- 根目录:
- fs
- ubifs
- replay.c
/*
* 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 contains journal replay code. It runs when the file-system is being
* mounted and requires no locking.
*
* The larger is the journal, the longer it takes to scan it, so the longer it
* takes to mount UBIFS. This is why the journal has limited size which may be
* changed depending on the system requirements. But a larger journal gives
* faster I/O speed because it writes the index less frequently. So this is a
* trade-off. Also, the journal is indexed by the in-memory index (TNC), so the
* larger is the journal, the more memory its index may consume.
*/
#include "ubifs.h"
#include <linux/list_sort.h>
/**
* struct replay_entry - replay list entry.
* @lnum: logical eraseblock number of the node
* @offs: node offset
* @len: node length
* @deletion: non-zero if this entry corresponds to a node deletion
* @sqnum: node sequence number
* @list: links the replay list
* @key: node key
* @nm: directory entry name
* @old_size: truncation old size
* @new_size: truncation new size
*
* The replay process first scans all buds and builds the replay list, then
* sorts the replay list in nodes sequence number order, and then inserts all
* the replay entries to the TNC.
*/
struct replay_entry {
int lnum;
int offs;
int len;
unsigned int deletion:1;
unsigned long long sqnum;
struct list_head list;
union ubifs_key key;
union {
struct qstr nm;
struct {
loff_t old_size;
loff_t new_size;
};
};
};
/**
* struct bud_entry - entry in the list of buds to replay.
* @list: next bud in the list
* @bud: bud description object
* @sqnum: reference node sequence number
* @free: free bytes in the bud
* @dirty: dirty bytes in the bud
*/
struct bud_entry {
struct list_head list;
struct ubifs_bud *bud;
unsigned long long sqnum;
int free;
int dirty;
};
/**
* set_bud_lprops - set free and dirty space used by a bud.
* @c: UBIFS file-system description object
* @b: bud entry which describes the bud
*
* This function makes sure the LEB properties of bud @b are set correctly
* after the replay. Returns zero in case of success and a negative error code
* in case of failure.
*/
static int set_bud_lprops(struct ubifs_info *c, struct bud_entry *b)
{
const struct ubifs_lprops *lp;
int err = 0, dirty;
ubifs_get_lprops(c);
lp = ubifs_lpt_lookup_dirty(c, b->bud->lnum);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
dirty = lp->dirty;
if (b->bud->start == 0 && (lp->free != c->leb_size || lp->dirty != 0)) {
/*
* The LEB was added to the journal with a starting offset of
* zero which means the LEB must have been empty. The LEB
* property values should be @lp->free == @c->leb_size and
* @lp->dirty == 0, but that is not the case. The reason is that
* the LEB had been garbage collected before it became the bud,
* and there was not commit inbetween. The garbage collector
* resets the free and dirty space without recording it
* anywhere except lprops, so if there was no commit then
* lprops does not have that information.
*
* We do not need to adjust free space because the scan has told
* us the exact value which is recorded in the replay entry as
* @b->free.
*
* However we do need to subtract from the dirty space the
* amount of space that the garbage collector reclaimed, which
* is the whole LEB minus the amount of space that was free.
*/
dbg_mnt("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
lp->free, lp->dirty);
dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", b->bud->lnum,
lp->free, lp->dirty);
dirty -= c->leb_size - lp->free;
/*
* If the replay order was perfect the dirty space would now be
* zero. The order is not perfect because the journal heads
* race with each other. This is not a problem but is does mean
* that the dirty space may temporarily exceed c->leb_size
* during the replay.
*/
if (dirty != 0)
dbg_mnt("LEB %d lp: %d free %d dirty replay: %d free %d dirty",
b->bud->lnum, lp->free, lp->dirty, b->free,
b->dirty);
}
lp = ubifs_change_lp(c, lp, b->free, dirty + b->dirty,
lp->flags | LPROPS_TAKEN, 0);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
/* Make sure the journal head points to the latest bud */
err = ubifs_wbuf_seek_nolock(&c->jheads[b->bud->jhead].wbuf,
b->bud->lnum, c->leb_size - b->free);
out:
ubifs_release_lprops(c);
return err;
}
/**
* set_buds_lprops - set free and dirty space for all replayed buds.
