blob: 098cd78fe708433fdf77306637626d6b69400582 [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
87 ASSERT(dp->i_d.di_size >= xfs_dir2_sf_hdr_size(sfp->i8count));
88
89 /*
90 * If the block number in the offset is out of range, we're done.
91 */
Dave Chinner7dda6e82014-06-06 15:11:18 +100092 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
Dave Chinner4a8af272013-08-12 20:49:36 +100093 return 0;
94
95 /*
96 * Precalculate offsets for . and .. as we will always need them.
97 *
98 * XXX(hch): the second argument is sometimes 0 and sometimes
Dave Chinner7dda6e82014-06-06 15:11:18 +100099 * geo->datablk
Dave Chinner4a8af272013-08-12 20:49:36 +1000100 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000101 dot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100102 dp->d_ops->data_dot_offset);
Dave Chinner7dda6e82014-06-06 15:11:18 +1000103 dotdot_offset = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100104 dp->d_ops->data_dotdot_offset);
Dave Chinner4a8af272013-08-12 20:49:36 +1000105
106 /*
107 * Put . entry unless we're starting past it.
108 */
109 if (ctx->pos <= dot_offset) {
110 ctx->pos = dot_offset & 0x7fffffff;
111 if (!dir_emit(ctx, ".", 1, dp->i_ino, DT_DIR))
112 return 0;
113 }
114
115 /*
116 * Put .. entry unless we're starting past it.
117 */
118 if (ctx->pos <= dotdot_offset) {
Dave Chinner47401752013-10-29 22:11:47 +1100119 ino = dp->d_ops->sf_get_parent_ino(sfp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000120 ctx->pos = dotdot_offset & 0x7fffffff;
121 if (!dir_emit(ctx, "..", 2, ino, DT_DIR))
122 return 0;
123 }
124
125 /*
126 * Loop while there are more entries and put'ing works.
127 */
128 sfep = xfs_dir2_sf_firstentry(sfp);
129 for (i = 0; i < sfp->count; i++) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000130 __uint8_t filetype;
131
Dave Chinner7dda6e82014-06-06 15:11:18 +1000132 off = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner4a8af272013-08-12 20:49:36 +1000133 xfs_dir2_sf_get_offset(sfep));
134
135 if (ctx->pos > off) {
Dave Chinner32c54832013-10-29 22:11:46 +1100136 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000137 continue;
138 }
139
Dave Chinner47401752013-10-29 22:11:47 +1100140 ino = dp->d_ops->sf_get_ino(sfp, sfep);
141 filetype = dp->d_ops->sf_get_ftype(sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000142 ctx->pos = off & 0x7fffffff;
Dave Chinner0cb97762013-08-12 20:50:09 +1000143 if (!dir_emit(ctx, (char *)sfep->name, sfep->namelen, ino,
Dave Chinner53f82db2014-06-06 15:20:32 +1000144 xfs_dir3_get_dtype(dp->i_mount, filetype)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000145 return 0;
Dave Chinner32c54832013-10-29 22:11:46 +1100146 sfep = dp->d_ops->sf_nextentry(sfp, sfep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000147 }
148
Dave Chinner7dda6e82014-06-06 15:11:18 +1000149 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
Dave Chinner53f82db2014-06-06 15:20:32 +1000150 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000151 return 0;
152}
153
154/*
155 * Readdir for block directories.
156 */
157STATIC int
158xfs_dir2_block_getdents(
Dave Chinner53f82db2014-06-06 15:20:32 +1000159 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000160 struct dir_context *ctx)
161{
Dave Chinner53f82db2014-06-06 15:20:32 +1000162 struct xfs_inode *dp = args->dp; /* incore directory inode */
Dave Chinner4a8af272013-08-12 20:49:36 +1000163 xfs_dir2_data_hdr_t *hdr; /* block header */
164 struct xfs_buf *bp; /* buffer for block */
165 xfs_dir2_block_tail_t *btp; /* block tail */
166 xfs_dir2_data_entry_t *dep; /* block data entry */
167 xfs_dir2_data_unused_t *dup; /* block unused entry */
168 char *endptr; /* end of the data entries */
169 int error; /* error return value */
Dave Chinner4a8af272013-08-12 20:49:36 +1000170 char *ptr; /* current data entry */
171 int wantoff; /* starting block offset */
172 xfs_off_t cook;
Dave Chinner53f82db2014-06-06 15:20:32 +1000173 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +1000174
Dave Chinner4a8af272013-08-12 20:49:36 +1000175 /*
176 * If the block number in the offset is out of range, we're done.
