blob: 29816981b50a92c1657b19778fd9e09f1d199c16 [file] [log] [blame]
Dave Chinner4a8af272013-08-12 20:49:36 +10001/*
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"
Dave Chinnera4fbe6a2013-10-23 10:51:50 +110021#include "xfs_format.h"
Dave Chinner239880e2013-10-23 10:50:10 +110022#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100024#include "xfs_bit.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100025#include "xfs_mount.h"
Dave Chinner57062782013-10-15 09:17:51 +110026#include "xfs_da_format.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100027#include "xfs_da_btree.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100028#include "xfs_inode.h"
Dave Chinner2b9ab5a2013-08-12 20:49:37 +100029#include "xfs_dir2.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100030#include "xfs_dir2_priv.h"
31#include "xfs_error.h"
32#include "xfs_trace.h"
33#include "xfs_bmap.h"
Dave Chinner239880e2013-10-23 10:50:10 +110034#include "xfs_trans.h"
Dave Chinner4a8af272013-08-12 20:49:36 +100035
Dave Chinner0cb97762013-08-12 20:50:09 +100036/*
37 * Directory file type support functions
38 */
39static unsigned char xfs_dir3_filetype_table[] = {
40 DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK,
41 DT_FIFO, DT_SOCK, DT_LNK, DT_WHT,
42};
43
Dave Chinner1b767ee2014-12-04 09:43:17 +110044static unsigned char
Dave Chinner0cb97762013-08-12 20:50:09 +100045xfs_dir3_get_dtype(
46 struct xfs_mount *mp,
47 __uint8_t filetype)
48{
49 if (!xfs_sb_version_hasftype(&mp->m_sb))
50 return DT_UNKNOWN;
51
52 if (filetype >= XFS_DIR3_FT_MAX)
53 return DT_UNKNOWN;
54
55 return xfs_dir3_filetype_table[filetype];
56}
Dave Chinner0cb97762013-08-12 20:50:09 +100057
Dave Chinner4a8af272013-08-12 20:49:36 +100058STATIC int
59xfs_dir2_sf_getdents(
Dave Chinner53f82db2014-06-06 15:20:32 +100060 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +100061 struct dir_context *ctx)
62{
63 int i; /* shortform entry number */
Dave Chinner53f82db2014-06-06 15:20:32 +100064 struct xfs_inode *dp = args->dp; /* incore directory inode */
Dave Chinner4a8af272013-08-12 20:49:36 +100065 xfs_dir2_dataptr_t off; /* current entry's offset */
66 xfs_dir2_sf_entry_t *sfep; /* shortform directory entry */
67 xfs_dir2_sf_hdr_t *sfp; /* shortform structure */
68 xfs_dir2_dataptr_t dot_offset;
69 xfs_dir2_dataptr_t dotdot_offset;
70 xfs_ino_t ino;
Dave Chinner53f82db2014-06-06 15:20:32 +100071 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +100072
73 ASSERT(dp->i_df.if_flags & XFS_IFINLINE);
74 /*
75 * Give up if the directory is way too short.
76 */
77 if (dp->i_d.di_size < offsetof(xfs_dir2_sf_hdr_t, parent)) {
Dave Chinner53f82db2014-06-06 15:20:32 +100078 ASSERT(XFS_FORCED_SHUTDOWN(dp->i_mount));
Dave Chinner24513372014-06-25 14:58:08 +100079 return -EIO;
Dave Chinner4a8af272013-08-12 20:49:36 +100080 }
81
82 ASSERT(dp->i_df.if_bytes == dp->i_d.di_size);
83 ASSERT(dp->i_df.if_u1.if_data != NULL);
84
85 sfp = (xfs_dir2_sf_hdr_t *)dp->i_df.if_u1.if_data;
86
Darrick J. Wong9cdafd82016-10-03 09:11:15 -070087 if (dp->i_d.di_size < xfs_dir2_sf_hdr_size(sfp->i8count))
88 return -EFSCORRUPTED;
Dave Chinner4a8af272013-08-12 20:49:36 +100089
90 /*
91 * If the block number in the offset is out of range, we're done.
