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0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * This file is part of UBIFS.
0004  *
0005  * Copyright (C) 2006-2008 Nokia Corporation.
0006  *
0007  * Authors: Adrian Hunter
0008  *          Artem Bityutskiy (Битюцкий Артём)
0009  */
0010 
0011 /*
0012  * This file implements commit-related functionality of the LEB properties
0013  * subsystem.
0014  */
0015 
0016 #include <linux/crc16.h>
0017 #include <linux/slab.h>
0018 #include <linux/random.h>
0019 #include "ubifs.h"
0020 
0021 static int dbg_populate_lsave(struct ubifs_info *c);
0022 
0023 /**
0024  * first_dirty_cnode - find first dirty cnode.
0025  * @c: UBIFS file-system description object
0026  * @nnode: nnode at which to start
0027  *
0028  * This function returns the first dirty cnode or %NULL if there is not one.
0029  */
0030 static struct ubifs_cnode *first_dirty_cnode(const struct ubifs_info *c, struct ubifs_nnode *nnode)
0031 {
0032     ubifs_assert(c, nnode);
0033     while (1) {
0034         int i, cont = 0;
0035 
0036         for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
0037             struct ubifs_cnode *cnode;
0038 
0039             cnode = nnode->nbranch[i].cnode;
0040             if (cnode &&
0041                 test_bit(DIRTY_CNODE, &cnode->flags)) {
0042                 if (cnode->level == 0)
0043                     return cnode;
0044                 nnode = (struct ubifs_nnode *)cnode;
0045                 cont = 1;
0046                 break;
0047             }
0048         }
0049         if (!cont)
0050             return (struct ubifs_cnode *)nnode;
0051     }
0052 }
0053 
0054 /**
0055  * next_dirty_cnode - find next dirty cnode.
0056  * @c: UBIFS file-system description object
0057  * @cnode: cnode from which to begin searching
0058  *
0059  * This function returns the next dirty cnode or %NULL if there is not one.
0060  */
0061 static struct ubifs_cnode *next_dirty_cnode(const struct ubifs_info *c, struct ubifs_cnode *cnode)
0062 {
0063     struct ubifs_nnode *nnode;
0064     int i;
0065 
0066     ubifs_assert(c, cnode);
0067     nnode = cnode->parent;
0068     if (!nnode)
0069         return NULL;
0070     for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
0071         cnode = nnode->nbranch[i].cnode;
0072         if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
0073             if (cnode->level == 0)
0074                 return cnode; /* cnode is a pnode */
0075             /* cnode is a nnode */
0076             return first_dirty_cnode(c, (struct ubifs_nnode *)cnode);
0077         }
0078     }
0079     return (struct ubifs_cnode *)nnode;
0080 }
0081 
0082 /**
0083  * get_cnodes_to_commit - create list of dirty cnodes to commit.
0084  * @c: UBIFS file-system description object
0085  *
0086  * This function returns the number of cnodes to commit.
0087  */
0088 static int get_cnodes_to_commit(struct ubifs_info *c)
0089 {
0090     struct ubifs_cnode *cnode, *cnext;
0091     int cnt = 0;
0092 
0093     if (!c->nroot)
0094         return 0;
0095 
0096     if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
0097         return 0;
0098 
0099     c->lpt_cnext = first_dirty_cnode(c, c->nroot);
0100     cnode = c->lpt_cnext;
0101     if (!cnode)
0102         return 0;
0103     cnt += 1;
0104     while (1) {
0105         ubifs_assert(c, !test_bit(COW_CNODE, &cnode->flags));
0106         __set_bit(COW_CNODE, &cnode->flags);
0107         cnext = next_dirty_cnode(c, cnode);
0108         if (!cnext) {
0109             cnode->cnext = c->lpt_cnext;
0110             break;
0111         }
0112         cnode->cnext = cnext;
0113         cnode = cnext;
0114         cnt += 1;
0115     }
0116     dbg_cmt("committing %d cnodes", cnt);
0117     dbg_lp("committing %d cnodes", cnt);
0118     ubifs_assert(c, cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
0119     return cnt;
0120 }
0121 
0122 /**
0123  * upd_ltab - update LPT LEB properties.
0124  * @c: UBIFS file-system description object
0125  * @lnum: LEB number
0126  * @free: amount of free space
0127  * @dirty: amount of dirty space to add
0128  */
0129 static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
0130 {
0131     dbg_lp("LEB %d free %d dirty %d to %d +%d",
0132            lnum, c->ltab[lnum - c->lpt_first].free,
0133            c->ltab[lnum - c->lpt_first].dirty, free, dirty);
0134     ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last);
0135     c->ltab[lnum - c->lpt_first].free = free;
0136     c->ltab[lnum - c->lpt_first].dirty += dirty;
0137 }
0138 
0139 /**
0140  * alloc_lpt_leb - allocate an LPT LEB that is empty.
0141  * @c: UBIFS file-system description object
0142  * @lnum: LEB number is passed and returned here
0143  *
0144  * This function finds the next empty LEB in the ltab starting from @lnum. If a
0145  * an empty LEB is found it is returned in @lnum and the function returns %0.
0146  * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
0147  * never to run out of space.
0148  */
0149 static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
0150 {
0151     int i, n;
0152 
0153     n = *lnum - c->lpt_first + 1;
0154     for (i = n; i < c->lpt_lebs; i++) {
0155         if (c->ltab[i].tgc || c->ltab[i].cmt)
0156             continue;
0157         if (c->ltab[i].free == c->leb_size) {
0158             c->ltab[i].cmt = 1;
0159             *lnum = i + c->lpt_first;
0160             return 0;
0161         }
0162     }
0163 
0164     for (i = 0; i < n; i++) {
0165         if (c->ltab[i].tgc || c->ltab[i].cmt)
0166             continue;
0167         if (c->ltab[i].free == c->leb_size) {
0168             c->ltab[i].cmt = 1;
0169             *lnum = i + c->lpt_first;
0170             return 0;
0171         }
0172     }
0173     return -ENOSPC;
0174 }
0175 
0176 /**
0177  * layout_cnodes - layout cnodes for commit.
0178  * @c: UBIFS file-system description object
0179  *
0180  * This function returns %0 on success and a negative error code on failure.
