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authorMark Fasheh <mark.fasheh@oracle.com>2007-07-03 16:27:22 -0400
committerMark Fasheh <mark.fasheh@oracle.com>2007-07-10 20:32:05 -0400
commitd0c7d7082ee1ec4f95ee57bf86ed39d1a27c4037 (patch)
treea4b25631aca30589a4227b42638ee5d300bf4585 /fs/ocfs2
parent2ae99a60374f360ba07037ebbf33d19b89ac43a6 (diff)
ocfs2: btree support for removal of arbirtrary extents
Add code to the btree paths to support the removal of arbitrary regions within an existing extent. With proper higher level support this can be used to "punch holes" in a file. Truncate (a special case of hole punching) could also be converted to use these methods. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Diffstat (limited to 'fs/ocfs2')
-rw-r--r--fs/ocfs2/alloc.c367
1 files changed, 367 insertions, 0 deletions
diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 2e3898316468..fac1adb3880a 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -4139,6 +4139,373 @@ out:
4139 return ret; 4139 return ret;
4140} 4140}
4141 4141
4142static int ocfs2_split_tree(struct inode *inode, struct buffer_head *di_bh,
4143 handle_t *handle, struct ocfs2_path *path,
4144 int index, u32 new_range,
4145 struct ocfs2_alloc_context *meta_ac)
4146{
4147 int ret, depth, credits = handle->h_buffer_credits;
4148 struct ocfs2_dinode *di = (struct ocfs2_dinode *)di_bh->b_data;
4149 struct buffer_head *last_eb_bh = NULL;
4150 struct ocfs2_extent_block *eb;
4151 struct ocfs2_extent_list *rightmost_el, *el;
4152 struct ocfs2_extent_rec split_rec;
4153 struct ocfs2_extent_rec *rec;
4154 struct ocfs2_insert_type insert;
4155
4156 /*
4157 * Setup the record to split before we grow the tree.
4158 */
4159 el = path_leaf_el(path);
4160 rec = &el->l_recs[index];
4161 ocfs2_make_right_split_rec(inode->i_sb, &split_rec, new_range, rec);
4162
4163 depth = path->p_tree_depth;
4164 if (depth > 0) {
4165 ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
4166 le64_to_cpu(di->i_last_eb_blk),
4167 &last_eb_bh, OCFS2_BH_CACHED, inode);
4168 if (ret < 0) {
4169 mlog_errno(ret);
4170 goto out;
4171 }
4172
4173 eb = (struct ocfs2_extent_block *) last_eb_bh->b_data;
4174 rightmost_el = &eb->h_list;
4175 } else
4176 rightmost_el = path_leaf_el(path);
4177
4178 credits += path->p_tree_depth + ocfs2_extend_meta_needed(di);
4179 ret = ocfs2_extend_trans(handle, credits);
4180 if (ret) {
4181 mlog_errno(ret);
4182 goto out;
4183 }
4184
4185 if (le16_to_cpu(rightmost_el->l_next_free_rec) ==
4186 le16_to_cpu(rightmost_el->l_count)) {
4187 int old_depth = depth;
4188
4189 ret = ocfs2_grow_tree(inode, handle, di_bh, &depth, &last_eb_bh,
4190 meta_ac);
4191 if (ret) {
4192 mlog_errno(ret);
4193 goto out;
4194 }
4195
4196 if (old_depth != depth) {
4197 eb = (struct ocfs2_extent_block *)last_eb_bh->b_data;
4198 rightmost_el = &eb->h_list;
4199 }
4200 }
4201
4202 memset(&insert, 0, sizeof(struct ocfs2_insert_type));
4203 insert.ins_appending = APPEND_NONE;
4204 insert.ins_contig = CONTIG_NONE;
4205 insert.ins_split = SPLIT_RIGHT;
4206 insert.ins_free_records = le16_to_cpu(rightmost_el->l_count)
4207 - le16_to_cpu(rightmost_el->l_next_free_rec);
4208 insert.ins_tree_depth = depth;
4209
4210 ret = ocfs2_do_insert_extent(inode, handle, di_bh, &split_rec, &insert);
4211 if (ret)