* @c: UBIFS file-system description object
*
* This function sets LEB properties for all replayed buds. Returns zero in
* case of success and a negative error code in case of failure.
*/
static int set_buds_lprops(struct ubifs_info *c)
{
struct bud_entry *b;
int err;
list_for_each_entry(b, &c->replay_buds, list) {
err = set_bud_lprops(c, b);
if (err)
return err;
}
return 0;
}
/**
* trun_remove_range - apply a replay entry for a truncation to the TNC.
* @c: UBIFS file-system description object
* @r: replay entry of truncation
*/
static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
{
unsigned min_blk, max_blk;
union ubifs_key min_key, max_key;
ino_t ino;
min_blk = r->new_size / UBIFS_BLOCK_SIZE;
if (r->new_size & (UBIFS_BLOCK_SIZE - 1))
min_blk += 1;
max_blk = r->old_size / UBIFS_BLOCK_SIZE;
if ((r->old_size & (UBIFS_BLOCK_SIZE - 1)) == 0)
max_blk -= 1;
ino = key_inum(c, &r->key);
data_key_init(c, &min_key, ino, min_blk);
data_key_init(c, &max_key, ino, max_blk);
return ubifs_tnc_remove_range(c, &min_key, &max_key);
}
/**
* apply_replay_entry - apply a replay entry to the TNC.
* @c: UBIFS file-system description object
* @r: replay entry to apply
*
* Apply a replay entry to the TNC.
*/
static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
{
int err;
dbg_mntk(&r->key, "LEB %d:%d len %d deletion %d sqnum %llu key ",
r->lnum, r->offs, r->len, r->deletion, r->sqnum);
/* Set c->replay_sqnum to help deal with dangling branches. */
c->replay_sqnum = r->sqnum;
if (is_hash_key(c, &r->key)) {
if (r->deletion)
err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
else
err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
r->len, &r->nm);
} else {
if (r->deletion)
switch (key_type(c, &r->key)) {
case UBIFS_INO_KEY:
{
ino_t inum = key_inum(c, &r->key);
err = ubifs_tnc_remove_ino(c, inum);
break;
}
case UBIFS_TRUN_KEY:
err = trun_remove_range(c, r);
break;
default:
err = ubifs_tnc_remove(c, &r->key);
break;
}
else
err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
r->len);
if (err)
return err;
if (c->need_recovery)
err = ubifs_recover_size_accum(c, &r->key, r->deletion,
r->new_size);
}
return err;
}
/**
* replay_entries_cmp - compare 2 replay entries.
* @priv: UBIFS file-system description object
* @a: first replay entry
* @a: second replay entry
*
* This is a comparios function for 'list_sort()' which compares 2 replay
* entries @a and @b by comparing their sequence numer. Returns %1 if @a has
* greater sequence number and %-1 otherwise.
*/
static int replay_entries_cmp(void *priv, struct list_head *a,
struct list_head *b)
{
struct replay_entry *ra, *rb;
cond_resched();
if (a == b)
return 0;
ra = list_entry(a, struct replay_entry, list);
rb = list_entry(b, struct replay_entry, list);
ubifs_assert(ra->sqnum != rb->sqnum);
if (ra->sqnum > rb->sqnum)
return 1;
return -1;
}
/**
* apply_replay_list - apply the replay list to the TNC.
* @c: UBIFS file-system description object
*
* Apply all entries in the replay list to the TNC. Returns zero in case of
* success and a negative error code in case of failure.
*/
static int apply_replay_list(struct ubifs_info *c)
{
struct replay_entry *r;
int err;
list_sort(c, &c->replay_list, &replay_entries_cmp);
list_for_each_entry(r, &c->replay_list, list) {
cond_resched();
err = apply_replay_entry(c, r);
if (err)
return err;
}
return 0;
}
/**
* destroy_replay_list - destroy the replay.
* @c: UBIFS file-system description object
*
* Destroy the replay list.
