diff options
| -rw-r--r-- | fs/ubifs/budget.c | 151 |
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 @@ /* * When pessimistic budget calculations say that there is no enough space, * UBIFS starts writing back dirty inodes and pages, doing garbage collection, - * or committing. The below constants define maximum number of times UBIFS + * or committing. The below constant defines maximum number of times UBIFS * repeats the operations. */ -#define MAX_SHRINK_RETRIES 8 -#define MAX_GC_RETRIES 4 -#define MAX_CMT_RETRIES 2 -#define MAX_NOSPC_RETRIES 1 +#define MAX_MKSPC_RETRIES 3 /* * The below constant defines amount of dirty pages which should be written @@ -52,30 +49,6 @@ #define NR_TO_WRITE 16 /** - * struct retries_info - information about re-tries while making free space. - * @prev_liability: previous liability - * @shrink_cnt: how many times the liability was shrinked - * @shrink_retries: count of liability shrink re-tries (increased when - * liability does not shrink) - * @try_gc: GC should be tried first - * @gc_retries: how many times GC was run - * @cmt_retries: how many times commit has been done - * @nospc_retries: how many times GC returned %-ENOSPC - * - * Since we consider budgeting to be the fast-path, and this structure has to - * be allocated on stack and zeroed out, we make it smaller using bit-fields. - */ -struct retries_info { - long long prev_liability; - unsigned int shrink_cnt; - unsigned int shrink_retries:5; - unsigned int try_gc:1; - unsigned int gc_retries:4; - unsigned int cmt_retries:3; - unsigned int nospc_retries:1; -}; - -/** * shrink_liability - write-back some dirty pages/inodes. * @c: UBIFS file-system description object * @nr_to_write: how many dirty pages to write-back @@ -147,9 +120,25 @@ static int run_gc(struct ubifs_info *c) } /** + * get_liability - calculate current liability. + * @c: UBIFS file-system description object + * + * This function calculates and returns current UBIFS liability, i.e. the + * amount of bytes UBIFS has "promised" to write to the media. + */ +static long long get_liability(struct ubifs_info *c) +{ + long long liab; + + spin_lock(&c->space_lock); + liab = c->budg_idx_growth + c->budg_data_growth + c->budg_dd_growth; + spin_unlock(&c->space_lock); + return liab; +} + +/** * make_free_space - make more free space on the file-system. * @c: UBIFS file-system description object - * @ri: information about previous invocations of this function * * This function is called when an operation cannot be budgeted because there * 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) * Returns %-ENOSPC if it couldn't do more free space, and other negative error * codes on failures. */ -static int make_free_space(struct ubifs_info *c, struct retries_info *ri) +static int make_free_space(struct ubifs_info *c) { - int err; - - /* - * If we have some dirty pages and inodes (liability), try to write - * them back unless this was tried too many times without effect - * already. - */ - if (ri->shrink_retries < MAX_SHRINK_RETRIES && !ri->try_gc) { - long long liability; - - spin_lock(&c->space_lock); - liability = c->budg_idx_growth + c->budg_data_growth + - c->budg_dd_growth; - spin_unlock(&c->space_lock); + int err, retries = 0; + long long liab1, liab2; - if (ri->prev_liability >= liability) { - /* Liability does not shrink, next time try GC then */ - ri->shrink_retries += 1; - if (ri->gc_retries < MAX_GC_RETRIES) - ri->try_gc = 1; - dbg_budg("liability did not shrink: retries %d of %d", - ri->shrink_retries, MAX_SHRINK_RETRIES); - } - - dbg_budg("force write-back (count %d)", ri->shrink_cnt); - shrink_liability(c, NR_TO_WRITE + ri->shrink_cnt); + do { + liab1 = get_liability(c); + /* + * We probably have some dirty pages or inodes (liability), try + * to write them back. + */ + dbg_budg("liability %lld, run write-back", liab1); + shrink_liability(c, NR_TO_WRITE); - ri->prev_liability = liability; - ri->shrink_cnt += 1; - return -EAGAIN; - } + liab2 = get_liability(c); + if (liab2 < liab1) + return -EAGAIN; - /* - * Try to run garbage collector unless it was already tried too many - * times. - */ - if (ri->gc_retries < MAX_GC_RETRIES) { - ri->gc_retries += 1; - dbg_budg("run GC, retries %d of %d", - ri->gc_retries, MAX_GC_RETRIES); + dbg_budg("new liability %lld (not shrinked)", liab2); - ri->try_gc = 0; + /* Liability did not shrink again, try GC */ + dbg_budg("Run GC"); err = run_gc(c); if (!err) return -EAGAIN; - if (err == -EAGAIN) { - dbg_budg("GC asked to commit"); - err = ubifs_run_commit(c); - if (err) - return err; - return -EAGAIN; - } - - if (err != -ENOSPC) + if (err != -EAGAIN && err != -ENOSPC) + /* Some real error happened */ return err; - /* - * GC could not make any progress. If this is the first time, - * then it makes sense to try to commit, because it might make - * some dirty space. - */ - dbg_budg("GC returned -ENOSPC, retries %d", - ri->nospc_retries); - if (ri->nospc_retries >= MAX_NOSPC_RETRIES) - return err; - ri->nospc_retries += 1; - } - - /* Neither GC nor write-back helped, try to commit */ - if (ri->cmt_retries < MAX_CMT_RETRIES) { - ri->cmt_retries += 1; - dbg_budg("run commit, retries %d of %d", - ri->cmt_retries, MAX_CMT_RETRIES); + dbg_budg("Run commit (retries %d)", retries); err = ubifs_run_commit(c); if (err) return err; - return -EAGAIN; - } + } while (retries++ < MAX_MKSPC_RETRIES); + return -ENOSPC; } @@ -523,8 +467,7 @@ static int calc_dd_growth(const struct ubifs_info *c, int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req) { int uninitialized_var(cmt_retries), uninitialized_var(wb_retries); - int err, idx_growth, data_growth, dd_growth; - struct retries_info ri; + int err, idx_growth, data_growth, dd_growth, retried = 0; ubifs_assert(req->new_page <= 1); ubifs_assert(req->dirtied_page <= 1); @@ -542,7 +485,6 @@ int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req) if (!data_growth && !dd_growth) return 0; idx_growth = calc_idx_growth(c, req); - memset(&ri, 0, sizeof(struct retries_info)); again: spin_lock(&c->space_lock); @@ -580,12 +522,17 @@ again: return err; } - err = make_free_space(c, &ri); + err = make_free_space(c); + cond_resched(); if (err == -EAGAIN) { dbg_budg("try again"); - cond_resched(); goto again; } else if (err == -ENOSPC) { + if (!retried) { + retried = 1; + dbg_budg("-ENOSPC, but anyway try once again"); + goto again; + } dbg_budg("FS is full, -ENOSPC"); c->nospace = 1; if (can_use_rp(c) || c->rp_size == 0) |