v4.19.13 snapshot.
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
new file mode 100644
index 0000000..7ce3099
--- /dev/null
+++ b/fs/ubifs/lpt_commit.c
@@ -0,0 +1,2037 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Adrian Hunter
+ * Artem Bityutskiy (Битюцкий Артём)
+ */
+
+/*
+ * This file implements commit-related functionality of the LEB properties
+ * subsystem.
+ */
+
+#include <linux/crc16.h>
+#include <linux/slab.h>
+#include <linux/random.h>
+#include "ubifs.h"
+
+static int dbg_populate_lsave(struct ubifs_info *c);
+
+/**
+ * first_dirty_cnode - find first dirty cnode.
+ * @c: UBIFS file-system description object
+ * @nnode: nnode at which to start
+ *
+ * This function returns the first dirty cnode or %NULL if there is not one.
+ */
+static struct ubifs_cnode *first_dirty_cnode(const struct ubifs_info *c, struct ubifs_nnode *nnode)
+{
+ ubifs_assert(c, nnode);
+ while (1) {
+ int i, cont = 0;
+
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ struct ubifs_cnode *cnode;
+
+ cnode = nnode->nbranch[i].cnode;
+ if (cnode &&
+ test_bit(DIRTY_CNODE, &cnode->flags)) {
+ if (cnode->level == 0)
+ return cnode;
+ nnode = (struct ubifs_nnode *)cnode;
+ cont = 1;
+ break;
+ }
+ }
+ if (!cont)
+ return (struct ubifs_cnode *)nnode;
+ }
+}
+
+/**
+ * next_dirty_cnode - find next dirty cnode.
+ * @c: UBIFS file-system description object
+ * @cnode: cnode from which to begin searching
+ *
+ * This function returns the next dirty cnode or %NULL if there is not one.
+ */
+static struct ubifs_cnode *next_dirty_cnode(const struct ubifs_info *c, struct ubifs_cnode *cnode)
+{
+ struct ubifs_nnode *nnode;
+ int i;
+
+ ubifs_assert(c, cnode);
+ nnode = cnode->parent;
+ if (!nnode)
+ return NULL;
+ for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
+ cnode = nnode->nbranch[i].cnode;
+ if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
+ if (cnode->level == 0)
+ return cnode; /* cnode is a pnode */
+ /* cnode is a nnode */
+ return first_dirty_cnode(c, (struct ubifs_nnode *)cnode);
+ }
+ }
+ return (struct ubifs_cnode *)nnode;
+}
+
+/**
+ * get_cnodes_to_commit - create list of dirty cnodes to commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns the number of cnodes to commit.
+ */
+static int get_cnodes_to_commit(struct ubifs_info *c)
+{
+ struct ubifs_cnode *cnode, *cnext;
+ int cnt = 0;
+
+ if (!c->nroot)
+ return 0;
+
+ if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
+ return 0;
+
+ c->lpt_cnext = first_dirty_cnode(c, c->nroot);
+ cnode = c->lpt_cnext;
+ if (!cnode)
+ return 0;
+ cnt += 1;
+ while (1) {
+ ubifs_assert(c, !test_bit(COW_CNODE, &cnode->flags));
+ __set_bit(COW_CNODE, &cnode->flags);
+ cnext = next_dirty_cnode(c, cnode);
+ if (!cnext) {
+ cnode->cnext = c->lpt_cnext;
+ break;
+ }
+ cnode->cnext = cnext;
+ cnode = cnext;
+ cnt += 1;
+ }
+ dbg_cmt("committing %d cnodes", cnt);
+ dbg_lp("committing %d cnodes", cnt);
+ ubifs_assert(c, cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
+ return cnt;
+}
+
+/**
+ * upd_ltab - update LPT LEB properties.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number
+ * @free: amount of free space
+ * @dirty: amount of dirty space to add
+ */
+static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
+{
+ dbg_lp("LEB %d free %d dirty %d to %d +%d",
+ lnum, c->ltab[lnum - c->lpt_first].free,
+ c->ltab[lnum - c->lpt_first].dirty, free, dirty);
+ ubifs_assert(c, lnum >= c->lpt_first && lnum <= c->lpt_last);
+ c->ltab[lnum - c->lpt_first].free = free;
+ c->ltab[lnum - c->lpt_first].dirty += dirty;
+}
+
+/**
+ * alloc_lpt_leb - allocate an LPT LEB that is empty.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number is passed and returned here
+ *
+ * This function finds the next empty LEB in the ltab starting from @lnum. If a
+ * an empty LEB is found it is returned in @lnum and the function returns %0.
+ * Otherwise the function returns -ENOSPC. Note however, that LPT is designed
+ * never to run out of space.
+ */
+static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
+{
+ int i, n;
+
+ n = *lnum - c->lpt_first + 1;
+ for (i = n; i < c->lpt_lebs; i++) {
+ if (c->ltab[i].tgc || c->ltab[i].cmt)
+ continue;
+ if (c->ltab[i].free == c->leb_size) {
+ c->ltab[i].cmt = 1;
+ *lnum = i + c->lpt_first;
+ return 0;
+ }
+ }
+
+ for (i = 0; i < n; i++) {
+ if (c->ltab[i].tgc || c->ltab[i].cmt)
+ continue;
+ if (c->ltab[i].free == c->leb_size) {
+ c->ltab[i].cmt = 1;
+ *lnum = i + c->lpt_first;
+ return 0;
+ }
+ }
+ return -ENOSPC;
+}
+
+/**
+ * layout_cnodes - layout cnodes for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int layout_cnodes(struct ubifs_info *c)
+{
+ int lnum, offs, len, alen, done_lsave, done_ltab, err;
+ struct ubifs_cnode *cnode;
+
+ err = dbg_chk_lpt_sz(c, 0, 0);
+ if (err)
+ return err;
+ cnode = c->lpt_cnext;
+ if (!cnode)
+ return 0;
+ lnum = c->nhead_lnum;
+ offs = c->nhead_offs;
+ /* Try to place lsave and ltab nicely */
+ done_lsave = !c->big_lpt;
+ done_ltab = 0;
+ if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
+ done_lsave = 1;
+ c->lsave_lnum = lnum;
+ c->lsave_offs = offs;
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ }
+
+ if (offs + c->ltab_sz <= c->leb_size) {
+ done_ltab = 1;
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ }
+
+ do {
+ if (cnode->level) {
+ len = c->nnode_sz;
+ c->dirty_nn_cnt -= 1;
+ } else {
+ len = c->pnode_sz;
+ c->dirty_pn_cnt -= 1;
+ }
+ while (offs + len > c->leb_size) {
+ alen = ALIGN(offs, c->min_io_size);
+ upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ /* Try to place lsave and ltab nicely */
+ if (!done_lsave) {
+ done_lsave = 1;
+ c->lsave_lnum = lnum;
+ c->lsave_offs = offs;
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ continue;
+ }
+ if (!done_ltab) {
+ done_ltab = 1;
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ continue;
+ }
+ break;
+ }
+ if (cnode->parent) {
+ cnode->parent->nbranch[cnode->iip].lnum = lnum;
+ cnode->parent->nbranch[cnode->iip].offs = offs;
+ } else {
+ c->lpt_lnum = lnum;
+ c->lpt_offs = offs;
+ }
+ offs += len;
+ dbg_chk_lpt_sz(c, 1, len);
+ cnode = cnode->cnext;
+ } while (cnode && cnode != c->lpt_cnext);
+
+ /* Make sure to place LPT's save table */
+ if (!done_lsave) {
+ if (offs + c->lsave_sz > c->leb_size) {
+ alen = ALIGN(offs, c->min_io_size);
+ upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ }
+ done_lsave = 1;
+ c->lsave_lnum = lnum;
+ c->lsave_offs = offs;
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ }
+
+ /* Make sure to place LPT's own lprops table */
+ if (!done_ltab) {
+ if (offs + c->ltab_sz > c->leb_size) {
+ alen = ALIGN(offs, c->min_io_size);
+ upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ }
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ }
+
+ alen = ALIGN(offs, c->min_io_size);
+ upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
+ dbg_chk_lpt_sz(c, 4, alen - offs);
+ err = dbg_chk_lpt_sz(c, 3, alen);
+ if (err)
+ return err;
+ return 0;
+
+no_space:
+ ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
+ lnum, offs, len, done_ltab, done_lsave);
+ ubifs_dump_lpt_info(c);
+ ubifs_dump_lpt_lebs(c);
+ dump_stack();
+ return err;
+}
+
+/**
+ * realloc_lpt_leb - allocate an LPT LEB that is empty.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number is passed and returned here
+ *
+ * This function duplicates exactly the results of the function alloc_lpt_leb.
