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