^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * This file is part of UBIFS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2006-2008 Nokia Corporation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * Authors: Adrian Hunter
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Artem Bityutskiy (Битюцкий Артём)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * This file implements the budgeting sub-system which is responsible for UBIFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * space management.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) * Factors such as compression, wasted space at the ends of LEBs, space in other
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) * journal heads, the effect of updates on the index, and so on, make it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) * impossible to accurately predict the amount of space needed. Consequently
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) * approximations are used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include "ubifs.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/writeback.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/math64.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) * When pessimistic budget calculations say that there is no enough space,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) * UBIFS starts writing back dirty inodes and pages, doing garbage collection,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) * or committing. The below constant defines maximum number of times UBIFS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) * repeats the operations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #define MAX_MKSPC_RETRIES 3
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) * The below constant defines amount of dirty pages which should be written
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) * back at when trying to shrink the liability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) #define NR_TO_WRITE 16
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) * shrink_liability - write-back some dirty pages/inodes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) * @nr_to_write: how many dirty pages to write-back
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * This function shrinks UBIFS liability by means of writing back some amount
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * of dirty inodes and their pages.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) * Note, this function synchronizes even VFS inodes which are locked
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) * (@i_mutex) by the caller of the budgeting function, because write-back does
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) * not touch @i_mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) static void shrink_liability(struct ubifs_info *c, int nr_to_write)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) down_read(&c->vfs_sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) writeback_inodes_sb_nr(c->vfs_sb, nr_to_write, WB_REASON_FS_FREE_SPACE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) up_read(&c->vfs_sb->s_umount);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) * run_gc - run garbage collector.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) * This function runs garbage collector to make some more free space. Returns
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) * zero if a free LEB has been produced, %-EAGAIN if commit is required, and a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) * negative error code in case of failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) static int run_gc(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) int err, lnum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) /* Make some free space by garbage-collecting dirty space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) down_read(&c->commit_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) lnum = ubifs_garbage_collect(c, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) up_read(&c->commit_sem);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) if (lnum < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) return lnum;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) /* GC freed one LEB, return it to lprops */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) dbg_budg("GC freed LEB %d", lnum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) err = ubifs_return_leb(c, lnum);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) * get_liability - calculate current liability.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) * This function calculates and returns current UBIFS liability, i.e. the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) * amount of bytes UBIFS has "promised" to write to the media.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static long long get_liability(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) long long liab;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) spin_lock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) liab = c->bi.idx_growth + c->bi.data_growth + c->bi.dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) return liab;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) * make_free_space - make more free space on the file-system.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) * This function is called when an operation cannot be budgeted because there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) * is supposedly no free space. But in most cases there is some free space:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) * o budgeting is pessimistic, so it always budgets more than it is actually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) * needed, so shrinking the liability is one way to make free space - the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) * cached data will take less space then it was budgeted for;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) * o GC may turn some dark space into free space (budgeting treats dark space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) * as not available);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) * o commit may free some LEB, i.e., turn freeable LEBs into free LEBs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * So this function tries to do the above. Returns %-EAGAIN if some free space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * was presumably made and the caller has to re-try budgeting the operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) * Returns %-ENOSPC if it couldn't do more free space, and other negative error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) * codes on failures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static int make_free_space(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) int err, retries = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) long long liab1, liab2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) liab1 = get_liability(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) * We probably have some dirty pages or inodes (liability), try
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) * to write them back.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) dbg_budg("liability %lld, run write-back", liab1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) shrink_liability(c, NR_TO_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) liab2 = get_liability(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) if (liab2 < liab1)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) dbg_budg("new liability %lld (not shrunk)", liab2);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) /* Liability did not shrink again, try GC */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) dbg_budg("Run GC");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142) err = run_gc(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) if (!err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) return -EAGAIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) if (err != -EAGAIN && err != -ENOSPC)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) /* Some real error happened */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) dbg_budg("Run commit (retries %d)", retries);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) err = ubifs_run_commit(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) if (err)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) } while (retries++ < MAX_MKSPC_RETRIES);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) * ubifs_calc_min_idx_lebs - calculate amount of LEBs for the index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) * This function calculates and returns the number of LEBs which should be kept
