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-rw-r--r--fs/ubifs/budget.c151
1 files changed, 49 insertions, 102 deletions
diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c
index 3715d0114952..4d270f0a8564 100644
--- a/fs/ubifs/budget.c
+++ b/fs/ubifs/budget.c
@@ -37,13 +37,10 @@
37/* 37/*
38 * When pessimistic budget calculations say that there is no enough space, 38 * When pessimistic budget calculations say that there is no enough space,
39 * UBIFS starts writing back dirty inodes and pages, doing garbage collection, 39 * UBIFS starts writing back dirty inodes and pages, doing garbage collection,
40 * or committing. The below constants define maximum number of times UBIFS 40 * or committing. The below constant defines maximum number of times UBIFS
41 * repeats the operations. 41 * repeats the operations.
42 */ 42 */
43#define MAX_SHRINK_RETRIES 8 43#define MAX_MKSPC_RETRIES 3
44#define MAX_GC_RETRIES 4
45#define MAX_CMT_RETRIES 2
46#define MAX_NOSPC_RETRIES 1
47 44
48/* 45/*
49 * The below constant defines amount of dirty pages which should be written 46 * The below constant defines amount of dirty pages which should be written
@@ -52,30 +49,6 @@
52#define NR_TO_WRITE 16 49#define NR_TO_WRITE 16
53 50
54/** 51/**
55 * struct retries_info - information about re-tries while making free space.
56 * @prev_liability: previous liability
57 * @shrink_cnt: how many times the liability was shrinked
58 * @shrink_retries: count of liability shrink re-tries (increased when
59 * liability does not shrink)
60 * @try_gc: GC should be tried first
61 * @gc_retries: how many times GC was run
62 * @cmt_retries: how many times commit has been done
63 * @nospc_retries: how many times GC returned %-ENOSPC
64 *
65 * Since we consider budgeting to be the fast-path, and this structure has to
66 * be allocated on stack and zeroed out, we make it smaller using bit-fields.
67 */
68struct retries_info {
69 long long prev_liability;
70 unsigned int shrink_cnt;
71 unsigned int shrink_retries:5;
72 unsigned int try_gc:1;
73 unsigned int gc_retries:4;
74 unsigned int cmt_retries:3;
75 unsigned int nospc_retries:1;
76};
77
78/**
79 * shrink_liability - write-back some dirty pages/inodes. 52 * shrink_liability - write-back some dirty pages/inodes.
80 * @c: UBIFS file-system description object 53 * @c: UBIFS file-system description object
81 * @nr_to_write: how many dirty pages to write-back 54 * @nr_to_write: how many dirty pages to write-back
@@ -147,9 +120,25 @@ static int run_gc(struct ubifs_info *c)
147} 120}
148 121
149/** 122/**
123 * get_liability - calculate current liability.
124 * @c: UBIFS file-system description object
125 *
126 * This function calculates and returns current UBIFS liability, i.e. the
127 * amount of bytes UBIFS has "promised" to write to the media.
128 */
129static long long get_liability(struct ubifs_info *c)
130{
131 long long liab;
132
133 spin_lock(&c->space_lock);
134 liab = c->budg_idx_growth + c->budg_data_growth + c->budg_dd_growth;
135 spin_unlock(&c->space_lock);
136 return liab;
137}
138
139/**
150 * make_free_space - make more free space on the file-system. 140 * make_free_space - make more free space on the file-system.
151 * @c: UBIFS file-system description object 141 * @c: UBIFS file-system description object
152 * @ri: information about previous invocations of this function
153 * 142 *
154 * This function is called when an operation cannot be budgeted because there 143 * This function is called when an operation cannot be budgeted because there
155 * is supposedly no free space. But in most cases there is some free space: 144 * is supposedly no free space. But in most cases there is some free space:
@@ -165,87 +154,42 @@ static int run_gc(struct ubifs_info *c)
165 * Returns %-ENOSPC if it couldn't do more free space, and other negative error 154 * Returns %-ENOSPC if it couldn't do more free space, and other negative error
166 * codes on failures. 155 * codes on failures.
167 */ 156 */
168static int make_free_space(struct ubifs_info *c, struct retries_info *ri) 157static int make_free_space(struct ubifs_info *c)
169{ 158{
170 int err; 159 int err, retries = 0;
171 160 long long liab1, liab2;
172 /*
173 * If we have some dirty pages and inodes (liability), try to write
174 * them back unless this was tried too many times without effect
175 * already.
176 */
177 if (ri->shrink_retries < MAX_SHRINK_RETRIES && !ri->try_gc) {
178 long long liability;
179
180 spin_lock(&c->space_lock);
181 liability = c->budg_idx_growth + c->budg_data_growth +
182 c->budg_dd_growth;
183 spin_unlock(&c->space_lock);
184 161
185 if (ri->prev_liability >= liability) { 162 do {
186 /* Liability does not shrink, next time try GC then */ 163 liab1 = get_liability(c);
187 ri->shrink_retries += 1; 164 /*
188 if (ri->gc_retries < MAX_GC_RETRIES) 165 * We probably have some dirty pages or inodes (liability), try
189 ri->try_gc = 1; 166 * to write them back.