177 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000178 if (xfs_dir2_dataptr_to_db(geo, ctx->pos) > geo->datablk)
Dave Chinner4a8af272013-08-12 20:49:36 +1000179 return 0;
180
181 error = xfs_dir3_block_read(NULL, dp, &bp);
182 if (error)
183 return error;
184
185 /*
186 * Extract the byte offset we start at from the seek pointer.
187 * We'll skip entries before this.
188 */
Dave Chinner30028032014-06-06 15:08:18 +1000189 wantoff = xfs_dir2_dataptr_to_off(geo, ctx->pos);
Dave Chinner4a8af272013-08-12 20:49:36 +1000190 hdr = bp->b_addr;
191 xfs_dir3_data_check(dp, bp);
192 /*
193 * Set up values for the loop.
194 */
Dave Chinner8f661932014-06-06 15:15:59 +1000195 btp = xfs_dir2_block_tail_p(geo, hdr);
Dave Chinner2ca98772013-10-29 22:11:49 +1100196 ptr = (char *)dp->d_ops->data_entry_p(hdr);
Dave Chinner4a8af272013-08-12 20:49:36 +1000197 endptr = (char *)xfs_dir2_block_leaf_p(btp);
198
199 /*
200 * Loop over the data portion of the block.
201 * Each object is a real entry (dep) or an unused one (dup).
202 */
203 while (ptr < endptr) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000204 __uint8_t filetype;
205
Dave Chinner4a8af272013-08-12 20:49:36 +1000206 dup = (xfs_dir2_data_unused_t *)ptr;
207 /*
208 * Unused, skip it.
209 */
210 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
211 ptr += be16_to_cpu(dup->length);
212 continue;
213 }
214
215 dep = (xfs_dir2_data_entry_t *)ptr;
216
217 /*
218 * Bump pointer for the next iteration.
219 */
Dave Chinner9d23fc82013-10-29 22:11:48 +1100220 ptr += dp->d_ops->data_entsize(dep->namelen);
Dave Chinner4a8af272013-08-12 20:49:36 +1000221 /*
222 * The entry is before the desired starting point, skip it.
223 */
224 if ((char *)dep - (char *)hdr < wantoff)
225 continue;
226
Dave Chinner7dda6e82014-06-06 15:11:18 +1000227 cook = xfs_dir2_db_off_to_dataptr(geo, geo->datablk,
Dave Chinner4a8af272013-08-12 20:49:36 +1000228 (char *)dep - (char *)hdr);
229
230 ctx->pos = cook & 0x7fffffff;
Dave Chinner9d23fc82013-10-29 22:11:48 +1100231 filetype = dp->d_ops->data_get_ftype(dep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000232 /*
233 * If it didn't fit, set the final offset to here & return.
234 */
235 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
Dave Chinner0cb97762013-08-12 20:50:09 +1000236 be64_to_cpu(dep->inumber),
Dave Chinner53f82db2014-06-06 15:20:32 +1000237 xfs_dir3_get_dtype(dp->i_mount, filetype))) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000238 xfs_trans_brelse(NULL, bp);
239 return 0;
240 }
241 }
242
243 /*
244 * Reached the end of the block.
245 * Set the offset to a non-existent block 1 and return.