+ * It is used during end commit to reallocate the same LEB numbers that were
+ * allocated by alloc_lpt_leb during start commit.
+ *
+ * This function finds the next LEB that was allocated by the alloc_lpt_leb
+ * function starting from @lnum. If a LEB is found it is returned in @lnum and
+ * the function returns %0. Otherwise the function returns -ENOSPC.
+ * Note however, that LPT is designed never to run out of space.
+ */
+static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
+{
+ int i, n;
+
+ n = *lnum - c->lpt_first + 1;
+ for (i = n; i < c->lpt_lebs; i++)
+ if (c->ltab[i].cmt) {
+ c->ltab[i].cmt = 0;
+ *lnum = i + c->lpt_first;
+ return 0;
+ }
+
+ for (i = 0; i < n; i++)
+ if (c->ltab[i].cmt) {
+ c->ltab[i].cmt = 0;
+ *lnum = i + c->lpt_first;
+ return 0;
+ }
+ return -ENOSPC;
+}
+
+/**
+ * write_cnodes - write cnodes for commit.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int write_cnodes(struct ubifs_info *c)
+{
+ int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
+ struct ubifs_cnode *cnode;
+ void *buf = c->lpt_buf;
+
+ cnode = c->lpt_cnext;
+ if (!cnode)
+ return 0;
+ lnum = c->nhead_lnum;
+ offs = c->nhead_offs;
+ from = offs;
+ /* Ensure empty LEB is unmapped */
+ if (offs == 0) {
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ /* Try to place lsave and ltab nicely */
+ done_lsave = !c->big_lpt;
+ done_ltab = 0;
+ if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
+ done_lsave = 1;
+ ubifs_pack_lsave(c, buf + offs, c->lsave);
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ }
+
+ if (offs + c->ltab_sz <= c->leb_size) {
+ done_ltab = 1;
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ }
+
+ /* Loop for each cnode */
+ do {
+ if (cnode->level)
+ len = c->nnode_sz;
+ else
+ len = c->pnode_sz;
+ while (offs + len > c->leb_size) {
+ wlen = offs - from;
+ if (wlen) {
+ alen = ALIGN(wlen, c->min_io_size);
+ memset(buf + offs, 0xff, alen - wlen);
+ err = ubifs_leb_write(c, lnum, buf + from, from,
+ alen);
+ if (err)
+ return err;
+ }
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = from = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ /* Try to place lsave and ltab nicely */
+ if (!done_lsave) {
+ done_lsave = 1;
+ ubifs_pack_lsave(c, buf + offs, c->lsave);
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ continue;
+ }
+ if (!done_ltab) {
+ done_ltab = 1;
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ continue;
+ }
+ break;
+ }
+ if (cnode->level)
+ ubifs_pack_nnode(c, buf + offs,
+ (struct ubifs_nnode *)cnode);
+ else
+ ubifs_pack_pnode(c, buf + offs,
+ (struct ubifs_pnode *)cnode);
+ /*
+ * The reason for the barriers is the same as in case of TNC.
+ * See comment in 'write_index()'. 'dirty_cow_nnode()' and
+ * 'dirty_cow_pnode()' are the functions for which this is
+ * important.
+ */
+ clear_bit(DIRTY_CNODE, &cnode->flags);
+ smp_mb__before_atomic();
+ clear_bit(COW_CNODE, &cnode->flags);
+ smp_mb__after_atomic();
+ offs += len;
+ dbg_chk_lpt_sz(c, 1, len);
+ cnode = cnode->cnext;
+ } while (cnode && cnode != c->lpt_cnext);
+
+ /* Make sure to place LPT's save table */
+ if (!done_lsave) {
+ if (offs + c->lsave_sz > c->leb_size) {
+ wlen = offs - from;
+ alen = ALIGN(wlen, c->min_io_size);
+ memset(buf + offs, 0xff, alen - wlen);
+ err = ubifs_leb_write(c, lnum, buf + from, from, alen);
+ if (err)
+ return err;
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = from = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ done_lsave = 1;
+ ubifs_pack_lsave(c, buf + offs, c->lsave);
+ offs += c->lsave_sz;
+ dbg_chk_lpt_sz(c, 1, c->lsave_sz);
+ }
+
+ /* Make sure to place LPT's own lprops table */
+ if (!done_ltab) {
+ if (offs + c->ltab_sz > c->leb_size) {
+ wlen = offs - from;
+ alen = ALIGN(wlen, c->min_io_size);
+ memset(buf + offs, 0xff, alen - wlen);
+ err = ubifs_leb_write(c, lnum, buf + from, from, alen);
+ if (err)
+ return err;
+ dbg_chk_lpt_sz(c, 2, c->leb_size - offs);
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ goto no_space;
+ offs = from = 0;
+ ubifs_assert(c, lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += c->ltab_sz;
+ dbg_chk_lpt_sz(c, 1, c->ltab_sz);
+ }
+
+ /* Write remaining data in buffer */
+ wlen = offs - from;
+ alen = ALIGN(wlen, c->min_io_size);
+ memset(buf + offs, 0xff, alen - wlen);
+ err = ubifs_leb_write(c, lnum, buf + from, from, alen);
+ if (err)
+ return err;
+
+ dbg_chk_lpt_sz(c, 4, alen - wlen);
+ err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
+ if (err)
+ return err;
+
+ c->nhead_lnum = lnum;
+ c->nhead_offs = ALIGN(offs, c->min_io_size);
+
+ dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
+ dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
+ dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
+ if (c->big_lpt)
+ dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
+
+ return 0;
+
+no_space:
+ ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d",
+ lnum, offs, len, done_ltab, done_lsave);
+ ubifs_dump_lpt_info(c);
+ ubifs_dump_lpt_lebs(c);
+ dump_stack();
+ return err;
+}
+
+/**
+ * next_pnode_to_dirty - find next pnode to dirty.
