptr(ip, whichfork);
393 	if (rec_diff > 0) {
394 		/*
395 		 * If there wasn't any memory allocated before, just
396 		 * allocate it now and get out.
397 		 */
398 		if (ifp->if_broot_bytes == 0) {
399 			new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, rec_diff);
400 			ifp->if_broot = kmem_alloc(new_size, KM_NOFS);
401 			ifp->if_broot_bytes = (int)new_size;
402 			return;
403 		}
404 
405 		/*
406 		 * If there is already an existing if_broot, then we need
407 		 * to realloc() it and shift the pointers to their new
408 		 * location.  The records don't change location because
409 		 * they are kept butted up against the btree block header.
410 		 */
411 		cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
412 		new_max = cur_max + rec_diff;
413 		new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
414 		ifp->if_broot = krealloc(ifp->if_broot, new_size,
415 					 GFP_NOFS | __GFP_NOFAIL);
416 		op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
417 						     ifp->if_broot_bytes);
418 		np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
419 						     (int)new_size);
420 		ifp->if_broot_bytes = (int)new_size;
421 		ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
422 			xfs_inode_fork_size(ip, whichfork));
423 		memmove(np, op, cur_max * (uint)sizeof(xfs_fsblock_t));
424 		return;
425 	}
426 
427 	/*
428 	 * rec_diff is less than 0.  In this case, we are shrinking the
429 	 * if_broot buffer.  It must already exist.  If we go to zero
430 	 * records, just get rid of the root and clear the status bit.
431 	 */
432 	ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
433 	cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
434 	new_max = cur_max + rec_diff;
435 	ASSERT(new_max >= 0);
436 	if (new_max > 0)
437 		new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
438 	else
439 		new_size = 0;
440 	if (new_size > 0) {
441 		new_broot = kmem_alloc(new_size, KM_NOFS);
442 		/*
443 		 * First copy over the btree block header.
444 		 */
445 		memcpy(new_broot, ifp->if_broot,
446 			XFS_BMBT_BLOCK_LEN(ip->i_mount));
447 	} else {
448 		new_broot = NULL;
449 	}
450 
451 	/*
452 	 * Only copy the records and pointers if there are any.
453 	 */
454 	if (new_max > 0) {
455 		/*
456 		 * First copy the records.
457 		 */
458 		op = (char *)XFS_BMBT_REC_ADDR(mp, ifp->if_broot, 1);
459 		np = (char *)XFS_BMBT_REC_ADDR(mp, new_broot, 1);
460 		memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t));
461 
462 		/*
463 		 * Then copy the pointers.
464 		 */
465 		op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
466 						     ifp->if_broot_bytes);
467 		np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, new_broot, 1,
468 						     (int)new_size);
469 		memcpy(np, op, new_max * (uint)sizeof(xfs_fsblock_t));
470 	}
471 	kmem_free(ifp->if_broot);
472 	ifp->if_broot = new_broot;
473 	ifp->if_broot_bytes = (int)new_size;
474 	if (ifp->if_broot)
475 		ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
476 			xfs_inode_fork_size(ip, whichfork));
477 	return;
478 }
479 
480 
481 /*
482  * This is called when the amount of space needed for if_data
483  * is increased or decreased.  The change in size is indicated by
484  * the number of bytes that need to be added or deleted in the
485  * byte_diff parameter.
486  *
487  * If the amount of space needed has decreased below the size of the
488  * inline buffer, then switch to using the inline buffer.  Otherwise,
489  * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
490  * to what is needed.
491  *
492  * ip -- the inode whose if_data area is changing
493  * byte_diff -- the change in the number of bytes, positive or negative,
494  *	 requested for the if_data array.
495  */
496 void
xfs_idata_realloc(struct xfs_inode * ip,int64_t byte_diff,int whichfork)497 xfs_idata_realloc(
498 	struct xfs_inode	*ip,
499 	int64_t			byte_diff,
500 	int			whichfork)
501 {
502 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
503 	int64_t			new_size = ifp->if_bytes + byte_diff;
504 
505 	ASSERT(new_size >= 0);
506 	ASSERT(new_size <= xfs_inode_fork_size(ip, whichfork));
507 
508 	if (byte_diff == 0)
509 		return;
510 
511 	if (new_size == 0) {
512 		kmem_free(ifp->if_u1.if_data);
513 		ifp->if_u1.if_data = NULL;
514 		ifp->if_bytes = 0;
515 		return;
516 	}
517 
518 	ifp->if_u1.if_data = krealloc(ifp->if_u1.if_data, new_size,
519 				      GFP_NOFS | __GFP_NOFAIL);
520 	ifp->if_bytes = new_size;
521 }
522 
523 void
xfs_idestroy_fork(struct xfs_ifork * ifp)524 xfs_idestroy_fork(
525 	struct xfs_ifork	*ifp)
526 {
527 	if (ifp->if_broot != NULL) {
528 		kmem_free(ifp->if_broot);
529 		ifp->if_broot = NULL;
530 	}
531 
532 	switch (ifp->if_format) {
533 	case XFS_DINODE_FMT_LOCAL:
534 		kmem_free(ifp->if_u1.if_data);
535 		ifp->if_u1.if_data = NULL;
536 		break;
537 	case XFS_DINODE_FMT_EXTENTS:
538 	case XFS_DINODE_FMT_BTREE:
539 		if (ifp->if_height)
540 			xfs_iext_destroy(ifp);
541 		break;
542 	}
543 }
544 
545 /*
546  * Convert in-core extents to on-disk form
547  *
548  * In the case of the data fork, the in-core and on-disk fork sizes can be
549  * different due to delayed allocation extents. We only copy on-disk extents
550  * here, so callers must always use the physical fork size to determine the
551  * size of the buffer passed to this routine.  We will return the size actually
552  * used.