92 */
Dave Chinner7dda6e82014-06-06 15:11:18 +100093 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
Dave Chinner4a8af272013-08-12 20:49:36 +100094 return 0;
95
96 /*
97 * Precalculate offsets for . and .. as we will always need them.
98 *
99 * XXX(hch): the second argument is sometimes 0 and sometimes
Dave Chinner7dda6e82014-06-06 15:11:18 +1000100 * geo->datablk
Dave Chinner4a8af272013-08-12 20:49:36 +1000101 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000102 dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100103 dp->d_ops->data_dot_offset);
Dave Chinner7dda6e82014-06-06 15:11:18 +1000104 dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100105 dp->d_ops->data_dotdot_offset);
Dave Chinner4a8af272013-08-12 20:49:36 +1000106
107 /*
108 * Put . entry unless we're starting past it.
109 */
110 if (ctx->pos <= dot_offset) {
111 ctx->pos = dot_offset & 0x7fffffff;
112 if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR))
113 return 0;
114 }
115
116 /*
117 * Put .. entry unless we're starting past it.
118 */
119 if (ctx->pos <= dotdot_offset) {
Dave Chinner47401752013-10-29 22:11:47 +1100120 ino = dp->d_ops->sf_get_parent_ino(sfp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000121 ctx->pos = dotdot_offset & 0x7fffffff;
122 if (!dir_emit(ctx, "..", 2, ino, DT_DIR))
123 return 0;
124 }
125
126 /*
127 * Loop while there are more entries and put'ing works.
128 */
129 sfep = xfs_dir2_sf_firstentry(sfp);
130 for (i = 0; i < sfp->count; i++) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000131 __uint8_t filetype;
132
Dave Chinner7dda6e82014-06-06 15:11:18 +1000133 off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner4a8af272013-08-12 20:49:36 +1000134 xfs_dir2_sf_get_offset(sfep));
135
136 if (ctx->pos > off) {
Dave Chinner32c54832013-10-29 22:11:46 +1100137 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000138 continue;
139 }
140
Dave Chinner47401752013-10-29 22:11:47 +1100141 ino = dp->d_ops->sf_get_ino(sfp, sfep);
142 filetype = dp->d_ops->sf_get_ftype(sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000143 ctx->pos = off & 0x7fffffff;
Dave Chinner0cb97762013-08-12 20:50:09 +1000144 if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino,
Dave Chinner53f82db2014-06-06 15:20:32 +1000145 xfs_dir3_get_dtype(dp->i_mount, filetype)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000146 return 0;
Dave Chinner32c54832013-10-29 22:11:46 +1100147 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000148 }
149
Dave Chinner7dda6e82014-06-06 15:11:18 +1000150 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
Dave Chinner53f82db2014-06-06 15:20:32 +1000151 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000152 return 0;
153}
154
155/*
156 * Readdir for block directories.
157 */
158STATIC int
159xfs_dir2_block_getdents(
Dave Chinner53f82db2014-06-06 15:20:32 +1000160 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000161 struct dir_context *ctx)
162{
Dave Chinner53f82db2014-06-06 15:20:32 +1000163 struct xfs_inode *dp = args->dp; /* incore directory inode */
Dave Chinner4a8af272013-08-12 20:49:36 +1000164 xfs_dir2_data_hdr_t *hdr; /* block header */
165 struct xfs_buf *bp; /* buffer for block */
166 xfs_dir2_block_tail_t *btp; /* block tail */
167 xfs_dir2_data_entry_t *dep; /* block data entry */
168 xfs_dir2_data_unused_t *dup; /* block unused entry */
169 char *endptr; /* end of the data entries */
170 int error; /* error return value */
Dave Chinner4a8af272013-08-12 20:49:36 +1000171 char *ptr; /* current data entry */
172 int wantoff; /* starting block offset */
173 xfs_off_t cook;
Dave Chinner53f82db2014-06-06 15:20:32 +1000174 struct xfs_da_geometry *geo = args->geo;
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000175 int lock_mode;
Dave Chinner4a8af272013-08-12 20:49:36 +1000176
Dave Chinner4a8af272013-08-12 20:49:36 +1000177 /*
178 * If the block number in the offset is out of range, we're done.