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) * for index usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) int idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) long long idx_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) idx_size = c->bi.old_idx_sz + c->bi.idx_growth + c->bi.uncommitted_idx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) /* And make sure we have thrice the index size of space reserved */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) idx_size += idx_size << 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) * pair, nor similarly the two variables for the new index size, so we
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) * have to do this costly 64-bit division on fast-path.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) idx_lebs = div_u64(idx_size + c->idx_leb_size - 1, c->idx_leb_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) * The index head is not available for the in-the-gaps method, so add an
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) * extra LEB to compensate.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) idx_lebs += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) if (idx_lebs < MIN_INDEX_LEBS)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186) idx_lebs = MIN_INDEX_LEBS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) return idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) * ubifs_calc_available - calculate available FS space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) * @min_idx_lebs: minimum number of LEBs reserved for the index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) * This function calculates and returns amount of FS space available for use.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197) long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) int subtract_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) long long available;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) available = c->main_bytes - c->lst.total_used;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) * Now 'available' contains theoretically available flash space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) * assuming there is no index, so we have to subtract the space which
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207) * is reserved for the index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) subtract_lebs = min_idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) /* Take into account that GC reserves one LEB for its own needs */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212) subtract_lebs += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) * The GC journal head LEB is not really accessible. And since
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216) * different write types go to different heads, we may count only on
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) * one head's space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) subtract_lebs += c->jhead_cnt - 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221) /* We also reserve one LEB for deletions, which bypass budgeting */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) subtract_lebs += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224) available -= (long long)subtract_lebs * c->leb_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) /* Subtract the dead space which is not available for use */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) available -= c->lst.total_dead;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) * Subtract dark space, which might or might not be usable - it depends
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) * on the data which we have on the media and which will be written. If
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232) * this is a lot of uncompressed or not-compressible data, the dark
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) * space cannot be used.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) available -= c->lst.total_dark;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) * However, there is more dark space. The index may be bigger than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) * @min_idx_lebs. Those extra LEBs are assumed to be available, but
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) * their dark space is not included in total_dark, so it is subtracted
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) * here.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) if (c->lst.idx_lebs > min_idx_lebs) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244) subtract_lebs = c->lst.idx_lebs - min_idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) available -= subtract_lebs * c->dark_wm;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) /* The calculations are rough and may end up with a negative number */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) return available > 0 ? available : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) * can_use_rp - check whether the user is allowed to use reserved pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * UBIFS has so-called "reserved pool" which is flash space reserved
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * for the superuser and for uses whose UID/GID is recorded in UBIFS superblock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) * This function checks whether current user is allowed to use reserved pool.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) * Returns %1 current user is allowed to use reserved pool and %0 otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) static int can_use_rp(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) if (uid_eq(current_fsuid(), c->rp_uid) || capable(CAP_SYS_RESOURCE) ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) (!gid_eq(c->rp_gid, GLOBAL_ROOT_GID) && in_group_p(c->rp_gid)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) return 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * do_budget_space - reserve flash space for index and data growth.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * This function makes sure UBIFS has enough free LEBs for index growth and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) * data.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) * When budgeting index space, UBIFS reserves thrice as many LEBs as the index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) * would take if it was consolidated and written to the flash. This guarantees
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) * that the "in-the-gaps" commit method always succeeds and UBIFS will always
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) * be able to commit dirty index. So this function basically adds amount of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280) * budgeted index space to the size of the current index, multiplies this by 3,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) * and makes sure this does not exceed the amount of free LEBs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) * Notes about @c->bi.min_idx_lebs and @c->lst.idx_lebs variables:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) * be large, because UBIFS does not do any index consolidation as long as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286) * there is free space. IOW, the index may take a lot of LEBs, but the LEBs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) * will contain a lot of dirt.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) * o @c->bi.min_idx_lebs is the number of LEBS the index presumably takes. IOW,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) * the index may be consolidated to take up to @c->bi.min_idx_lebs LEBs.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) * This function returns zero in case of success, and %-ENOSPC in case of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) * failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) static int do_budget_space(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) long long outstanding, available;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) int lebs, rsvd_idx_lebs, min_idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299) /* First budget index space */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) min_idx_lebs = ubifs_calc_min_idx_lebs(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) /* Now 'min_idx_lebs' contains number of LEBs to reserve */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303) if (min_idx_lebs > c->lst.idx_lebs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) rsvd_idx_lebs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) * The number of LEBs that are available to be used by the index is:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311) * @c->lst.empty_lebs + @c->freeable_cnt + @c->idx_gc_cnt -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) * @c->lst.taken_empty_lebs
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) * @c->lst.empty_lebs are available because they are empty.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) * @c->freeable_cnt are available because they contain only free and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) * dirty space, @c->idx_gc_cnt are available because they are index
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) * LEBs that have been garbage collected and are awaiting the commit