+ * @c: UBIFS file-system description object
+ * @pnode: pnode
+ *
+ * This function returns the next pnode to dirty or %NULL if there are no more
+ * pnodes. Note that pnodes that have never been written (lnum == 0) are
+ * skipped.
+ */
+static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
+ struct ubifs_pnode *pnode)
+{
+ struct ubifs_nnode *nnode;
+ int iip;
+
+ /* Try to go right */
+ nnode = pnode->parent;
+ for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
+ if (nnode->nbranch[iip].lnum)
+ return ubifs_get_pnode(c, nnode, iip);
+ }
+
+ /* Go up while can't go right */
+ do {
+ iip = nnode->iip + 1;
+ nnode = nnode->parent;
+ if (!nnode)
+ return NULL;
+ for (; iip < UBIFS_LPT_FANOUT; iip++) {
+ if (nnode->nbranch[iip].lnum)
+ break;
+ }
+ } while (iip >= UBIFS_LPT_FANOUT);
+
+ /* Go right */
+ nnode = ubifs_get_nnode(c, nnode, iip);
+ if (IS_ERR(nnode))
+ return (void *)nnode;
+
+ /* Go down to level 1 */
+ while (nnode->level > 1) {
+ for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
+ if (nnode->nbranch[iip].lnum)
+ break;
+ }
+ if (iip >= UBIFS_LPT_FANOUT) {
+ /*
+ * Should not happen, but we need to keep going
+ * if it does.
+ */
+ iip = 0;
+ }
+ nnode = ubifs_get_nnode(c, nnode, iip);
+ if (IS_ERR(nnode))
+ return (void *)nnode;
+ }
+
+ for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
+ if (nnode->nbranch[iip].lnum)
+ break;
+ if (iip >= UBIFS_LPT_FANOUT)
+ /* Should not happen, but we need to keep going if it does */
+ iip = 0;
+ return ubifs_get_pnode(c, nnode, iip);
+}
+
+/**
+ * pnode_lookup - lookup a pnode in the LPT.
+ * @c: UBIFS file-system description object
+ * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT))
+ *
+ * This function returns a pointer to the pnode on success or a negative
+ * error code on failure.
+ */
+static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
+{
+ int err, h, iip, shft;
+ struct ubifs_nnode *nnode;
+
+ if (!c->nroot) {
+ err = ubifs_read_nnode(c, NULL, 0);
+ if (err)
+ return ERR_PTR(err);
+ }
+ i <<= UBIFS_LPT_FANOUT_SHIFT;
+ nnode = c->nroot;
+ shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
+ for (h = 1; h < c->lpt_hght; h++) {
+ iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+ shft -= UBIFS_LPT_FANOUT_SHIFT;
+ nnode = ubifs_get_nnode(c, nnode, iip);
+ if (IS_ERR(nnode))
+ return ERR_CAST(nnode);
+ }
+ iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
+ return ubifs_get_pnode(c, nnode, iip);
+}
+
+/**
+ * add_pnode_dirt - add dirty space to LPT LEB properties.
+ * @c: UBIFS file-system description object
+ * @pnode: pnode for which to add dirt
+ */
+static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
+{
+ ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
+ c->pnode_sz);
+}
+
+/**
+ * do_make_pnode_dirty - mark a pnode dirty.
+ * @c: UBIFS file-system description object
+ * @pnode: pnode to mark dirty
+ */
+static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
+{
+ /* Assumes cnext list is empty i.e. not called during commit */
+ if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
+ struct ubifs_nnode *nnode;
+
+ c->dirty_pn_cnt += 1;
+ add_pnode_dirt(c, pnode);
+ /* Mark parent and ancestors dirty too */
+ nnode = pnode->parent;
+ while (nnode) {
+ if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
+ c->dirty_nn_cnt += 1;
+ ubifs_add_nnode_dirt(c, nnode);
+ nnode = nnode->parent;
+ } else
+ break;
+ }
+ }
+}
+
+/**
+ * make_tree_dirty - mark the entire LEB properties tree dirty.
+ * @c: UBIFS file-system description object
+ *
+ * This function is used by the "small" LPT model to cause the entire LEB
+ * properties tree to be written. The "small" LPT model does not use LPT
+ * garbage collection because it is more efficient to write the entire tree
+ * (because it is small).
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_tree_dirty(struct ubifs_info *c)
+{
+ struct ubifs_pnode *pnode;
+
+ pnode = pnode_lookup(c, 0);
+ if (IS_ERR(pnode))
+ return PTR_ERR(pnode);
+
+ while (pnode) {
+ do_make_pnode_dirty(c, pnode);
+ pnode = next_pnode_to_dirty(c, pnode);
+ if (IS_ERR(pnode))
+ return PTR_ERR(pnode);
+ }
+ return 0;
+}
+
+/**
+ * need_write_all - determine if the LPT area is running out of free space.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns %1 if the LPT area is running out of free space and %0
+ * if it is not.
+ */
+static int need_write_all(struct ubifs_info *c)
+{
+ long long free = 0;
+ int i;
+
+ for (i = 0; i < c->lpt_lebs; i++) {
+ if (i + c->lpt_first == c->nhead_lnum)
+ free += c->leb_size - c->nhead_offs;
+ else if (c->ltab[i].free == c->leb_size)
+ free += c->leb_size;
+ else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
+ free += c->leb_size;
+ }
+ /* Less than twice the size left */
+ if (free <= c->lpt_sz * 2)
+ return 1;
+ return 0;
+}
+
+/**
+ * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
+ * @c: UBIFS file-system description object
+ *
+ * LPT trivial garbage collection is where a LPT LEB contains only dirty and
+ * free space and so may be reused as soon as the next commit is completed.
+ * This function is called during start commit to mark LPT LEBs for trivial GC.
+ */
+static void lpt_tgc_start(struct ubifs_info *c)
+{
+ int i;
+
+ for (i = 0; i < c->lpt_lebs; i++) {
+ if (i + c->lpt_first == c->nhead_lnum)
+ continue;
+ if (c->ltab[i].dirty > 0 &&
+ c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
+ c->ltab[i].tgc = 1;
+ c->ltab[i].free = c->leb_size;
+ c->ltab[i].dirty = 0;
+ dbg_lp("LEB %d", i + c->lpt_first);
+ }
+ }
+}
+
+/**
+ * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
+ * @c: UBIFS file-system description object
+ *
+ * LPT trivial garbage collection is where a LPT LEB contains only dirty and
+ * free space and so may be reused as soon as the next commit is completed.
+ * This function is called after the commit is completed (master node has been
+ * written) and un-maps LPT LEBs that were marked for trivial GC.
+ */
+static int lpt_tgc_end(struct ubifs_info *c)
+{
+ int i, err;
+
+ for (i = 0; i < c->lpt_lebs; i++)
+ if (c->ltab[i].tgc) {
+ err = ubifs_leb_unmap(c, i + c->lpt_first);
+ if (err)
+ return err;
+ c->ltab[i].tgc = 0;
+ dbg_lp("LEB %d", i + c->lpt_first);
+ }
+ return 0;
+}
+
+/**
+ * populate_lsave - fill the lsave array with important LEB numbers.