179 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000180 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
Dave Chinner4a8af272013-08-12 20:49:36 +1000181 return 0;
182
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000183 lock_mode = xfs_ilock_data_map_shared(dp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000184 error = xfs_dir3_block_read(NULL, dp, &bp);
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000185 xfs_iunlock(dp, lock_mode);
Dave Chinner4a8af272013-08-12 20:49:36 +1000186 if (error)
187 return error;
188
189 /*
190 * Extract the byte offset we start at from the seek pointer.
191 * We'll skip entries before this.
192 */
Dave Chinner30028032014-06-06 15:08:18 +1000193 wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos);
Dave Chinner4a8af272013-08-12 20:49:36 +1000194 hdr = bp->b_addr;
195 xfs_dir3_data_check(dp, bp);
196 /*
197 * Set up values for the loop.
198 */
Dave Chinner8f661932014-06-06 15:15:59 +1000199 btp = xfs_dir2_block_tail_p(geo, hdr);
Dave Chinner2ca98772013-10-29 22:11:49 +1100200 ptr = (char *)dp->d_ops->data_entry_p(hdr);
Dave Chinner4a8af272013-08-12 20:49:36 +1000201 endptr = (char *)xfs_dir2_block_leaf_p(btp);
202
203 /*
204 * Loop over the data portion of the block.
205 * Each object is a real entry (dep) or an unused one (dup).
206 */
207 while (ptr < endptr) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000208 __uint8_t filetype;
209
Dave Chinner4a8af272013-08-12 20:49:36 +1000210 dup = (xfs_dir2_data_unused_t *)ptr;
211 /*
212 * Unused, skip it.
213 */
214 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
215 ptr += be16_to_cpu(dup->length);
216 continue;
217 }
218
219 dep = (xfs_dir2_data_entry_t *)ptr;
220
221 /*
222 * Bump pointer for the next iteration.
223 */
Dave Chinner9d23fc82013-10-29 22:11:48 +1100224 ptr += dp->d_ops->data_entsize(dep->namelen);
Dave Chinner4a8af272013-08-12 20:49:36 +1000225 /*
226 * The entry is before the desired starting point, skip it.
227 */
228 if ((char *)dep - (char *)hdr < wantoff)
229 continue;
230
Dave Chinner7dda6e82014-06-06 15:11:18 +1000231 cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner4a8af272013-08-12 20:49:36 +1000232 (char *)dep - (char *)hdr);
233
234 ctx->pos = cook & 0x7fffffff;
Dave Chinner9d23fc82013-10-29 22:11:48 +1100235 filetype = dp->d_ops->data_get_ftype(dep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000236 /*
237 * If it didn't fit, set the final offset to here & return.
238 */
239 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
Dave Chinner0cb97762013-08-12 20:50:09 +1000240 be64_to_cpu(dep->inumber),
Dave Chinner53f82db2014-06-06 15:20:32 +1000241 xfs_dir3_get_dtype(dp->i_mount, filetype))) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000242 xfs_trans_brelse(NULL, bp);
243 return 0;
244 }
245 }
246
247 /*
248 * Reached the end of the block.
249 * Set the offset to a non-existent block 1 and return.
