xref: /linux/fs/xfs/xfs_attr_inactive.c (revision 3577cfd738e29b3d54cdb10c45a56730346dfe8b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4  * Copyright (c) 2013 Red Hat, Inc.
5  * All Rights Reserved.
6  */
7 #include "xfs_platform.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_bit.h"
14 #include "xfs_mount.h"
15 #include "xfs_da_format.h"
16 #include "xfs_da_btree.h"
17 #include "xfs_inode.h"
18 #include "xfs_attr.h"
19 #include "xfs_attr_remote.h"
20 #include "xfs_trans.h"
21 #include "xfs_bmap.h"
22 #include "xfs_attr_leaf.h"
23 #include "xfs_quota.h"
24 #include "xfs_dir2.h"
25 #include "xfs_error.h"
26 #include "xfs_health.h"
27 
28 /*
29  * Invalidate any incore buffers associated with this remote attribute value
30  * extent.   We never log remote attribute value buffers, which means that they
31  * won't be attached to a transaction and are therefore safe to mark stale.
32  * The actual bunmapi will be taken care of later.
33  */
34 STATIC int
xfs_attr3_rmt_stale(struct xfs_inode * dp,xfs_dablk_t blkno,int blkcnt)35 xfs_attr3_rmt_stale(
36 	struct xfs_inode	*dp,
37 	xfs_dablk_t		blkno,
38 	int			blkcnt)
39 {
40 	struct xfs_bmbt_irec	map;
41 	int			nmap;
42 	int			error;
43 
44 	/*
45 	 * Roll through the "value", invalidating the attribute value's
46 	 * blocks.
47 	 */
48 	while (blkcnt > 0) {
49 		/*
50 		 * Try to remember where we decided to put the value.
51 		 */
52 		nmap = 1;
53 		error = xfs_bmapi_read(dp, (xfs_fileoff_t)blkno, blkcnt,
54 				       &map, &nmap, XFS_BMAPI_ATTRFORK);
55 		if (error)
56 			return error;
57 		if (XFS_IS_CORRUPT(dp->i_mount, nmap != 1))
58 			return -EFSCORRUPTED;
59 
60 		/*
61 		 * Mark any incore buffers for the remote value as stale.  We
62 		 * never log remote attr value buffers, so the buffer should be
63 		 * easy to kill.
64 		 */
65 		error = xfs_attr_rmtval_stale(dp, &map, 0);
66 		if (error)
67 			return error;
68 
69 		blkno += map.br_blockcount;
70 		blkcnt -= map.br_blockcount;
71 	}
72 
73 	return 0;
74 }
75 
76 /*
77  * Invalidate all of the "remote" value regions pointed to by a particular
78  * leaf block.
79  * Note that we must release the lock on the buffer so that we are not
80  * caught holding something that the logging code wants to flush to disk.
81  */
82 STATIC int
xfs_attr3_leaf_inactive(struct xfs_trans ** trans,struct xfs_inode * dp,struct xfs_buf * bp)83 xfs_attr3_leaf_inactive(
84 	struct xfs_trans		**trans,
85 	struct xfs_inode		*dp,
86 	struct xfs_buf			*bp)
87 {
88 	struct xfs_attr3_icleaf_hdr	ichdr;
89 	struct xfs_mount		*mp = bp->b_mount;
90 	struct xfs_attr_leafblock	*leaf = bp->b_addr;
91 	struct xfs_attr_leaf_entry	*entry;
92 	struct xfs_attr_leaf_name_remote *name_rmt;
93 	int				error = 0;
94 	int				i;
95 
96 	xfs_attr3_leaf_hdr_from_disk(mp->m_attr_geo, &ichdr, leaf);
97 
98 	/*
99 	 * Find the remote value extents for this leaf and invalidate their
100 	 * incore buffers.
101 	 */
102 	entry = xfs_attr3_leaf_entryp(leaf);
103 	for (i = 0; i < ichdr.count; entry++, i++) {
104 		int		blkcnt;
105 
106 		if (!entry->nameidx || (entry->flags & XFS_ATTR_LOCAL))
107 			continue;
108 
109 		name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
110 		if (!name_rmt->valueblk)
111 			continue;
112 
113 		blkcnt = xfs_attr3_rmt_blocks(dp->i_mount,
114 				be32_to_cpu(name_rmt->valuelen));
115 		error = xfs_attr3_rmt_stale(dp,
116 				be32_to_cpu(name_rmt->valueblk), blkcnt);
117 		if (error)
118 			goto err;
119 	}
120 
121 	xfs_trans_brelse(*trans, bp);
122 err:
123 	return error;
124 }
125 
126 /*
127  * Recurse (gasp!) through the attribute nodes until we find leaves.
128  * We're doing a depth-first traversal in order to invalidate everything.