0181  */
0182 static int layout_cnodes(struct ubifs_info *c)
0183 {
0184     int lnum, offs, len, alen, done_lsave, done_ltab, err;
0185     struct ubifs_cnode *cnode;
0186 
0187     err = dbg_chk_lpt_sz(c, 0, 0);
0188     if (err)
0189         return err;
0190     cnode = c->lpt_cnext;
0191     if (!cnode)
0192         return 0;
0193     lnum = c->nhead_lnum;
0194     offs = c->nhead_offs;
0195     /* Try to place lsave and ltab nicely */
0196     done_lsave = !c->big_lpt;
0197     done_ltab = 0;
0198     if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
0199         done_lsave = 1;
0200         c->lsave_lnum = lnum;
0201         c->lsave_offs = offs;
0202         offs += c->lsave_sz;
0203         dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0204     }
0205 
0206     if (offs + c->ltab_sz <= c->leb_size) {
0207         done_ltab = 1;
0208         c->ltab_lnum = lnum;
0209         c->ltab_offs = offs;
0210         offs += c->ltab_sz;
0211         dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0212     }
0213 
0214     do {
0215         if (cnode->level) {
0216             len = c->nnode_sz;
0217             c->dirty_nn_cnt -= 1;
0218         } else {
0219             len = c->pnode_sz;
0220             c->dirty_pn_cnt -= 1;
0221         }
0222         while (offs + len > c->leb_size) {
0223             alen = ALIGN(offs, c->min_io_size);
0224             upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
0225             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0226             err = alloc_lpt_leb(c, &lnum);
0227             if (err)
0228                 goto no_space;
0229             offs = 0;
0230             ubifs_assert(c, lnum >= c->lpt_first &&
0231                      lnum <= c->lpt_last);
0232             /* Try to place lsave and ltab nicely */
0233             if (!done_lsave) {
0234                 done_lsave = 1;
0235                 c->lsave_lnum = lnum;
0236                 c->lsave_offs = offs;
0237                 offs += c->lsave_sz;
0238                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0239                 continue;
0240             }
0241             if (!done_ltab) {
0242                 done_ltab = 1;
0243                 c->ltab_lnum = lnum;
0244                 c->ltab_offs = offs;
0245                 offs += c->ltab_sz;
0246                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0247                 continue;
0248             }
0249             break;
0250         }
0251         if (cnode->parent) {
0252             cnode->parent->nbranch[cnode->iip].lnum = lnum;
0253             cnode->parent->nbranch[cnode->iip].offs = offs;
0254         } else {
0255             c->lpt_lnum = lnum;
0256             c->lpt_offs = offs;
0257         }
0258         offs += len;
0259         dbg_chk_lpt_sz(c, 1, len);
0260         cnode = cnode->cnext;
0261     } while (cnode && cnode != c->lpt_cnext);
0262 
0263     /* Make sure to place LPT's save table */
0264     if (!done_lsave) {
0265         if (offs + c->lsave_sz > c->leb_size) {
0266             alen = ALIGN(offs, c->min_io_size);
0267             upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
0268             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0269             err = alloc_lpt_leb(c, &lnum);
0270             if (err)
0271                 goto no_space;
0272             offs = 0;
0273             ubifs_assert(c, lnum >= c->lpt_first &&
0274                      lnum <= c->lpt_last);
0275         }
0276         done_lsave = 1;
0277         c->lsave_lnum = lnum;
0278         c->lsave_offs = offs;
0279         offs += c->lsave_sz;
0280         dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0281     }
0282 
0283     /* Make sure to place LPT's own lprops table */
0284     if (!done_ltab) {
0285         if (offs + c->ltab_sz > c->leb_size) {
0286             alen = ALIGN(offs, c->min_io_size);
0287             upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
0288             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0289             err = alloc_lpt_leb(c, &lnum);
0290             if (err)
0291                 goto no_space;
0292             offs = 0;
0293             ubifs_assert(c, lnum >= c->lpt_first &&
0294                      lnum <= c->lpt_last);
0295         }
0296         c->ltab_lnum = lnum;
0297         c->ltab_offs = offs;
0298         offs += c->ltab_sz;
0299         dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0300     }
0301 
0302     alen = ALIGN(offs, c->min_io_size);
0303     upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
0304     dbg_chk_lpt_sz(c, 4, alen - offs);
0305     err = dbg_chk_lpt_sz(c, 3, alen);
0306     if (err)
0307         return err;
0308     return 0;
0309 
0310 no_space:
0311     ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
0312           lnum, offs, len, done_ltab, done_lsave);
0313     ubifs_dump_lpt_info(c);
0314     ubifs_dump_lpt_lebs(c);
0315     dump_stack();
0316     return err;
0317 }
0318 
0319 /**
0320  * realloc_lpt_leb - allocate an LPT LEB that is empty.
0321  * @c: UBIFS file-system description object
0322  * @lnum: LEB number is passed and returned here
0323  *
0324  * This function duplicates exactly the results of the function alloc_lpt_leb.
0325  * It is used during end commit to reallocate the same LEB numbers that were
0326  * allocated by alloc_lpt_leb during start commit.
0327  *
0328  * This function finds the next LEB that was allocated by the alloc_lpt_leb
0329  * function starting from @lnum. If a LEB is found it is returned in @lnum and
0330  * the function returns %0. Otherwise the function returns -ENOSPC.
0331  * Note however, that LPT is designed never to run out of space.
0332  */
0333 static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
0334 {
0335     int i, n;
0336 
0337     n = *lnum - c->lpt_first + 1;
0338     for (i = n; i < c->lpt_lebs; i++)
0339         if (c->ltab[i].cmt) {
0340             c->ltab[i].cmt = 0;
0341             *lnum = i + c->lpt_first;
0342             return 0;
0343         }
0344 
0345     for (i = 0; i < n; i++)
0346         if (c->ltab[i].cmt) {
0347             c->ltab[i].cmt = 0;
0348             *lnum = i + c->lpt_first;
0349             return 0;
0350         }
0351     return -ENOSPC;
0352 }
0353 
0354 /**
0355  * write_cnodes - write cnodes for commit.
0356  * @c: UBIFS file-system description object
0357  *
0358  * This function returns %0 on success and a negative error code on failure.
0359  */
0360 static int write_cnodes(struct ubifs_info *c)
0361 {
0362     int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
0363     struct ubifs_cnode *cnode;
0364     void *buf = c->lpt_buf;
0365 
0366     cnode = c->lpt_cnext;
0367     if (!cnode)
0368         return 0;
0369     lnum = c->nhead_lnum;
0370     offs = c->nhead_offs;
0371     from = offs;
0372     /* Ensure empty LEB is unmapped */
0373     if (offs == 0) {
0374         err = ubifs_leb_unmap(c, lnum);
0375         if (err)
0376             return err;
0377     }
0378     /* Try to place lsave and ltab nicely */
0379     done_lsave = !c->big_lpt;
0380     done_ltab = 0;
0381     if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
0382         done_lsave = 1;
0383         ubifs_pack_lsave(c, buf + offs, c->lsave);
0384         offs += c->lsave_sz;
0385         dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0386     }
0387 
0388     if (offs + c->ltab_sz <= c->leb_size) {
0389         done_ltab = 1;
0390         ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
0391         offs += c->ltab_sz;
0392         dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0393     }
0394 
0395     /* Loop for each cnode */
0396     do {
0397         if (cnode->level)
0398             len = c->nnode_sz;
0399         else
0400             len = c->pnode_sz;
0401         while (offs + len > c->leb_size) {
0402             wlen = offs - from;
0403             if (wlen) {
0404                 alen = ALIGN(wlen, c->min_io_size);
0405                 memset(buf + offs, 0xff, alen - wlen);
0406                 err = ubifs_leb_write(c, lnum, buf + from, from,
0407                                alen);
0408                 if (err)
0409                     return err;
0410             }
0411             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0412             err = realloc_lpt_leb(c, &lnum);
0413             if (err)
0414                 goto no_space;
0415             offs = from = 0;
0416             ubifs_assert(c, lnum >= c->lpt_first &&
0417                      lnum <= c->lpt_last);
0418             err = ubifs_leb_unmap(c, lnum);
0419             if (err)
0420                 return err;
0421             /* Try to place lsave and ltab nicely */
0422             if (!done_lsave) {
0423                 done_lsave = 1;
0424                 ubifs_pack_lsave(c, buf + offs, c->lsave);
0425                 offs += c->lsave_sz;
0426                 dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0427                 continue;
0428             }
0429             if (!done_ltab) {
0430                 done_ltab = 1;
0431                 ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
0432                 offs += c->ltab_sz;
0433                 dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0434                 continue;
0435             }
0436             break;
0437         }
0438         if (cnode->level)
0439             ubifs_pack_nnode(c, buf + offs,
0440                      (struct ubifs_nnode *)cnode);
0441         else
0442             ubifs_pack_pnode(c, buf + offs,
0443                      (struct ubifs_pnode *)cnode);
0444         /*
0445          * The reason for the barriers is the same as in case of TNC.
0446          * See comment in 'write_index()'. 'dirty_cow_nnode()' and
0447          * 'dirty_cow_pnode()' are the functions for which this is
0448          * important.