250 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000251 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
Dave Chinner53f82db2014-06-06 15:20:32 +1000252 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000253 xfs_trans_brelse(NULL, bp);
254 return 0;
255}
256
257struct xfs_dir2_leaf_map_info {
258 xfs_extlen_t map_blocks; /* number of fsbs in map */
259 xfs_dablk_t map_off; /* last mapped file offset */
260 int map_size; /* total entries in *map */
261 int map_valid; /* valid entries in *map */
262 int nmap; /* mappings to ask xfs_bmapi */
263 xfs_dir2_db_t curdb; /* db for current block */
264 int ra_current; /* number of read-ahead blks */
265 int ra_index; /* *map index for read-ahead */
266 int ra_offset; /* map entry offset for ra */
267 int ra_want; /* readahead count wanted */
268 struct xfs_bmbt_irec map[]; /* map vector for blocks */
269};
270
271STATIC int
272xfs_dir2_leaf_readbuf(
Dave Chinner53f82db2014-06-06 15:20:32 +1000273 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000274 size_t bufsize,
275 struct xfs_dir2_leaf_map_info *mip,
276 xfs_dir2_off_t *curoff,
Dave Chinner9f541802016-05-19 00:17:26 +1000277 struct xfs_buf **bpp,
278 bool trim_map)
Dave Chinner4a8af272013-08-12 20:49:36 +1000279{
Dave Chinner53f82db2014-06-06 15:20:32 +1000280 struct xfs_inode *dp = args->dp;
Dave Chinner9f541802016-05-19 00:17:26 +1000281 struct xfs_buf *bp = NULL;
Dave Chinner4a8af272013-08-12 20:49:36 +1000282 struct xfs_bmbt_irec *map = mip->map;
283 struct blk_plug plug;
284 int error = 0;
285 int length;
286 int i;
287 int j;
Dave Chinner53f82db2014-06-06 15:20:32 +1000288 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +1000289
290 /*
Dave Chinner9f541802016-05-19 00:17:26 +1000291 * If the caller just finished processing a buffer, it will tell us
292 * we need to trim that block out of the mapping now it is done.
Dave Chinner4a8af272013-08-12 20:49:36 +1000293 */
Dave Chinner9f541802016-05-19 00:17:26 +1000294 if (trim_map) {
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000295 mip->map_blocks -= geo->fsbcount;
Dave Chinner4a8af272013-08-12 20:49:36 +1000296 /*
297 * Loop to get rid of the extents for the
298 * directory block.
299 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000300 for (i = geo->fsbcount; i > 0; ) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000301 j = min_t(int, map->br_blockcount, i);
302 map->br_blockcount -= j;
303 map->br_startblock += j;
304 map->br_startoff += j;
305 /*
306 * If mapping is done, pitch it from
307 * the table.
308 */
309 if (!map->br_blockcount && --mip->map_valid)
310 memmove(&map[0], &map[1],
311 sizeof(map[0]) * mip->map_valid);
312 i -= j;
313 }
314 }
315
316 /*
317 * Recalculate the readahead blocks wanted.
318 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000319 mip->ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog)) - 1;
Dave Chinner4a8af272013-08-12 20:49:36 +1000320 ASSERT(mip->ra_want >= 0);
321
322 /*
323 * If we don't have as many as we want, and we haven't
324 * run out of data blocks, get some more mappings.
325 */
326 if (1 + mip->ra_want > mip->map_blocks &&
Dave Chinner30028032014-06-06 15:08:18 +1000327 mip->map_off < xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET)) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000328 /*
329 * Get more bmaps, fill in after the ones
330 * we already have in the table.
331 */
332 mip->nmap = mip->map_size - mip->map_valid;
333 error = xfs_bmapi_read(dp, mip->map_off,
Dave Chinner30028032014-06-06 15:08:18 +1000334 xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET) -
Dave Chinner4a8af272013-08-12 20:49:36 +1000335 mip->map_off,
336 &map[mip->map_valid], &mip->nmap, 0);
337
338 /*
339 * Don't know if we should ignore this or try to return an
340 * error. The trouble with returning errors is that readdir
341 * will just stop without actually passing the error through.
342 */
343 if (error)
344 goto out; /* XXX */
345
346 /*
347 * If we got all the mappings we asked for, set the final map
348 * offset based on the last bmap value received. Otherwise,
349 * we've reached the end.