129  */
130 STATIC int
xfs_attr3_node_inactive(struct xfs_trans ** trans,struct xfs_inode * dp,struct xfs_buf * bp,int level)131 xfs_attr3_node_inactive(
132 	struct xfs_trans	**trans,
133 	struct xfs_inode	*dp,
134 	struct xfs_buf		*bp,
135 	int			level)
136 {
137 	struct xfs_mount	*mp = dp->i_mount;
138 	struct xfs_da_blkinfo	*info;
139 	xfs_dablk_t		child_fsb;
140 	xfs_daddr_t		parent_blkno, child_blkno;
141 	struct xfs_buf		*child_bp;
142 	struct xfs_da3_icnode_hdr ichdr;
143 	int			error;
144 
145 	/*
146 	 * Since this code is recursive (gasp!) we must protect ourselves.
147 	 */
148 	if (level > XFS_DA_NODE_MAXDEPTH) {
149 		xfs_buf_mark_corrupt(bp);
150 		xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
151 		xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
152 		return -EFSCORRUPTED;
153 	}
154 
155 	xfs_da3_node_hdr_from_disk(mp, &ichdr, bp->b_addr);
156 	parent_blkno = xfs_buf_daddr(bp);
157 	if (!ichdr.count) {
158 		xfs_trans_brelse(*trans, bp);
159 		return 0;
160 	}
161 	child_fsb = be32_to_cpu(ichdr.btree[0].before);
162 	xfs_trans_brelse(*trans, bp);	/* no locks for later trans */
163 	bp = NULL;
164 
165 	/*
166 	 * If this is the node level just above the leaves, simply loop
167 	 * over the leaves removing all of them.  If this is higher up
168 	 * in the tree, recurse downward.
169 	 */
170 	while (ichdr.count > 0) {
171 		/*
172 		 * Read the subsidiary block to see what we have to work with.
173 		 * Don't do this in a transaction.  This is a depth-first
174 		 * traversal of the tree so we may deal with many blocks
175 		 * before we come back to this one.
176 		 */
177 		error = xfs_da3_node_read(*trans, dp, child_fsb, &child_bp,
178 					  XFS_ATTR_FORK);
179 		if (error)
180 			return error;
181 
182 		/* save for re-read later */
183 		child_blkno = xfs_buf_daddr(child_bp);
184 
185 		/*
186 		 * Invalidate the subtree, however we have to.
187 		 */
188 		info = child_bp->b_addr;
189 		switch (info->magic) {
190 		case cpu_to_be16(XFS_DA_NODE_MAGIC):
191 		case cpu_to_be16(XFS_DA3_NODE_MAGIC):
192 			error = xfs_attr3_node_inactive(trans, dp, child_bp,
193 							level + 1);
194 			break;
195 		case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
196 		case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
197 			error = xfs_attr3_leaf_inactive(trans, dp, child_bp);
198 			break;
199 		default:
200 			xfs_buf_mark_corrupt(child_bp);
201 			xfs_trans_brelse(*trans, child_bp);
202 			xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
203 			error = -EFSCORRUPTED;
204 			break;
205 		}
206 		if (error)
207 			return error;
208 
209 		/*
210 		 * Remove the subsidiary block from the cache and from the log.
211 		 */
212 		error = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
213 				child_blkno,
214 				XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0,
215 				&child_bp);
216 		if (error)
217 			return error;
218 		xfs_trans_binval(*trans, child_bp);
219 		child_bp = NULL;
220 
221 		error = xfs_da3_node_read_mapped(*trans, dp,
222 				parent_blkno, &bp, XFS_ATTR_FORK);
223 		if (error)
224 			return error;
225 
226 		/*
227 		 * Remove entry from parent node, prevents being indexed to.
228 		 */
229 		xfs_attr3_node_entry_remove(*trans, dp, bp, 0);
230 
231 		xfs_da3_node_hdr_from_disk(mp, &ichdr, bp->b_addr);
232 		bp = NULL;
233 
234 		if (ichdr.count > 0) {
235 			/*
236 			 * If we're not done, get the next child block number.
237 			 */
238 			child_fsb = be32_to_cpu(ichdr.btree[0].before);
239 
240 			/*
241 			 * Atomically commit the whole invalidate stuff.
242 			 */
243 			error = xfs_trans_roll_inode(trans, dp);
244 			if (error)
245 				return error;
246 		}
247 	}
248 
249 	return 0;
250 }
251 
252 /*
253  * Indiscriminately delete the entire attribute fork
254  *
255  * Recurse (gasp!) through the attribute nodes until we find leaves.
256  * We're doing a depth-first traversal in order to invalidate everything.
257  */
258 static int
xfs_attr3_root_inactive(struct xfs_trans ** trans,struct xfs_inode * dp)259 xfs_attr3_root_inactive(
260 	struct xfs_trans	**trans,
261 	struct xfs_inode	*dp)
262 {
263 	struct xfs_da_blkinfo	*info;
264 	struct xfs_buf		*bp;
265 	int			error;
266 
267 	/*
268 	 * Read block 0 to see what we have to work with.
269 	 * We only get here if we have extents, since we remove
270 	 * the extents in reverse order the extent containing
271 	 * block 0 must still be there.
272 	 */
273 	error = xfs_da3_node_read(*trans, dp, 0, &bp, XFS_ATTR_FORK);
274 	if (error)
275 		return error;
276 
277 	/*
278 	 * Invalidate the tree, even if the "tree" is only a single leaf block.