246 */
Dave Chinner7dda6e82014-06-06 15:11:18 +1000247 ctx->pos = xfs_dir2_db_off_to_dataptr(geo, geo->datablk + 1, 0) &
Dave Chinner53f82db2014-06-06 15:20:32 +1000248 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000249 xfs_trans_brelse(NULL, bp);
250 return 0;
251}
252
253struct xfs_dir2_leaf_map_info {
254 xfs_extlen_t map_blocks; /* number of fsbs in map */
255 xfs_dablk_t map_off; /* last mapped file offset */
256 int map_size; /* total entries in *map */
257 int map_valid; /* valid entries in *map */
258 int nmap; /* mappings to ask xfs_bmapi */
259 xfs_dir2_db_t curdb; /* db for current block */
260 int ra_current; /* number of read-ahead blks */
261 int ra_index; /* *map index for read-ahead */
262 int ra_offset; /* map entry offset for ra */
263 int ra_want; /* readahead count wanted */
264 struct xfs_bmbt_irec map[]; /* map vector for blocks */
265};
266
267STATIC int
268xfs_dir2_leaf_readbuf(
Dave Chinner53f82db2014-06-06 15:20:32 +1000269 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000270 size_t bufsize,
271 struct xfs_dir2_leaf_map_info *mip,
272 xfs_dir2_off_t *curoff,
273 struct xfs_buf **bpp)
274{
Dave Chinner53f82db2014-06-06 15:20:32 +1000275 struct xfs_inode *dp = args->dp;
Dave Chinner4a8af272013-08-12 20:49:36 +1000276 struct xfs_buf *bp = *bpp;
277 struct xfs_bmbt_irec *map = mip->map;
278 struct blk_plug plug;
279 int error = 0;
280 int length;
281 int i;
282 int j;
Dave Chinner53f82db2014-06-06 15:20:32 +1000283 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +1000284
285 /*
286 * If we have a buffer, we need to release it and
287 * take it out of the mapping.
288 */
289
290 if (bp) {
291 xfs_trans_brelse(NULL, bp);
292 bp = NULL;
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000293 mip->map_blocks -= geo->fsbcount;
Dave Chinner4a8af272013-08-12 20:49:36 +1000294 /*
295 * Loop to get rid of the extents for the
296 * directory block.
297 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000298 for (i = geo->fsbcount; i > 0; ) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000299 j = min_t(int, map->br_blockcount, i);
300 map->br_blockcount -= j;
301 map->br_startblock += j;
302 map->br_startoff += j;
303 /*
304 * If mapping is done, pitch it from
305 * the table.
306 */
307 if (!map->br_blockcount && --mip->map_valid)
308 memmove(&map[0], &map[1],
309 sizeof(map[0]) * mip->map_valid);
310 i -= j;
311 }
312 }
313
314 /*
315 * Recalculate the readahead blocks wanted.
316 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000317 mip->ra_want = howmany(bufsize + geo->blksize, (1 << geo->fsblog)) - 1;
Dave Chinner4a8af272013-08-12 20:49:36 +1000318 ASSERT(mip->ra_want >= 0);
319
320 /*
321 * If we don't have as many as we want, and we haven't
322 * run out of data blocks, get some more mappings.
323 */
324 if (1 + mip->ra_want > mip->map_blocks &&
Dave Chinner30028032014-06-06 15:08:18 +1000325 mip->map_off < xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET)) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000326 /*
327 * Get more bmaps, fill in after the ones
328 * we already have in the table.
329 */
330 mip->nmap = mip->map_size - mip->map_valid;
331 error = xfs_bmapi_read(dp, mip->map_off,
Dave Chinner30028032014-06-06 15:08:18 +1000332 xfs_dir2_byte_to_da(geo, XFS_DIR2_LEAF_OFFSET) -
Dave Chinner4a8af272013-08-12 20:49:36 +1000333 mip->map_off,
334 &map[mip->map_valid], &mip->nmap, 0);
335
336 /*
337 * Don't know if we should ignore this or try to return an
338 * error. The trouble with returning errors is that readdir
339 * will just stop without actually passing the error through.
340 */
341 if (error)
342 goto out; /* XXX */
343
344 /*
345 * If we got all the mappings we asked for, set the final map
346 * offset based on the last bmap value received. Otherwise,
347 * we've reached the end.