0449          */
0450         clear_bit(DIRTY_CNODE, &cnode->flags);
0451         smp_mb__before_atomic();
0452         clear_bit(COW_CNODE, &cnode->flags);
0453         smp_mb__after_atomic();
0454         offs += len;
0455         dbg_chk_lpt_sz(c, 1, len);
0456         cnode = cnode->cnext;
0457     } while (cnode && cnode != c->lpt_cnext);
0458 
0459     /* Make sure to place LPT's save table */
0460     if (!done_lsave) {
0461         if (offs + c->lsave_sz > c->leb_size) {
0462             wlen = offs - from;
0463             alen = ALIGN(wlen, c->min_io_size);
0464             memset(buf + offs, 0xff, alen - wlen);
0465             err = ubifs_leb_write(c, lnum, buf + from, from, alen);
0466             if (err)
0467                 return err;
0468             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0469             err = realloc_lpt_leb(c, &lnum);
0470             if (err)
0471                 goto no_space;
0472             offs = from = 0;
0473             ubifs_assert(c, lnum >= c->lpt_first &&
0474                      lnum <= c->lpt_last);
0475             err = ubifs_leb_unmap(c, lnum);
0476             if (err)
0477                 return err;
0478         }
0479         done_lsave = 1;
0480         ubifs_pack_lsave(c, buf + offs, c->lsave);
0481         offs += c->lsave_sz;
0482         dbg_chk_lpt_sz(c, 1, c->lsave_sz);
0483     }
0484 
0485     /* Make sure to place LPT's own lprops table */
0486     if (!done_ltab) {
0487         if (offs + c->ltab_sz > c->leb_size) {
0488             wlen = offs - from;
0489             alen = ALIGN(wlen, c->min_io_size);
0490             memset(buf + offs, 0xff, alen - wlen);
0491             err = ubifs_leb_write(c, lnum, buf + from, from, alen);
0492             if (err)
0493                 return err;
0494             dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
0495             err = realloc_lpt_leb(c, &lnum);
0496             if (err)
0497                 goto no_space;
0498             offs = from = 0;
0499             ubifs_assert(c, lnum >= c->lpt_first &&
0500                      lnum <= c->lpt_last);
0501             err = ubifs_leb_unmap(c, lnum);
0502             if (err)
0503                 return err;
0504         }
0505         ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
0506         offs += c->ltab_sz;
0507         dbg_chk_lpt_sz(c, 1, c->ltab_sz);
0508     }
0509 
0510     /* Write remaining data in buffer */
0511     wlen = offs - from;
0512     alen = ALIGN(wlen, c->min_io_size);
0513     memset(buf + offs, 0xff, alen - wlen);
0514     err = ubifs_leb_write(c, lnum, buf + from, from, alen);
0515     if (err)
0516         return err;
0517 
0518     dbg_chk_lpt_sz(c, 4, alen - wlen);
0519     err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
0520     if (err)
0521         return err;
0522 
0523     c->nhead_lnum = lnum;
0524     c->nhead_offs = ALIGN(offs, c->min_io_size);
0525 
0526     dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
0527     dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
0528     dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
0529     if (c->big_lpt)
0530         dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
0531 
0532     return 0;
0533 
0534 no_space:
0535     ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
0536           lnum, offs, len, done_ltab, done_lsave);
0537     ubifs_dump_lpt_info(c);
0538     ubifs_dump_lpt_lebs(c);
0539     dump_stack();
0540     return err;
0541 }
0542 
0543 /**
0544  * next_pnode_to_dirty - find next pnode to dirty.
0545  * @c: UBIFS file-system description object
0546  * @pnode: pnode
0547  *
0548  * This function returns the next pnode to dirty or %NULL if there are no more
0549  * pnodes.  Note that pnodes that have never been written (lnum == 0) are
0550  * skipped.
0551  */
0552 static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
0553                            struct ubifs_pnode *pnode)
0554 {
0555     struct ubifs_nnode *nnode;
0556     int iip;
0557 
0558     /* Try to go right */
0559     nnode = pnode->parent;
0560     for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
0561         if (nnode->nbranch[iip].lnum)
0562             return ubifs_get_pnode(c, nnode, iip);
0563     }
0564 
0565     /* Go up while can't go right */
0566     do {
0567         iip = nnode->iip + 1;
0568         nnode = nnode->parent;
0569         if (!nnode)
0570             return NULL;
0571         for (; iip < UBIFS_LPT_FANOUT; iip++) {
0572             if (nnode->nbranch[iip].lnum)
0573                 break;
0574         }
0575     } while (iip >= UBIFS_LPT_FANOUT);
0576 
0577     /* Go right */
0578     nnode = ubifs_get_nnode(c, nnode, iip);
0579     if (IS_ERR(nnode))
0580         return (void *)nnode;
0581 
0582     /* Go down to level 1 */
0583     while (nnode->level > 1) {
0584         for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
0585             if (nnode->nbranch[iip].lnum)
0586                 break;
0587         }
0588         if (iip >= UBIFS_LPT_FANOUT) {
0589             /*
0590              * Should not happen, but we need to keep going
0591              * if it does.
0592              */
0593             iip = 0;
0594         }
0595         nnode = ubifs_get_nnode(c, nnode, iip);
0596         if (IS_ERR(nnode))
0597             return (void *)nnode;
0598     }
0599 
0600     for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
0601         if (nnode->nbranch[iip].lnum)
0602             break;
0603     if (iip >= UBIFS_LPT_FANOUT)
0604         /* Should not happen, but we need to keep going if it does */
0605         iip = 0;
0606     return ubifs_get_pnode(c, nnode, iip);
0607 }
0608 
0609 /**
0610  * add_pnode_dirt - add dirty space to LPT LEB properties.
0611  * @c: UBIFS file-system description object
0612  * @pnode: pnode for which to add dirt
0613  */
0614 static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
0615 {
0616     ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
0617                c->pnode_sz);
0618 }
0619 
0620 /**
0621  * do_make_pnode_dirty - mark a pnode dirty.
0622  * @c: UBIFS file-system description object
0623  * @pnode: pnode to mark dirty
0624  */
0625 static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
0626 {
0627     /* Assumes cnext list is empty i.e. not called during commit */
0628     if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
0629         struct ubifs_nnode *nnode;
0630 
0631         c->dirty_pn_cnt += 1;
0632         add_pnode_dirt(c, pnode);
0633         /* Mark parent and ancestors dirty too */
0634         nnode = pnode->parent;
0635         while (nnode) {
0636             if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
0637                 c->dirty_nn_cnt += 1;
0638                 ubifs_add_nnode_dirt(c, nnode);
0639                 nnode = nnode->parent;
0640             } else
0641                 break;
0642         }
0643     }
0644 }
0645 
0646 /**
0647  * make_tree_dirty - mark the entire LEB properties tree dirty.
0648  * @c: UBIFS file-system description object
0649  *
0650  * This function is used by the "small" LPT model to cause the entire LEB
0651  * properties tree to be written.  The "small" LPT model does not use LPT
0652  * garbage collection because it is more efficient to write the entire tree
0653  * (because it is small).
0654  *
0655  * This function returns %0 on success and a negative error code on failure.
0656  */
0657 static int make_tree_dirty(struct ubifs_info *c)
0658 {
0659     struct ubifs_pnode *pnode;
0660 
0661     pnode = ubifs_pnode_lookup(c, 0);
0662     if (IS_ERR(pnode))
0663         return PTR_ERR(pnode);
0664 
0665     while (pnode) {
0666         do_make_pnode_dirty(c, pnode);
0667         pnode = next_pnode_to_dirty(c, pnode);
0668         if (IS_ERR(pnode))
0669             return PTR_ERR(pnode);
0670     }
0671     return 0;
0672 }
0673 
0674 /**
0675  * need_write_all - determine if the LPT area is running out of free space.
0676  * @c: UBIFS file-system description object
0677  *
0678  * This function returns %1 if the LPT area is running out of free space and %0
0679  * if it is not.
0680  */
0681 static int need_write_all(struct ubifs_info *c)
0682 {
0683     long long free = 0;
0684     int i;
0685 
0686     for (i = 0; i < c->lpt_lebs; i++) {
0687         if (i + c->lpt_first == c->nhead_lnum)
0688             free += c->leb_size - c->nhead_offs;
0689         else if (c->ltab[i].free == c->leb_size)
0690             free += c->leb_size;
0691         else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
0692             free += c->leb_size;
0693     }
0694     /* Less than twice the size left */
0695     if (free <= c->lpt_sz * 2)
0696         return 1;
0697     return 0;
0698 }
0699 
0700 /**
0701  * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
0702  * @c: UBIFS file-system description object
0703  *
0704  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
0705  * free space and so may be reused as soon as the next commit is completed.
0706  * This function is called during start commit to mark LPT LEBs for trivial GC.
0707  */
0708 static void lpt_tgc_start(struct ubifs_info *c)
0709 {
0710     int i;
0711 
0712     for (i = 0; i < c->lpt_lebs; i++) {
0713         if (i + c->lpt_first == c->nhead_lnum)
0714             continue;
0715         if (c->ltab[i].dirty > 0 &&
0716             c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
0717             c->ltab[i].tgc = 1;
0718             c->ltab[i].free = c->leb_size;
0719             c->ltab[i].dirty = 0;
0720             dbg_lp("LEB %d", i + c->lpt_first);
0721         }
0722     }
0723 }
0724 
0725 /**
0726  * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
0727  * @c: UBIFS file-system description object
0728  *
0729  * LPT trivial garbage collection is where a LPT LEB contains only dirty and
0730  * free space and so may be reused as soon as the next commit is completed.
0731  * This function is called after the commit is completed (master node has been
0732  * written) and un-maps LPT LEBs that were marked for trivial GC.
