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Message-Id: <1210070159-22794-20-git-send-email-Artem.Bityutskiy@nokia.com>
Date: Tue, 6 May 2008 13:35:50 +0300
From: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Adrian Hunter <ext-adrian.hunter@...ia.com>,
Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Subject: [PATCH take 2 19/28] UBIFS: add LEB properties tree
This is the commit-related part of the lprops sub-system.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@...ia.com>
---
fs/ubifs/lpt_commit.c | 1625 +++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1625 insertions(+), 0 deletions(-)
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c
new file mode 100644
index 0000000..797c56d
--- /dev/null
+++ b/fs/ubifs/lpt_commit.c
@@ -0,0 +1,1625 @@
+/*
+ * 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 "ubifs.h"
+
+/**
+ * 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(struct ubifs_nnode *nnode)
+{
+ ubifs_assert(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.
+ * @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(struct ubifs_cnode *cnode)
+{
+ struct ubifs_nnode *nnode;
+ int i;
+
+ ubifs_assert(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((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->nroot);
+ cnode = c->lpt_cnext;
+ if (!cnode)
+ return 0;
+ cnt += 1;
+ while (1) {
+ ubifs_assert(!test_bit(COW_ZNODE, &cnode->flags));
+ set_bit(COW_ZNODE, &cnode->flags);
+ cnext = next_dirty_cnode(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(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(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;
+ }
+ }
+ dbg_err("last LEB %d", *lnum);
+ dump_stack();
+ 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;
+
+ 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;
+ }
+
+ if (offs + c->ltab_sz <= c->leb_size) {
+ done_ltab = 1;
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += 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);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ ubifs_assert(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;
+ continue;
+ }
+ if (!done_ltab) {
+ done_ltab = 1;
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += 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;
+ 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);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ ubifs_assert(lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ }
+ done_lsave = 1;
+ c->lsave_lnum = lnum;
+ c->lsave_offs = offs;
+ offs += 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);
+ err = alloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ ubifs_assert(lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ }
+ done_ltab = 1;
+ c->ltab_lnum = lnum;
+ c->ltab_offs = offs;
+ offs += c->ltab_sz;
+ }
+
+ alen = ALIGN(offs, c->min_io_size);
+ upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
+ return 0;
+}
+
+/**
+ * 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;
+ }
+ dbg_err("last LEB %d", *lnum);
+ dump_stack();
+ 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;
+ }
+
+ if (offs + c->ltab_sz <= c->leb_size) {
+ done_ltab = 1;
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += 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, UBI_SHORTTERM);
+ if (err)
+ return err;
+ }
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ from = 0;
+ ubifs_assert(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;
+ continue;
+ }
+ if (!done_ltab) {
+ done_ltab = 1;
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += 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);
+ clear_bit(DIRTY_CNODE, &cnode->flags);
+ smp_mb__before_clear_bit();
+ clear_bit(COW_ZNODE, &cnode->flags);
+ smp_mb__after_clear_bit();
+ offs += 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,
+ UBI_SHORTTERM);
+ if (err)
+ return err;
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ ubifs_assert(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;
+ }
+
+ /* 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,
+ UBI_SHORTTERM);
+ if (err)
+ return err;
+ err = realloc_lpt_leb(c, &lnum);
+ if (err)
+ return err;
+ offs = 0;
+ ubifs_assert(lnum >= c->lpt_first &&
+ lnum <= c->lpt_last);
+ err = ubifs_leb_unmap(c, lnum);
+ if (err)
+ return err;
+ }
+ done_ltab = 1;
+ ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
+ offs += 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, UBI_SHORTTERM);
+ 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;
+}
+
+/**
+ * next_pnode - find next pnode.
+ * @c: UBIFS file-system description object
+ * @pnode: pnode
+ *
+ * This function returns the next pnode or %NULL if there are no more pnodes.
+ */
+static struct ubifs_pnode *next_pnode(struct ubifs_info *c,
+ struct ubifs_pnode *pnode)
+{
+ struct ubifs_nnode *nnode;
+ int iip;
+
+ /* Try to go right */
+ nnode = pnode->parent;
+ iip = pnode->iip + 1;
+ if (iip < UBIFS_LPT_FANOUT) {
+ /* We assume here that LEB zero is never an LPT LEB */
+ if (nnode->nbranch[iip].lnum)
+ return ubifs_get_pnode(c, nnode, iip);
+ else
+ return NULL;
+ }
+
+ /* Go up while can't go right */
+ do {
+ iip = nnode->iip + 1;
+ nnode = nnode->parent;
+ if (!nnode)
+ return NULL;
+ /* We assume here that LEB zero is never an LPT LEB */
+ } while (iip >= UBIFS_LPT_FANOUT || !nnode->nbranch[iip].lnum);
+
+ /* 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) {
+ nnode = ubifs_get_nnode(c, nnode, 0);
+ if (IS_ERR(nnode))
+ return (void *)nnode;
+ }
+
+ return ubifs_get_pnode(c, nnode, 0);
+}
+
+/**
+ * pnode_lookup - lookup a pnode in the LPT.
+ * @c: UBIFS file-system description object
+ * @i: pnode number (0 to main_lebs - 1)
+ *
+ * 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_PTR(PTR_ERR(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);
+ while (pnode) {
+ do_make_pnode_dirty(c, pnode);
+ pnode = next_pnode(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 unmaps 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->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);
+ }
+ 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;
+}
+
+/**
+ * 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_check_ltab(c);
+ if (err)
+ goto out;
+
+ 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(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;
+}
+
+/**
+ * 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(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(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(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(&addr, &pos, UBIFS_LPT_TYPE_BITS);
+ *node_num = ubifs_unpack_bits(&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(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;
+
+ node_type = ubifs_unpack_bits(&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(&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 = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
+ if (err) {
+ ubifs_err("cannot read LEB %d, error %d", lnum, 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(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->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_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);
+}
+
+#ifdef CONFIG_UBIFS_FS_DEBUG
+
+/**
+ * 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
+ * @offs: offset 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 = c->dbg_buf;
+
+ dbg_lp("LEB %d", lnum);
+ err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
+ if (err) {
+ dbg_msg("ubi_read failed, LEB %d, error %d", lnum, err);
+ return err;
+ }
+ while (1) {
+ if (!is_a_node(c, buf, len)) {
+ int i, pad_len;
+
+ pad_len = get_pad_len(c, buf, len);
+ if (pad_len) {
+ buf += pad_len;
+ len -= pad_len;
+ dirty += pad_len;
+ continue;
+ }
+ if (!dbg_is_all_ff(buf, len)) {
+ dbg_msg("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) {
+ dbg_msg("invalid free space in LEB %d "
+ "(free %d, expected %d)",
+ lnum, len, c->ltab[i].free);
+ err = -EINVAL;
+ }
+ if (dirty != c->ltab[i].dirty) {
+ dbg_msg("invalid dirty space in LEB %d "
+ "(dirty %d, expected %d)",
+ lnum, dirty, c->ltab[i].dirty);
+ err = -EINVAL;
+ }
+ return err;
+ }
+ node_type = get_lpt_node_type(c, buf, &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;
+ buf += node_len;
+ len -= node_len;
+ }
+}
+
+/**
+ * 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 (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
+ 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) {
+ dbg_err("failed at LEB %d", lnum);
+ return err;
+ }
+ }
+
+ dbg_lp("succeeded");
+ return 0;
+}
+
+#endif /* CONFIG_UBIFS_FS_DEBUG */
--
1.5.4.1
--
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