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Diffstat (limited to 'ANDROID_3.4.5/fs/ubifs/budget.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ubifs/budget.c | 732 |
1 files changed, 0 insertions, 732 deletions
diff --git a/ANDROID_3.4.5/fs/ubifs/budget.c b/ANDROID_3.4.5/fs/ubifs/budget.c deleted file mode 100644 index bc4f94b2..00000000 --- a/ANDROID_3.4.5/fs/ubifs/budget.c +++ /dev/null @@ -1,732 +0,0 @@ -/* - * This file is part of UBIFS. - * - * Copyright (C) 2006-2008 Nokia Corporation. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 as published by - * the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 51 - * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA - * - * Authors: Adrian Hunter - * Artem Bityutskiy (Битюцкий Артём) - */ - -/* - * This file implements the budgeting sub-system which is responsible for UBIFS - * space management. - * - * Factors such as compression, wasted space at the ends of LEBs, space in other - * journal heads, the effect of updates on the index, and so on, make it - * impossible to accurately predict the amount of space needed. Consequently - * approximations are used. - */ - -#include "ubifs.h" -#include <linux/writeback.h> -#include <linux/math64.h> - -/* - * 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 constant defines maximum number of times UBIFS - * repeats the operations. - */ -#define MAX_MKSPC_RETRIES 3 - -/* - * The below constant defines amount of dirty pages which should be written - * back at when trying to shrink the liability. - */ -#define NR_TO_WRITE 16 - -/** - * shrink_liability - write-back some dirty pages/inodes. - * @c: UBIFS file-system description object - * @nr_to_write: how many dirty pages to write-back - * - * This function shrinks UBIFS liability by means of writing back some amount - * of dirty inodes and their pages. - * - * Note, this function synchronizes even VFS inodes which are locked - * (@i_mutex) by the caller of the budgeting function, because write-back does - * not touch @i_mutex. - */ -static void shrink_liability(struct ubifs_info *c, int nr_to_write) -{ - down_read(&c->vfs_sb->s_umount); - writeback_inodes_sb(c->vfs_sb, WB_REASON_FS_FREE_SPACE); - up_read(&c->vfs_sb->s_umount); -} - -/** - * run_gc - run garbage collector. - * @c: UBIFS file-system description object - * - * This function runs garbage collector to make some more free space. Returns - * zero if a free LEB has been produced, %-EAGAIN if commit is required, and a - * negative error code in case of failure. - */ -static int run_gc(struct ubifs_info *c) -{ - int err, lnum; - - /* Make some free space by garbage-collecting dirty space */ - down_read(&c->commit_sem); - lnum = ubifs_garbage_collect(c, 1); - up_read(&c->commit_sem); - if (lnum < 0) - return lnum; - - /* GC freed one LEB, return it to lprops */ - dbg_budg("GC freed LEB %d", lnum); - err = ubifs_return_leb(c, lnum); - if (err) - return err; - 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->bi.idx_growth + c->bi.data_growth + c->bi.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 - * - * 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: - * o budgeting is pessimistic, so it always budgets more than it is actually - * needed, so shrinking the liability is one way to make free space - the - * cached data will take less space then it was budgeted for; - * o GC may turn some dark space into free space (budgeting treats dark space - * as not available); - * o commit may free some LEB, i.e., turn freeable LEBs into free LEBs. - * - * So this function tries to do the above. Returns %-EAGAIN if some free space - * was presumably made and the caller has to re-try budgeting the operation. - * 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) -{ - int err, retries = 0; - long long liab1, liab2; - - 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); - - liab2 = get_liability(c); - if (liab2 < liab1) - return -EAGAIN; - - dbg_budg("new liability %lld (not shrunk)", liab2); - - /* Liability did not shrink again, try GC */ - dbg_budg("Run GC"); - err = run_gc(c); - if (!err) - return -EAGAIN; - - if (err != -EAGAIN && err != -ENOSPC) - /* Some real error happened */ - return err; - - dbg_budg("Run commit (retries %d)", retries); - err = ubifs_run_commit(c); - if (err) - return err; - } while (retries++ < MAX_MKSPC_RETRIES); - - return -ENOSPC; -} - -/** - * ubifs_calc_min_idx_lebs - calculate amount of LEBs for the index. - * @c: UBIFS file-system