xref: /openbmc/linux/fs/xfs/xfs_attr_inactive.c (revision b96fc2f3)
1 /*
2  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3  * Copyright (c) 2013 Red Hat, Inc.
4  * All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License as
8  * published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it would be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  * You should have received a copy of the GNU General Public License
16  * along with this program; if not, write the Free Software Foundation,
17  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
18  */
19 #include "xfs.h"
20 #include "xfs_fs.h"
21 #include "xfs_shared.h"
22 #include "xfs_format.h"
23 #include "xfs_log_format.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_bit.h"
26 #include "xfs_mount.h"
27 #include "xfs_da_format.h"
28 #include "xfs_da_btree.h"
29 #include "xfs_inode.h"
30 #include "xfs_alloc.h"
31 #include "xfs_attr_remote.h"
32 #include "xfs_trans.h"
33 #include "xfs_inode_item.h"
34 #include "xfs_bmap.h"
35 #include "xfs_attr.h"
36 #include "xfs_attr_leaf.h"
37 #include "xfs_error.h"
38 #include "xfs_quota.h"
39 #include "xfs_trace.h"
40 #include "xfs_dir2.h"
41 
42 /*
43  * Look at all the extents for this logical region,
44  * invalidate any buffers that are incore/in transactions.
45  */
46 STATIC int
47 xfs_attr3_leaf_freextent(
48 	struct xfs_trans	**trans,
49 	struct xfs_inode	*dp,
50 	xfs_dablk_t		blkno,
51 	int			blkcnt)
52 {
53 	struct xfs_bmbt_irec	map;
54 	struct xfs_buf		*bp;
55 	xfs_dablk_t		tblkno;
56 	xfs_daddr_t		dblkno;
57 	int			tblkcnt;
58 	int			dblkcnt;
59 	int			nmap;
60 	int			error;
61 
62 	/*
63 	 * Roll through the "value", invalidating the attribute value's
64 	 * blocks.
65 	 */
66 	tblkno = blkno;
67 	tblkcnt = blkcnt;
68 	while (tblkcnt > 0) {
69 		/*
70 		 * Try to remember where we decided to put the value.
71 		 */
72 		nmap = 1;
73 		error = xfs_bmapi_read(dp, (xfs_fileoff_t)tblkno, tblkcnt,
74 				       &map, &nmap, XFS_BMAPI_ATTRFORK);
75 		if (error) {
76 			return error;
77 		}
78 		ASSERT(nmap == 1);
79 		ASSERT(map.br_startblock != DELAYSTARTBLOCK);
80 
81 		/*
82 		 * If it's a hole, these are already unmapped
83 		 * so there's nothing to invalidate.
84 		 */
85 		if (map.br_startblock != HOLESTARTBLOCK) {
86 
87 			dblkno = XFS_FSB_TO_DADDR(dp->i_mount,
88 						  map.br_startblock);
89 			dblkcnt = XFS_FSB_TO_BB(dp->i_mount,
90 						map.br_blockcount);
91 			bp = xfs_trans_get_buf(*trans,
92 					dp->i_mount->m_ddev_targp,
93 					dblkno, dblkcnt, 0);
94 			if (!bp)
95 				return -ENOMEM;
96 			xfs_trans_binval(*trans, bp);
97 			/*
98 			 * Roll to next transaction.
99 			 */
100 			error = xfs_trans_roll(trans, dp);
101 			if (error)
102 				return error;
103 		}
104 
105 		tblkno += map.br_blockcount;
106 		tblkcnt -= map.br_blockcount;
107 	}
108 
109 	return 0;
110 }
111 
112 /*
113  * Invalidate all of the "remote" value regions pointed to by a particular
114  * leaf block.
115  * Note that we must release the lock on the buffer so that we are not
116  * caught holding something that the logging code wants to flush to disk.