*/
static void destroy_replay_list(struct ubifs_info *c)
{
struct replay_entry *r, *tmp;
list_for_each_entry_safe(r, tmp, &c->replay_list, list) {
if (is_hash_key(c, &r->key))
kfree(r->nm.name);
list_del(&r->list);
kfree(r);
}
}
/**
* insert_node - insert a node to the replay list
* @c: UBIFS file-system description object
* @lnum: node logical eraseblock number
* @offs: node offset
* @len: node length
* @key: node key
* @sqnum: sequence number
* @deletion: non-zero if this is a deletion
* @used: number of bytes in use in a LEB
* @old_size: truncation old size
* @new_size: truncation new size
*
* This function inserts a scanned non-direntry node to the replay list. The
* replay list contains @struct replay_entry elements, and we sort this list in
* sequence number order before applying it. The replay list is applied at the
* very end of the replay process. Since the list is sorted in sequence number
* order, the older modifications are applied first. This function returns zero
* in case of success and a negative error code in case of failure.
*/
static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
union ubifs_key *key, unsigned long long sqnum,
int deletion, int *used, loff_t old_size,
loff_t new_size)
{
struct replay_entry *r;
dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
if (key_inum(c, key) >= c->highest_inum)
c->highest_inum = key_inum(c, key);
r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
if (!r)
return -ENOMEM;
if (!deletion)
*used += ALIGN(len, 8);
r->lnum = lnum;
r->offs = offs;
r->len = len;
r->deletion = !!deletion;
r->sqnum = sqnum;
key_copy(c, key, &r->key);
r->old_size = old_size;
r->new_size = new_size;
list_add_tail(&r->list, &c->replay_list);
return 0;
}
/**
* insert_dent - insert a directory entry node into the replay list.
* @c: UBIFS file-system description object
* @lnum: node logical eraseblock number
* @offs: node offset
* @len: node length
* @key: node key
* @name: directory entry name
* @nlen: directory entry name length
* @sqnum: sequence number
* @deletion: non-zero if this is a deletion
* @used: number of bytes in use in a LEB
*
* This function inserts a scanned directory entry node or an extended
* attribute entry to the replay list. Returns zero in case of success and a
* negative error code in case of failure.
*/
static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
union ubifs_key *key, const char *name, int nlen,
unsigned long long sqnum, int deletion, int *used)
{
struct replay_entry *r;
char *nbuf;
dbg_mntk(key, "add LEB %d:%d, key ", lnum, offs);
if (key_inum(c, key) >= c->highest_inum)
c->highest_inum = key_inum(c, key);
r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
if (!r)
return -ENOMEM;
nbuf = kmalloc(nlen + 1, GFP_KERNEL);
if (!nbuf) {
kfree(r);
return -ENOMEM;
}
if (!deletion)
*used += ALIGN(len, 8);
r->lnum = lnum;
r->offs = offs;
r->len = len;
r->deletion = !!deletion;
r->sqnum = sqnum;
key_copy(c, key, &r->key);
r->nm.len = nlen;
memcpy(nbuf, name, nlen);
nbuf[nlen] = '\0';
r->nm.name = nbuf;
list_add_tail(&r->list, &c->replay_list);
return 0;
}
/**
* ubifs_validate_entry - validate directory or extended attribute entry node.
* @c: UBIFS file-system description object
* @dent: the node to validate
*
* This function validates directory or extended attribute entry node @dent.
* Returns zero if the node is all right and a %-EINVAL if not.
*/
int ubifs_validate_entry(struct ubifs_info *c,
const struct ubifs_dent_node *dent)
{
int key_type = key_type_flash(c, dent->key);
int nlen = le16_to_cpu(dent->nlen);
if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
dent->type >= UBIFS_ITYPES_CNT ||
nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
strnlen(dent->name, nlen) != nlen ||
le64_to_cpu(dent->inum) > MAX_INUM) {
ubifs_err(c, "bad %s node", key_type == UBIFS_DENT_KEY ?
"directory entry" : "extended attribute entry");
return -EINVAL;
}
if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
ubifs_err(c, "bad key type %d", key_type);
return -EINVAL;
}
return 0;
}
/**
* is_last_bud - check if the bud is the last in the journal head.
* @c: UBIFS file-system description object
* @bud: bud description object
*
* This function checks if bud @bud is the last bud in its journal head. This
* information is then used by 'replay_bud()' to decide whether the bud can
* have corruptions or not. Indeed, only last buds can be corrupted by power
* cuts. Returns %1 if this is the last bud, and %0 if not.