0733  */
0734 static int lpt_tgc_end(struct ubifs_info *c)
0735 {
0736     int i, err;
0737 
0738     for (i = 0; i < c->lpt_lebs; i++)
0739         if (c->ltab[i].tgc) {
0740             err = ubifs_leb_unmap(c, i + c->lpt_first);
0741             if (err)
0742                 return err;
0743             c->ltab[i].tgc = 0;
0744             dbg_lp("LEB %d", i + c->lpt_first);
0745         }
0746     return 0;
0747 }
0748 
0749 /**
0750  * populate_lsave - fill the lsave array with important LEB numbers.
0751  * @c: the UBIFS file-system description object
0752  *
0753  * This function is only called for the "big" model. It records a small number
0754  * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
0755  * most important to least important): empty, freeable, freeable index, dirty
0756  * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
0757  * their pnodes into memory.  That will stop us from having to scan the LPT
0758  * straight away. For the "small" model we assume that scanning the LPT is no
0759  * big deal.
0760  */
0761 static void populate_lsave(struct ubifs_info *c)
0762 {
0763     struct ubifs_lprops *lprops;
0764     struct ubifs_lpt_heap *heap;
0765     int i, cnt = 0;
0766 
0767     ubifs_assert(c, c->big_lpt);
0768     if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
0769         c->lpt_drty_flgs |= LSAVE_DIRTY;
0770         ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
0771     }
0772 
0773     if (dbg_populate_lsave(c))
0774         return;
0775 
0776     list_for_each_entry(lprops, &c->empty_list, list) {
0777         c->lsave[cnt++] = lprops->lnum;
0778         if (cnt >= c->lsave_cnt)
0779             return;
0780     }
0781     list_for_each_entry(lprops, &c->freeable_list, list) {
0782         c->lsave[cnt++] = lprops->lnum;
0783         if (cnt >= c->lsave_cnt)
0784             return;
0785     }
0786     list_for_each_entry(lprops, &c->frdi_idx_list, list) {
0787         c->lsave[cnt++] = lprops->lnum;
0788         if (cnt >= c->lsave_cnt)
0789             return;
0790     }
0791     heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
0792     for (i = 0; i < heap->cnt; i++) {
0793         c->lsave[cnt++] = heap->arr[i]->lnum;
0794         if (cnt >= c->lsave_cnt)
0795             return;
0796     }
0797     heap = &c->lpt_heap[LPROPS_DIRTY - 1];
0798     for (i = 0; i < heap->cnt; i++) {
0799         c->lsave[cnt++] = heap->arr[i]->lnum;
0800         if (cnt >= c->lsave_cnt)
0801             return;
0802     }
0803     heap = &c->lpt_heap[LPROPS_FREE - 1];
0804     for (i = 0; i < heap->cnt; i++) {
0805         c->lsave[cnt++] = heap->arr[i]->lnum;
0806         if (cnt >= c->lsave_cnt)
0807             return;
0808     }
0809     /* Fill it up completely */
0810     while (cnt < c->lsave_cnt)
0811         c->lsave[cnt++] = c->main_first;
0812 }
0813 
0814 /**
0815  * nnode_lookup - lookup a nnode in the LPT.
0816  * @c: UBIFS file-system description object
0817  * @i: nnode number
0818  *
0819  * This function returns a pointer to the nnode on success or a negative
0820  * error code on failure.
0821  */
0822 static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
0823 {
0824     int err, iip;
0825     struct ubifs_nnode *nnode;
0826 
0827     if (!c->nroot) {
0828         err = ubifs_read_nnode(c, NULL, 0);
0829         if (err)
0830             return ERR_PTR(err);
0831     }
0832     nnode = c->nroot;
0833     while (1) {
0834         iip = i & (UBIFS_LPT_FANOUT - 1);
0835         i >>= UBIFS_LPT_FANOUT_SHIFT;
0836         if (!i)
0837             break;
0838         nnode = ubifs_get_nnode(c, nnode, iip);
0839         if (IS_ERR(nnode))
0840             return nnode;
0841     }
0842     return nnode;
0843 }
0844 
0845 /**
0846  * make_nnode_dirty - find a nnode and, if found, make it dirty.
0847  * @c: UBIFS file-system description object
0848  * @node_num: nnode number of nnode to make dirty
0849  * @lnum: LEB number where nnode was written
0850  * @offs: offset where nnode was written
0851  *
0852  * This function is used by LPT garbage collection.  LPT garbage collection is
0853  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
0854  * simply involves marking all the nodes in the LEB being garbage-collected as
0855  * dirty.  The dirty nodes are written next commit, after which the LEB is free
0856  * to be reused.
0857  *
0858  * This function returns %0 on success and a negative error code on failure.
0859  */
0860 static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
0861                 int offs)
0862 {
0863     struct ubifs_nnode *nnode;
0864 
0865     nnode = nnode_lookup(c, node_num);
0866     if (IS_ERR(nnode))
0867         return PTR_ERR(nnode);
0868     if (nnode->parent) {
0869         struct ubifs_nbranch *branch;
0870 
0871         branch = &nnode->parent->nbranch[nnode->iip];
0872         if (branch->lnum != lnum || branch->offs != offs)
0873             return 0; /* nnode is obsolete */
0874     } else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
0875             return 0; /* nnode is obsolete */
0876     /* Assumes cnext list is empty i.e. not called during commit */
0877     if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
0878         c->dirty_nn_cnt += 1;
0879         ubifs_add_nnode_dirt(c, nnode);
0880         /* Mark parent and ancestors dirty too */
0881         nnode = nnode->parent;
0882         while (nnode) {
0883             if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
0884                 c->dirty_nn_cnt += 1;
0885                 ubifs_add_nnode_dirt(c, nnode);
0886                 nnode = nnode->parent;
0887             } else
0888                 break;
0889         }
0890     }
0891     return 0;
0892 }
0893 
0894 /**
0895  * make_pnode_dirty - find a pnode and, if found, make it dirty.
0896  * @c: UBIFS file-system description object
0897  * @node_num: pnode number of pnode to make dirty
0898  * @lnum: LEB number where pnode was written
0899  * @offs: offset where pnode was written
0900  *
0901  * This function is used by LPT garbage collection.  LPT garbage collection is
0902  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
0903  * simply involves marking all the nodes in the LEB being garbage-collected as
0904  * dirty.  The dirty nodes are written next commit, after which the LEB is free
0905  * to be reused.
0906  *
0907  * This function returns %0 on success and a negative error code on failure.
0908  */
0909 static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
0910                 int offs)
0911 {
0912     struct ubifs_pnode *pnode;
0913     struct ubifs_nbranch *branch;
0914 
0915     pnode = ubifs_pnode_lookup(c, node_num);
0916     if (IS_ERR(pnode))
0917         return PTR_ERR(pnode);
0918     branch = &pnode->parent->nbranch[pnode->iip];
0919     if (branch->lnum != lnum || branch->offs != offs)
0920         return 0;
0921     do_make_pnode_dirty(c, pnode);
0922     return 0;
0923 }
0924 
0925 /**
0926  * make_ltab_dirty - make ltab node dirty.
0927  * @c: UBIFS file-system description object
0928  * @lnum: LEB number where ltab was written
0929  * @offs: offset where ltab was written
0930  *
0931  * This function is used by LPT garbage collection.  LPT garbage collection is
0932  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
0933  * simply involves marking all the nodes in the LEB being garbage-collected as
0934  * dirty.  The dirty nodes are written next commit, after which the LEB is free
0935  * to be reused.
0936  *
0937  * This function returns %0 on success and a negative error code on failure.
0938  */
0939 static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
0940 {
0941     if (lnum != c->ltab_lnum || offs != c->ltab_offs)
0942         return 0; /* This ltab node is obsolete */
0943     if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
0944         c->lpt_drty_flgs |= LTAB_DIRTY;
0945         ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
0946     }
0947     return 0;
0948 }
0949 
0950 /**
0951  * make_lsave_dirty - make lsave node dirty.
0952  * @c: UBIFS file-system description object
0953  * @lnum: LEB number where lsave was written
0954  * @offs: offset where lsave was written
0955  *
0956  * This function is used by LPT garbage collection.  LPT garbage collection is
0957  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
0958  * simply involves marking all the nodes in the LEB being garbage-collected as
0959  * dirty.  The dirty nodes are written next commit, after which the LEB is free
0960  * to be reused.
0961  *
0962  * This function returns %0 on success and a negative error code on failure.