+ * @c: the UBIFS file-system description object
+ *
+ * This function is only called for the "big" model. It records a small number
+ * of LEB numbers of important LEBs. Important LEBs are ones that are (from
+ * most important to least important): empty, freeable, freeable index, dirty
+ * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
+ * their pnodes into memory. That will stop us from having to scan the LPT
+ * straight away. For the "small" model we assume that scanning the LPT is no
+ * big deal.
+ */
+static void populate_lsave(struct ubifs_info *c)
+{
+ struct ubifs_lprops *lprops;
+ struct ubifs_lpt_heap *heap;
+ int i, cnt = 0;
+
+ ubifs_assert(c, c->big_lpt);
+ if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
+ c->lpt_drty_flgs |= LSAVE_DIRTY;
+ ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
+ }
+
+ if (dbg_populate_lsave(c))
+ return;
+
+ list_for_each_entry(lprops, &c->empty_list, list) {
+ c->lsave[cnt++] = lprops->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ list_for_each_entry(lprops, &c->freeable_list, list) {
+ c->lsave[cnt++] = lprops->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ list_for_each_entry(lprops, &c->frdi_idx_list, list) {
+ c->lsave[cnt++] = lprops->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
+ for (i = 0; i < heap->cnt; i++) {
+ c->lsave[cnt++] = heap->arr[i]->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ heap = &c->lpt_heap[LPROPS_DIRTY - 1];
+ for (i = 0; i < heap->cnt; i++) {
+ c->lsave[cnt++] = heap->arr[i]->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ heap = &c->lpt_heap[LPROPS_FREE - 1];
+ for (i = 0; i < heap->cnt; i++) {
+ c->lsave[cnt++] = heap->arr[i]->lnum;
+ if (cnt >= c->lsave_cnt)
+ return;
+ }
+ /* Fill it up completely */
+ while (cnt < c->lsave_cnt)
+ c->lsave[cnt++] = c->main_first;
+}
+
+/**
+ * nnode_lookup - lookup a nnode in the LPT.
+ * @c: UBIFS file-system description object
+ * @i: nnode number
+ *
+ * This function returns a pointer to the nnode on success or a negative
+ * error code on failure.
+ */
+static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
+{
+ int err, iip;
+ struct ubifs_nnode *nnode;
+
+ if (!c->nroot) {
+ err = ubifs_read_nnode(c, NULL, 0);
+ if (err)
+ return ERR_PTR(err);
+ }
+ nnode = c->nroot;
+ while (1) {
+ iip = i & (UBIFS_LPT_FANOUT - 1);
+ i >>= UBIFS_LPT_FANOUT_SHIFT;
+ if (!i)
+ break;
+ nnode = ubifs_get_nnode(c, nnode, iip);
+ if (IS_ERR(nnode))
+ return nnode;
+ }
+ return nnode;
+}
+
+/**
+ * make_nnode_dirty - find a nnode and, if found, make it dirty.
+ * @c: UBIFS file-system description object
+ * @node_num: nnode number of nnode to make dirty
+ * @lnum: LEB number where nnode was written
+ * @offs: offset where nnode was written
+ *
+ * This function is used by LPT garbage collection. LPT garbage collection is
+ * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection
+ * simply involves marking all the nodes in the LEB being garbage-collected as
+ * dirty. The dirty nodes are written next commit, after which the LEB is free
+ * to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
+ int offs)
+{
+ struct ubifs_nnode *nnode;
+
+ nnode = nnode_lookup(c, node_num);
+ if (IS_ERR(nnode))
+ return PTR_ERR(nnode);
+ if (nnode->parent) {
+ struct ubifs_nbranch *branch;
+
+ branch = &nnode->parent->nbranch[nnode->iip];
+ if (branch->lnum != lnum || branch->offs != offs)
+ return 0; /* nnode is obsolete */
+ } else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
+ return 0; /* nnode is obsolete */
+ /* Assumes cnext list is empty i.e. not called during commit */
+ if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
+ c->dirty_nn_cnt += 1;
+ ubifs_add_nnode_dirt(c, nnode);
+ /* Mark parent and ancestors dirty too */
+ nnode = nnode->parent;
+ while (nnode) {
+ if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
+ c->dirty_nn_cnt += 1;
+ ubifs_add_nnode_dirt(c, nnode);
+ nnode = nnode->parent;
+ } else
+ break;
+ }
+ }
+ return 0;
+}
+
+/**
+ * make_pnode_dirty - find a pnode and, if found, make it dirty.
+ * @c: UBIFS file-system description object
+ * @node_num: pnode number of pnode to make dirty
+ * @lnum: LEB number where pnode was written
+ * @offs: offset where pnode was written
+ *
+ * This function is used by LPT garbage collection. LPT garbage collection is
+ * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection
+ * simply involves marking all the nodes in the LEB being garbage-collected as
+ * dirty. The dirty nodes are written next commit, after which the LEB is free
+ * to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
+ int offs)
+{
+ struct ubifs_pnode *pnode;
+ struct ubifs_nbranch *branch;
+
+ pnode = pnode_lookup(c, node_num);
+ if (IS_ERR(pnode))
+ return PTR_ERR(pnode);
+ branch = &pnode->parent->nbranch[pnode->iip];
+ if (branch->lnum != lnum || branch->offs != offs)
+ return 0;
+ do_make_pnode_dirty(c, pnode);
+ return 0;
+}
+
+/**
+ * make_ltab_dirty - make ltab node dirty.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number where ltab was written
+ * @offs: offset where ltab was written
+ *
+ * This function is used by LPT garbage collection. LPT garbage collection is
+ * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection
+ * simply involves marking all the nodes in the LEB being garbage-collected as
+ * dirty. The dirty nodes are written next commit, after which the LEB is free
+ * to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ if (lnum != c->ltab_lnum || offs != c->ltab_offs)
+ return 0; /* This ltab node is obsolete */
+ if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
+ c->lpt_drty_flgs |= LTAB_DIRTY;
+ ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
+ }
+ return 0;
+}
+
+/**
+ * make_lsave_dirty - make lsave node dirty.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number where lsave was written
+ * @offs: offset where lsave was written
+ *
+ * This function is used by LPT garbage collection. LPT garbage collection is
+ * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection
+ * simply involves marking all the nodes in the LEB being garbage-collected as
+ * dirty. The dirty nodes are written next commit, after which the LEB is free
+ * to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ if (lnum != c->lsave_lnum || offs != c->lsave_offs)
+ return 0; /* This lsave node is obsolete */
+ if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
+ c->lpt_drty_flgs |= LSAVE_DIRTY;
+ ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
+ }
+ return 0;
+}
+
+/**
+ * make_node_dirty - make node dirty.