description object - * - * This function calculates and returns the number of LEBs which should be kept - * for index usage. - */ -int ubifs_calc_min_idx_lebs(struct ubifs_info *c) -{ - int idx_lebs; - long long idx_size; - - idx_size = c->bi.old_idx_sz + c->bi.idx_growth + c->bi.uncommitted_idx; - /* And make sure we have thrice the index size of space reserved */ - idx_size += idx_size << 1; - /* - * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes' - * pair, nor similarly the two variables for the new index size, so we - * have to do this costly 64-bit division on fast-path. - */ - idx_lebs = div_u64(idx_size + c->idx_leb_size - 1, c->idx_leb_size); - /* - * The index head is not available for the in-the-gaps method, so add an - * extra LEB to compensate. - */ - idx_lebs += 1; - if (idx_lebs < MIN_INDEX_LEBS) - idx_lebs = MIN_INDEX_LEBS; - return idx_lebs; -} - -/** - * ubifs_calc_available - calculate available FS space. - * @c: UBIFS file-system description object - * @min_idx_lebs: minimum number of LEBs reserved for the index - * - * This function calculates and returns amount of FS space available for use. - */ -long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs) -{ - int subtract_lebs; - long long available; - - available = c->main_bytes - c->lst.total_used; - - /* - * Now 'available' contains theoretically available flash space - * assuming there is no index, so we have to subtract the space which - * is reserved for the index. - */ - subtract_lebs = min_idx_lebs; - - /* Take into account that GC reserves one LEB for its own needs */ - subtract_lebs += 1; - - /* - * The GC journal head LEB is not really accessible. And since - * different write types go to different heads, we may count only on - * one head's space. - */ - subtract_lebs += c->jhead_cnt - 1; - - /* We also reserve one LEB for deletions, which bypass budgeting */ - subtract_lebs += 1; - - available -= (long long)subtract_lebs * c->leb_size; - - /* Subtract the dead space which is not available for use */ - available -= c->lst.total_dead; - - /* - * Subtract dark space, which might or might not be usable - it depends - * on the data which we have on the media and which will be written. If - * this is a lot of uncompressed or not-compressible data, the dark - * space cannot be used. - */ - available -= c->lst.total_dark; - - /* - * However, there is more dark space. The index may be bigger than - * @min_idx_lebs. Those extra LEBs are assumed to be available, but - * their dark space is not included in total_dark, so it is subtracted - * here. - */ - if (c->lst.idx_lebs > min_idx_lebs) { - subtract_lebs = c->lst.idx_lebs - min_idx_lebs; - available -= subtract_lebs * c->dark_wm; - } - - /* The calculations are rough and may end up with a negative number */ - return available > 0 ? available : 0; -} - -/** - * can_use_rp - check whether the user is allowed to use reserved pool. - * @c: UBIFS file-system description object - * - * UBIFS has so-called "reserved pool" which is flash space reserved - * for the superuser and for uses whose UID/GID is recorded in UBIFS superblock. - * This function checks whether current user is allowed to use reserved pool. - * Returns %1 current user is allowed to use reserved pool and %0 otherwise. - */ -static int can_use_rp(struct ubifs_info *c) -{ - if (current_fsuid() == c->rp_uid || capable(CAP_SYS_RESOURCE) || - (c->rp_gid != 0 && in_group_p(c->rp_gid))) - return 1; - return 0; -} - -/** - * do_budget_space - reserve flash space for index and data growth. - * @c: UBIFS file-system description object - * - * This function makes sure UBIFS has enough free LEBs for index growth and - * data. - * - * When budgeting index space, UBIFS reserves thrice as many LEBs as the index - * would take if it was consolidated and written to the flash. This guarantees - * that the "in-the-gaps" commit method always succeeds and UBIFS will always - * be able to commit dirty index. So this function basically adds amount of - * budgeted index space to the size of the current index, multiplies this by 3, - * and makes sure this does not exceed the amount of free LEBs. - * - * Notes about @c->bi.min_idx_lebs and @c->lst.idx_lebs variables: - * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might - * be large, because UBIFS does not do any index consolidation as long as - * there is free space. IOW, the index may take a lot of LEBs, but the LEBs - * will contain a lot of dirt. - * o @c->bi.min_idx_lebs