4212 mlog_errno(ret);
4213
4214out:
4215 brelse(last_eb_bh);
4216 return ret;
4217}
4218
4219static int ocfs2_truncate_rec(struct inode *inode, handle_t *handle,
4220 struct ocfs2_path *path, int index,
4221 struct ocfs2_cached_dealloc_ctxt *dealloc,
4222 u32 cpos, u32 len)
4223{
4224 int ret;
4225 u32 left_cpos, rec_range, trunc_range;
4226 int wants_rotate = 0, is_rightmost_tree_rec = 0;
4227 struct super_block *sb = inode->i_sb;
4228 struct ocfs2_path *left_path = NULL;
4229 struct ocfs2_extent_list *el = path_leaf_el(path);
4230 struct ocfs2_extent_rec *rec;
4231 struct ocfs2_extent_block *eb;
4232
4233 if (ocfs2_is_empty_extent(&el->l_recs[0]) && index > 0) {
4234 ret = ocfs2_rotate_tree_left(inode, handle, path, dealloc);
4235 if (ret) {
4236 mlog_errno(ret);
4237 goto out;
4238 }
4239
4240 index--;
4241 }
4242
4243 if (index == (le16_to_cpu(el->l_next_free_rec) - 1) &&
4244 path->p_tree_depth) {
4245 /*
4246 * Check whether this is the rightmost tree record. If
4247 * we remove all of this record or part of its right
4248 * edge then an update of the record lengths above it
4249 * will be required.
4250 */
4251 eb = (struct ocfs2_extent_block *)path_leaf_bh(path)->b_data;
4252 if (eb->h_next_leaf_blk == 0)
4253 is_rightmost_tree_rec = 1;
4254 }
4255
4256 rec = &el->l_recs[index];
4257 if (index == 0 && path->p_tree_depth &&
4258 le32_to_cpu(rec->e_cpos) == cpos) {
4259 /*
4260 * Changing the leftmost offset (via partial or whole
4261 * record truncate) of an interior (or rightmost) path
4262 * means we have to update the subtree that is formed
4263 * by this leaf and the one to it's left.
4264 *
4265 * There are two cases we can skip:
4266 * 1) Path is the leftmost one in our inode tree.
4267 * 2) The leaf is rightmost and will be empty after
4268 * we remove the extent record - the rotate code
4269 * knows how to update the newly formed edge.
4270 */
4271
4272 ret = ocfs2_find_cpos_for_left_leaf(inode->i_sb, path,
4273 &left_cpos);
4274 if (ret) {
4275 mlog_errno(ret);
4276 goto out;
4277 }
4278
4279 if (left_cpos && le16_to_cpu(el->l_next_free_rec) > 1) {
4280 left_path = ocfs2_new_path(path_root_bh(path),
4281 path_root_el(path));
4282 if (!left_path) {
4283 ret = -ENOMEM;
4284 mlog_errno(ret);
4285 goto out;
4286 }
4287
4288 ret = ocfs2_find_path(inode, left_path, left_cpos);
4289 if (ret) {
4290 mlog_errno(ret);
4291 goto out;
4292 }
4293 }
4294 }
4295
4296 ret = ocfs2_extend_rotate_transaction(handle, 0,
4297 handle->h_buffer_credits,
4298 path);
4299 if (ret) {
4300 mlog_errno(ret);
4301 goto out;
4302 }
4303
4304 ret = ocfs2_journal_access_path(inode, handle, path);
4305 if (ret) {
4306 mlog_errno(ret);
4307 goto out;
4308 }
4309
4310 ret = ocfs2_journal_access_path(inode, handle, left_path);
4311 if (ret) {
4312 mlog_errno(ret);
4313 goto out;
4314 }
4315
4316 rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
4317 trunc_range = cpos + len;
4318
4319 if (le32_to_cpu(rec->e_cpos) == cpos && rec_range == trunc_range) {
4320 int next_free;
4321
4322 memset(rec, 0, sizeof(*rec));
4323 ocfs2_cleanup_merge(el, index);
4324 wants_rotate = 1;
4325
4326 next_free = le16_to_cpu(el->l_next_free_rec);
4327 if (is_rightmost_tree_rec && next_free > 1) {
4328 /*
4329 * We skip the edge update if this path will
4330 * be deleted by the rotate code.