+ * @c: UBIFS file-system description object
+ * @node_type: LPT node type
+ * @node_num: node number
+ * @lnum: LEB number where node was written
+ * @offs: offset where node was written
+ *
+ * This function is used by LPT garbage collection. LPT garbage collection is
+ * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection
+ * simply involves marking all the nodes in the LEB being garbage-collected as
+ * dirty. The dirty nodes are written next commit, after which the LEB is free
+ * to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
+ int lnum, int offs)
+{
+ switch (node_type) {
+ case UBIFS_LPT_NNODE:
+ return make_nnode_dirty(c, node_num, lnum, offs);
+ case UBIFS_LPT_PNODE:
+ return make_pnode_dirty(c, node_num, lnum, offs);
+ case UBIFS_LPT_LTAB:
+ return make_ltab_dirty(c, lnum, offs);
+ case UBIFS_LPT_LSAVE:
+ return make_lsave_dirty(c, lnum, offs);
+ }
+ return -EINVAL;
+}
+
+/**
+ * get_lpt_node_len - return the length of a node based on its type.
+ * @c: UBIFS file-system description object
+ * @node_type: LPT node type
+ */
+static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
+{
+ switch (node_type) {
+ case UBIFS_LPT_NNODE:
+ return c->nnode_sz;
+ case UBIFS_LPT_PNODE:
+ return c->pnode_sz;
+ case UBIFS_LPT_LTAB:
+ return c->ltab_sz;
+ case UBIFS_LPT_LSAVE:
+ return c->lsave_sz;
+ }
+ return 0;
+}
+
+/**
+ * get_pad_len - return the length of padding in a buffer.
+ * @c: UBIFS file-system description object
+ * @buf: buffer
+ * @len: length of buffer
+ */
+static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
+{
+ int offs, pad_len;
+
+ if (c->min_io_size == 1)
+ return 0;
+ offs = c->leb_size - len;
+ pad_len = ALIGN(offs, c->min_io_size) - offs;
+ return pad_len;
+}
+
+/**
+ * get_lpt_node_type - return type (and node number) of a node in a buffer.
+ * @c: UBIFS file-system description object
+ * @buf: buffer
+ * @node_num: node number is returned here
+ */
+static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
+ int *node_num)
+{
+ uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
+ int pos = 0, node_type;
+
+ node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS);
+ *node_num = ubifs_unpack_bits(c, &addr, &pos, c->pcnt_bits);
+ return node_type;
+}
+
+/**
+ * is_a_node - determine if a buffer contains a node.
+ * @c: UBIFS file-system description object
+ * @buf: buffer
+ * @len: length of buffer
+ *
+ * This function returns %1 if the buffer contains a node or %0 if it does not.
+ */
+static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
+{
+ uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
+ int pos = 0, node_type, node_len;
+ uint16_t crc, calc_crc;
+
+ if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
+ return 0;
+ node_type = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_TYPE_BITS);
+ if (node_type == UBIFS_LPT_NOT_A_NODE)
+ return 0;
+ node_len = get_lpt_node_len(c, node_type);
+ if (!node_len || node_len > len)
+ return 0;
+ pos = 0;
+ addr = buf;
+ crc = ubifs_unpack_bits(c, &addr, &pos, UBIFS_LPT_CRC_BITS);
+ calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
+ node_len - UBIFS_LPT_CRC_BYTES);
+ if (crc != calc_crc)
+ return 0;
+ return 1;
+}
+
+/**
+ * lpt_gc_lnum - garbage collect a LPT LEB.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number to garbage collect
+ *
+ * LPT garbage collection is used only for the "big" LPT model
+ * (c->big_lpt == 1). Garbage collection simply involves marking all the nodes
+ * in the LEB being garbage-collected as dirty. The dirty nodes are written
+ * next commit, after which the LEB is free to be reused.
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
+{
+ int err, len = c->leb_size, node_type, node_num, node_len, offs;
+ void *buf = c->lpt_buf;
+
+ dbg_lp("LEB %d", lnum);
+
+ err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
+ if (err)
+ return err;
+
+ while (1) {
+ if (!is_a_node(c, buf, len)) {
+ int pad_len;
+
+ pad_len = get_pad_len(c, buf, len);
+ if (pad_len) {
+ buf += pad_len;
+ len -= pad_len;
+ continue;
+ }
+ return 0;
+ }
+ node_type = get_lpt_node_type(c, buf, &node_num);
+ node_len = get_lpt_node_len(c, node_type);
+ offs = c->leb_size - len;
+ ubifs_assert(c, node_len != 0);
+ mutex_lock(&c->lp_mutex);
+ err = make_node_dirty(c, node_type, node_num, lnum, offs);
+ mutex_unlock(&c->lp_mutex);
+ if (err)
+ return err;
+ buf += node_len;
+ len -= node_len;
+ }
+ return 0;
+}
+
+/**
+ * lpt_gc - LPT garbage collection.
+ * @c: UBIFS file-system description object
+ *
+ * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
+ * Returns %0 on success and a negative error code on failure.
+ */
+static int lpt_gc(struct ubifs_info *c)
+{
+ int i, lnum = -1, dirty = 0;
+
+ mutex_lock(&c->lp_mutex);
+ for (i = 0; i < c->lpt_lebs; i++) {
+ ubifs_assert(c, !c->ltab[i].tgc);
+ if (i + c->lpt_first == c->nhead_lnum ||
+ c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
+ continue;
+ if (c->ltab[i].dirty > dirty) {
+ dirty = c->ltab[i].dirty;
+ lnum = i + c->lpt_first;
+ }
+ }
+ mutex_unlock(&c->lp_mutex);
+ if (lnum == -1)
+ return -ENOSPC;
+ return lpt_gc_lnum(c, lnum);
+}
+
+/**
+ * ubifs_lpt_start_commit - UBIFS commit starts.
+ * @c: the UBIFS file-system description object
+ *
+ * This function has to be called when UBIFS starts the commit operation.
+ * This function "freezes" all currently dirty LEB properties and does not
+ * change them anymore. Further changes are saved and tracked separately
+ * because they are not part of this commit. This function returns zero in case
+ * of success and a negative error code in case of failure.
+ */
+int ubifs_lpt_start_commit(struct ubifs_info *c)
+{
+ int err, cnt;
+
+ dbg_lp("");
+
+ mutex_lock(&c->lp_mutex);
+ err = dbg_chk_lpt_free_spc(c);
+ if (err)
+ goto out;
+ err = dbg_check_ltab(c);
+ if (err)
+ goto out;
+
+ if (c->check_lpt_free) {
+ /*
+ * We ensure there is enough free space in
+ * ubifs_lpt_post_commit() by marking nodes dirty. That
+ * information is lost when we unmount, so we also need
+ * to check free space once after mounting also.
+ */
+ c->check_lpt_free = 0;
+ while (need_write_all(c)) {
+ mutex_unlock(&c->lp_mutex);
+ err = lpt_gc(c);
+ if (err)
+ return err;
+ mutex_lock(&c->lp_mutex);
+ }
+ }
+
+ lpt_tgc_start(c);
+
+ if (!c->dirty_pn_cnt) {
+ dbg_cmt("no cnodes to commit");
+ err = 0;
+ goto out;
+ }
+
+ if (!c->big_lpt && need_write_all(c)) {
+ /* If needed, write everything */
+ err = make_tree_dirty(c);
+ if (err)
+ goto out;
+ lpt_tgc_start(c);
+ }
+
+ if (c->big_lpt)
+ populate_lsave(c);
+
+ cnt = get_cnodes_to_commit(c);
+ ubifs_assert(c, cnt != 0);
+
+ err = layout_cnodes(c);
+ if (err)
+ goto out;
+
+ /* Copy the LPT's own lprops for end commit to write */
+ memcpy(c->ltab_cmt, c->ltab,
+ sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
+ c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
+
+out:
+ mutex_unlock(&c->lp_mutex);
+ return err;
+}
+
+/**
+ * free_obsolete_cnodes - free obsolete cnodes for commit end.