348 */
349 if (mip->nmap == mip->map_size - mip->map_valid) {
350 i = mip->map_valid + mip->nmap - 1;
351 mip->map_off = map[i].br_startoff + map[i].br_blockcount;
352 } else
Dave Chinner30028032014-06-06 15:08:18 +1000353 mip->map_off = xfs_dir2_byte_to_da(geo,
Dave Chinner4a8af272013-08-12 20:49:36 +1000354 XFS_DIR2_LEAF_OFFSET);
355
356 /*
357 * Look for holes in the mapping, and eliminate them. Count up
358 * the valid blocks.
359 */
360 for (i = mip->map_valid; i < mip->map_valid + mip->nmap; ) {
361 if (map[i].br_startblock == HOLESTARTBLOCK) {
362 mip->nmap--;
363 length = mip->map_valid + mip->nmap - i;
364 if (length)
365 memmove(&map[i], &map[i + 1],
366 sizeof(map[i]) * length);
367 } else {
368 mip->map_blocks += map[i].br_blockcount;
369 i++;
370 }
371 }
372 mip->map_valid += mip->nmap;
373 }
374
375 /*
376 * No valid mappings, so no more data blocks.
377 */
378 if (!mip->map_valid) {
Dave Chinner30028032014-06-06 15:08:18 +1000379 *curoff = xfs_dir2_da_to_byte(geo, mip->map_off);
Dave Chinner4a8af272013-08-12 20:49:36 +1000380 goto out;
381 }
382
383 /*
384 * Read the directory block starting at the first mapping.
385 */
Dave Chinner30028032014-06-06 15:08:18 +1000386 mip->curdb = xfs_dir2_da_to_db(geo, map->br_startoff);
Dave Chinner4a8af272013-08-12 20:49:36 +1000387 error = xfs_dir3_data_read(NULL, dp, map->br_startoff,
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000388 map->br_blockcount >= geo->fsbcount ?
Dave Chinner53f82db2014-06-06 15:20:32 +1000389 XFS_FSB_TO_DADDR(dp->i_mount, map->br_startblock) :
390 -1, &bp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000391 /*
392 * Should just skip over the data block instead of giving up.
393 */
394 if (error)
395 goto out; /* XXX */
396
397 /*
398 * Adjust the current amount of read-ahead: we just read a block that
399 * was previously ra.
400 */
401 if (mip->ra_current)
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000402 mip->ra_current -= geo->fsbcount;
Dave Chinner4a8af272013-08-12 20:49:36 +1000403
404 /*
405 * Do we need more readahead?
406 */
407 blk_start_plug(&plug);
408 for (mip->ra_index = mip->ra_offset = i = 0;
409 mip->ra_want > mip->ra_current && i < mip->map_blocks;
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000410 i += geo->fsbcount) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000411 ASSERT(mip->ra_index < mip->map_valid);
412 /*
413 * Read-ahead a contiguous directory block.
414 */
415 if (i > mip->ra_current &&
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000416 map[mip->ra_index].br_blockcount >= geo->fsbcount) {
Eric Sandeen9df2dd02014-04-14 19:01:59 +1000417 xfs_dir3_data_readahead(dp,
Dave Chinner4a8af272013-08-12 20:49:36 +1000418 map[mip->ra_index].br_startoff + mip->ra_offset,
Dave Chinner53f82db2014-06-06 15:20:32 +1000419 XFS_FSB_TO_DADDR(dp->i_mount,
Dave Chinner4a8af272013-08-12 20:49:36 +1000420 map[mip->ra_index].br_startblock +
421 mip->ra_offset));
422 mip->ra_current = i;
423 }
424
425 /*
426 * Read-ahead a non-contiguous directory block. This doesn't
427 * use our mapping, but this is a very rare case.
428 */
429 else if (i > mip->ra_current) {
Eric Sandeen9df2dd02014-04-14 19:01:59 +1000430 xfs_dir3_data_readahead(dp,
Dave Chinner4a8af272013-08-12 20:49:36 +1000431 map[mip->ra_index].br_startoff +
432 mip->ra_offset, -1);
433 mip->ra_current = i;
434 }
435
436 /*
437 * Advance offset through the mapping table.
438 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000439 for (j = 0; j < geo->fsbcount; j += length ) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000440 /*
441 * The rest of this extent but not more than a dir
442 * block.