4331 */
4332 rec = &el->l_recs[next_free - 1];
4333 ocfs2_adjust_rightmost_records(inode, handle, path,
4334 rec);
4335 }
4336 } else if (le32_to_cpu(rec->e_cpos) == cpos) {
4337 /* Remove leftmost portion of the record. */
4338 le32_add_cpu(&rec->e_cpos, len);
4339 le64_add_cpu(&rec->e_blkno, ocfs2_clusters_to_blocks(sb, len));
4340 le16_add_cpu(&rec->e_leaf_clusters, -len);
4341 } else if (rec_range == trunc_range) {
4342 /* Remove rightmost portion of the record */
4343 le16_add_cpu(&rec->e_leaf_clusters, -len);
4344 if (is_rightmost_tree_rec)
4345 ocfs2_adjust_rightmost_records(inode, handle, path, rec);
4346 } else {
4347 /* Caller should have trapped this. */
4348 mlog(ML_ERROR, "Inode %llu: Invalid record truncate: (%u, %u) "
4349 "(%u, %u)\n", (unsigned long long)OCFS2_I(inode)->ip_blkno,
4350 le32_to_cpu(rec->e_cpos),
4351 le16_to_cpu(rec->e_leaf_clusters), cpos, len);
4352 BUG();
4353 }
4354
4355 if (left_path) {
4356 int subtree_index;
4357
4358 subtree_index = ocfs2_find_subtree_root(inode, left_path, path);
4359 ocfs2_complete_edge_insert(inode, handle, left_path, path,
4360 subtree_index);
4361 }
4362
4363 ocfs2_journal_dirty(handle, path_leaf_bh(path));
4364
4365 ret = ocfs2_rotate_tree_left(inode, handle, path, dealloc);
4366 if (ret) {
4367 mlog_errno(ret);
4368 goto out;
4369 }
4370
4371out:
4372 ocfs2_free_path(left_path);
4373 return ret;
4374}
4375
4376static int ocfs2_remove_extent(struct inode *inode, struct buffer_head *di_bh,
4377 u32 cpos, u32 len, handle_t *handle,
4378 struct ocfs2_alloc_context *meta_ac,
4379 struct ocfs2_cached_dealloc_ctxt *dealloc)
4380{
4381 int ret, index;
4382 u32 rec_range, trunc_range;
4383 struct ocfs2_extent_rec *rec;
4384 struct ocfs2_extent_list *el;
4385 struct ocfs2_path *path;
4386
4387 ocfs2_extent_map_trunc(inode, 0);
4388
4389 path = ocfs2_new_inode_path(di_bh);
4390 if (!path) {
4391 ret = -ENOMEM;
4392 mlog_errno(ret);
4393 goto out;
4394 }
4395
4396 ret = ocfs2_find_path(inode, path, cpos);
4397 if (ret) {
4398 mlog_errno(ret);
4399 goto out;
4400 }
4401
4402 el = path_leaf_el(path);
4403 index = ocfs2_search_extent_list(el, cpos);
4404 if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
4405 ocfs2_error(inode->i_sb,
4406 "Inode %llu has an extent at cpos %u which can no "
4407 "longer be found.\n",
4408 (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos);
4409 ret = -EROFS;
4410 goto out;
4411 }
4412
4413 /*
4414 * We have 3 cases of extent removal:
4415 * 1) Range covers the entire extent rec
4416 * 2) Range begins or ends on one edge of the extent rec
4417 * 3) Range is in the middle of the extent rec (no shared edges)
4418 *
4419 * For case 1 we remove the extent rec and left rotate to
4420 * fill the hole.