+ * @c: UBIFS file-system description object
+ */
+static void free_obsolete_cnodes(struct ubifs_info *c)
+{
+ struct ubifs_cnode *cnode, *cnext;
+
+ cnext = c->lpt_cnext;
+ if (!cnext)
+ return;
+ do {
+ cnode = cnext;
+ cnext = cnode->cnext;
+ if (test_bit(OBSOLETE_CNODE, &cnode->flags))
+ kfree(cnode);
+ else
+ cnode->cnext = NULL;
+ } while (cnext != c->lpt_cnext);
+ c->lpt_cnext = NULL;
+}
+
+/**
+ * ubifs_lpt_end_commit - finish the commit operation.
+ * @c: the UBIFS file-system description object
+ *
+ * This function has to be called when the commit operation finishes. It
+ * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
+ * the media. Returns zero in case of success and a negative error code in case
+ * of failure.
+ */
+int ubifs_lpt_end_commit(struct ubifs_info *c)
+{
+ int err;
+
+ dbg_lp("");
+
+ if (!c->lpt_cnext)
+ return 0;
+
+ err = write_cnodes(c);
+ if (err)
+ return err;
+
+ mutex_lock(&c->lp_mutex);
+ free_obsolete_cnodes(c);
+ mutex_unlock(&c->lp_mutex);
+
+ return 0;
+}
+
+/**
+ * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
+ * @c: UBIFS file-system description object
+ *
+ * LPT trivial GC is completed after a commit. Also LPT GC is done after a
+ * commit for the "big" LPT model.
+ */
+int ubifs_lpt_post_commit(struct ubifs_info *c)
+{
+ int err;
+
+ mutex_lock(&c->lp_mutex);
+ err = lpt_tgc_end(c);
+ if (err)
+ goto out;
+ if (c->big_lpt)
+ while (need_write_all(c)) {
+ mutex_unlock(&c->lp_mutex);
+ err = lpt_gc(c);
+ if (err)
+ return err;
+ mutex_lock(&c->lp_mutex);
+ }
+out:
+ mutex_unlock(&c->lp_mutex);
+ return err;
+}
+
+/**
+ * first_nnode - find the first nnode in memory.
+ * @c: UBIFS file-system description object
+ * @hght: height of tree where nnode found is returned here
+ *
+ * This function returns a pointer to the nnode found or %NULL if no nnode is
+ * found. This function is a helper to 'ubifs_lpt_free()'.
+ */
+static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
+{
+ struct ubifs_nnode *nnode;
+ int h, i, found;
+
+ nnode = c->nroot;
+ *hght = 0;
+ if (!nnode)
+ return NULL;
+ for (h = 1; h < c->lpt_hght; h++) {
+ found = 0;
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ if (nnode->nbranch[i].nnode) {
+ found = 1;
+ nnode = nnode->nbranch[i].nnode;
+ *hght = h;
+ break;
+ }
+ }
+ if (!found)
+ break;
+ }
+ return nnode;
+}
+
+/**
+ * next_nnode - find the next nnode in memory.
+ * @c: UBIFS file-system description object
+ * @nnode: nnode from which to start.
+ * @hght: height of tree where nnode is, is passed and returned here
+ *
+ * This function returns a pointer to the nnode found or %NULL if no nnode is
+ * found. This function is a helper to 'ubifs_lpt_free()'.
+ */
+static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
+ struct ubifs_nnode *nnode, int *hght)
+{
+ struct ubifs_nnode *parent;
+ int iip, h, i, found;
+
+ parent = nnode->parent;
+ if (!parent)
+ return NULL;
+ if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
+ *hght -= 1;
+ return parent;
+ }
+ for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
+ nnode = parent->nbranch[iip].nnode;
+ if (nnode)
+ break;
+ }
+ if (!nnode) {
+ *hght -= 1;
+ return parent;
+ }
+ for (h = *hght + 1; h < c->lpt_hght; h++) {
+ found = 0;
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ if (nnode->nbranch[i].nnode) {
+ found = 1;
+ nnode = nnode->nbranch[i].nnode;
+ *hght = h;
+ break;
+ }
+ }
+ if (!found)
+ break;
+ }
+ return nnode;
+}
+
+/**
+ * ubifs_lpt_free - free resources owned by the LPT.
+ * @c: UBIFS file-system description object
+ * @wr_only: free only resources used for writing
+ */
+void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
+{
+ struct ubifs_nnode *nnode;
+ int i, hght;
+
+ /* Free write-only things first */
+
+ free_obsolete_cnodes(c); /* Leftover from a failed commit */
+
+ vfree(c->ltab_cmt);
+ c->ltab_cmt = NULL;
+ vfree(c->lpt_buf);
+ c->lpt_buf = NULL;
+ kfree(c->lsave);
+ c->lsave = NULL;
+
+ if (wr_only)
+ return;
+
+ /* Now free the rest */
+
+ nnode = first_nnode(c, &hght);
+ while (nnode) {
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++)
+ kfree(nnode->nbranch[i].nnode);
+ nnode = next_nnode(c, nnode, &hght);
+ }
+ for (i = 0; i < LPROPS_HEAP_CNT; i++)
+ kfree(c->lpt_heap[i].arr);
+ kfree(c->dirty_idx.arr);
+ kfree(c->nroot);
+ vfree(c->ltab);
+ kfree(c->lpt_nod_buf);
+}
+
+/*
+ * Everything below is related to debugging.
+ */
+
+/**
+ * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
+ * @buf: buffer
+ * @len: buffer length
+ */
+static int dbg_is_all_ff(uint8_t *buf, int len)
+{
+ int i;
+
+ for (i = 0; i < len; i++)
+ if (buf[i] != 0xff)
+ return 0;
+ return 1;
+}
+
+/**
+ * dbg_is_nnode_dirty - determine if a nnode is dirty.
+ * @c: the UBIFS file-system description object
+ * @lnum: LEB number where nnode was written
+ * @offs: offset where nnode was written
+ */
+static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ struct ubifs_nnode *nnode;
+ int hght;
+
+ /* Entire tree is in memory so first_nnode / next_nnode are OK */
+ nnode = first_nnode(c, &hght);
+ for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
+ struct ubifs_nbranch *branch;
+
+ cond_resched();
+ if (nnode->parent) {
+ branch = &nnode->parent->nbranch[nnode->iip];
+ if (branch->lnum != lnum || branch->offs != offs)
+ continue;
+ if (test_bit(DIRTY_CNODE, &nnode->flags))
+ return 1;
+ return 0;
+ } else {
+ if (c->lpt_lnum != lnum || c->lpt_offs != offs)
+ continue;
+ if (test_bit(DIRTY_CNODE, &nnode->flags))
+ return 1;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+/**
+ * dbg_is_pnode_dirty - determine if a pnode is dirty.