443 */
Dave Chinnerd6cf1302014-06-06 15:14:11 +1000444 length = min_t(int, geo->fsbcount,
Dave Chinner4a8af272013-08-12 20:49:36 +1000445 map[mip->ra_index].br_blockcount -
446 mip->ra_offset);
Dave Chinner4a8af272013-08-12 20:49:36 +1000447 mip->ra_offset += length;
448
449 /*
450 * Advance to the next mapping if this one is used up.
451 */
452 if (mip->ra_offset == map[mip->ra_index].br_blockcount) {
453 mip->ra_offset = 0;
454 mip->ra_index++;
455 }
456 }
457 }
458 blk_finish_plug(&plug);
459
460out:
461 *bpp = bp;
462 return error;
463}
464
465/*
466 * Getdents (readdir) for leaf and node directories.
467 * This reads the data blocks only, so is the same for both forms.
468 */
469STATIC int
470xfs_dir2_leaf_getdents(
Dave Chinner53f82db2014-06-06 15:20:32 +1000471 struct xfs_da_args *args,
Dave Chinner4a8af272013-08-12 20:49:36 +1000472 struct dir_context *ctx,
473 size_t bufsize)
474{
Dave Chinner53f82db2014-06-06 15:20:32 +1000475 struct xfs_inode *dp = args->dp;
Dave Chinner4a8af272013-08-12 20:49:36 +1000476 struct xfs_buf *bp = NULL; /* data block buffer */
477 xfs_dir2_data_hdr_t *hdr; /* data block header */
478 xfs_dir2_data_entry_t *dep; /* data entry */
479 xfs_dir2_data_unused_t *dup; /* unused entry */
480 int error = 0; /* error return value */
481 int length; /* temporary length value */
Dave Chinner4a8af272013-08-12 20:49:36 +1000482 int byteoff; /* offset in current block */
483 xfs_dir2_off_t curoff; /* current overall offset */
484 xfs_dir2_off_t newoff; /* new curoff after new blk */
485 char *ptr = NULL; /* pointer to current data */
486 struct xfs_dir2_leaf_map_info *map_info;
Dave Chinner53f82db2014-06-06 15:20:32 +1000487 struct xfs_da_geometry *geo = args->geo;
Dave Chinner4a8af272013-08-12 20:49:36 +1000488
489 /*
490 * If the offset is at or past the largest allowed value,
491 * give up right away.
492 */
493 if (ctx->pos >= XFS_DIR2_MAX_DATAPTR)
494 return 0;
495
Dave Chinner4a8af272013-08-12 20:49:36 +1000496 /*
497 * Set up to bmap a number of blocks based on the caller's
498 * buffer size, the directory block size, and the filesystem
499 * block size.
500 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000501 length = howmany(bufsize + geo->blksize, (1 << geo->fsblog));
Dave Chinner4a8af272013-08-12 20:49:36 +1000502 map_info = kmem_zalloc(offsetof(struct xfs_dir2_leaf_map_info, map) +
503 (length * sizeof(struct xfs_bmbt_irec)),
504 KM_SLEEP | KM_NOFS);
505 map_info->map_size = length;
506
507 /*
508 * Inside the loop we keep the main offset value as a byte offset
509 * in the directory file.
510 */
Eric Sandeen25994052014-04-14 19:02:30 +1000511 curoff = xfs_dir2_dataptr_to_byte(ctx->pos);
Dave Chinner4a8af272013-08-12 20:49:36 +1000512
513 /*
514 * Force this conversion through db so we truncate the offset
515 * down to get the start of the data block.
516 */
Dave Chinner30028032014-06-06 15:08:18 +1000517 map_info->map_off = xfs_dir2_db_to_da(geo,
518 xfs_dir2_byte_to_db(geo, curoff));
Dave Chinner4a8af272013-08-12 20:49:36 +1000519
520 /*
521 * Loop over directory entries until we reach the end offset.
522 * Get more blocks and readahead as necessary.