4421 *
4422 * For case 2 we just shrink the existing extent rec, with a
4423 * tree update if the shrinking edge is also the edge of an
4424 * extent block.
4425 *
4426 * For case 3 we do a right split to turn the extent rec into
4427 * something case 2 can handle.
4428 */
4429 rec = &el->l_recs[index];
4430 rec_range = le32_to_cpu(rec->e_cpos) + ocfs2_rec_clusters(el, rec);
4431 trunc_range = cpos + len;
4432
4433 BUG_ON(cpos < le32_to_cpu(rec->e_cpos) || trunc_range > rec_range);
4434
4435 mlog(0, "Inode %llu, remove (cpos %u, len %u). Existing index %d "
4436 "(cpos %u, len %u)\n",
4437 (unsigned long long)OCFS2_I(inode)->ip_blkno, cpos, len, index,
4438 le32_to_cpu(rec->e_cpos), ocfs2_rec_clusters(el, rec));
4439
4440 if (le32_to_cpu(rec->e_cpos) == cpos || rec_range == trunc_range) {
4441 ret = ocfs2_truncate_rec(inode, handle, path, index, dealloc,
4442 cpos, len);
4443 if (ret) {
4444 mlog_errno(ret);
4445 goto out;
4446 }
4447 } else {
4448 ret = ocfs2_split_tree(inode, di_bh, handle, path, index,
4449 trunc_range, meta_ac);
4450 if (ret) {
4451 mlog_errno(ret);
4452 goto out;
4453 }
4454
4455 /*
4456 * The split could have manipulated the tree enough to
4457 * move the record location, so we have to look for it again.
4458 */
4459 ocfs2_reinit_path(path, 1);
4460
4461 ret = ocfs2_find_path(inode, path, cpos);
4462 if (ret) {
4463 mlog_errno(ret);
4464 goto out;
4465 }
4466
4467 el = path_leaf_el(path);
4468 index = ocfs2_search_extent_list(el, cpos);
4469 if (index == -1 || index >= le16_to_cpu(el->l_next_free_rec)) {
4470 ocfs2_error(inode->i_sb,
4471 "Inode %llu: split at cpos %u lost record.",
4472 (unsigned long long)OCFS2_I(inode)->ip_blkno,
4473 cpos);
4474 ret = -EROFS;
4475 goto out;
4476 }
4477
4478 /*
4479 * Double check our values here. If anything is fishy,
4480 * it's easier to catch it at the top level.
4481 */
4482 rec = &el->l_recs[index];
4483 rec_range = le32_to_cpu(rec->e_cpos) +
4484 ocfs2_rec_clusters(el, rec);
4485 if (rec_range != trunc_range) {
4486 ocfs2_error(inode->i_sb,
4487 "Inode %llu: error after split at cpos %u"
4488 "trunc len %u, existing record is (%u,%u)",
4489 (unsigned long long)OCFS2_I(inode)->ip_blkno,
4490 cpos, len, le32_to_cpu(rec->e_cpos),
4491 ocfs2_rec_clusters(el, rec));
4492 ret = -EROFS;
4493 goto out;
4494 }
4495
4496 ret = ocfs2_truncate_rec(inode, handle, path, index, dealloc,
4497 cpos, len);
4498 if (ret) {
4499 mlog_errno(ret);
4500 goto out;
4501 }
4502 }
4503
4504out:
4505 ocfs2_free_path(path);
4506 return ret;
4507}
4508
4142static inline int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb) 4509static inline int ocfs2_truncate_log_needs_flush(struct ocfs2_super *osb)
4143{ 4510{
4144 struct buffer_head *tl_bh = osb->osb_tl_bh; 4511 struct buffer_head *tl_bh = osb->osb_tl_bh;