350 */
351 if (mip->nmap == mip->map_size - mip->map_valid) {
352 i = mip->map_valid + mip->nmap - 1;
353 mip->map_off = map[i].br_startoff + map[i].br_blockcount;
354 } else
Dave Chinner30028032014-06-06 15:08:18 +1000355 mip->map_off = xfs_dir2_byte_to_da(geo,
Dave Chinner4a8af272013-08-12 20:49:36 +1000356 XFS_DIR2_LEAF_OFFSET);
357
358 /*
359 * Look for holes in the mapping, and eliminate them. Count up
360 * the valid blocks.
361 */
362 for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) {
363 if (map[i].br_startblock == HOLESTARTBLOCK) {
364 mip->nmap--;
365 length = mip->map_valid + mip->nmap - i;
366 if (length)
367 memmove(&map[i], &map[i + 1],
368 sizeof(map[i]) * length);
369 } else {
370 mip->map_blocks += map[i].br_blockcount;
371 i++;
372 }
373 }
374 mip->map_valid += mip->nmap;
375 }
376
377 /*
378 * No valid mappings, so no more data blocks.
379 */
380 if (!mip->map_valid) {
Dave Chinner30028032014-06-06 15:08:18 +1000381 *curoff = xfs_dir2_da_to_byte(geo, mip->map_off);
Dave Chinner4a8af272013-08-12 20:49:36 +1000382 goto out;
383 }
384
385 /*
386 * Read the directory block starting at the first mapping.
387 */
Dave Chinner30028032014-06-06 15:08:18 +1000388 mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff);
Dave Chinner4a8af272013-08-12 20:49:36 +1000389 error = xfs_dir3_data_read(NULL, dp, map->br_startoff,
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000390 map->br_blockcount >= geo->fsbcount ?
Dave Chinner53f82db2014-06-06 15:20:32 +1000391 XFS_FSB_TO_DADDR(dp->i_mount, map->br_startblock) :
392 -1, &bp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000393 /*
394 * Should just skip over the data block instead of giving up.
395 */
396 if (error)
397 goto out; /* XXX */
398
399 /*
400 * Adjust the current amount of read-ahead: we just read a block that
401 * was previously ra.
402 */
403 if (mip->ra_current)
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000404 mip->ra_current -= geo->fsbcount;
Dave Chinner4a8af272013-08-12 20:49:36 +1000405
406 /*
407 * Do we need more readahead?
408 */
409 blk_start_plug(&plug);
410 for (mip->ra_index = mip->ra_offset = i = 0;
411 mip->ra_want > mip->ra_current && i < mip->map_blocks;
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000412 i += geo->fsbcount) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000413 ASSERT(mip->ra_index < mip->map_valid);
414 /*
415 * Read-ahead a contiguous directory block.
416 */
417 if (i > mip->ra_current &&
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000418 map[mip->ra_index].br_blockcount >= geo->fsbcount) {
Eric Sandeen9df2dd02014-04-14 19:01:59 +1000419 xfs_dir3_data_readahead(dp,
Dave Chinner4a8af272013-08-12 20:49:36 +1000420 map[mip->ra_index].br_startoff + mip->ra_offset,
Dave Chinner53f82db2014-06-06 15:20:32 +1000421 XFS_FSB_TO_DADDR(dp->i_mount,
Dave Chinner4a8af272013-08-12 20:49:36 +1000422 map[mip->ra_index].br_startblock +
423 mip->ra_offset));
424 mip->ra_current = i;
425 }
426
427 /*
428 * Read-ahead a non-contiguous directory block. This doesn't
429 * use our mapping, but this is a very rare case.
430 */
431 else if (i > mip->ra_current) {
Eric Sandeen9df2dd02014-04-14 19:01:59 +1000432 xfs_dir3_data_readahead(dp,
Dave Chinner4a8af272013-08-12 20:49:36 +1000433 map[mip->ra_index].br_startoff +
434 mip->ra_offset, -1);
435 mip->ra_current = i;
436 }
437
438 /*
439 * Advance offset through the mapping table.
