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-rw-r--r--fs/ubifs/budget.c33
1 files changed, 15 insertions, 18 deletions
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index f393620890ee..8cd425b628ee 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -194,29 +194,26 @@ static int make_free_space(struct ubifs_info *c)
194} 194}
195 195
196/** 196/**
197 * ubifs_calc_min_idx_lebs - calculate amount of eraseblocks for the index. 197 * ubifs_calc_min_idx_lebs - calculate amount of LEBs for the index.
198 * @c: UBIFS file-system description object 198 * @c: UBIFS file-system description object
199 * 199 *
200 * This function calculates and returns the number of eraseblocks which should 200 * This function calculates and returns the number of LEBs which should be kept
201 * be kept for index usage. 201 * for index usage.
202 */ 202 */
203int ubifs_calc_min_idx_lebs(struct ubifs_info *c) 203int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
204{ 204{
205 int idx_lebs, eff_leb_size = c->leb_size - c->max_idx_node_sz; 205 int idx_lebs;
206 long long idx_size; 206 long long idx_size;
207 207
208 idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx; 208 idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
209
210 /* And make sure we have thrice the index size of space reserved */ 209 /* And make sure we have thrice the index size of space reserved */
211 idx_size = idx_size + (idx_size << 1); 210 idx_size += idx_size << 1;
212
213 /* 211 /*
214 * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes' 212 * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
215 * pair, nor similarly the two variables for the new index size, so we 213 * pair, nor similarly the two variables for the new index size, so we
216 * have to do this costly 64-bit division on fast-path. 214 * have to do this costly 64-bit division on fast-path.
217 */ 215 */
218 idx_size += eff_leb_size - 1; 216 idx_lebs = div_u64(idx_size + c->idx_leb_size - 1, c->idx_leb_size);
219 idx_lebs = div_u64(idx_size, eff_leb_size);
220 /* 217 /*
221 * The index head is not available for the in-the-gaps method, so add an 218 * The index head is not available for the in-the-gaps method, so add an
222 * extra LEB to compensate. 219 * extra LEB to compensate.
@@ -310,15 +307,15 @@ static int can_use_rp(struct ubifs_info *c)
310 * do_budget_space - reserve flash space for index and data growth. 307 * do_budget_space - reserve flash space for index and data growth.
311 * @c: UBIFS file-system description object 308 * @c: UBIFS file-system description object
312 * 309 *
313 * This function makes sure UBIFS has enough free eraseblocks for index growth 310 * This function makes sure UBIFS has enough free LEBs for index growth and
314 * and data. 311 * data.
315 * 312 *
316 * When budgeting index space, UBIFS reserves thrice as many LEBs as the index 313 * When budgeting index space, UBIFS reserves thrice as many LEBs as the index
317 * would take if it was consolidated and written to the flash. This guarantees 314 * would take if it was consolidated and written to the flash. This guarantees
318 * that the "in-the-gaps" commit method always succeeds and UBIFS will always 315 * that the "in-the-gaps" commit method always succeeds and UBIFS will always
319 * be able to commit dirty index. So this function basically adds amount of 316 * be able to commit dirty index. So this function basically adds amount of
320 * budgeted index space to the size of the current index, multiplies this by 3, 317 * budgeted index space to the size of the current index, multiplies this by 3,
321 * and makes sure this does not exceed the amount of free eraseblocks. 318 * and makes sure this does not exceed the amount of free LEBs.
322 * 319 *
323 * Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables: 320 * Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:
324 * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might 321 * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
@@ -695,12 +692,12 @@ long long ubifs_reported_space(const struct ubifs_info *c, long long free)
695 * This function calculates amount of free space to report to user-space. 692 * This function calculates amount of free space to report to user-space.
696 * 693 *
697 * Because UBIFS may introduce substantial overhead (the index, node headers, 694 * Because UBIFS may introduce substantial overhead (the index, node headers,
698 * alignment, wastage at the end of eraseblocks, etc), it cannot report real 695 * alignment, wastage at the end of LEBs, etc), it cannot report real amount of
699 * amount of free flash space it has (well, because not all dirty space is 696 * free flash space it has (well, because not all dirty space is reclaimable,
700 * reclaimable, UBIFS does not actually know the real amount). If UBIFS did so, 697 * UBIFS does not actually know the real amount). If UBIFS did so, it would
701 * it would bread user expectations about what free space is. Users seem to 698 * bread user expectations about what free space is. Users seem to accustomed
702 * accustomed to assume that if the file-system reports N bytes of free space, 699 * to assume that if the file-system reports N bytes of free space, they would
703 * they would be able to fit a file of N bytes to the FS. This almost works for 700 * be able to fit a file of N bytes to the FS. This almost works for
704 * traditional file-systems, because they have way less overhead than UBIFS. 701 * traditional file-systems, because they have way less overhead than UBIFS.
705 * So, to keep users happy, UBIFS tries to take the overhead into account. 702 * So, to keep users happy, UBIFS tries to take the overhead into account.
706 */ 703 */