is the number of LEBS the index presumably takes. IOW, - * the index may be consolidated to take up to @c->bi.min_idx_lebs LEBs. - * - * This function returns zero in case of success, and %-ENOSPC in case of - * failure. - */ -static int do_budget_space(struct ubifs_info *c) -{ - long long outstanding, available; - int lebs, rsvd_idx_lebs, min_idx_lebs; - - /* First budget index space */ - min_idx_lebs = ubifs_calc_min_idx_lebs(c); - - /* Now 'min_idx_lebs' contains number of LEBs to reserve */ - if (min_idx_lebs > c->lst.idx_lebs) - rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs; - else - rsvd_idx_lebs = 0; - - /* - * The number of LEBs that are available to be used by the index is: - * - * @c->lst.empty_lebs + @c->freeable_cnt + @c->idx_gc_cnt - - * @c->lst.taken_empty_lebs - * - * @c->lst.empty_lebs are available because they are empty. - * @c->freeable_cnt are available because they contain only free and - * dirty space, @c->idx_gc_cnt are available because they are index - * LEBs that have been garbage collected and are awaiting the commit - * before they can be used. And the in-the-gaps method will grab these - * if it needs them. @c->lst.taken_empty_lebs are empty LEBs that have - * already been allocated for some purpose. - * - * Note, @c->idx_gc_cnt is included to both @c->lst.empty_lebs (because - * these LEBs are empty) and to @c->lst.taken_empty_lebs (because they - * are taken until after the commit). - * - * Note, @c->lst.taken_empty_lebs may temporarily be higher by one - * because of the way we serialize LEB allocations and budgeting. See a - * comment in 'ubifs_find_free_space()'. - */ - lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt - - c->lst.taken_empty_lebs; - if (unlikely(rsvd_idx_lebs > lebs)) { - dbg_budg("out of indexing space: min_idx_lebs %d (old %d), " - "rsvd_idx_lebs %d", min_idx_lebs, c->bi.min_idx_lebs, - rsvd_idx_lebs); - return -ENOSPC; - } - - available = ubifs_calc_available(c, min_idx_lebs); - outstanding = c->bi.data_growth + c->bi.dd_growth; - - if (unlikely(available < outstanding)) { - dbg_budg("out of data space: available %lld, outstanding %lld", - available, outstanding); - return -ENOSPC; - } - - if (available - outstanding <= c->rp_size && !can_use_rp(c)) - return -ENOSPC; - - c->bi.min_idx_lebs = min_idx_lebs; - return 0; -} - -/** - * calc_idx_growth - calculate approximate index growth from budgeting request. - * @c: UBIFS file-system description object - * @req: budgeting request - * - * For now we assume each new node adds one znode. But this is rather poor - * approximation, though. - */ -static int calc_idx_growth(const struct ubifs_info *c, - const struct ubifs_budget_req *req) -{ - int znodes; - - znodes = req->new_ino + (req->new_page << UBIFS_BLOCKS_PER_PAGE_SHIFT) + - req->new_dent; - return znodes * c->max_idx_node_sz; -} - -/** - * calc_data_growth - calculate approximate amount of new data from budgeting - * request. - * @c: UBIFS file-system description object - * @req: budgeting request - */ -static int calc_data_growth(const struct ubifs_info *c, - const struct ubifs_budget_req *req) -{ - int data_growth; - - data_growth = req->new_ino ? c->bi.inode_budget : 0; - if (req->new_page) - data_growth += c->bi.page_budget; - if (req->new_dent) - data_growth += c->bi.dent_budget; - data_growth += req->new_ino_d; - return data_growth; -} - -/** - * calc_dd_growth - calculate approximate amount of data which makes other data - * dirty from budgeting request. - * @c: UBIFS file-system description object - * @req: budgeting request - */ -static int calc_dd_growth(const struct ubifs_info *c, - const struct ubifs_budget_req *req) -{ - int dd_growth; - - dd_growth = req->dirtied_page ? c->bi.page_budget : 0; - - if (req->dirtied_ino) - dd_growth += c->bi.inode_budget << (req->dirtied_ino - 1); - if (req->mod_dent) - dd_growth += c->bi.dent_budget; - dd_growth += req->dirtied_ino_d; - return dd_growth; -} - -/** - * ubifs_budget_space - ensure there is enough space to complete an operation. - * @c: UBIFS file-system description object - * @req: budget request - * - * This function allocates budget for an operation. It uses pessimistic - * approximation of how much flash space the operation needs. The goal of this - * function is to make sure UBIFS always has flash space to flush all dirty - * pages, dirty inodes, and dirty znodes (liability). This function may force - * commit, garbage-collection or write-back. Returns zero in case of success, - * %-ENOSPC if there is no free space and other negative error codes in case of - * failures. - */ -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, retried = 0; - - ubifs_assert(req->new_page <= 1); - ubifs_assert(req->dirtied_page <= 1); - ubifs_assert(req->new_dent <= 1); - ubifs_assert(req->mod_dent <= 1); - ubifs_assert(req->new_ino <= 1); - ubifs_assert(req->new_ino_d <= UBIFS_MAX_INO_DATA); - ubifs_assert(req->dirtied_ino <= 4); - ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4); - ubifs_assert(!