440 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000441 for (j = 0; j < geo->fsbcount; j += length ) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000442 /*
443 * The rest of this extent but not more than a dir
444 * block.
445 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000446 length = min_t(int, geo->fsbcount,
Dave Chinner4a8af272013-08-12 20:49:36 +1000447 map[mip->ra_index].br_blockcount -
448 mip->ra_offset);
Dave Chinner4a8af272013-08-12 20:49:36 +1000449 mip->ra_offset += length;
450
451 /*
452 * Advance to the next mapping if this one is used up.
453 */
454 if (mip->ra_offset == map[mip->ra_index].br_blockcount) {
455 mip->ra_offset = 0;
456 mip->ra_index++;
457 }
458 }
459 }
460 blk_finish_plug(&plug);
461
462out:
463 *bpp = bp;
464 return error;
465}
466
467/*
468 * Getdents (readdir) for leaf and node directories.
469 * This reads the data blocks only, so is the same for both forms.
470 */
471STATIC int
472xfs_dir2_leaf_getdents(
Dave Chinner53f82db2014-06-06 15:20:32 +1000473 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000474 struct dir_context *ctx,
475 size_t bufsize)
476{
Dave Chinner53f82db2014-06-06 15:20:32 +1000477 struct xfs_inode *dp = args->dp;
Dave Chinner4a8af272013-08-12 20:49:36 +1000478 struct xfs_buf *bp = NULL; /* data block buffer */
479 xfs_dir2_data_hdr_t *hdr; /* data block header */
480 xfs_dir2_data_entry_t *dep; /* data entry */
481 xfs_dir2_data_unused_t *dup; /* unused entry */
482 int error = 0; /* error return value */
483 int length; /* temporary length value */
Dave Chinner4a8af272013-08-12 20:49:36 +1000484 int byteoff; /* offset in current block */
485 xfs_dir2_off_t curoff; /* current overall offset */
486 xfs_dir2_off_t newoff; /* new curoff after new blk */
487 char *ptr = NULL; /* pointer to current data */
488 struct xfs_dir2_leaf_map_info *map_info;
Dave Chinner53f82db2014-06-06 15:20:32 +1000489 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +1000490
491 /*
492 * If the offset is at or past the largest allowed value,
493 * give up right away.
494 */
495 if (ctx->pos >= XFS_DIR2_MAX_DATAPTR)
496 return 0;
497
Dave Chinner4a8af272013-08-12 20:49:36 +1000498 /*
499 * Set up to bmap a number of blocks based on the caller's
500 * buffer size, the directory block size, and the filesystem
501 * block size.
502 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000503 length = howmany(bufsize + geo->blksize, (1 << geo->fsblog));
Dave Chinner4a8af272013-08-12 20:49:36 +1000504 map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) +
505 (length * sizeof(struct xfs_bmbt_irec)),
506 KM_SLEEP | KM_NOFS);
507 map_info->map_size = length;
508
509 /*
510 * Inside the loop we keep the main offset value as a byte offset
511 * in the directory file.
512 */
Eric Sandeen25994052014-04-14 19:02:30 +1000513 curoff = xfs_dir2_dataptr_to_byte(ctx->pos);
Dave Chinner4a8af272013-08-12 20:49:36 +1000514
515 /*
516 * Force this conversion through db so we truncate the offset
517 * down to get the start of the data block.
518 */
Dave Chinner30028032014-06-06 15:08:18 +1000519 map_info->map_off = xfs_dir2_db_to_da(geo,
520 xfs_dir2_byte_to_db(geo, curoff));
Dave Chinner4a8af272013-08-12 20:49:36 +1000521
522 /*
523 * Loop over directory entries until we reach the end offset.
524 * Get more blocks and readahead as necessary.
525 */
526 while (curoff < XFS_DIR2_LEAF_OFFSET) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000527 __uint8_t filetype;
528
Dave Chinner4a8af272013-08-12 20:49:36 +1000529 /*
530 * If we have no buffer, or we're off the end of the
531 * current buffer, need to get another one.