117  */
118 STATIC int
119 xfs_attr3_leaf_inactive(
120 	struct xfs_trans	**trans,
121 	struct xfs_inode	*dp,
122 	struct xfs_buf		*bp)
123 {
124 	struct xfs_attr_leafblock *leaf;
125 	struct xfs_attr3_icleaf_hdr ichdr;
126 	struct xfs_attr_leaf_entry *entry;
127 	struct xfs_attr_leaf_name_remote *name_rmt;
128 	struct xfs_attr_inactive_list *list;
129 	struct xfs_attr_inactive_list *lp;
130 	int			error;
131 	int			count;
132 	int			size;
133 	int			tmp;
134 	int			i;
135 	struct xfs_mount	*mp = bp->b_target->bt_mount;
136 
137 	leaf = bp->b_addr;
138 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
139 
140 	/*
141 	 * Count the number of "remote" value extents.
142 	 */
143 	count = 0;
144 	entry = xfs_attr3_leaf_entryp(leaf);
145 	for (i = 0; i < ichdr.count; entry++, i++) {
146 		if (be16_to_cpu(entry->nameidx) &&
147 		    ((entry->flags & XFS_ATTR_LOCAL) == 0)) {
148 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
149 			if (name_rmt->valueblk)
150 				count++;
151 		}
152 	}
153 
154 	/*
155 	 * If there are no "remote" values, we're done.
156 	 */
157 	if (count == 0) {
158 		xfs_trans_brelse(*trans, bp);
159 		return 0;
160 	}
161 
162 	/*
163 	 * Allocate storage for a list of all the "remote" value extents.
164 	 */
165 	size = count * sizeof(xfs_attr_inactive_list_t);
166 	list = kmem_alloc(size, KM_SLEEP);
167 
168 	/*
169 	 * Identify each of the "remote" value extents.
170 	 */
171 	lp = list;
172 	entry = xfs_attr3_leaf_entryp(leaf);
173 	for (i = 0; i < ichdr.count; entry++, i++) {
174 		if (be16_to_cpu(entry->nameidx) &&
175 		    ((entry->flags & XFS_ATTR_LOCAL) == 0)) {
176 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
177 			if (name_rmt->valueblk) {
178 				lp->valueblk = be32_to_cpu(name_rmt->valueblk);
179 				lp->valuelen = xfs_attr3_rmt_blocks(dp->i_mount,
180 						    be32_to_cpu(name_rmt->valuelen));
181 				lp++;
182 			}
183 		}
184 	}
185 	xfs_trans_brelse(*trans, bp);	/* unlock for trans. in freextent() */
186 
187 	/*
188 	 * Invalidate each of the "remote" value extents.
189 	 */
190 	error = 0;
191 	for (lp = list, i = 0; i < count; i++, lp++) {
192 		tmp = xfs_attr3_leaf_freextent(trans, dp,
193 				lp->valueblk, lp->valuelen);
194 
195 		if (error == 0)
196 			error = tmp;	/* save only the 1st errno */
197 	}
198 
199 	kmem_free(list);
200 	return error;
201 }
202 
203 /*
204  * Recurse (gasp!) through the attribute nodes until we find leaves.
205  * We're doing a depth-first traversal in order to invalidate everything.
206  */
207 STATIC int
208 xfs_attr3_node_inactive(
209 	struct xfs_trans **trans,
210 	struct xfs_inode *dp,
211 	struct xfs_buf	*bp,
212 	int		level)
213 {
214 	xfs_da_blkinfo_t *info;
215 	xfs_da_intnode_t *node;
216 	xfs_dablk_t child_fsb;
217 	xfs_daddr_t parent_blkno, child_blkno;
218 	int error, i;
219 	struct xfs_buf *child_bp;
220 	struct xfs_da_node_entry *btree;
221 	struct xfs_da3_icnode_hdr ichdr;
222 
223 	/*
224 	 * Since this code is recursive (gasp!) we must protect ourselves.
225 	 */
226 	if (level > XFS_DA_NODE_MAXDEPTH) {
227 		xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
228 		return -EIO;
229 	}
230 
231 	node = bp->b_addr;
232 	dp->d_ops->node_hdr_from_disk(&ichdr, node);
233 	parent_blkno = bp->b_bn;
234 	if (!ichdr.count) {
235 		xfs_trans_brelse(*trans, bp);
236 		return 0;
237 	}
238 	btree = dp->d_ops->node_tree_p(node);
239 	child_fsb = be32_to_cpu(btree[0].before);
240 	xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
241 
242 	/*
243 	 * If this is the node level just above the leaves, simply loop
244 	 * over the leaves removing all of them.  If this is higher up
245 	 * in the tree, recurse downward.