(req->new_ino_d & 7)); - ubifs_assert(!(req->dirtied_ino_d & 7)); - - data_growth = calc_data_growth(c, req); - dd_growth = calc_dd_growth(c, req); - if (!data_growth && !dd_growth) - return 0; - idx_growth = calc_idx_growth(c, req); - -again: - spin_lock(&c->space_lock); - ubifs_assert(c->bi.idx_growth >= 0); - ubifs_assert(c->bi.data_growth >= 0); - ubifs_assert(c->bi.dd_growth >= 0); - - if (unlikely(c->bi.nospace) && (c->bi.nospace_rp || !can_use_rp(c))) { - dbg_budg("no space"); - spin_unlock(&c->space_lock); - return -ENOSPC; - } - - c->bi.idx_growth += idx_growth; - c->bi.data_growth += data_growth; - c->bi.dd_growth += dd_growth; - - err = do_budget_space(c); - if (likely(!err)) { - req->idx_growth = idx_growth; - req->data_growth = data_growth; - req->dd_growth = dd_growth; - spin_unlock(&c->space_lock); - return 0; - } - - /* Restore the old values */ - c->bi.idx_growth -= idx_growth; - c->bi.data_growth -= data_growth; - c->bi.dd_growth -= dd_growth; - spin_unlock(&c->space_lock); - - if (req->fast) { - dbg_budg("no space for fast budgeting"); - return err; - } - - err = make_free_space(c); - cond_resched(); - if (err == -EAGAIN) { - dbg_budg("try again"); - 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->bi.nospace = 1; - if (can_use_rp(c) || c->rp_size == 0) - c->bi.nospace_rp = 1; - smp_wmb(); - } else - ubifs_err("cannot budget space, error %d", err); - return err; -} - -/** - * ubifs_release_budget - release budgeted free space. - * @c: UBIFS file-system description object - * @req: budget request - * - * This function releases the space budgeted by 'ubifs_budget_space()'. Note, - * since the index changes (which were budgeted for in @req->idx_growth) will - * only be written to the media on commit, this function moves the index budget - * from @c->bi.idx_growth to @c->bi.uncommitted_idx. The latter will be zeroed - * by the commit operation. - */ -void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req) -{ - ubifs_assert(req->new_page <= 1); - ubifs_assert(req->dirtied_page <= 1); - ubifs_assert(req->new_dent <= 1); - ubifs_assert(req->mod_dent <= 1); - ubifs_assert(req->new_ino <= 1); - ubifs_assert(req->new_ino_d <= UBIFS_MAX_INO_DATA); - ubifs_assert(req->dirtied_ino <= 4); - ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4); - ubifs_assert(!(req->new_ino_d & 7)); - ubifs_assert(!(req->dirtied_ino_d & 7)); - if (!req->recalculate) { - ubifs_assert(req->idx_growth >= 0); - ubifs_assert(req->data_growth >= 0); - ubifs_assert(req->dd_growth >= 0); - } - - if (req->recalculate) { - req->data_growth = calc_data_growth(c, req); - req->dd_growth = calc_dd_growth(c, req); - req->idx_growth = calc_idx_growth(c, req); - } - - if (!req->data_growth && !req->dd_growth) - return; - - c->bi.nospace = c->bi.nospace_rp = 0; - smp_wmb(); - - spin_lock(&c->space_lock); - c->bi.idx_growth -= req->idx_growth; - c->bi.uncommitted_idx += req->idx_growth; - c->bi.data_growth -= req->data_growth; - c->bi.dd_growth -= req->dd_growth; - c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); - - ubifs_assert(c->bi.idx_growth >= 0); - ubifs_assert(c->bi.data_growth >= 0); - ubifs_assert(c->bi.dd_growth >= 0); - ubifs_assert(c->bi.min_idx_lebs < c->main_lebs); - ubifs_assert(!(c->bi.idx_growth & 7)); - ubifs_assert(!(c->bi.data_growth & 7)); - ubifs_assert(!