0963  */
0964 static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
0965 {
0966     if (lnum != c->lsave_lnum || offs != c->lsave_offs)
0967         return 0; /* This lsave node is obsolete */
0968     if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
0969         c->lpt_drty_flgs |= LSAVE_DIRTY;
0970         ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
0971     }
0972     return 0;
0973 }
0974 
0975 /**
0976  * make_node_dirty - make node dirty.
0977  * @c: UBIFS file-system description object
0978  * @node_type: LPT node type
0979  * @node_num: node number
0980  * @lnum: LEB number where node was written
0981  * @offs: offset where node was written
0982  *
0983  * This function is used by LPT garbage collection.  LPT garbage collection is
0984  * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
0985  * simply involves marking all the nodes in the LEB being garbage-collected as
0986  * dirty.  The dirty nodes are written next commit, after which the LEB is free
0987  * to be reused.
0988  *
0989  * This function returns %0 on success and a negative error code on failure.
0990  */
0991 static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
0992                int lnum, int offs)
0993 {
0994     switch (node_type) {
0995     case UBIFS_LPT_NNODE:
0996         return make_nnode_dirty(c, node_num, lnum, offs);
0997     case UBIFS_LPT_PNODE:
0998         return make_pnode_dirty(c, node_num, lnum, offs);
0999     case UBIFS_LPT_LTAB:
1000         return make_ltab_dirty(c, lnum, offs);
1001     case UBIFS_LPT_LSAVE:
1002         return make_lsave_dirty(c, lnum, offs);
1003     }
1004     return -EINVAL;
1005 }
1006 
1007 /**
1008  * get_lpt_node_len - return the length of a node based on its type.
1009  * @c: UBIFS file-system description object
1010  * @node_type: LPT node type
1011  */
1012 static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
1013 {
1014     switch (node_type) {
1015     case UBIFS_LPT_NNODE:
1016         return c->nnode_sz;
1017     case UBIFS_LPT_PNODE:
1018         return c->pnode_sz;
1019     case UBIFS_LPT_LTAB:
1020         return c->ltab_sz;
1021     case UBIFS_LPT_LSAVE:
1022         return c->lsave_sz;
1023     }
1024     return 0;
1025 }
1026 
1027 /**
1028  * get_pad_len - return the length of padding in a buffer.
1029  * @c: UBIFS file-system description object
1030  * @buf: buffer
1031  * @len: length of buffer
1032  */
1033 static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
1034 {
1035     int offs, pad_len;
1036 
1037     if (c->min_io_size == 1)
1038         return 0;
1039     offs = c->leb_size - len;
1040     pad_len = ALIGN(offs, c->min_io_size) - offs;
1041     return pad_len;
1042 }
1043 
1044 /**
1045  * get_lpt_node_type - return type (and node number) of a node in a buffer.
1046  * @c: UBIFS file-system description object
1047  * @buf: buffer
1048  * @node_num: node number is returned here
1049  */
1050 static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
1051                  int *node_num)
1052 {
1053     uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1054     int pos = 0, node_type;
1055 
1056     node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS);
1057     *node_num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits);
1058     return node_type;
1059 }
1060 
1061 /**
1062  * is_a_node - determine if a buffer contains a node.
1063  * @c: UBIFS file-system description object
1064  * @buf: buffer
1065  * @len: length of buffer
1066  *
1067  * This function returns %1 if the buffer contains a node or %0 if it does not.
1068  */
1069 static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
1070 {
1071     uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
1072     int pos = 0, node_type, node_len;
1073     uint16_t crc, calc_crc;
1074 
1075     if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
1076         return 0;
1077     node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS);
1078     if (node_type == UBIFS_LPT_NOT_A_NODE)
1079         return 0;
1080     node_len = get_lpt_node_len(c, node_type);
1081     if (!node_len || node_len > len)
1082         return 0;
1083     pos = 0;
1084     addr = buf;
1085     crc = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_CRC_BITS);
1086     calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
1087              node_len - UBIFS_LPT_CRC_BYTES);
1088     if (crc != calc_crc)
1089         return 0;
1090     return 1;
1091 }
1092 
1093 /**
1094  * lpt_gc_lnum - garbage collect a LPT LEB.
1095  * @c: UBIFS file-system description object
1096  * @lnum: LEB number to garbage collect
1097  *
1098  * LPT garbage collection is used only for the "big" LPT model
1099  * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
1100  * in the LEB being garbage-collected as dirty.  The dirty nodes are written
1101  * next commit, after which the LEB is free to be reused.
1102  *
1103  * This function returns %0 on success and a negative error code on failure.
1104  */
1105 static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
1106 {
1107     int err, len = c->leb_size, node_type, node_num, node_len, offs;
1108     void *buf = c->lpt_buf;
1109 
1110     dbg_lp("LEB %d", lnum);
1111 
1112     err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1113     if (err)
1114         return err;
1115 
1116     while (1) {
1117         if (!is_a_node(c, buf, len)) {
1118             int pad_len;
1119 
1120             pad_len = get_pad_len(c, buf, len);
1121             if (pad_len) {
1122                 buf += pad_len;
1123                 len -= pad_len;
1124                 continue;
1125             }
1126             return 0;
1127         }
1128         node_type = get_lpt_node_type(c, buf, &node_num);
1129         node_len = get_lpt_node_len(c, node_type);
1130         offs = c->leb_size - len;
1131         ubifs_assert(c, node_len != 0);
1132         mutex_lock(&c->lp_mutex);
1133         err = make_node_dirty(c, node_type, node_num, lnum, offs);
1134         mutex_unlock(&c->lp_mutex);
1135         if (err)
1136             return err;
1137         buf += node_len;
1138         len -= node_len;
1139     }
1140     return 0;
1141 }
1142 
1143 /**
1144  * lpt_gc - LPT garbage collection.
1145  * @c: UBIFS file-system description object
1146  *
1147  * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
1148  * Returns %0 on success and a negative error code on failure.
1149  */
1150 static int lpt_gc(struct ubifs_info *c)
1151 {
1152     int i, lnum = -1, dirty = 0;
1153 
1154     mutex_lock(&c->lp_mutex);
1155     for (i = 0; i < c->lpt_lebs; i++) {
1156         ubifs_assert(c, !c->ltab[i].tgc);
1157         if (i + c->lpt_first == c->nhead_lnum ||
1158             c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
1159             continue;
1160         if (c->ltab[i].dirty > dirty) {
1161             dirty = c->ltab[i].dirty;
1162             lnum = i + c->lpt_first;
1163         }
1164     }
1165     mutex_unlock(&c->lp_mutex);
1166     if (lnum == -1)
1167         return -ENOSPC;
1168     return lpt_gc_lnum(c, lnum);
1169 }
1170 
1171 /**
1172  * ubifs_lpt_start_commit - UBIFS commit starts.
1173  * @c: the UBIFS file-system description object
1174  *
1175  * This function has to be called when UBIFS starts the commit operation.
1176  * This function "freezes" all currently dirty LEB properties and does not
1177  * change them anymore. Further changes are saved and tracked separately
1178  * because they are not part of this commit. This function returns zero in case
1179  * of success and a negative error code in case of failure.
1180  */
1181 int ubifs_lpt_start_commit(struct ubifs_info *c)
1182 {
1183     int err, cnt;
1184 
1185     dbg_lp("");
1186 
1187     mutex_lock(&c->lp_mutex);
1188     err = dbg_chk_lpt_free_spc(c);
1189     if (err)
1190         goto out;
1191     err = dbg_check_ltab(c);
1192     if (err)
1193         goto out;
1194 
1195     if (c->check_lpt_free) {
1196         /*
1197          * We ensure there is enough free space in
1198          * ubifs_lpt_post_commit() by marking nodes dirty. That
1199          * information is lost when we unmount, so we also need
1200          * to check free space once after mounting also.