*/
static int is_last_bud(struct ubifs_info *c, struct ubifs_bud *bud)
{
struct ubifs_jhead *jh = &c->jheads[bud->jhead];
struct ubifs_bud *next;
uint32_t data;
int err;
if (list_is_last(&bud->list, &jh->buds_list))
return 1;
/*
* The following is a quirk to make sure we work correctly with UBIFS
* images used with older UBIFS.
*
* Normally, the last bud will be the last in the journal head's list
* of bud. However, there is one exception if the UBIFS image belongs
* to older UBIFS. This is fairly unlikely: one would need to use old
* UBIFS, then have a power cut exactly at the right point, and then
* try to mount this image with new UBIFS.
*
* The exception is: it is possible to have 2 buds A and B, A goes
* before B, and B is the last, bud B is contains no data, and bud A is
* corrupted at the end. The reason is that in older versions when the
* journal code switched the next bud (from A to B), it first added a
* log reference node for the new bud (B), and only after this it
* synchronized the write-buffer of current bud (A). But later this was
* changed and UBIFS started to always synchronize the write-buffer of
* the bud (A) before writing the log reference for the new bud (B).
*
* But because older UBIFS always synchronized A's write-buffer before
* writing to B, we can recognize this exceptional situation but
* checking the contents of bud B - if it is empty, then A can be
* treated as the last and we can recover it.
*
* TODO: remove this piece of code in a couple of years (today it is
* 16.05.2011).
*/
next = list_entry(bud->list.next, struct ubifs_bud, list);
if (!list_is_last(&next->list, &jh->buds_list))
return 0;
err = ubifs_leb_read(c, next->lnum, (char *)&data, next->start, 4, 1);
if (err)
return 0;
return data == 0xFFFFFFFF;
}
/**
* replay_bud - replay a bud logical eraseblock.
* @c: UBIFS file-system description object
* @b: bud entry which describes the bud
*
* This function replays bud @bud, recovers it if needed, and adds all nodes
* from this bud to the replay list. Returns zero in case of success and a
* negative error code in case of failure.
*/
static int replay_bud(struct ubifs_info *c, struct bud_entry *b)
{
int is_last = is_last_bud(c, b->bud);
int err = 0, used = 0, lnum = b->bud->lnum, offs = b->bud->start;
struct ubifs_scan_leb *sleb;
struct ubifs_scan_node *snod;
dbg_mnt("replay bud LEB %d, head %d, offs %d, is_last %d",
lnum, b->bud->jhead, offs, is_last);
if (c->need_recovery && is_last)
/*
* Recover only last LEBs in the journal heads, because power
* cuts may cause corruptions only in these LEBs, because only
* these LEBs could possibly be written to at the power cut
* time.
*/
sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, b->bud->jhead);
else
sleb = ubifs_scan(c, lnum, offs, c->sbuf, 0);
if (IS_ERR(sleb))
return PTR_ERR(sleb);
/*
* The bud does not have to start from offset zero - the beginning of
* the 'lnum' LEB may contain previously committed data. One of the
* things we have to do in replay is to correctly update lprops with
* newer information about this LEB.
*
* At this point lprops thinks that this LEB has 'c->leb_size - offs'
* bytes of free space because it only contain information about
* committed data.
*
* But we know that real amount of free space is 'c->leb_size -
* sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
* 'sleb->endpt' is used by bud data. We have to correctly calculate
* how much of these data are dirty and update lprops with this
* information.
*
* The dirt in that LEB region is comprised of padding nodes, deletion
* nodes, truncation nodes and nodes which are obsoleted by subsequent
* nodes in this LEB. So instead of calculating clean space, we
* calculate used space ('used' variable).