553  */
554 int
xfs_iextents_copy(struct xfs_inode * ip,struct xfs_bmbt_rec * dp,int whichfork)555 xfs_iextents_copy(
556 	struct xfs_inode	*ip,
557 	struct xfs_bmbt_rec	*dp,
558 	int			whichfork)
559 {
560 	int			state = xfs_bmap_fork_to_state(whichfork);
561 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
562 	struct xfs_iext_cursor	icur;
563 	struct xfs_bmbt_irec	rec;
564 	int64_t			copied = 0;
565 
566 	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
567 	ASSERT(ifp->if_bytes > 0);
568 
569 	for_each_xfs_iext(ifp, &icur, &rec) {
570 		if (isnullstartblock(rec.br_startblock))
571 			continue;
572 		ASSERT(xfs_bmap_validate_extent(ip, whichfork, &rec) == NULL);
573 		xfs_bmbt_disk_set_all(dp, &rec);
574 		trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
575 		copied += sizeof(struct xfs_bmbt_rec);
576 		dp++;
577 	}
578 
579 	ASSERT(copied > 0);
580 	ASSERT(copied <= ifp->if_bytes);
581 	return copied;
582 }
583 
584 /*
585  * Each of the following cases stores data into the same region
586  * of the on-disk inode, so only one of them can be valid at
587  * any given time. While it is possible to have conflicting formats
588  * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
589  * in EXTENTS format, this can only happen when the fork has
590  * changed formats after being modified but before being flushed.
591  * In these cases, the format always takes precedence, because the
592  * format indicates the current state of the fork.
593  */
594 void
xfs_iflush_fork(struct xfs_inode * ip,struct xfs_dinode * dip,struct xfs_inode_log_item * iip,int whichfork)595 xfs_iflush_fork(
596 	struct xfs_inode	*ip,
597 	struct xfs_dinode	*dip,
598 	struct xfs_inode_log_item *iip,
599 	int			whichfork)
600 {
601 	char			*cp;
602 	struct xfs_ifork	*ifp;
603 	xfs_mount_t		*mp;
604 	static const short	brootflag[2] =
605 		{ XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
606 	static const short	dataflag[2] =
607 		{ XFS_ILOG_DDATA, XFS_ILOG_ADATA };
608 	static const short	extflag[2] =
609 		{ XFS_ILOG_DEXT, XFS_ILOG_AEXT };
610 
611 	if (!iip)
612 		return;
613 	ifp = xfs_ifork_ptr(ip, whichfork);
614 	/*
615 	 * This can happen if we gave up in iformat in an error path,
616 	 * for the attribute fork.
617 	 */
618 	if (!ifp) {
619 		ASSERT(whichfork == XFS_ATTR_FORK);
620 		return;
621 	}
622 	cp = XFS_DFORK_PTR(dip, whichfork);
623 	mp = ip->i_mount;
624 	switch (ifp->if_format) {
625 	case XFS_DINODE_FMT_LOCAL:
626 		if ((iip->ili_fields & dataflag[whichfork]) &&
627 		    (ifp->if_bytes > 0)) {
628 			ASSERT(ifp->if_u1.if_data != NULL);
629 			ASSERT(ifp->if_bytes <= xfs_inode_fork_size(ip, whichfork));
630 			memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
631 		}
632 		break;
633 
634 	case XFS_DINODE_FMT_EXTENTS:
635 		if ((iip->ili_fields & extflag[whichfork]) &&
636 		    (ifp->if_bytes > 0)) {
637 			ASSERT(ifp->if_nextents > 0);
638 			(void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
639 				whichfork);
640 		}
641 		break;
642 
643 	case XFS_DINODE_FMT_BTREE:
644 		if ((iip->ili_fields & brootflag[whichfork]) &&
645 		    (ifp->if_broot_bytes > 0)) {
646 			ASSERT(ifp->if_broot != NULL);
647 			ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
648 			        xfs_inode_fork_size(ip, whichfork));
649 			xfs_bmbt_to_bmdr(mp, ifp->if_broot, ifp->if_broot_bytes,
650 				(xfs_bmdr_block_t *)cp,
651 				XFS_DFORK_SIZE(dip, mp, whichfork));
652 		}
653 		break;
654 
655 	case XFS_DINODE_FMT_DEV:
656 		if (iip->ili_fields & XFS_ILOG_DEV) {
657 			ASSERT(whichfork == XFS_DATA_FORK);
658 			xfs_dinode_put_rdev(dip,
659 					linux_to_xfs_dev_t(VFS_I(ip)->i_rdev));
660 		}
661 		break;
662 
663 	default:
664 		ASSERT(0);
665 		break;
666 	}
667 }
668 
669 /* Convert bmap state flags to an inode fork. */
670 struct xfs_ifork *
xfs_iext_state_to_fork(struct xfs_inode * ip,int state)671 xfs_iext_state_to_fork(
672 	struct xfs_inode	*ip,
673 	int			state)
674 {
675 	if (state & BMAP_COWFORK)
676 		return ip->i_cowfp;
677 	else if (state & BMAP_ATTRFORK)
678 		return &ip->i_af;
679 	return &ip->i_df;
680 }
681 
682 /*
683  * Initialize an inode's copy-on-write fork.