246 	 */
247 	for (i = 0; i < ichdr.count; i++) {
248 		/*
249 		 * Read the subsidiary block to see what we have to work with.
250 		 * Don't do this in a transaction.  This is a depth-first
251 		 * traversal of the tree so we may deal with many blocks
252 		 * before we come back to this one.
253 		 */
254 		error = xfs_da3_node_read(*trans, dp, child_fsb, -2, &child_bp,
255 						XFS_ATTR_FORK);
256 		if (error)
257 			return error;
258 		if (child_bp) {
259 						/* save for re-read later */
260 			child_blkno = XFS_BUF_ADDR(child_bp);
261 
262 			/*
263 			 * Invalidate the subtree, however we have to.
264 			 */
265 			info = child_bp->b_addr;
266 			switch (info->magic) {
267 			case cpu_to_be16(XFS_DA_NODE_MAGIC):
268 			case cpu_to_be16(XFS_DA3_NODE_MAGIC):
269 				error = xfs_attr3_node_inactive(trans, dp,
270 							child_bp, level + 1);
271 				break;
272 			case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
273 			case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
274 				error = xfs_attr3_leaf_inactive(trans, dp,
275 							child_bp);
276 				break;
277 			default:
278 				error = -EIO;
279 				xfs_trans_brelse(*trans, child_bp);
280 				break;
281 			}
282 			if (error)
283 				return error;
284 
285 			/*
286 			 * Remove the subsidiary block from the cache
287 			 * and from the log.
288 			 */
289 			error = xfs_da_get_buf(*trans, dp, 0, child_blkno,
290 				&child_bp, XFS_ATTR_FORK);
291 			if (error)
292 				return error;
293 			xfs_trans_binval(*trans, child_bp);
294 		}
295 
296 		/*
297 		 * If we're not done, re-read the parent to get the next
298 		 * child block number.
299 		 */
300 		if (i + 1 < ichdr.count) {
301 			error = xfs_da3_node_read(*trans, dp, 0, parent_blkno,
302 						 &bp, XFS_ATTR_FORK);
303 			if (error)
304 				return error;
305 			child_fsb = be32_to_cpu(btree[i + 1].before);
306 			xfs_trans_brelse(*trans, bp);
307 		}
308 		/*
309 		 * Atomically commit the whole invalidate stuff.
310 		 */
311 		error = xfs_trans_roll(trans, dp);
312 		if (error)
313 			return  error;
314 	}
315 
316 	return 0;
317 }
318 
319 /*
320  * Indiscriminately delete the entire attribute fork
321  *
322  * Recurse (gasp!) through the attribute nodes until we find leaves.
323  * We're doing a depth-first traversal in order to invalidate everything.
324  */
325 int
326 xfs_attr3_root_inactive(
327 	struct xfs_trans	**trans,
328 	struct xfs_inode	*dp)
329 {
330 	struct xfs_da_blkinfo	*info;
331 	struct xfs_buf		*bp;
332 	xfs_daddr_t		blkno;
333 	int			error;
334 
335 	/*
336 	 * Read block 0 to see what we have to work with.
337 	 * We only get here if we have extents, since we remove
338 	 * the extents in reverse order the extent containing
339 	 * block 0 must still be there.
340 	 */
341 	error = xfs_da3_node_read(*trans, dp, 0, -1, &bp, XFS_ATTR_FORK);
342 	if (error)
343 		return error;
344 	blkno = bp->b_bn;
345 
346 	/*
347 	 * Invalidate the tree, even if the "tree" is only a single leaf block.
348 	 * This is a depth-first traversal!
349 	 */
350 	info = bp->b_addr;
351 	switch (info->magic) {
352 	case cpu_to_be16(XFS_DA_NODE_MAGIC):
353 	case cpu_to_be16(XFS_DA3_NODE_MAGIC):
354 		error = xfs_attr3_node_inactive(trans, dp, bp, 1);
355 		break;
356 	case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
357 	case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
358 		error = xfs_attr3_leaf_inactive(trans, dp, bp);
359 		break;
360 	default:
361 		error = -EIO;
362 		xfs_trans_brelse(*trans, bp);
363 		break;
364 	}
365 	if (error)
366 		return error;
367 
368 	/*
369 	 * Invalidate the incore copy of the root block.