*/
list_for_each_entry(snod, &sleb->nodes, list) {
int deletion = 0;
cond_resched();
if (snod->sqnum >= SQNUM_WATERMARK) {
ubifs_err(c, "file system's life ended");
goto out_dump;
}
if (snod->sqnum > c->max_sqnum)
c->max_sqnum = snod->sqnum;
switch (snod->type) {
case UBIFS_INO_NODE:
{
struct ubifs_ino_node *ino = snod->node;
loff_t new_size = le64_to_cpu(ino->size);
if (le32_to_cpu(ino->nlink) == 0)
deletion = 1;
err = insert_node(c, lnum, snod->offs, snod->len,
&snod->key, snod->sqnum, deletion,
&used, 0, new_size);
break;
}
case UBIFS_DATA_NODE:
{
struct ubifs_data_node *dn = snod->node;
loff_t new_size = le32_to_cpu(dn->size) +
key_block(c, &snod->key) *
UBIFS_BLOCK_SIZE;
err = insert_node(c, lnum, snod->offs, snod->len,
&snod->key, snod->sqnum, deletion,
&used, 0, new_size);
break;
}
case UBIFS_DENT_NODE:
case UBIFS_XENT_NODE:
{
struct ubifs_dent_node *dent = snod->node;
err = ubifs_validate_entry(c, dent);
if (err)
goto out_dump;
err = insert_dent(c, lnum, snod->offs, snod->len,
&snod->key, dent->name,
le16_to_cpu(dent->nlen), snod->sqnum,
!le64_to_cpu(dent->inum), &used);
break;
}
case UBIFS_TRUN_NODE:
{
struct ubifs_trun_node *trun = snod->node;
loff_t old_size = le64_to_cpu(trun->old_size);
loff_t new_size = le64_to_cpu(trun->new_size);
union ubifs_key key;
/* Validate truncation node */
if (old_size < 0 || old_size > c->max_inode_sz ||
new_size < 0 || new_size > c->max_inode_sz ||
old_size <= new_size) {
ubifs_err(c, "bad truncation node");
goto out_dump;
}
/*
* Create a fake truncation key just to use the same
* functions which expect nodes to have keys.
*/
trun_key_init(c, &key, le32_to_cpu(trun->inum));
err = insert_node(c, lnum, snod->offs, snod->len,
&key, snod->sqnum, 1, &used,
old_size, new_size);
break;
}
default:
ubifs_err(c, "unexpected node type %d in bud LEB %d:%d",
snod->type, lnum, snod->offs);
err = -EINVAL;
goto out_dump;
}
if (err)
goto out;
}
ubifs_assert(ubifs_search_bud(c, lnum));
ubifs_assert(sleb->endpt - offs >= used);
ubifs_assert(sleb->endpt % c->min_io_size == 0);
b->dirty = sleb->endpt - offs - used;
b->free = c->leb_size - sleb->endpt;
dbg_mnt("bud LEB %d replied: dirty %d, free %d",
lnum, b->dirty, b->free);
out:
ubifs_scan_destroy(sleb);
return err;
out_dump:
ubifs_err(c, "bad node is at LEB %d:%d", lnum, snod->offs);
ubifs_dump_node(c, snod->node);
ubifs_scan_destroy(sleb);
return -EINVAL;
}
/**
* replay_buds - replay all buds.
* @c: UBIFS file-system description object
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int replay_buds(struct ubifs_info *c)
{
struct bud_entry *b;
int err;
unsigned long long prev_sqnum = 0;
list_for_each_entry(b, &c->replay_buds, list) {
err = replay_bud(c, b);
if (err)
return err;
ubifs_assert(b->sqnum > prev_sqnum);
prev_sqnum = b->sqnum;
}
return 0;
}
/**
* destroy_bud_list - destroy the list of buds to replay.
* @c: UBIFS file-system description object
*/
static void destroy_bud_list(struct ubifs_info *c)
{
struct bud_entry *b;
while (!list_empty(&c->replay_buds)) {
b = list_entry(c->replay_buds.next, struct bud_entry, list);
list_del(&b->list);
kfree(b);
}
}
/**
* add_replay_bud - add a bud to the list of buds to replay.
* @c: UBIFS file-system description object
* @lnum: bud logical eraseblock number to replay
* @offs: bud start offset
* @jhead: journal head to which this bud belongs
* @sqnum: reference node sequence number
*
* This function returns zero in case of success and a negative error code in
* case of failure.