(c->bi.dd_growth & 7)); - spin_unlock(&c->space_lock); -} - -/** - * ubifs_convert_page_budget - convert budget of a new page. - * @c: UBIFS file-system description object - * - * This function converts budget which was allocated for a new page of data to - * the budget of changing an existing page of data. The latter is smaller than - * the former, so this function only does simple re-calculation and does not - * involve any write-back. - */ -void ubifs_convert_page_budget(struct ubifs_info *c) -{ - spin_lock(&c->space_lock); - /* Release the index growth reservation */ - c->bi.idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT; - /* Release the data growth reservation */ - c->bi.data_growth -= c->bi.page_budget; - /* Increase the dirty data growth reservation instead */ - c->bi.dd_growth += c->bi.page_budget; - /* And re-calculate the indexing space reservation */ - c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c); - spin_unlock(&c->space_lock); -} - -/** - * ubifs_release_dirty_inode_budget - release dirty inode budget. - * @c: UBIFS file-system description object - * @ui: UBIFS inode to release the budget for - * - * This function releases budget corresponding to a dirty inode. It is usually - * called when after the inode has been written to the media and marked as - * clean. It also causes the "no space" flags to be cleared. - */ -void ubifs_release_dirty_inode_budget(struct ubifs_info *c, - struct ubifs_inode *ui) -{ - struct ubifs_budget_req req; - - memset(&req, 0, sizeof(struct ubifs_budget_req)); - /* The "no space" flags will be cleared because dd_growth is > 0 */ - req.dd_growth = c->bi.inode_budget + ALIGN(ui->data_len, 8); - ubifs_release_budget(c, &req); -} - -/** - * ubifs_reported_space - calculate reported free space. - * @c: the UBIFS file-system description object - * @free: amount of free space - * - * This function calculates amount of free space which will be reported to - * 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 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 - * space to write the index thrice). - * - * 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, long long free) -{ - int divisor, factor, f; - - /* - * Reported space size is @free * X, where X is UBIFS block size - * divided by UBIFS block size + all overhead one data block - * introduces. The overhead is the node header + indexing overhead. - * - * Indexing overhead calculations are based on the following formula: - * I = N/(f - 1) + 1, where I - number of indexing nodes, N - number - * 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 reserves thrice as more space - * for the index. - */ - f = c->fanout > 3 ? c->fanout >> 1 : 2; - factor = UBIFS_BLOCK_SIZE; - divisor = UBIFS_MAX_DATA_NODE_SZ; - divisor += (c->max_idx_node_sz * 3) / (f - 1); - free *= factor; - return div_u64(free, divisor); -} - -/** - * ubifs_get_free_space_nolock - return amount of free space. - * @c: UBIFS file-system description object - * - * This function calculates amount of free space to report to user-space. - * - * Because UBIFS may introduce substantial overhead (the index, node headers, - * alignment, wastage at the end of LEBs, etc), it cannot report real amount of - * free flash space it has (well, because not all dirty space is 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. - * So, to keep users happy, UBIFS tries to take the overhead into account. - */ -long long ubifs_get_free_space_nolock(struct ubifs_info *c) -{ - int rsvd_idx_lebs, lebs; - long long available, outstanding, free; - - ubifs_assert(c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c)); - outstanding = c->bi.data_growth + c->bi.dd_growth; - available = ubifs_calc_available(c, c->bi.min_idx_lebs); - - /* - * When reporting free space to user-space, UBIFS guarantees that it is - * possible to write a file of free space size. This means that for - * empty LEBs we may use more precise calculations than - * 'ubifs_calc_available()' is using. Namely, we know that in empty - * LEBs we would waste only @c->leb_overhead bytes, not @c->dark_wm. - * Thus, amend the available space. - * - * Note, the calculations below are similar to what we have in - * 'do_budget_space()', so refer there for comments. - */ - if (c->bi.min_idx_lebs > c->lst.idx_lebs) - rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs; - else - rsvd_idx_lebs = 0; - lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt - - c->lst.taken_empty_lebs; - lebs -= rsvd_idx_lebs; - available += lebs * (c->dark_wm - c->leb_overhead); - - if (available > outstanding) - free = ubifs_reported_space(c, available - outstanding); - else - free = 0; - return free; -} - -/** - * ubifs_get_free_space - return amount of free space. - * @c: UBIFS file-system description object - * - * This function calculates and returns amount of free space to report to - * user-space. - */ -long long ubifs_get_free_space(struct ubifs_info *c) -{ - long long free; - - spin_lock(&c->space_lock); - free = ubifs_get_free_space_nolock(c); - spin_unlock(&c->space_lock); - - return free; -} |