279 	 * This is a depth-first traversal!
280 	 */
281 	info = bp->b_addr;
282 	switch (info->magic) {
283 	case cpu_to_be16(XFS_DA_NODE_MAGIC):
284 	case cpu_to_be16(XFS_DA3_NODE_MAGIC):
285 		error = xfs_attr3_node_inactive(trans, dp, bp, 1);
286 		/*
287 		 * Empty root node block are not allowed, convert it to leaf.
288 		 */
289 		if (!error)
290 			error = xfs_attr3_leaf_init(*trans, dp, 0);
291 		if (!error)
292 			error = xfs_trans_roll_inode(trans, dp);
293 		break;
294 	case cpu_to_be16(XFS_ATTR_LEAF_MAGIC):
295 	case cpu_to_be16(XFS_ATTR3_LEAF_MAGIC):
296 		error = xfs_attr3_leaf_inactive(trans, dp, bp);
297 		/*
298 		 * Reinit the leaf before truncating extents so that a crash
299 		 * mid-truncation leaves an empty leaf rather than one with
300 		 * entries that may reference freed remote value blocks.
301 		 */
302 		if (!error)
303 			error = xfs_attr3_leaf_init(*trans, dp, 0);
304 		if (!error)
305 			error = xfs_trans_roll_inode(trans, dp);
306 		break;
307 	default:
308 		xfs_dirattr_mark_sick(dp, XFS_ATTR_FORK);
309 		error = -EFSCORRUPTED;
310 		xfs_buf_mark_corrupt(bp);
311 		xfs_trans_brelse(*trans, bp);
312 		break;
313 	}
314 
315 	return error;
316 }
317 
318 /*
319  * xfs_attr_inactive kills all traces of an attribute fork on an inode. It
320  * removes both the on-disk and in-memory inode fork. Note that this also has to
321  * handle the condition of inodes without attributes but with an attribute fork
322  * configured, so we can't use xfs_inode_hasattr() here.
323  *
324  * The in-memory attribute fork is removed even on error.
325  */
326 int
xfs_attr_inactive(struct xfs_inode * dp)327 xfs_attr_inactive(
328 	struct xfs_inode	*dp)
329 {
330 	struct xfs_trans	*trans;
331 	struct xfs_mount	*mp;
332 	struct xfs_buf          *bp;
333 	int			lock_mode = XFS_ILOCK_SHARED;
334 	int			error = 0;
335 
336 	mp = dp->i_mount;
337 
338 	xfs_ilock(dp, lock_mode);
339 	if (!xfs_inode_has_attr_fork(dp))
340 		goto out_destroy_fork;
341 	xfs_iunlock(dp, lock_mode);
342 
343 	lock_mode = 0;
344 
345 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_attrinval, 0, 0, 0, &trans);
346 	if (error)
347 		goto out_destroy_fork;
348 
349 	lock_mode = XFS_ILOCK_EXCL;
350 	xfs_ilock(dp, lock_mode);
351 
352 	if (!xfs_inode_has_attr_fork(dp))
353 		goto out_cancel;
354 
355 	/*
356 	 * No need to make quota reservations here. We expect to release some
357 	 * blocks, not allocate, in the common case.
358 	 */
359 	xfs_trans_ijoin(trans, dp, 0);
360 
361 	/*
362 	 * Invalidate and truncate the attribute fork extents. Make sure the
363 	 * fork actually has xattr blocks as otherwise the invalidation has no
364 	 * blocks to read and returns an error. In this case, just do the fork
365 	 * removal below.
366 	 */
367 	if (dp->i_af.if_nextents > 0) {
368 		/*
369 		 * Invalidate and truncate all blocks but leave the root block.
370 		 */
371 		error = xfs_attr3_root_inactive(&trans, dp);
372 		if (error)
373 			goto out_cancel;
374 
375 		error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK,
376 				XFS_FSB_TO_B(mp, mp->m_attr_geo->fsbcount));
377 		if (error)
378 			goto out_cancel;
379 
380 		/*
381 		 * Invalidate and truncate the root block and ensure that the
382 		 * operation is completed within a single transaction.
383 		 */
384 		error = xfs_da_get_buf(trans, dp, 0, &bp, XFS_ATTR_FORK);
385 		if (error)
386 			goto out_cancel;
387 
388 		xfs_trans_binval(trans, bp);
389 		error = xfs_itruncate_extents(&trans, dp, XFS_ATTR_FORK, 0);
390 		if (error)
391 			goto out_cancel;
392 	}
393 
394 	/* Reset the attribute fork - this also destroys the in-core fork */
395 	xfs_attr_fork_remove(dp, trans);
396 
397 	error = xfs_trans_commit(trans);
398 	xfs_iunlock(dp, lock_mode);
399 	return error;
400 
401 out_cancel:
402 	xfs_trans_cancel(trans);
403 out_destroy_fork:
404 	/* kill the in-core attr fork before we drop the inode lock */
405 	xfs_ifork_zap_attr(dp);
406 	if (lock_mode)
407 		xfs_iunlock(dp, lock_mode);
408 	return error;
409 }
410