370 	 */
371 	error = xfs_da_get_buf(*trans, dp, 0, blkno, &bp, XFS_ATTR_FORK);
372 	if (error)
373 		return error;
374 	xfs_trans_binval(*trans, bp);	/* remove from cache */
375 	/*
376 	 * Commit the invalidate and start the next transaction.
377 	 */
378 	error = xfs_trans_roll(trans, dp);
379 
380 	return error;
381 }
382 
383 /*
384  * xfs_attr_inactive kills all traces of an attribute fork on an inode. It
385  * removes both the on-disk and in-memory inode fork. Note that this also has to
386  * handle the condition of inodes without attributes but with an attribute fork
387  * configured, so we can't use xfs_inode_hasattr() here.
388  *
389  * The in-memory attribute fork is removed even on error.
390  */
391 int
392 xfs_attr_inactive(
393 	struct xfs_inode	*dp)
394 {
395 	struct xfs_trans	*trans;
396 	struct xfs_mount	*mp;
397 	int			lock_mode = XFS_ILOCK_SHARED;
398 	int			error = 0;
399 
400 	mp = dp->i_mount;
401 	ASSERT(! XFS_NOT_DQATTACHED(mp, dp));
402 
403 	xfs_ilock(dp, lock_mode);
404 	if (!XFS_IFORK_Q(dp))
405 		goto out_destroy_fork;
406 	xfs_iunlock(dp, lock_mode);
407 
408 	/*
409 	 * Start our first transaction of the day.
410 	 *
411 	 * All future transactions during this code must be "chained" off
412 	 * this one via the trans_dup() call.  All transactions will contain
413 	 * the inode, and the inode will always be marked with trans_ihold().
414 	 * Since the inode will be locked in all transactions, we must log
415 	 * the inode in every transaction to let it float upward through
416 	 * the log.
417 	 */
418 	lock_mode = 0;
419 	trans = xfs_trans_alloc(mp, XFS_TRANS_ATTRINVAL);
420 	error = xfs_trans_reserve(trans, &M_RES(mp)->tr_attrinval, 0, 0);
421 	if (error)
422 		goto out_cancel;
423 
424 	lock_mode = XFS_ILOCK_EXCL;
425 	xfs_ilock(dp, lock_mode);
426 
427 	if (!XFS_IFORK_Q(dp))
428 		goto out_cancel;
429 
430 	/*
431 	 * No need to make quota reservations here. We expect to release some
432 	 * blocks, not allocate, in the common case.
433 	 */
434 	xfs_trans_ijoin(trans, dp, 0);
435 
436 	/*
437 	 * Invalidate and truncate the attribute fork extents. Make sure the
438 	 * fork actually has attributes as otherwise the invalidation has no
439 	 * blocks to read and returns an error. In this case, just do the fork
440 	 * removal below.
441 	 */
442 	if (xfs_inode_hasattr(dp) &&
443 	    dp->i_d.di_aformat != XFS_DINODE_FMT_LOCAL) {
444 		error = xfs_attr3_root_inactive(&trans, dp);
445 		if (error)
446 			goto out_cancel;
447 
448 		error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
449 		if (error)
450 			goto out_cancel;
451 	}
452 
453 	/* Reset the attribute fork - this also destroys the in-core fork */
454 	xfs_attr_fork_remove(dp, trans);
455 
456 	error = xfs_trans_commit(trans);
457 	xfs_iunlock(dp, lock_mode);
458 	return error;
459 
460 out_cancel:
461 	xfs_trans_cancel(trans);
462 out_destroy_fork:
463 	/* kill the in-core attr fork before we drop the inode lock */
464 	if (dp->i_afp)
465 		xfs_idestroy_fork(dp, XFS_ATTR_FORK);
466 	if (lock_mode)
467 		xfs_iunlock(dp, lock_mode);
468 	return error;
469 }
470