*/
static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
unsigned long long sqnum)
{
struct ubifs_bud *bud;
struct bud_entry *b;
dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
if (!bud)
return -ENOMEM;
b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
if (!b) {
kfree(bud);
return -ENOMEM;
}
bud->lnum = lnum;
bud->start = offs;
bud->jhead = jhead;
ubifs_add_bud(c, bud);
b->bud = bud;
b->sqnum = sqnum;
list_add_tail(&b->list, &c->replay_buds);
return 0;
}
/**
* validate_ref - validate a reference node.
* @c: UBIFS file-system description object
* @ref: the reference node to validate
* @ref_lnum: LEB number of the reference node
* @ref_offs: reference node offset
*
* This function returns %1 if a bud reference already exists for the LEB. %0 is
* returned if the reference node is new, otherwise %-EINVAL is returned if
* validation failed.
*/
static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
{
struct ubifs_bud *bud;
int lnum = le32_to_cpu(ref->lnum);
unsigned int offs = le32_to_cpu(ref->offs);
unsigned int jhead = le32_to_cpu(ref->jhead);
/*
* ref->offs may point to the end of LEB when the journal head points
* to the end of LEB and we write reference node for it during commit.
* So this is why we require 'offs > c->leb_size'.
*/
if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
lnum < c->main_first || offs > c->leb_size ||
offs & (c->min_io_size - 1))
return -EINVAL;
/* Make sure we have not already looked at this bud */
bud = ubifs_search_bud(c, lnum);
if (bud) {
if (bud->jhead == jhead && bud->start <= offs)
return 1;
ubifs_err(c, "bud at LEB %d:%d was already referred", lnum, offs);
return -EINVAL;
}
return 0;
}
/**
* replay_log_leb - replay a log logical eraseblock.
* @c: UBIFS file-system description object
* @lnum: log logical eraseblock to replay
* @offs: offset to start replaying from
* @sbuf: scan buffer
*
* This function replays a log LEB and returns zero in case of success, %1 if
* this is the last LEB in the log, and a negative error code in case of
* failure.
*/
static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
{
int err;
struct ubifs_scan_leb *sleb;
struct ubifs_scan_node *snod;
const struct ubifs_cs_node *node;
dbg_mnt("replay log LEB %d:%d", lnum, offs);
sleb = ubifs_scan(c, lnum, offs, sbuf, c->need_recovery);
if (IS_ERR(sleb)) {
if (PTR_ERR(sleb) != -EUCLEAN || !c->need_recovery)
return PTR_ERR(sleb);
/*
* Note, the below function will recover this log LEB only if
* it is the last, because unclean reboots can possibly corrupt
* only the tail of the log.
*/
sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
if (IS_ERR(sleb))
return PTR_ERR(sleb);
}
if (sleb->nodes_cnt == 0) {
err = 1;
goto out;
}
node = sleb->buf;
snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
if (c->cs_sqnum == 0) {
/*
* This is the first log LEB we are looking at, make sure that
* the first node is a commit start node. Also record its
* sequence number so that UBIFS can determine where the log
* ends, because all nodes which were have higher sequence
* numbers.
*/
if (snod->type != UBIFS_CS_NODE) {
ubifs_err(c, "first log node at LEB %d:%d is not CS node",
lnum, offs);
goto out_dump;
}
if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
ubifs_err(c, "first CS node at LEB %d:%d has wrong commit number %llu expected %llu",
lnum, offs,
(unsigned long long)le64_to_cpu(node->cmt_no),
c->cmt_no);
goto out_dump;
}
c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
}
if (snod->sqnum < c->cs_sqnum) {
/*
* This means that we reached end of log and now
* look to the older log data, which was already
* committed but the eraseblock was not erased (UBIFS
* only un-maps it). So this basically means we have to
* exit with "end of log" code.