+ * @c: the UBIFS file-system description object
+ * @lnum: LEB number where pnode was written
+ * @offs: offset where pnode was written
+ */
+static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ int i, cnt;
+
+ cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
+ for (i = 0; i < cnt; i++) {
+ struct ubifs_pnode *pnode;
+ struct ubifs_nbranch *branch;
+
+ cond_resched();
+ pnode = pnode_lookup(c, i);
+ if (IS_ERR(pnode))
+ return PTR_ERR(pnode);
+ branch = &pnode->parent->nbranch[pnode->iip];
+ if (branch->lnum != lnum || branch->offs != offs)
+ continue;
+ if (test_bit(DIRTY_CNODE, &pnode->flags))
+ return 1;
+ return 0;
+ }
+ return 1;
+}
+
+/**
+ * dbg_is_ltab_dirty - determine if a ltab node is dirty.
+ * @c: the UBIFS file-system description object
+ * @lnum: LEB number where ltab node was written
+ * @offs: offset where ltab node was written
+ */
+static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ if (lnum != c->ltab_lnum || offs != c->ltab_offs)
+ return 1;
+ return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
+}
+
+/**
+ * dbg_is_lsave_dirty - determine if a lsave node is dirty.
+ * @c: the UBIFS file-system description object
+ * @lnum: LEB number where lsave node was written
+ * @offs: offset where lsave node was written
+ */
+static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
+{
+ if (lnum != c->lsave_lnum || offs != c->lsave_offs)
+ return 1;
+ return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
+}
+
+/**
+ * dbg_is_node_dirty - determine if a node is dirty.
+ * @c: the UBIFS file-system description object
+ * @node_type: node type
+ * @lnum: LEB number where node was written
+ * @offs: offset where node was written
+ */
+static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
+ int offs)
+{
+ switch (node_type) {
+ case UBIFS_LPT_NNODE:
+ return dbg_is_nnode_dirty(c, lnum, offs);
+ case UBIFS_LPT_PNODE:
+ return dbg_is_pnode_dirty(c, lnum, offs);
+ case UBIFS_LPT_LTAB:
+ return dbg_is_ltab_dirty(c, lnum, offs);
+ case UBIFS_LPT_LSAVE:
+ return dbg_is_lsave_dirty(c, lnum, offs);
+ }
+ return 1;
+}
+
+/**
+ * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
+ * @c: the UBIFS file-system description object
+ * @lnum: LEB number where node was written
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
+{
+ int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
+ int ret;
+ void *buf, *p;
+
+ if (!dbg_is_chk_lprops(c))
+ return 0;
+
+ buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
+ if (!buf) {
+ ubifs_err(c, "cannot allocate memory for ltab checking");
+ return 0;
+ }
+
+ dbg_lp("LEB %d", lnum);
+
+ err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
+ if (err)
+ goto out;
+
+ while (1) {
+ if (!is_a_node(c, p, len)) {
+ int i, pad_len;
+
+ pad_len = get_pad_len(c, p, len);
+ if (pad_len) {
+ p += pad_len;
+ len -= pad_len;
+ dirty += pad_len;
+ continue;
+ }
+ if (!dbg_is_all_ff(p, len)) {
+ ubifs_err(c, "invalid empty space in LEB %d at %d",
+ lnum, c->leb_size - len);
+ err = -EINVAL;
+ }
+ i = lnum - c->lpt_first;
+ if (len != c->ltab[i].free) {
+ ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)",
+ lnum, len, c->ltab[i].free);
+ err = -EINVAL;
+ }
+ if (dirty != c->ltab[i].dirty) {
+ ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)",
+ lnum, dirty, c->ltab[i].dirty);
+ err = -EINVAL;
+ }
+ goto out;
+ }
+ node_type = get_lpt_node_type(c, p, &node_num);
+ node_len = get_lpt_node_len(c, node_type);
+ ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
+ if (ret == 1)
+ dirty += node_len;
+ p += node_len;
+ len -= node_len;
+ }
+
+ err = 0;
+out:
+ vfree(buf);
+ return err;
+}
+
+/**
+ * dbg_check_ltab - check the free and dirty space in the ltab.
+ * @c: the UBIFS file-system description object
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_check_ltab(struct ubifs_info *c)
+{
+ int lnum, err, i, cnt;
+
+ if (!dbg_is_chk_lprops(c))
+ return 0;
+
+ /* Bring the entire tree into memory */
+ cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
+ for (i = 0; i < cnt; i++) {
+ struct ubifs_pnode *pnode;
+
+ pnode = pnode_lookup(c, i);
+ if (IS_ERR(pnode))
+ return PTR_ERR(pnode);
+ cond_resched();
+ }
+
+ /* Check nodes */
+ err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
+ if (err)
+ return err;
+
+ /* Check each LEB */
+ for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
+ err = dbg_check_ltab_lnum(c, lnum);
+ if (err) {
+ ubifs_err(c, "failed at LEB %d", lnum);
+ return err;
+ }
+ }
+
+ dbg_lp("succeeded");
+ return 0;
+}
+
+/**
+ * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
+ * @c: the UBIFS file-system description object
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int dbg_chk_lpt_free_spc(struct ubifs_info *c)
+{
+ long long free = 0;
+ int i;
+
+ if (!dbg_is_chk_lprops(c))
+ return 0;
+
+ for (i = 0; i < c->lpt_lebs; i++) {
+ if (c->ltab[i].tgc || c->ltab[i].cmt)
+ continue;
+ if (i + c->lpt_first == c->nhead_lnum)
+ free += c->leb_size - c->nhead_offs;
+ else if (c->ltab[i].free == c->leb_size)
+ free += c->leb_size;
+ }
+ if (free < c->lpt_sz) {
+ ubifs_err(c, "LPT space error: free %lld lpt_sz %lld",
+ free, c->lpt_sz);
+ ubifs_dump_lpt_info(c);
+ ubifs_dump_lpt_lebs(c);
+ dump_stack();
+ return -EINVAL;
+ }
+ return 0;
+}
+
+/**
+ * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
+ * @c: the UBIFS file-system description object
+ * @action: what to do
+ * @len: length written
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ * The @action argument may be one of:
+ * o %0 - LPT debugging checking starts, initialize debugging variables;
+ * o %1 - wrote an LPT node, increase LPT size by @len bytes;
+ * o %2 - switched to a different LEB and wasted @len bytes;
+ * o %3 - check that we've written the right number of bytes.