523 */
524 while (curoff < XFS_DIR2_LEAF_OFFSET) {
Dave Chinner0cb97762013-08-12 20:50:09 +1000525 __uint8_t filetype;
526
Dave Chinner4a8af272013-08-12 20:49:36 +1000527 /*
528 * If we have no buffer, or we're off the end of the
529 * current buffer, need to get another one.
530 */
Dave Chinner8f661932014-06-06 15:15:59 +1000531 if (!bp || ptr >= (char *)bp->b_addr + geo->blksize) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000532
Dave Chinner53f82db2014-06-06 15:20:32 +1000533 error = xfs_dir2_leaf_readbuf(args, bufsize, map_info,
Dave Chinner4a8af272013-08-12 20:49:36 +1000534 &curoff, &bp);
535 if (error || !map_info->map_valid)
536 break;
537
538 /*
539 * Having done a read, we need to set a new offset.
540 */
Dave Chinner53f82db2014-06-06 15:20:32 +1000541 newoff = xfs_dir2_db_off_to_byte(geo,
Dave Chinner9b3b5522014-06-06 15:06:53 +1000542 map_info->curdb, 0);
Dave Chinner4a8af272013-08-12 20:49:36 +1000543 /*
544 * Start of the current block.
545 */
546 if (curoff < newoff)
547 curoff = newoff;
548 /*
549 * Make sure we're in the right block.
550 */
551 else if (curoff > newoff)
Dave Chinner30028032014-06-06 15:08:18 +1000552 ASSERT(xfs_dir2_byte_to_db(geo, curoff) ==
Dave Chinner4a8af272013-08-12 20:49:36 +1000553 map_info->curdb);
554 hdr = bp->b_addr;
555 xfs_dir3_data_check(dp, bp);
556 /*
557 * Find our position in the block.
558 */
Dave Chinner2ca98772013-10-29 22:11:49 +1100559 ptr = (char *)dp->d_ops->data_entry_p(hdr);
Dave Chinner53f82db2014-06-06 15:20:32 +1000560 byteoff = xfs_dir2_byte_to_off(geo, curoff);
Dave Chinner4a8af272013-08-12 20:49:36 +1000561 /*
562 * Skip past the header.
563 */
564 if (byteoff == 0)
Dave Chinner1c9a5b22013-10-30 09:15:02 +1100565 curoff += dp->d_ops->data_entry_offset;
Dave Chinner4a8af272013-08-12 20:49:36 +1000566 /*
567 * Skip past entries until we reach our offset.
568 */
569 else {
570 while ((char *)ptr - (char *)hdr < byteoff) {
571 dup = (xfs_dir2_data_unused_t *)ptr;
572
573 if (be16_to_cpu(dup->freetag)
574 == XFS_DIR2_DATA_FREE_TAG) {
575
576 length = be16_to_cpu(dup->length);
577 ptr += length;
578 continue;
579 }
580 dep = (xfs_dir2_data_entry_t *)ptr;
581 length =
Dave Chinner9d23fc82013-10-29 22:11:48 +1100582 dp->d_ops->data_entsize(dep->namelen);
Dave Chinner4a8af272013-08-12 20:49:36 +1000583 ptr += length;
584 }
585 /*
586 * Now set our real offset.
587 */
588 curoff =
Dave Chinner30028032014-06-06 15:08:18 +1000589 xfs_dir2_db_off_to_byte(geo,
590 xfs_dir2_byte_to_db(geo, curoff),
Dave Chinner4a8af272013-08-12 20:49:36 +1000591 (char *)ptr - (char *)hdr);
Dave Chinner8f661932014-06-06 15:15:59 +1000592 if (ptr >= (char *)hdr + geo->blksize) {
Dave Chinner4a8af272013-08-12 20:49:36 +1000593 continue;
594 }
595 }
596 }
597 /*
598 * We have a pointer to an entry.
599 * Is it a live one?
600 */
601 dup = (xfs_dir2_data_unused_t *)ptr;
602 /*
603 * No, it's unused, skip over it.