684  */
685 void
xfs_ifork_init_cow(struct xfs_inode * ip)686 xfs_ifork_init_cow(
687 	struct xfs_inode	*ip)
688 {
689 	if (ip->i_cowfp)
690 		return;
691 
692 	ip->i_cowfp = kmem_cache_zalloc(xfs_ifork_cache,
693 				       GFP_NOFS | __GFP_NOFAIL);
694 	ip->i_cowfp->if_format = XFS_DINODE_FMT_EXTENTS;
695 }
696 
697 /* Verify the inline contents of the data fork of an inode. */
698 int
xfs_ifork_verify_local_data(struct xfs_inode * ip)699 xfs_ifork_verify_local_data(
700 	struct xfs_inode	*ip)
701 {
702 	xfs_failaddr_t		fa = NULL;
703 
704 	switch (VFS_I(ip)->i_mode & S_IFMT) {
705 	case S_IFDIR:
706 		fa = xfs_dir2_sf_verify(ip);
707 		break;
708 	case S_IFLNK:
709 		fa = xfs_symlink_shortform_verify(ip);
710 		break;
711 	default:
712 		break;
713 	}
714 
715 	if (fa) {
716 		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "data fork",
717 				ip->i_df.if_u1.if_data, ip->i_df.if_bytes, fa);
718 		return -EFSCORRUPTED;
719 	}
720 
721 	return 0;
722 }
723 
724 /* Verify the inline contents of the attr fork of an inode. */
725 int
xfs_ifork_verify_local_attr(struct xfs_inode * ip)726 xfs_ifork_verify_local_attr(
727 	struct xfs_inode	*ip)
728 {
729 	struct xfs_ifork	*ifp = &ip->i_af;
730 	xfs_failaddr_t		fa;
731 
732 	if (!xfs_inode_has_attr_fork(ip))
733 		fa = __this_address;
734 	else
735 		fa = xfs_attr_shortform_verify(ip);
736 
737 	if (fa) {
738 		xfs_inode_verifier_error(ip, -EFSCORRUPTED, "attr fork",
739 				ifp->if_u1.if_data, ifp->if_bytes, fa);
740 		return -EFSCORRUPTED;
741 	}
742 
743 	return 0;
744 }
745 
746 int
xfs_iext_count_may_overflow(struct xfs_inode * ip,int whichfork,int nr_to_add)747 xfs_iext_count_may_overflow(
748 	struct xfs_inode	*ip,
749 	int			whichfork,
750 	int			nr_to_add)
751 {
752 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
753 	uint64_t		max_exts;
754 	uint64_t		nr_exts;
755 
756 	if (whichfork == XFS_COW_FORK)
757 		return 0;
758 
759 	max_exts = xfs_iext_max_nextents(xfs_inode_has_large_extent_counts(ip),
760 				whichfork);
761 
762 	if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
763 		max_exts = 10;
764 
765 	nr_exts = ifp->if_nextents + nr_to_add;
766 	if (nr_exts < ifp->if_nextents || nr_exts > max_exts)
767 		return -EFBIG;
768 
769 	return 0;
770 }
771 
772 /*
773  * Upgrade this inode's extent counter fields to be able to handle a potential
774  * increase in the extent count by nr_to_add.  Normally this is the same
775  * quantity that caused xfs_iext_count_may_overflow() to return -EFBIG.
776  */
777 int
xfs_iext_count_upgrade(struct xfs_trans * tp,struct xfs_inode * ip,uint nr_to_add)778 xfs_iext_count_upgrade(
779 	struct xfs_trans	*tp,
780 	struct xfs_inode	*ip,
781 	uint			nr_to_add)
782 {
783 	ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);
784 
785 	if (!xfs_has_large_extent_counts(ip->i_mount) ||
786 	    xfs_inode_has_large_extent_counts(ip) ||
787 	    XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
788 		return -EFBIG;
789 
790 	ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
791 	xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
792 
793 	return 0;
794 }
795