+ * o %4 - wasted @len bytes;
+ */
+int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
+{
+ struct ubifs_debug_info *d = c->dbg;
+ long long chk_lpt_sz, lpt_sz;
+ int err = 0;
+
+ if (!dbg_is_chk_lprops(c))
+ return 0;
+
+ switch (action) {
+ case 0:
+ d->chk_lpt_sz = 0;
+ d->chk_lpt_sz2 = 0;
+ d->chk_lpt_lebs = 0;
+ d->chk_lpt_wastage = 0;
+ if (c->dirty_pn_cnt > c->pnode_cnt) {
+ ubifs_err(c, "dirty pnodes %d exceed max %d",
+ c->dirty_pn_cnt, c->pnode_cnt);
+ err = -EINVAL;
+ }
+ if (c->dirty_nn_cnt > c->nnode_cnt) {
+ ubifs_err(c, "dirty nnodes %d exceed max %d",
+ c->dirty_nn_cnt, c->nnode_cnt);
+ err = -EINVAL;
+ }
+ return err;
+ case 1:
+ d->chk_lpt_sz += len;
+ return 0;
+ case 2:
+ d->chk_lpt_sz += len;
+ d->chk_lpt_wastage += len;
+ d->chk_lpt_lebs += 1;
+ return 0;
+ case 3:
+ chk_lpt_sz = c->leb_size;
+ chk_lpt_sz *= d->chk_lpt_lebs;
+ chk_lpt_sz += len - c->nhead_offs;
+ if (d->chk_lpt_sz != chk_lpt_sz) {
+ ubifs_err(c, "LPT wrote %lld but space used was %lld",
+ d->chk_lpt_sz, chk_lpt_sz);
+ err = -EINVAL;
+ }
+ if (d->chk_lpt_sz > c->lpt_sz) {
+ ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld",
+ d->chk_lpt_sz, c->lpt_sz);
+ err = -EINVAL;
+ }
+ if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
+ ubifs_err(c, "LPT layout size %lld but wrote %lld",
+ d->chk_lpt_sz, d->chk_lpt_sz2);
+ err = -EINVAL;
+ }
+ if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
+ ubifs_err(c, "LPT new nhead offs: expected %d was %d",
+ d->new_nhead_offs, len);
+ err = -EINVAL;
+ }
+ lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
+ lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
+ lpt_sz += c->ltab_sz;
+ if (c->big_lpt)
+ lpt_sz += c->lsave_sz;
+ if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
+ ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
+ d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
+ err = -EINVAL;
+ }
+ if (err) {
+ ubifs_dump_lpt_info(c);
+ ubifs_dump_lpt_lebs(c);
+ dump_stack();
+ }
+ d->chk_lpt_sz2 = d->chk_lpt_sz;
+ d->chk_lpt_sz = 0;
+ d->chk_lpt_wastage = 0;
+ d->chk_lpt_lebs = 0;
+ d->new_nhead_offs = len;
+ return err;
+ case 4:
+ d->chk_lpt_sz += len;
+ d->chk_lpt_wastage += len;
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+/**
+ * dump_lpt_leb - dump an LPT LEB.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number to dump
+ *
+ * This function dumps an LEB from LPT area. Nodes in this area are very
+ * different to nodes in the main area (e.g., they do not have common headers,
+ * they do not have 8-byte alignments, etc), so we have a separate function to
+ * dump LPT area LEBs. Note, LPT has to be locked by the caller.
+ */
+static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
+{
+ int err, len = c->leb_size, node_type, node_num, node_len, offs;
+ void *buf, *p;
+
+ pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum);
+ buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL);
+ if (!buf) {
+ ubifs_err(c, "cannot allocate memory to dump LPT");
+ return;
+ }
+
+ err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1);
+ if (err)
+ goto out;
+
+ while (1) {
+ offs = c->leb_size - len;
+ if (!is_a_node(c, p, len)) {
+ int pad_len;
+
+ pad_len = get_pad_len(c, p, len);
+ if (pad_len) {
+ pr_err("LEB %d:%d, pad %d bytes\n",
+ lnum, offs, pad_len);
+ p += pad_len;
+ len -= pad_len;
+ continue;
+ }
+ if (len)
+ pr_err("LEB %d:%d, free %d bytes\n",
+ lnum, offs, len);
+ break;
+ }
+
+ node_type = get_lpt_node_type(c, p, &node_num);
+ switch (node_type) {
+ case UBIFS_LPT_PNODE:
+ {
+ node_len = c->pnode_sz;
+ if (c->big_lpt)
+ pr_err("LEB %d:%d, pnode num %d\n",
+ lnum, offs, node_num);
+ else
+ pr_err("LEB %d:%d, pnode\n", lnum, offs);
+ break;
+ }
+ case UBIFS_LPT_NNODE:
+ {
+ int i;
+ struct ubifs_nnode nnode;
+
+ node_len = c->nnode_sz;
+ if (c->big_lpt)
+ pr_err("LEB %d:%d, nnode num %d, ",
+ lnum, offs, node_num);
+ else
+ pr_err("LEB %d:%d, nnode, ",
+ lnum, offs);
+ err = ubifs_unpack_nnode(c, p, &nnode);
+ if (err) {
+ pr_err("failed to unpack_node, error %d\n",
+ err);
+ break;
+ }
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ pr_cont("%d:%d", nnode.nbranch[i].lnum,
+ nnode.nbranch[i].offs);
+ if (i != UBIFS_LPT_FANOUT - 1)
+ pr_cont(", ");
+ }
+ pr_cont("\n");
+ break;
+ }
+ case UBIFS_LPT_LTAB:
+ node_len = c->ltab_sz;
+ pr_err("LEB %d:%d, ltab\n", lnum, offs);
+ break;
+ case UBIFS_LPT_LSAVE:
+ node_len = c->lsave_sz;
+ pr_err("LEB %d:%d, lsave len\n", lnum, offs);
+ break;
+ default:
+ ubifs_err(c, "LPT node type %d not recognized", node_type);
+ goto out;
+ }
+
+ p += node_len;
+ len -= node_len;
+ }
+
+ pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum);
+out:
+ vfree(buf);
+ return;
+}
+
+/**
+ * ubifs_dump_lpt_lebs - dump LPT lebs.
+ * @c: UBIFS file-system description object
+ *
+ * This function dumps all LPT LEBs. The caller has to make sure the LPT is
+ * locked.
+ */
+void ubifs_dump_lpt_lebs(const struct ubifs_info *c)
+{
+ int i;
+
+ pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid);
+ for (i = 0; i < c->lpt_lebs; i++)
+ dump_lpt_leb(c, i + c->lpt_first);
+ pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid);
+}
+
+/**
+ * dbg_populate_lsave - debugging version of 'populate_lsave()'
+ * @c: UBIFS file-system description object
+ *
+ * This is a debugging version for 'populate_lsave()' which populates lsave
+ * with random LEBs instead of useful LEBs, which is good for test coverage.
+ * Returns zero if lsave has not been populated (this debugging feature is
+ * disabled) an non-zero if lsave has been populated.
+ */
+static int dbg_populate_lsave(struct ubifs_info *c)
+{
+ struct ubifs_lprops *lprops;
+ struct ubifs_lpt_heap *heap;
+ int i;
+
+ if (!dbg_is_chk_gen(c))
+ return 0;
+ if (prandom_u32() & 3)
+ return 0;
+
+ for (i = 0; i < c->lsave_cnt; i++)
+ c->lsave[i] = c->main_first;
+
+ list_for_each_entry(lprops, &c->empty_list, list)
+ c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+ list_for_each_entry(lprops, &c->freeable_list, list)
+ c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+ list_for_each_entry(lprops, &c->frdi_idx_list, list)
+ c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum;
+
+ heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
+ for (i = 0; i < heap->cnt; i++)
+ c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+ heap = &c->lpt_heap[LPROPS_DIRTY - 1];
+ for (i = 0; i < heap->cnt; i++)
+ c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+ heap = &c->lpt_heap[LPROPS_FREE - 1];
+ for (i = 0; i < heap->cnt; i++)
+ c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum;
+
+ return 1;
+}