X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fubifs%2Fbudget.c;h=0e5e54d829243afba459b97a72a303aad6654e00;hb=8e3bda0863c1578ddf47a015eac7dc6efb1ef48b;hp=1a4973e106643dd2badce2eaeb805f82be0744a4;hpb=268a3dcfea2077fca60d3715caa5c96f9b5e6ea7;p=linux-2.6-omap-h63xx.git diff --git a/fs/ubifs/budget.c b/fs/ubifs/budget.c index 1a4973e1066..0e5e54d8292 100644 --- a/fs/ubifs/budget.c +++ b/fs/ubifs/budget.c @@ -32,18 +32,15 @@ #include "ubifs.h" #include -#include +#include /* * 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 @@ -51,30 +48,6 @@ */ #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 @@ -146,10 +119,26 @@ static int run_gc(struct ubifs_info *c) return 0; } +/** + * 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); - } + 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); - dbg_budg("force write-back (count %d)", ri->shrink_cnt); - shrink_liability(c, NR_TO_WRITE + ri->shrink_cnt); + liab2 = get_liability(c); + if (liab2 < liab1) + return -EAGAIN; - ri->prev_liability = liability; - ri->shrink_cnt += 1; - return -EAGAIN; - } + dbg_budg("new liability %lld (not shrinked)", liab2); - /* - * 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); - - 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) - 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) + if (err != -EAGAIN && err != -ENOSPC) + /* Some real error happened */ 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; } @@ -258,8 +202,8 @@ static int make_free_space(struct ubifs_info *c, struct retries_info *ri) */ int ubifs_calc_min_idx_lebs(struct ubifs_info *c) { - int ret; - uint64_t idx_size; + int idx_lebs, eff_leb_size = c->leb_size - c->max_idx_node_sz; + long long idx_size; idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx; @@ -271,23 +215,16 @@ int ubifs_calc_min_idx_lebs(struct ubifs_info *c) * pair, nor similarly the two variables for the new index size, so we * have to do this costly 64-bit division on fast-path. */ - if (do_div(idx_size, c->leb_size - c->max_idx_node_sz)) - ret = idx_size + 1; - else - ret = idx_size; + idx_size += eff_leb_size - 1; + idx_lebs = div_u64(idx_size, eff_leb_size); /* * The index head is not available for the in-the-gaps method, so add an * extra LEB to compensate. */ - ret += 1; - /* - * At present the index needs at least 2 LEBs: one for the index head - * and one for in-the-gaps method (which currently does not cater for - * the index head and so excludes it from consideration). - */ - if (ret < 2) - ret = 2; - return ret; + idx_lebs += 1; + if (idx_lebs < MIN_INDEX_LEBS) + idx_lebs = MIN_INDEX_LEBS; + return idx_lebs; } /** @@ -363,7 +300,7 @@ long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs) */ static int can_use_rp(struct ubifs_info *c) { - if (current->fsuid == c->rp_uid || capable(CAP_SYS_RESOURCE) || + if (current_fsuid() == c->rp_uid || capable(CAP_SYS_RESOURCE) || (c->rp_gid != 0 && in_group_p(c->rp_gid))) return 1; return 0; @@ -530,8 +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); @@ -549,7 +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); @@ -587,12 +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) @@ -712,9 +652,9 @@ void ubifs_release_dirty_inode_budget(struct ubifs_info *c, * user-space. User-space application tend to expect that if the file-system * (e.g., via the 'statfs()' call) reports that it has N bytes available, they * are able to write a file of size N. UBIFS attaches node headers to each data - * node and it has to write indexind nodes as well. This introduces additional - * overhead, and UBIFS it has to report sligtly less free space to meet the - * above expectetion. + * node and it has to write indexing nodes as well. This introduces additional + * overhead, and UBIFS has to report slightly less free space to meet the above + * expectations. * * This function assumes free space is made up of uncompressed data nodes and * full index nodes (one per data node, tripled because we always allow enough @@ -723,7 +663,7 @@ void ubifs_release_dirty_inode_budget(struct ubifs_info *c, * Note, the calculation is pessimistic, which means that most of the time * UBIFS reports less space than it actually has. */ -long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) +long long ubifs_reported_space(const struct ubifs_info *c, long long free) { int divisor, factor, f; @@ -737,7 +677,7 @@ long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) * of data nodes, f - fanout. Because effective UBIFS fanout is twice * as less than maximum fanout, we assume that each data node * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes. - * Note, the multiplier 3 is because UBIFS reseves thrice as more space + * Note, the multiplier 3 is because UBIFS reserves thrice as more space * for the index. */ f = c->fanout > 3 ? c->fanout >> 1 : 2; @@ -745,8 +685,7 @@ long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) divisor = UBIFS_MAX_DATA_NODE_SZ; divisor += (c->max_idx_node_sz * 3) / (f - 1); free *= factor; - do_div(free, divisor); - return free; + return div_u64(free, divisor); } /** @@ -756,10 +695,10 @@ long long ubifs_reported_space(const struct ubifs_info *c, uint64_t free) * This function calculates amount of free space to report to user-space. * * Because UBIFS may introduce substantial overhead (the index, node headers, - * alighment, wastage at the end of eraseblocks, etc), it cannot report real + * alignment, wastage at the end of eraseblocks, etc), it cannot report real * amount of free flash space it has (well, because not all dirty space is - * reclamable, UBIFS does not actually know the real amount). If UBIFS did so, - * it would bread user expectetion about what free space is. Users seem to + * reclaimable, UBIFS does not actually know the real amount). If UBIFS did so, + * it would bread user expectations about what free space is. Users seem to * accustomed to assume that if the file-system reports N bytes of free space, * they would be able to fit a file of N bytes to the FS. This almost works for * traditional file-systems, because they have way less overhead than UBIFS. @@ -771,18 +710,9 @@ long long ubifs_get_free_space(struct ubifs_info *c) long long available, outstanding, free; spin_lock(&c->space_lock); - min_idx_lebs = ubifs_calc_min_idx_lebs(c); + min_idx_lebs = c->min_idx_lebs; + ubifs_assert(min_idx_lebs == ubifs_calc_min_idx_lebs(c)); outstanding = c->budg_data_growth + c->budg_dd_growth; - - /* - * Force the amount available to the total size reported if the used - * space is zero. - */ - if (c->lst.total_used <= UBIFS_INO_NODE_SZ && !outstanding) { - spin_unlock(&c->space_lock); - return (long long)c->block_cnt << UBIFS_BLOCK_SHIFT; - } - available = ubifs_calc_available(c, min_idx_lebs); /*