1201          */
1202         c->check_lpt_free = 0;
1203         while (need_write_all(c)) {
1204             mutex_unlock(&c->lp_mutex);
1205             err = lpt_gc(c);
1206             if (err)
1207                 return err;
1208             mutex_lock(&c->lp_mutex);
1209         }
1210     }
1211 
1212     lpt_tgc_start(c);
1213 
1214     if (!c->dirty_pn_cnt) {
1215         dbg_cmt("no cnodes to commit");
1216         err = 0;
1217         goto out;
1218     }
1219 
1220     if (!c->big_lpt && need_write_all(c)) {
1221         /* If needed, write everything */
1222         err = make_tree_dirty(c);
1223         if (err)
1224             goto out;
1225         lpt_tgc_start(c);
1226     }
1227 
1228     if (c->big_lpt)
1229         populate_lsave(c);
1230 
1231     cnt = get_cnodes_to_commit(c);
1232     ubifs_assert(c, cnt != 0);
1233 
1234     err = layout_cnodes(c);
1235     if (err)
1236         goto out;
1237 
1238     err = ubifs_lpt_calc_hash(c, c->mst_node->hash_lpt);
1239     if (err)
1240         goto out;
1241 
1242     /* Copy the LPT's own lprops for end commit to write */
1243     memcpy(c->ltab_cmt, c->ltab,
1244            sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
1245     c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
1246 
1247 out:
1248     mutex_unlock(&c->lp_mutex);
1249     return err;
1250 }
1251 
1252 /**
1253  * free_obsolete_cnodes - free obsolete cnodes for commit end.
1254  * @c: UBIFS file-system description object
1255  */
1256 static void free_obsolete_cnodes(struct ubifs_info *c)
1257 {
1258     struct ubifs_cnode *cnode, *cnext;
1259 
1260     cnext = c->lpt_cnext;
1261     if (!cnext)
1262         return;
1263     do {
1264         cnode = cnext;
1265         cnext = cnode->cnext;
1266         if (test_bit(OBSOLETE_CNODE, &cnode->flags))
1267             kfree(cnode);
1268         else
1269             cnode->cnext = NULL;
1270     } while (cnext != c->lpt_cnext);
1271     c->lpt_cnext = NULL;
1272 }
1273 
1274 /**
1275  * ubifs_lpt_end_commit - finish the commit operation.
1276  * @c: the UBIFS file-system description object
1277  *
1278  * This function has to be called when the commit operation finishes. It
1279  * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
1280  * the media. Returns zero in case of success and a negative error code in case
1281  * of failure.
1282  */
1283 int ubifs_lpt_end_commit(struct ubifs_info *c)
1284 {
1285     int err;
1286 
1287     dbg_lp("");
1288 
1289     if (!c->lpt_cnext)
1290         return 0;
1291 
1292     err = write_cnodes(c);
1293     if (err)
1294         return err;
1295 
1296     mutex_lock(&c->lp_mutex);
1297     free_obsolete_cnodes(c);
1298     mutex_unlock(&c->lp_mutex);
1299 
1300     return 0;
1301 }
1302 
1303 /**
1304  * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
1305  * @c: UBIFS file-system description object
1306  *
1307  * LPT trivial GC is completed after a commit. Also LPT GC is done after a
1308  * commit for the "big" LPT model.
1309  */
1310 int ubifs_lpt_post_commit(struct ubifs_info *c)
1311 {
1312     int err;
1313 
1314     mutex_lock(&c->lp_mutex);
1315     err = lpt_tgc_end(c);
1316     if (err)
1317         goto out;
1318     if (c->big_lpt)
1319         while (need_write_all(c)) {
1320             mutex_unlock(&c->lp_mutex);
1321             err = lpt_gc(c);
1322             if (err)
1323                 return err;
1324             mutex_lock(&c->lp_mutex);
1325         }
1326 out:
1327     mutex_unlock(&c->lp_mutex);
1328     return err;
1329 }
1330 
1331 /**
1332  * first_nnode - find the first nnode in memory.
1333  * @c: UBIFS file-system description object
1334  * @hght: height of tree where nnode found is returned here
1335  *
1336  * This function returns a pointer to the nnode found or %NULL if no nnode is
1337  * found. This function is a helper to 'ubifs_lpt_free()'.
1338  */
1339 static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
1340 {
1341     struct ubifs_nnode *nnode;
1342     int h, i, found;
1343 
1344     nnode = c->nroot;
1345     *hght = 0;
1346     if (!nnode)
1347         return NULL;
1348     for (h = 1; h < c->lpt_hght; h++) {
1349         found = 0;
1350         for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1351             if (nnode->nbranch[i].nnode) {
1352                 found = 1;
1353                 nnode = nnode->nbranch[i].nnode;
1354                 *hght = h;
1355                 break;
1356             }
1357         }
1358         if (!found)
1359             break;
1360     }
1361     return nnode;
1362 }
1363 
1364 /**
1365  * next_nnode - find the next nnode in memory.
1366  * @c: UBIFS file-system description object
1367  * @nnode: nnode from which to start.
1368  * @hght: height of tree where nnode is, is passed and returned here
1369  *
1370  * This function returns a pointer to the nnode found or %NULL if no nnode is
1371  * found. This function is a helper to 'ubifs_lpt_free()'.
1372  */
1373 static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
1374                       struct ubifs_nnode *nnode, int *hght)
1375 {
1376     struct ubifs_nnode *parent;
1377     int iip, h, i, found;
1378 
1379     parent = nnode->parent;
1380     if (!parent)
1381         return NULL;
1382     if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
1383         *hght -= 1;
1384         return parent;
1385     }
1386     for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
1387         nnode = parent->nbranch[iip].nnode;
1388         if (nnode)
1389             break;
1390     }
1391     if (!nnode) {
1392         *hght -= 1;
1393         return parent;
1394     }
1395     for (h = *hght + 1; h < c->lpt_hght; h++) {
1396         found = 0;
1397         for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1398             if (nnode->nbranch[i].nnode) {
1399                 found = 1;
1400                 nnode = nnode->nbranch[i].nnode;
1401                 *hght = h;
1402                 break;
1403             }
1404         }
1405         if (!found)
1406             break;
1407     }
1408     return nnode;
1409 }
1410 
1411 /**
1412  * ubifs_lpt_free - free resources owned by the LPT.
1413  * @c: UBIFS file-system description object
1414  * @wr_only: free only resources used for writing
1415  */
1416 void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
1417 {
1418     struct ubifs_nnode *nnode;
1419     int i, hght;
1420 
1421     /* Free write-only things first */
1422 
1423     free_obsolete_cnodes(c); /* Leftover from a failed commit */
1424 
1425     vfree(c->ltab_cmt);
1426     c->ltab_cmt = NULL;
1427     vfree(c->lpt_buf);
1428     c->lpt_buf = NULL;
1429     kfree(c->lsave);
1430     c->lsave = NULL;
1431 
1432     if (wr_only)
1433         return;
1434 
1435     /* Now free the rest */
1436 
1437     nnode = first_nnode(c, &hght);
1438     while (nnode) {
1439         for (i = 0; i < UBIFS_LPT_FANOUT; i++)
1440             kfree(nnode->nbranch[i].nnode);
1441         nnode = next_nnode(c, nnode, &hght);
1442     }
1443     for (i = 0; i < LPROPS_HEAP_CNT; i++)
1444         kfree(c->lpt_heap[i].arr);
1445     kfree(c->dirty_idx.arr);
1446     kfree(c->nroot);
1447     vfree(c->ltab);
1448     kfree(c->lpt_nod_buf);
1449 }
1450 
1451 /*
1452  * Everything below is related to debugging.
1453  */
1454 
1455 /**
1456  * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
1457  * @buf: buffer
1458  * @len: buffer length
1459  */
1460 static int dbg_is_all_ff(uint8_t *buf, int len)
1461 {
1462     int i;
1463 
1464     for (i = 0; i < len; i++)
1465         if (buf[i] != 0xff)
1466             return 0;
1467     return 1;
1468 }
1469 
1470 /**
1471  * dbg_is_nnode_dirty - determine if a nnode is dirty.
1472  * @c: the UBIFS file-system description object
1473  * @lnum: LEB number where nnode was written
1474  * @offs: offset where nnode was written
1475  */
1476 static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
1477 {
1478     struct ubifs_nnode *nnode;
1479     int hght;
1480 
1481     /* Entire tree is in memory so first_nnode / next_nnode are OK */
1482     nnode = first_nnode(c, &hght);
1483     for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
1484         struct ubifs_nbranch *branch;
1485 
1486         cond_resched();
1487         if (nnode->parent) {
1488             branch = &nnode->parent->nbranch[nnode->iip];
1489             if (branch->lnum != lnum || branch->offs != offs)
1490                 continue;
1491             if (test_bit(DIRTY_CNODE, &nnode->flags))
1492                 return 1;
1493             return 0;
1494         } else {
1495             if (c->lpt_lnum != lnum || c->lpt_offs != offs)
1496                 continue;
1497             if (test_bit(DIRTY_CNODE, &nnode->flags))
1498                 return 1;
1499             return 0;
1500         }
1501     }
1502     return 1;
1503 }
1504 
1505 /**
1506  * dbg_is_pnode_dirty - determine if a pnode is dirty.