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) * before they can be used. And the in-the-gaps method will grab these
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) * if it needs them. @c->lst.taken_empty_lebs are empty LEBs that have
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) * already been allocated for some purpose.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322) * Note, @c->idx_gc_cnt is included to both @c->lst.empty_lebs (because
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) * these LEBs are empty) and to @c->lst.taken_empty_lebs (because they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) * are taken until after the commit).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326) * Note, @c->lst.taken_empty_lebs may temporarily be higher by one
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) * because of the way we serialize LEB allocations and budgeting. See a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) * comment in 'ubifs_find_free_space()'.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) c->lst.taken_empty_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) if (unlikely(rsvd_idx_lebs > lebs)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) dbg_budg("out of indexing space: min_idx_lebs %d (old %d), rsvd_idx_lebs %d",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) min_idx_lebs, c->bi.min_idx_lebs, rsvd_idx_lebs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) available = ubifs_calc_available(c, min_idx_lebs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) outstanding = c->bi.data_growth + c->bi.dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) if (unlikely(available < outstanding)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) dbg_budg("out of data space: available %lld, outstanding %lld",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) available, outstanding);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) if (available - outstanding <= c->rp_size && !can_use_rp(c))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) c->bi.min_idx_lebs = min_idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) * calc_idx_growth - calculate approximate index growth from budgeting request.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357) * @req: budgeting request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) * For now we assume each new node adds one znode. But this is rather poor
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) * approximation, though.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) static int calc_idx_growth(const struct ubifs_info *c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) const struct ubifs_budget_req *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) int znodes;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) znodes = req->new_ino + (req->new_page << UBIFS_BLOCKS_PER_PAGE_SHIFT) +
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) req->new_dent;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369) return znodes * c->max_idx_node_sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) * calc_data_growth - calculate approximate amount of new data from budgeting
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) * request.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) * @req: budgeting request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) static int calc_data_growth(const struct ubifs_info *c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) const struct ubifs_budget_req *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) int data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) data_growth = req->new_ino ? c->bi.inode_budget : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) if (req->new_page)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) data_growth += c->bi.page_budget;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) if (req->new_dent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) data_growth += c->bi.dent_budget;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) data_growth += req->new_ino_d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) return data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) * calc_dd_growth - calculate approximate amount of data which makes other data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) * dirty from budgeting request.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) * @req: budgeting request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) static int calc_dd_growth(const struct ubifs_info *c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) const struct ubifs_budget_req *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) int dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) dd_growth = req->dirtied_page ? c->bi.page_budget : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405) if (req->dirtied_ino)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) dd_growth += c->bi.inode_budget << (req->dirtied_ino - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) if (req->mod_dent)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) dd_growth += c->bi.dent_budget;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) dd_growth += req->dirtied_ino_d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) return dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) * ubifs_budget_space - ensure there is enough space to complete an operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) * @req: budget request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * This function allocates budget for an operation. It uses pessimistic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * approximation of how much flash space the operation needs. The goal of this
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) * function is to make sure UBIFS always has flash space to flush all dirty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) * pages, dirty inodes, and dirty znodes (liability). This function may force
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) * commit, garbage-collection or write-back. Returns zero in case of success,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) * %-ENOSPC if there is no free space and other negative error codes in case of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) * failures.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) int err, idx_growth, data_growth, dd_growth, retried = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) ubifs_assert(c, req->new_page <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) ubifs_assert(c, req->dirtied_page <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) ubifs_assert(c, req->new_dent <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433) ubifs_assert(c, req->mod_dent <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) ubifs_assert(c, req->new_ino <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) ubifs_assert(c, req->new_ino_d <= UBIFS_MAX_INO_DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436) ubifs_assert(c, req->dirtied_ino <= 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) ubifs_assert(c, req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) ubifs_assert(c, !(req->new_ino_d & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) ubifs_assert(c, !(req->dirtied_ino_d & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) data_growth = calc_data_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) dd_growth = calc_dd_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) if (!data_growth && !dd_growth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) idx_growth = calc_idx_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) again:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) spin_lock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449) ubifs_assert(c, c->bi.idx_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) ubifs_assert(c, c->bi.data_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) ubifs_assert(c, c->bi.dd_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) if (unlikely(c->bi.nospace) && (c->bi.nospace_rp || !can_use_rp(c))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) dbg_budg("no space");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456) return -ENOSPC;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459) c->bi.idx_growth += idx_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) c->bi.data_growth += data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) c->bi.dd_growth += dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) err = do_budget_space(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) if (likely(!err)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) req->idx_growth = idx_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) req->data_growth = data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) req->dd_growth = dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472) /* Restore the old values */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) c->bi.idx_growth -= idx_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) c->bi.data_growth -= data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475) c->bi.dd_growth -= dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478) if (req->fast) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) dbg_budg("no space for fast budgeting");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) err = make_free_space(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) cond_resched();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) if (err == -EAGAIN) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) dbg_budg("try again");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487) goto again;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) } else if (err == -ENOSPC) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) if (!retried) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490) retried = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) dbg_budg("-ENOSPC, but anyway try once again");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492) goto again;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494) dbg_budg("FS is full, -ENOSPC");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) c->bi.nospace = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) if (can_use_rp(c) || c->rp_size == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) c->bi.nospace_rp = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) ubifs_err(c, "cannot budget space, error %d", err);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505) * ubifs_release_budget - release budgeted free space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507) * @req: budget request
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509) * This function releases the space budgeted by 'ubifs_budget_space()'. Note,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) * since the index changes (which were budgeted for in @req->idx_growth) will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) * only be written to the media on commit, this function moves the index budget
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) * from @c->bi.idx_growth to @c->bi.uncommitted_idx. The latter will be zeroed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) * by the commit operation.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) ubifs_assert(c, req->new_page <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) ubifs_assert(c, req->dirtied_page <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) ubifs_assert(c, req->new_dent <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) ubifs_assert(c, req->mod_dent <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) ubifs_assert(c, req->new_ino <= 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) ubifs_assert(c, req->new_ino_d <= UBIFS_MAX_INO_DATA);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) ubifs_assert(c, req->dirtied_ino <= 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524) ubifs_assert(c, req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) ubifs_assert(c, !(req->new_ino_d & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) ubifs_assert(c, !(req->dirtied_ino_d & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527) if (!req->recalculate) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) ubifs_assert(c, req->idx_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) ubifs_assert(c, req->data_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530) ubifs_assert(c, req->dd_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533) if (req->recalculate) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) req->data_growth = calc_data_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) req->dd_growth = calc_dd_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) req->idx_growth = calc_idx_growth(c, req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539) if (!req->data_growth && !req->dd_growth)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) c->bi.nospace = c->bi.nospace_rp = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) smp_wmb();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) spin_lock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) c->bi.idx_growth -= req->idx_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) c->bi.uncommitted_idx += req->idx_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) c->bi.data_growth -= req->data_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549) c->bi.dd_growth -= req->dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) ubifs_assert(c, c->bi.idx_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553) ubifs_assert(c, c->bi.data_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) ubifs_assert(c, c->bi.dd_growth >= 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) ubifs_assert(c, c->bi.min_idx_lebs < c->main_lebs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) ubifs_assert(c, !(c->bi.idx_growth & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557) ubifs_assert(c, !(c->bi.data_growth & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) ubifs_assert(c, !(c->bi.dd_growth & 7));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) * ubifs_convert_page_budget - convert budget of a new page.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566) * This function converts budget which was allocated for a new page of data to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) * the budget of changing an existing page of data. The latter is smaller than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568) * the former, so this function only does simple re-calculation and does not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) * involve any write-back.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) void ubifs_convert_page_budget(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573) spin_lock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) /* Release the index growth reservation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) c->bi.idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576) /* Release the data growth reservation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) c->bi.data_growth -= c->bi.page_budget;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) /* Increase the dirty data growth reservation instead */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) c->bi.dd_growth += c->bi.page_budget;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) /* And re-calculate the indexing space reservation */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) * ubifs_release_dirty_inode_budget - release dirty inode budget.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) * @ui: UBIFS inode to release the budget for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590) * This function releases budget corresponding to a dirty inode. It is usually
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) * called when after the inode has been written to the media and marked as
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) * clean. It also causes the "no space" flags to be cleared.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595) struct ubifs_inode *ui)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597) struct ubifs_budget_req req;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) memset(&req, 0, sizeof(struct ubifs_budget_req));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) /* The "no space" flags will be cleared because dd_growth is > 0 */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601) req.dd_growth = c->bi.inode_budget + ALIGN(ui->data_len, 8);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) ubifs_release_budget(c, &req);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) * ubifs_reported_space - calculate reported free space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) * @c: the UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608) * @free: amount of free space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) * This function calculates amount of free space which will be reported to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611) * user-space. User-space application tend to expect that if the file-system
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) * (e.g., via the 'statfs()' call) reports that it has N bytes available, they
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) * are able to write a file of size N. UBIFS attaches node headers to each data
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614) * node and it has to write indexing nodes as well. This introduces additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) * overhead, and UBIFS has to report slightly less free space to meet the above
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) * expectations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) * This function assumes free space is made up of uncompressed data nodes and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) * full index nodes (one per data node, tripled because we always allow enough
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) * space to write the index thrice).