532 */
Dave Chinner8f661932014-06-06 15:15:59 +1000533 if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) {
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000534 int lock_mode;
Dave Chinner9f541802016-05-19 00:17:26 +1000535 bool trim_map = false;
536
537 if (bp) {
538 xfs_trans_brelse(NULL, bp);
539 bp = NULL;
540 trim_map = true;
541 }
Dave Chinner4a8af272013-08-12 20:49:36 +1000542
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000543 lock_mode = xfs_ilock_data_map_shared(dp);
Dave Chinner53f82db2014-06-06 15:20:32 +1000544 error = xfs_dir2_leaf_readbuf(args, bufsize, map_info,
Dave Chinner9f541802016-05-19 00:17:26 +1000545 &curoff, &bp, trim_map);
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000546 xfs_iunlock(dp, lock_mode);
Dave Chinner4a8af272013-08-12 20:49:36 +1000547 if (error || !map_info->map_valid)
548 break;
549
550 /*
551 * Having done a read, we need to set a new offset.
552 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000553 newoff = xfs_dir2_db_off_to_byte(geo,
Dave Chinner9b3b5522014-06-06 15:06:53 +1000554 map_info->curdb, 0);
Dave Chinner4a8af272013-08-12 20:49:36 +1000555 /*
556 * Start of the current block.
557 */
558 if (curoff < newoff)
559 curoff = newoff;
560 /*
561 * Make sure we're in the right block.
562 */
563 else if (curoff > newoff)
Dave Chinner30028032014-06-06 15:08:18 +1000564 ASSERT(xfs_dir2_byte_to_db(geo, curoff) ==
Dave Chinner4a8af272013-08-12 20:49:36 +1000565 map_info->curdb);
566 hdr = bp->b_addr;
567 xfs_dir3_data_check(dp, bp);
568 /*
569 * Find our position in the block.
570 */
Dave Chinner2ca98772013-10-29 22:11:49 +1100571 ptr = (char *)dp->d_ops->data_entry_p(hdr);
Dave Chinner53f82db2014-06-06 15:20:32 +1000572 byteoff = xfs_dir2_byte_to_off(geo, curoff);
Dave Chinner4a8af272013-08-12 20:49:36 +1000573 /*
574 * Skip past the header.
575 */
576 if (byteoff == 0)
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100577 curoff += dp->d_ops->data_entry_offset;
Dave Chinner4a8af272013-08-12 20:49:36 +1000578 /*
579 * Skip past entries until we reach our offset.
580 */
581 else {
582 while ((char *)ptr - (char *)hdr < byteoff) {
583 dup = (xfs_dir2_data_unused_t *)ptr;
584
585 if (be16_to_cpu(dup->freetag)
586 == XFS_DIR2_DATA_FREE_TAG) {
587
588 length = be16_to_cpu(dup->length);
589 ptr += length;
590 continue;
591 }
592 dep = (xfs_dir2_data_entry_t *)ptr;
593 length =
Dave Chinner9d23fc82013-10-29 22:11:48 +1100594 dp->d_ops->data_entsize(dep->namelen);
Dave Chinner4a8af272013-08-12 20:49:36 +1000595 ptr += length;
596 }
597 /*
598 * Now set our real offset.
599 */
600 curoff =
Dave Chinner30028032014-06-06 15:08:18 +1000601 xfs_dir2_db_off_to_byte(geo,
602 xfs_dir2_byte_to_db(geo, curoff),
Dave Chinner4a8af272013-08-12 20:49:36 +1000603 (char *)ptr - (char *)hdr);
Dave Chinner8f661932014-06-06 15:15:59 +1000604 if (ptr >= (char *)hdr + geo->blksize) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000605 continue;
606 }
607 }
608 }
609 /*
610 * We have a pointer to an entry.
611 * Is it a live one?