1507  * @c: the UBIFS file-system description object
1508  * @lnum: LEB number where pnode was written
1509  * @offs: offset where pnode was written
1510  */
1511 static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
1512 {
1513     int i, cnt;
1514 
1515     cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1516     for (i = 0; i < cnt; i++) {
1517         struct ubifs_pnode *pnode;
1518         struct ubifs_nbranch *branch;
1519 
1520         cond_resched();
1521         pnode = ubifs_pnode_lookup(c, i);
1522         if (IS_ERR(pnode))
1523             return PTR_ERR(pnode);
1524         branch = &pnode->parent->nbranch[pnode->iip];
1525         if (branch->lnum != lnum || branch->offs != offs)
1526             continue;
1527         if (test_bit(DIRTY_CNODE, &pnode->flags))
1528             return 1;
1529         return 0;
1530     }
1531     return 1;
1532 }
1533 
1534 /**
1535  * dbg_is_ltab_dirty - determine if a ltab node is dirty.
1536  * @c: the UBIFS file-system description object
1537  * @lnum: LEB number where ltab node was written
1538  * @offs: offset where ltab node was written
1539  */
1540 static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
1541 {
1542     if (lnum != c->ltab_lnum || offs != c->ltab_offs)
1543         return 1;
1544     return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
1545 }
1546 
1547 /**
1548  * dbg_is_lsave_dirty - determine if a lsave node is dirty.
1549  * @c: the UBIFS file-system description object
1550  * @lnum: LEB number where lsave node was written
1551  * @offs: offset where lsave node was written
1552  */
1553 static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
1554 {
1555     if (lnum != c->lsave_lnum || offs != c->lsave_offs)
1556         return 1;
1557     return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
1558 }
1559 
1560 /**
1561  * dbg_is_node_dirty - determine if a node is dirty.
1562  * @c: the UBIFS file-system description object
1563  * @node_type: node type
1564  * @lnum: LEB number where node was written
1565  * @offs: offset where node was written
1566  */
1567 static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
1568                  int offs)
1569 {
1570     switch (node_type) {
1571     case UBIFS_LPT_NNODE:
1572         return dbg_is_nnode_dirty(c, lnum, offs);
1573     case UBIFS_LPT_PNODE:
1574         return dbg_is_pnode_dirty(c, lnum, offs);
1575     case UBIFS_LPT_LTAB:
1576         return dbg_is_ltab_dirty(c, lnum, offs);
1577     case UBIFS_LPT_LSAVE:
1578         return dbg_is_lsave_dirty(c, lnum, offs);
1579     }
1580     return 1;
1581 }
1582 
1583 /**
1584  * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
1585  * @c: the UBIFS file-system description object
1586  * @lnum: LEB number where node was written
1587  *
1588  * This function returns %0 on success and a negative error code on failure.
1589  */
1590 static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
1591 {
1592     int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
1593     int ret;
1594     void *buf, *p;
1595 
1596     if (!dbg_is_chk_lprops(c))
1597         return 0;
1598 
1599     buf = p = __vmalloc(c->leb_size, GFP_NOFS);
1600     if (!buf) {
1601         ubifs_err(c, "cannot allocate memory for ltab checking");
1602         return 0;
1603     }
1604 
1605     dbg_lp("LEB %d", lnum);
1606 
1607     err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1608     if (err)
1609         goto out;
1610 
1611     while (1) {
1612         if (!is_a_node(c, p, len)) {
1613             int i, pad_len;
1614 
1615             pad_len = get_pad_len(c, p, len);
1616             if (pad_len) {
1617                 p += pad_len;
1618                 len -= pad_len;
1619                 dirty += pad_len;
1620                 continue;
1621             }
1622             if (!dbg_is_all_ff(p, len)) {
1623                 ubifs_err(c, "invalid empty space in LEB %d at %d",
1624                       lnum, c->leb_size - len);
1625                 err = -EINVAL;
1626             }
1627             i = lnum - c->lpt_first;
1628             if (len != c->ltab[i].free) {
1629                 ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)",
1630                       lnum, len, c->ltab[i].free);
1631                 err = -EINVAL;
1632             }
1633             if (dirty != c->ltab[i].dirty) {
1634                 ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)",
1635                       lnum, dirty, c->ltab[i].dirty);
1636                 err = -EINVAL;
1637             }
1638             goto out;
1639         }
1640         node_type = get_lpt_node_type(c, p, &node_num);
1641         node_len = get_lpt_node_len(c, node_type);
1642         ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
1643         if (ret == 1)
1644             dirty += node_len;
1645         p += node_len;
1646         len -= node_len;
1647     }
1648 
1649     err = 0;
1650 out:
1651     vfree(buf);
1652     return err;
1653 }
1654 
1655 /**
1656  * dbg_check_ltab - check the free and dirty space in the ltab.
1657  * @c: the UBIFS file-system description object
1658  *
1659  * This function returns %0 on success and a negative error code on failure.
1660  */
1661 int dbg_check_ltab(struct ubifs_info *c)
1662 {
1663     int lnum, err, i, cnt;
1664 
1665     if (!dbg_is_chk_lprops(c))
1666         return 0;
1667 
1668     /* Bring the entire tree into memory */
1669     cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
1670     for (i = 0; i < cnt; i++) {
1671         struct ubifs_pnode *pnode;
1672 
1673         pnode = ubifs_pnode_lookup(c, i);
1674         if (IS_ERR(pnode))
1675             return PTR_ERR(pnode);
1676         cond_resched();
1677     }
1678 
1679     /* Check nodes */
1680     err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
1681     if (err)
1682         return err;
1683 
1684     /* Check each LEB */
1685     for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
1686         err = dbg_check_ltab_lnum(c, lnum);
1687         if (err) {
1688             ubifs_err(c, "failed at LEB %d", lnum);
1689             return err;
1690         }
1691     }
1692 
1693     dbg_lp("succeeded");
1694     return 0;
1695 }
1696 
1697 /**
1698  * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
1699  * @c: the UBIFS file-system description object
1700  *
1701  * This function returns %0 on success and a negative error code on failure.
1702  */
1703 int dbg_chk_lpt_free_spc(struct ubifs_info *c)
1704 {
1705     long long free = 0;
1706     int i;
1707 
1708     if (!dbg_is_chk_lprops(c))
1709         return 0;
1710 
1711     for (i = 0; i < c->lpt_lebs; i++) {
1712         if (c->ltab[i].tgc || c->ltab[i].cmt)
1713             continue;
1714         if (i + c->lpt_first == c->nhead_lnum)
1715             free += c->leb_size - c->nhead_offs;
1716         else if (c->ltab[i].free == c->leb_size)
1717             free += c->leb_size;
1718     }
1719     if (free < c->lpt_sz) {
1720         ubifs_err(c, "LPT space error: free %lld lpt_sz %lld",
1721               free, c->lpt_sz);
1722         ubifs_dump_lpt_info(c);
1723         ubifs_dump_lpt_lebs(c);
1724         dump_stack();
1725         return -EINVAL;
1726     }
1727     return 0;
1728 }
1729 
1730 /**
1731  * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
1732  * @c: the UBIFS file-system description object
1733  * @action: what to do
1734  * @len: length written
1735  *
1736  * This function returns %0 on success and a negative error code on failure.
1737  * The @action argument may be one of:
1738  *   o %0 - LPT debugging checking starts, initialize debugging variables;
1739  *   o %1 - wrote an LPT node, increase LPT size by @len bytes;
1740  *   o %2 - switched to a different LEB and wasted @len bytes;
1741  *   o %3 - check that we've written the right number of bytes.