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) * Note, the calculation is pessimistic, which means that most of the time
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) * UBIFS reports less space than it actually has.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) long long ubifs_reported_space(const struct ubifs_info *c, long long free)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) int divisor, factor, f;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) * Reported space size is @free * X, where X is UBIFS block size
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) * divided by UBIFS block size + all overhead one data block
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) * introduces. The overhead is the node header + indexing overhead.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) * Indexing overhead calculations are based on the following formula:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) * I = N/(f - 1) + 1, where I - number of indexing nodes, N - number
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) * of data nodes, f - fanout. Because effective UBIFS fanout is twice
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637) * as less than maximum fanout, we assume that each data node
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639) * Note, the multiplier 3 is because UBIFS reserves thrice as more space
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) * for the index.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) f = c->fanout > 3 ? c->fanout >> 1 : 2;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) factor = UBIFS_BLOCK_SIZE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) divisor = UBIFS_MAX_DATA_NODE_SZ;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) divisor += (c->max_idx_node_sz * 3) / (f - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646) free *= factor;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) return div_u64(free, divisor);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651) * ubifs_get_free_space_nolock - return amount of free space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) * This function calculates amount of free space to report to user-space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) * Because UBIFS may introduce substantial overhead (the index, node headers,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) * alignment, wastage at the end of LEBs, etc), it cannot report real amount of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) * free flash space it has (well, because not all dirty space is reclaimable,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) * UBIFS does not actually know the real amount). If UBIFS did so, it would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) * bread user expectations about what free space is. Users seem to accustomed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) * to assume that if the file-system reports N bytes of free space, they would
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) * be able to fit a file of N bytes to the FS. This almost works for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) * traditional file-systems, because they have way less overhead than UBIFS.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) * So, to keep users happy, UBIFS tries to take the overhead into account.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) long long ubifs_get_free_space_nolock(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) int rsvd_idx_lebs, lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) long long available, outstanding, free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) ubifs_assert(c, c->bi.min_idx_lebs == ubifs_calc_min_idx_lebs(c));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) outstanding = c->bi.data_growth + c->bi.dd_growth;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) available = ubifs_calc_available(c, c->bi.min_idx_lebs);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) * When reporting free space to user-space, UBIFS guarantees that it is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) * possible to write a file of free space size. This means that for
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) * empty LEBs we may use more precise calculations than
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) * 'ubifs_calc_available()' is using. Namely, we know that in empty
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) * LEBs we would waste only @c->leb_overhead bytes, not @c->dark_wm.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) * Thus, amend the available space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) * Note, the calculations below are similar to what we have in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684) * 'do_budget_space()', so refer there for comments.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) if (c->bi.min_idx_lebs > c->lst.idx_lebs)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) rsvd_idx_lebs = c->bi.min_idx_lebs - c->lst.idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689) rsvd_idx_lebs = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) c->lst.taken_empty_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692) lebs -= rsvd_idx_lebs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) available += lebs * (c->dark_wm - c->leb_overhead);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695) if (available > outstanding)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) free = ubifs_reported_space(c, available - outstanding);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) free = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) return free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703) * ubifs_get_free_space - return amount of free space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) * @c: UBIFS file-system description object
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) * This function calculates and returns amount of free space to report to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) * user-space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) long long ubifs_get_free_space(struct ubifs_info *c)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) long long free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) spin_lock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) free = ubifs_get_free_space_nolock(c);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715) spin_unlock(&c->space_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) return free;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) }
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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