612 */
613 dup = (xfs_dir2_data_unused_t *)ptr;
614 /*
615 * No, it's unused, skip over it.
616 */
617 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
618 length = be16_to_cpu(dup->length);
619 ptr += length;
620 curoff += length;
621 continue;
622 }
623
624 dep = (xfs_dir2_data_entry_t *)ptr;
Dave Chinner9d23fc82013-10-29 22:11:48 +1100625 length = dp->d_ops->data_entsize(dep->namelen);
626 filetype = dp->d_ops->data_get_ftype(dep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000627
Eric Sandeen25994052014-04-14 19:02:30 +1000628 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000629 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
Dave Chinner0cb97762013-08-12 20:50:09 +1000630 be64_to_cpu(dep->inumber),
Dave Chinner53f82db2014-06-06 15:20:32 +1000631 xfs_dir3_get_dtype(dp->i_mount, filetype)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000632 break;
633
634 /*
635 * Advance to next entry in the block.
636 */
637 ptr += length;
638 curoff += length;
639 /* bufsize may have just been a guess; don't go negative */
640 bufsize = bufsize > length ? bufsize - length : 0;
641 }
642
643 /*
644 * All done. Set output offset value to current offset.
645 */
Eric Sandeen25994052014-04-14 19:02:30 +1000646 if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR))
Dave Chinner4a8af272013-08-12 20:49:36 +1000647 ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
648 else
Eric Sandeen25994052014-04-14 19:02:30 +1000649 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000650 kmem_free(map_info);
651 if (bp)
652 xfs_trans_brelse(NULL, bp);
653 return error;
654}
655
656/*
657 * Read a directory.
658 */
659int
660xfs_readdir(
Dave Chinner53f82db2014-06-06 15:20:32 +1000661 struct xfs_inode *dp,
662 struct dir_context *ctx,
663 size_t bufsize)
Dave Chinner4a8af272013-08-12 20:49:36 +1000664{
Dave Chinner35f46c52014-06-10 07:30:36 +1000665 struct xfs_da_args args = { NULL };
Dave Chinner53f82db2014-06-06 15:20:32 +1000666 int rval;
667 int v;
Dave Chinner4a8af272013-08-12 20:49:36 +1000668
669 trace_xfs_readdir(dp);
670
671 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
Dave Chinner24513372014-06-25 14:58:08 +1000672 return -EIO;
Dave Chinner4a8af272013-08-12 20:49:36 +1000673
Dave Chinnerc19b3b052016-02-09 16:54:58 +1100674 ASSERT(S_ISDIR(VFS_I(dp)->i_mode));
Bill O'Donnellff6d6af2015-10-12 18:21:22 +1100675 XFS_STATS_INC(dp->i_mount, xs_dir_getdents);
Dave Chinner4a8af272013-08-12 20:49:36 +1000676
Dave Chinner53f82db2014-06-06 15:20:32 +1000677 args.dp = dp;
678 args.geo = dp->i_mount->m_dir_geo;
679
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000680 xfs_ilock(dp, XFS_IOLOCK_SHARED);
Dave Chinner4a8af272013-08-12 20:49:36 +1000681 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
Dave Chinner53f82db2014-06-06 15:20:32 +1000682 rval = xfs_dir2_sf_getdents(&args, ctx);
683 else if ((rval = xfs_dir2_isblock(&args, &v)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000684 ;
685 else if (v)
Dave Chinner53f82db2014-06-06 15:20:32 +1000686 rval = xfs_dir2_block_getdents(&args, ctx);
Dave Chinner4a8af272013-08-12 20:49:36 +1000687 else
Dave Chinner53f82db2014-06-06 15:20:32 +1000688 rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize);
Dave Chinnerdbad7c92015-08-19 10:33:00 +1000689 xfs_iunlock(dp, XFS_IOLOCK_SHARED);
Ben Myers40194ec2013-12-06 12:30:11 -0800690
Dave Chinner4a8af272013-08-12 20:49:36 +1000691 return rval;
692}