*/
err = 1;
goto out;
}
/* Make sure the first node sits at offset zero of the LEB */
if (snod->offs != 0) {
ubifs_err(c, "first node is not at zero offset");
goto out_dump;
}
list_for_each_entry(snod, &sleb->nodes, list) {
cond_resched();
if (snod->sqnum >= SQNUM_WATERMARK) {
ubifs_err(c, "file system's life ended");
goto out_dump;
}
if (snod->sqnum < c->cs_sqnum) {
ubifs_err(c, "bad sqnum %llu, commit sqnum %llu",
snod->sqnum, c->cs_sqnum);
goto out_dump;
}
if (snod->sqnum > c->max_sqnum)
c->max_sqnum = snod->sqnum;
switch (snod->type) {
case UBIFS_REF_NODE: {
const struct ubifs_ref_node *ref = snod->node;
err = validate_ref(c, ref);
if (err == 1)
break; /* Already have this bud */
if (err)
goto out_dump;
err = add_replay_bud(c, le32_to_cpu(ref->lnum),
le32_to_cpu(ref->offs),
le32_to_cpu(ref->jhead),
snod->sqnum);
if (err)
goto out;
break;
}
case UBIFS_CS_NODE:
/* Make sure it sits at the beginning of LEB */
if (snod->offs != 0) {
ubifs_err(c, "unexpected node in log");
goto out_dump;
}
break;
default:
ubifs_err(c, "unexpected node in log");
goto out_dump;
}
}
if (sleb->endpt || c->lhead_offs >= c->leb_size) {
c->lhead_lnum = lnum;
c->lhead_offs = sleb->endpt;
}
err = !sleb->endpt;
out:
ubifs_scan_destroy(sleb);
return err;
out_dump:
ubifs_err(c, "log error detected while replaying the log at LEB %d:%d",
lnum, offs + snod->offs);
ubifs_dump_node(c, snod->node);
ubifs_scan_destroy(sleb);
return -EINVAL;
}
/**
* take_ihead - update the status of the index head in lprops to 'taken'.
* @c: UBIFS file-system description object
*
* This function returns the amount of free space in the index head LEB or a
* negative error code.
*/
static int take_ihead(struct ubifs_info *c)
{
const struct ubifs_lprops *lp;
int err, free;
ubifs_get_lprops(c);
lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
free = lp->free;
lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
lp->flags | LPROPS_TAKEN, 0);
if (IS_ERR(lp)) {
err = PTR_ERR(lp);
goto out;
}
err = free;
out:
ubifs_release_lprops(c);
return err;
}
/**
* ubifs_replay_journal - replay journal.
* @c: UBIFS file-system description object
*
* This function scans the journal, replays and cleans it up. It makes sure all
* memory data structures related to uncommitted journal are built (dirty TNC
* tree, tree of buds, modified lprops, etc).
*/
int ubifs_replay_journal(struct ubifs_info *c)
{
int err, lnum, free;
BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
/* Update the status of the index head in lprops to 'taken' */
free = take_ihead(c);
if (free < 0)
return free; /* Error code */
if (c->ihead_offs != c->leb_size - free) {
ubifs_err(c, "bad index head LEB %d:%d", c->ihead_lnum,
c->ihead_offs);
return -EINVAL;
}
dbg_mnt("start replaying the journal");
c->replaying = 1;
lnum = c->ltail_lnum = c->lhead_lnum;
do {
err = replay_log_leb(c, lnum, 0, c->sbuf);
if (err == 1) {
if (lnum != c->lhead_lnum)
/* We hit the end of the log */
break;
/*
* The head of the log must always start with the
* "commit start" node on a properly formatted UBIFS.
* But we found no nodes at all, which means that
* someting went wrong and we cannot proceed mounting
* the file-system.
*/
ubifs_err(c, "no UBIFS nodes found at the log head LEB %d:%d, possibly corrupted",
lnum, 0);
err = -EINVAL;
}
if (err)
goto out;
lnum = ubifs_next_log_lnum(c, lnum);
} while (lnum != c->ltail_lnum);
err = replay_buds(c);
if (err)
goto out;
err = apply_replay_list(c);
if (err)
goto out;
err = set_buds_lprops(c);
if (err)
goto out;
/*
* UBIFS budgeting calculations use @c->bi.uncommitted_idx variable
* to roughly estimate index growth. Things like @c->bi.min_idx_lebs
* depend on it. This means we have to initialize it to make sure
* budgeting works properly.
*/
c->bi.uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
c->bi.uncommitted_idx *= c->max_idx_node_sz;
ubifs_assert(c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, highest_inum %lu",
c->lhead_lnum, c->lhead_offs, c->max_sqnum,
(unsigned long)c->highest_inum);
out:
destroy_replay_list(c);
destroy_bud_list(c);
c->replaying = 0;
return err;
}