604 */
605 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
606 length = be16_to_cpu(dup->length);
607 ptr += length;
608 curoff += length;
609 continue;
610 }
611
612 dep = (xfs_dir2_data_entry_t *)ptr;
Dave Chinner9d23fc82013-10-29 22:11:48 +1100613 length = dp->d_ops->data_entsize(dep->namelen);
614 filetype = dp->d_ops->data_get_ftype(dep);
Dave Chinner4a8af272013-08-12 20:49:36 +1000615
Eric Sandeen25994052014-04-14 19:02:30 +1000616 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000617 if (!dir_emit(ctx, (char *)dep->name, dep->namelen,
Dave Chinner0cb97762013-08-12 20:50:09 +1000618 be64_to_cpu(dep->inumber),
Dave Chinner53f82db2014-06-06 15:20:32 +1000619 xfs_dir3_get_dtype(dp->i_mount, filetype)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000620 break;
621
622 /*
623 * Advance to next entry in the block.
624 */
625 ptr += length;
626 curoff += length;
627 /* bufsize may have just been a guess; don't go negative */
628 bufsize = bufsize > length ? bufsize - length : 0;
629 }
630
631 /*
632 * All done. Set output offset value to current offset.
633 */
Eric Sandeen25994052014-04-14 19:02:30 +1000634 if (curoff > xfs_dir2_dataptr_to_byte(XFS_DIR2_MAX_DATAPTR))
Dave Chinner4a8af272013-08-12 20:49:36 +1000635 ctx->pos = XFS_DIR2_MAX_DATAPTR & 0x7fffffff;
636 else
Eric Sandeen25994052014-04-14 19:02:30 +1000637 ctx->pos = xfs_dir2_byte_to_dataptr(curoff) & 0x7fffffff;
Dave Chinner4a8af272013-08-12 20:49:36 +1000638 kmem_free(map_info);
639 if (bp)
640 xfs_trans_brelse(NULL, bp);
641 return error;
642}
643
644/*
645 * Read a directory.
646 */
647int
648xfs_readdir(
Dave Chinner53f82db2014-06-06 15:20:32 +1000649 struct xfs_inode *dp,
650 struct dir_context *ctx,
651 size_t bufsize)
Dave Chinner4a8af272013-08-12 20:49:36 +1000652{
Dave Chinner35f46c52014-06-10 07:30:36 +1000653 struct xfs_da_args args = { NULL };
Dave Chinner53f82db2014-06-06 15:20:32 +1000654 int rval;
655 int v;
656 uint lock_mode;
Dave Chinner4a8af272013-08-12 20:49:36 +1000657
658 trace_xfs_readdir(dp);
659
660 if (XFS_FORCED_SHUTDOWN(dp->i_mount))
Dave Chinner24513372014-06-25 14:58:08 +1000661 return -EIO;
Dave Chinner4a8af272013-08-12 20:49:36 +1000662
663 ASSERT(S_ISDIR(dp->i_d.di_mode));
664 XFS_STATS_INC(xs_dir_getdents);
665
Dave Chinner53f82db2014-06-06 15:20:32 +1000666 args.dp = dp;
667 args.geo = dp->i_mount->m_dir_geo;
668
Ben Myers40194ec2013-12-06 12:30:11 -0800669 lock_mode = xfs_ilock_data_map_shared(dp);
Dave Chinner4a8af272013-08-12 20:49:36 +1000670 if (dp->i_d.di_format == XFS_DINODE_FMT_LOCAL)
Dave Chinner53f82db2014-06-06 15:20:32 +1000671 rval = xfs_dir2_sf_getdents(&args, ctx);
672 else if ((rval = xfs_dir2_isblock(&args, &v)))
Dave Chinner4a8af272013-08-12 20:49:36 +1000673 ;
674 else if (v)
Dave Chinner53f82db2014-06-06 15:20:32 +1000675 rval = xfs_dir2_block_getdents(&args, ctx);
Dave Chinner4a8af272013-08-12 20:49:36 +1000676 else
Dave Chinner53f82db2014-06-06 15:20:32 +1000677 rval = xfs_dir2_leaf_getdents(&args, ctx, bufsize);
Ben Myers40194ec2013-12-06 12:30:11 -0800678 xfs_iunlock(dp, lock_mode);
679
Dave Chinner4a8af272013-08-12 20:49:36 +1000680 return rval;
681}