190 dbg_budg("liability did not shrink: retries %d of %d", 167 */
191 ri->shrink_retries, MAX_SHRINK_RETRIES); 168 dbg_budg("liability %lld, run write-back", liab1);
192 } 169 shrink_liability(c, NR_TO_WRITE);
193
194 dbg_budg("force write-back (count %d)", ri->shrink_cnt);
195 shrink_liability(c, NR_TO_WRITE + ri->shrink_cnt);
196 170
197 ri->prev_liability = liability; 171 liab2 = get_liability(c);
198 ri->shrink_cnt += 1; 172 if (liab2 < liab1)
199 return -EAGAIN; 173 return -EAGAIN;
200 }
201 174
202 /* 175 dbg_budg("new liability %lld (not shrinked)", liab2);
203 * Try to run garbage collector unless it was already tried too many
204 * times.
205 */
206 if (ri->gc_retries < MAX_GC_RETRIES) {
207 ri->gc_retries += 1;
208 dbg_budg("run GC, retries %d of %d",
209 ri->gc_retries, MAX_GC_RETRIES);
210 176
211 ri->try_gc = 0; 177 /* Liability did not shrink again, try GC */
178 dbg_budg("Run GC");
212 err = run_gc(c); 179 err = run_gc(c);
213 if (!err) 180 if (!err)
214 return -EAGAIN; 181 return -EAGAIN;
215 182
216 if (err == -EAGAIN) { 183 if (err != -EAGAIN && err != -ENOSPC)
217 dbg_budg("GC asked to commit"); 184 /* Some real error happened */
218 err = ubifs_run_commit(c);
219 if (err)
220 return err;
221 return -EAGAIN;
222 }
223
224 if (err != -ENOSPC)
225 return err; 185 return err;
226 186
227 /* 187 dbg_budg("Run commit (retries %d)", retries);
228 * GC could not make any progress. If this is the first time,
229 * then it makes sense to try to commit, because it might make
230 * some dirty space.
231 */
232 dbg_budg("GC returned -ENOSPC, retries %d",
233 ri->nospc_retries);
234 if (ri->nospc_retries >= MAX_NOSPC_RETRIES)
235 return err;
236 ri->nospc_retries += 1;
237 }
238
239 /* Neither GC nor write-back helped, try to commit */
240 if (ri->cmt_retries < MAX_CMT_RETRIES) {
241 ri->cmt_retries += 1;
242 dbg_budg("run commit, retries %d of %d",
243 ri->cmt_retries, MAX_CMT_RETRIES);
244 err = ubifs_run_commit(c); 188 err = ubifs_run_commit(c);
245 if (err) 189 if (err)
246 return err; 190 return err;
247 return -EAGAIN; 191 } while (retries++ < MAX_MKSPC_RETRIES);
248 } 192
249 return -ENOSPC; 193 return -ENOSPC;
250} 194}
251 195
@@ -523,8 +467,7 @@ static int calc_dd_growth(const struct ubifs_info *c,
523int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req) 467int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
524{ 468{
525 int uninitialized_var(cmt_retries), uninitialized_var(wb_retries); 469 int uninitialized_var(cmt_retries), uninitialized_var(wb_retries);
526 int err, idx_growth, data_growth, dd_growth; 470 int err, idx_growth, data_growth, dd_growth, retried = 0;
527 struct retries_info ri;
528 471
529 ubifs_assert(req->new_page <= 1); 472 ubifs_assert(req->new_page <= 1);
530 ubifs_assert(req->dirtied_page <= 1); 473 ubifs_assert(req->dirtied_page <= 1);
@@ -542,7 +485,6 @@ int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
542 if (!data_growth && !dd_growth) 485 if (!data_growth && !dd_growth)
543 return 0; 486 return 0;
544 idx_growth = calc_idx_growth(c, req); 487 idx_growth = calc_idx_growth(c, req);
545 memset(&ri, 0, sizeof(struct retries_info));
546 488
547again: 489again:
548 spin_lock(&c->space_lock); 490 spin_lock(&c->space_lock);
@@ -580,12 +522,17 @@ again:
580 return err; 522 return err;
581 } 523 }
582 524
583 err = make_free_space(c, &ri); 525 err = make_free_space(c);
526 cond_resched();
584 if (err == -EAGAIN) { 527 if (err == -EAGAIN) {
585 dbg_budg("try again"); 528 dbg_budg("try again");
586 cond_resched();
587 goto again; 529 goto again;
588 } else if (err == -ENOSPC) { 530 } else if (err == -ENOSPC) {
531 if (!retried) {
532 retried = 1;
533 dbg_budg("-ENOSPC, but anyway try once again");
534 goto again;
535 }
589 dbg_budg("FS is full, -ENOSPC"); 536 dbg_budg("FS is full, -ENOSPC");
590 c->nospace = 1; 537 c->nospace = 1;
591 if (can_use_rp(c) || c->rp_size == 0) 538 if (can_use_rp(c) || c->rp_size == 0)