1742  *   o %4 - wasted @len bytes;
1743  */
1744 int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
1745 {
1746     struct ubifs_debug_info *d = c->dbg;
1747     long long chk_lpt_sz, lpt_sz;
1748     int err = 0;
1749 
1750     if (!dbg_is_chk_lprops(c))
1751         return 0;
1752 
1753     switch (action) {
1754     case 0:
1755         d->chk_lpt_sz = 0;
1756         d->chk_lpt_sz2 = 0;
1757         d->chk_lpt_lebs = 0;
1758         d->chk_lpt_wastage = 0;
1759         if (c->dirty_pn_cnt > c->pnode_cnt) {
1760             ubifs_err(c, "dirty pnodes %d exceed max %d",
1761                   c->dirty_pn_cnt, c->pnode_cnt);
1762             err = -EINVAL;
1763         }
1764         if (c->dirty_nn_cnt > c->nnode_cnt) {
1765             ubifs_err(c, "dirty nnodes %d exceed max %d",
1766                   c->dirty_nn_cnt, c->nnode_cnt);
1767             err = -EINVAL;
1768         }
1769         return err;
1770     case 1:
1771         d->chk_lpt_sz += len;
1772         return 0;
1773     case 2:
1774         d->chk_lpt_sz += len;
1775         d->chk_lpt_wastage += len;
1776         d->chk_lpt_lebs += 1;
1777         return 0;
1778     case 3:
1779         chk_lpt_sz = c->leb_size;
1780         chk_lpt_sz *= d->chk_lpt_lebs;
1781         chk_lpt_sz += len - c->nhead_offs;
1782         if (d->chk_lpt_sz != chk_lpt_sz) {
1783             ubifs_err(c, "LPT wrote %lld but space used was %lld",
1784                   d->chk_lpt_sz, chk_lpt_sz);
1785             err = -EINVAL;
1786         }
1787         if (d->chk_lpt_sz > c->lpt_sz) {
1788             ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld",
1789                   d->chk_lpt_sz, c->lpt_sz);
1790             err = -EINVAL;
1791         }
1792         if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
1793             ubifs_err(c, "LPT layout size %lld but wrote %lld",
1794                   d->chk_lpt_sz, d->chk_lpt_sz2);
1795             err = -EINVAL;
1796         }
1797         if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
1798             ubifs_err(c, "LPT new nhead offs: expected %d was %d",
1799                   d->new_nhead_offs, len);
1800             err = -EINVAL;
1801         }
1802         lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
1803         lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
1804         lpt_sz += c->ltab_sz;
1805         if (c->big_lpt)
1806             lpt_sz += c->lsave_sz;
1807         if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
1808             ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
1809                   d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
1810             err = -EINVAL;
1811         }
1812         if (err) {
1813             ubifs_dump_lpt_info(c);
1814             ubifs_dump_lpt_lebs(c);
1815             dump_stack();
1816         }
1817         d->chk_lpt_sz2 = d->chk_lpt_sz;
1818         d->chk_lpt_sz = 0;
1819         d->chk_lpt_wastage = 0;
1820         d->chk_lpt_lebs = 0;
1821         d->new_nhead_offs = len;
1822         return err;
1823     case 4:
1824         d->chk_lpt_sz += len;
1825         d->chk_lpt_wastage += len;
1826         return 0;
1827     default:
1828         return -EINVAL;
1829     }
1830 }
1831 
1832 /**
1833  * dump_lpt_leb - dump an LPT LEB.
1834  * @c: UBIFS file-system description object
1835  * @lnum: LEB number to dump
1836  *
1837  * This function dumps an LEB from LPT area. Nodes in this area are very
1838  * different to nodes in the main area (e.g., they do not have common headers,
1839  * they do not have 8-byte alignments, etc), so we have a separate function to
1840  * dump LPT area LEBs. Note, LPT has to be locked by the caller.
1841  */
1842 static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
1843 {
1844     int err, len = c->leb_size, node_type, node_num, node_len, offs;
1845     void *buf, *p;
1846 
1847     pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
1848     buf = p = __vmalloc(c->leb_size, GFP_NOFS);
1849     if (!buf) {
1850         ubifs_err(c, "cannot allocate memory to dump LPT");
1851         return;
1852     }
1853 
1854     err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
1855     if (err)
1856         goto out;
1857 
1858     while (1) {
1859         offs = c->leb_size - len;
1860         if (!is_a_node(c, p, len)) {
1861             int pad_len;
1862 
1863             pad_len = get_pad_len(c, p, len);
1864             if (pad_len) {
1865                 pr_err("LEB %d:%d, pad %d bytes\n",
1866                        lnum, offs, pad_len);
1867                 p += pad_len;
1868                 len -= pad_len;
1869                 continue;
1870             }
1871             if (len)
1872                 pr_err("LEB %d:%d, free %d bytes\n",
1873                        lnum, offs, len);
1874             break;
1875         }
1876 
1877         node_type = get_lpt_node_type(c, p, &node_num);
1878         switch (node_type) {
1879         case UBIFS_LPT_PNODE:
1880         {
1881             node_len = c->pnode_sz;
1882             if (c->big_lpt)
1883                 pr_err("LEB %d:%d, pnode num %d\n",
1884                        lnum, offs, node_num);
1885             else
1886                 pr_err("LEB %d:%d, pnode\n", lnum, offs);
1887             break;
1888         }
1889         case UBIFS_LPT_NNODE:
1890         {
1891             int i;
1892             struct ubifs_nnode nnode;
1893 
1894             node_len = c->nnode_sz;
1895             if (c->big_lpt)
1896                 pr_err("LEB %d:%d, nnode num %d, ",
1897                        lnum, offs, node_num);
1898             else
1899                 pr_err("LEB %d:%d, nnode, ",
1900                        lnum, offs);
1901             err = ubifs_unpack_nnode(c, p, &nnode);
1902             if (err) {
1903                 pr_err("failed to unpack_node, error %d\n",
1904                        err);
1905                 break;
1906             }
1907             for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
1908                 pr_cont("%d:%d", nnode.nbranch[i].lnum,
1909                        nnode.nbranch[i].offs);
1910                 if (i != UBIFS_LPT_FANOUT - 1)
1911                     pr_cont(", ");
1912             }
1913             pr_cont("\n");
1914             break;
1915         }
1916         case UBIFS_LPT_LTAB:
1917             node_len = c->ltab_sz;
1918             pr_err("LEB %d:%d, ltab\n", lnum, offs);
1919             break;
1920         case UBIFS_LPT_LSAVE:
1921             node_len = c->lsave_sz;
1922             pr_err("LEB %d:%d, lsave len\n", lnum, offs);
1923             break;
1924         default:
1925             ubifs_err(c, "LPT node type %d not recognized", node_type);
1926             goto out;
1927         }
1928 
1929         p += node_len;
1930         len -= node_len;
1931     }
1932 
1933     pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
1934 out:
1935     vfree(buf);
1936     return;
1937 }
1938 
1939 /**
1940  * ubifs_dump_lpt_lebs - dump LPT lebs.
1941  * @c: UBIFS file-system description object
1942  *
1943  * This function dumps all LPT LEBs. The caller has to make sure the LPT is
1944  * locked.
1945  */
1946 void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
1947 {
1948     int i;
1949 
1950     pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid);
1951     for (i = 0; i < c->lpt_lebs; i++)
1952         dump_lpt_leb(c, i + c->lpt_first);
1953     pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid);
1954 }
1955 
1956 /**
1957  * dbg_populate_lsave - debugging version of 'populate_lsave()'
1958  * @c: UBIFS file-system description object
1959  *
1960  * This is a debugging version for 'populate_lsave()' which populates lsave
1961  * with random LEBs instead of useful LEBs, which is good for test coverage.
1962  * Returns zero if lsave has not been populated (this debugging feature is
1963  * disabled) an non-zero if lsave has been populated.
1964  */
1965 static int dbg_populate_lsave(struct ubifs_info *c)
1966 {
1967     struct ubifs_lprops *lprops;
1968     struct ubifs_lpt_heap *heap;
1969     int i;
1970 
1971     if (!dbg_is_chk_gen(c))
1972         return 0;
1973     if (prandom_u32() & 3)
1974         return 0;
1975 
1976     for (i = 0; i < c->lsave_cnt; i++)
1977         c->lsave[i] = c->main_first;
1978 
1979     list_for_each_entry(lprops, &c->empty_list, list)
1980         c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
1981     list_for_each_entry(lprops, &c->freeable_list, list)
1982         c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
1983     list_for_each_entry(lprops, &c->frdi_idx_list, list)
1984         c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
1985 
1986     heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
1987     for (i = 0; i < heap->cnt; i++)
1988         c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
1989     heap = &c->lpt_heap[LPROPS_DIRTY - 1];
1990     for (i = 0; i < heap->cnt; i++)
1991         c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
1992     heap = &c->lpt_heap[LPROPS_FREE - 1];
1993     for (i = 0; i < heap->cnt; i++)
1994         c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
1995 
1996     return 1;
1997 }
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