diff options
Diffstat (limited to 'fs/ubifs/replay.c')
| -rw-r--r-- | fs/ubifs/replay.c | 1075 |
1 files changed, 1075 insertions, 0 deletions
diff --git a/fs/ubifs/replay.c b/fs/ubifs/replay.c new file mode 100644 index 000000000000..7399692af859 --- /dev/null +++ b/fs/ubifs/replay.c @@ -0,0 +1,1075 @@ +/* + * 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" + +/* + * Replay flags. + * + * REPLAY_DELETION: node was deleted + * REPLAY_REF: node is a reference node + */ +enum { + REPLAY_DELETION = 1, + REPLAY_REF = 2, +}; + +/** + * struct replay_entry - replay tree entry. + * @lnum: logical eraseblock number of the node + * @offs: node offset + * @len: node length + * @sqnum: node sequence number + * @flags: replay flags + * @rb: links the replay tree + * @key: node key + * @nm: directory entry name + * @old_size: truncation old size + * @new_size: truncation new size + * @free: amount of free space in a bud + * @dirty: amount of dirty space in a bud from padding and deletion nodes + * + * UBIFS journal replay must compare node sequence numbers, which means it must + * build a tree of node information to insert into the TNC. + */ +struct replay_entry { + int lnum; + int offs; + int len; + unsigned long long sqnum; + int flags; + struct rb_node rb; + union ubifs_key key; + union { + struct qstr nm; + struct { + loff_t old_size; + loff_t new_size; + }; + struct { + int free; + int dirty; + }; + }; +}; + +/** + * struct bud_entry - entry in the list of buds to replay. + * @list: next bud in the list + * @bud: bud description object + * @free: free bytes in the bud + * @sqnum: reference node sequence number + */ +struct bud_entry { + struct list_head list; + struct ubifs_bud *bud; + int free; + unsigned long long sqnum; +}; + +/** + * set_bud_lprops - set free and dirty space used by a bud. + * @c: UBIFS file-system description object + * @r: replay entry of bud + */ +static int set_bud_lprops(struct ubifs_info *c, struct replay_entry *r) +{ + const struct ubifs_lprops *lp; + int err = 0, dirty; + + ubifs_get_lprops(c); + + lp = ubifs_lpt_lookup_dirty(c, r->lnum); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } + + dirty = lp->dirty; + if (r->offs == 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 was garbage collected. The garbage collector resets + * the free and dirty space without recording it anywhere except + * lprops, so if there is not a commit then lprops does not have + * that information next time the file system is mounted. + * + * 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 + * r->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)", r->lnum, + lp->free, lp->dirty); + dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", r->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 the journal heads + * race with eachother. 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_msg("LEB %d lp: %d free %d dirty " + "replay: %d free %d dirty", r->lnum, lp->free, + lp->dirty, r->free, r->dirty); + } + lp = ubifs_change_lp(c, lp, r->free, dirty + r->dirty, + lp->flags | LPROPS_TAKEN, 0); + if (IS_ERR(lp)) { + err = PTR_ERR(lp); + goto out; + } +out: + ubifs_release_lprops(c); + return err; +} + +/** + * 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, deletion = ((r->flags & REPLAY_DELETION) != 0); + + dbg_mnt("LEB %d:%d len %d flgs %d sqnum %llu %s", r->lnum, + r->offs, r->len, r->flags, r->sqnum, DBGKEY(&r->key)); + + /* Set c->replay_sqnum to help deal with dangling branches. */ + c->replay_sqnum = r->sqnum; + + if (r->flags & REPLAY_REF) + err = set_bud_lprops(c, r); + else if (is_hash_key(c, &r->key)) { + if (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 (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, deletion, + r->new_size); + } + + return err; +} + +/** + * destroy_replay_tree - destroy the replay. + * @c: UBIFS file-system description object + * + * Destroy the replay tree. + */ +static void destroy_replay_tree(struct ubifs_info *c) +{ + struct rb_node *this = c->replay_tree.rb_node; + struct replay_entry *r; + + while (this) { + if (this->rb_left) { + this = this->rb_left; + continue; + } else if (this->rb_right) { + this = this->rb_right; + continue; + } + r = rb_entry(this, struct replay_entry, rb); + this = rb_parent(this); + if (this) { + if (this->rb_left == &r->rb) + this->rb_left = NULL; + else + this->rb_right = NULL; + } + if (is_hash_key(c, &r->key)) + kfree(r->nm.name); + kfree(r); + } + c->replay_tree = RB_ROOT; +} + +/** + * apply_replay_tree - apply the replay tree to the TNC. + * @c: UBIFS file-system description object + * + * Apply the replay tree. + * Returns zero in case of success and a negative error code in case of + * failure. + */ +static int apply_replay_tree(struct ubifs_info *c) +{ + struct rb_node *this = rb_first(&c->replay_tree); + + while (this) { + struct replay_entry *r; + int err; + + cond_resched(); + + r = rb_entry(this, struct replay_entry, rb); + err = apply_replay_entry(c, r); + if (err) + return err; + this = rb_next(this); + } + return 0; +} + +/** + * insert_node - insert a node to the replay tree. + * @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 tree. The + * replay tree is an RB-tree containing @struct replay_entry elements which are + * indexed by the sequence number. The replay tree is applied at the very end + * of the replay process. Since the tree 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 rb_node **p = &c->replay_tree.rb_node, *parent = NULL; + struct replay_entry *r; + + if (key_inum(c, key) >= c->highest_inum) + c->highest_inum = key_inum(c, key); + + dbg_mnt("add LEB %d:%d, key %s", lnum, offs, DBGKEY(key)); + while (*p) { + parent = *p; + r = rb_entry(parent, struct replay_entry, rb); + if (sqnum < r->sqnum) { + p = &(*p)->rb_left; + continue; + } else if (sqnum > r->sqnum) { + p = &(*p)->rb_right; + continue; + } + ubifs_err("duplicate sqnum in replay"); + return -EINVAL; + } + + 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->sqnum = sqnum; + r->flags = (deletion ? REPLAY_DELETION : 0); + r->old_size = old_size; + r->new_size = new_size; + key_copy(c, key, &r->key); + + rb_link_node(&r->rb, parent, p); + rb_insert_color(&r->rb, &c->replay_tree); + return 0; +} + +/** + * insert_dent - insert a directory entry node into the replay tree. + * @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 to the replay tree. + * Returns zero in case of success and a negative error code in case of + * failure. + * + * This function is also used for extended attribute entries because they are + * implemented as directory entry nodes. + */ +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 rb_node **p = &c->replay_tree.rb_node, *parent = NULL; + struct replay_entry *r; + char *nbuf; + + if (key_inum(c, key) >= c->highest_inum) + c->highest_inum = key_inum(c, key); + + dbg_mnt("add LEB %d:%d, key %s", lnum, offs, DBGKEY(key)); + while (*p) { + parent = *p; + r = rb_entry(parent, struct replay_entry, rb); + if (sqnum < r->sqnum) { + p = &(*p)->rb_left; + continue; + } + if (sqnum > r->sqnum) { + p = &(*p)->rb_right; + continue; + } + ubifs_err("duplicate sqnum in replay"); + return -EINVAL; + } + + 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->sqnum = sqnum; + r->nm.len = nlen; + memcpy(nbuf, name, nlen); + nbuf[nlen] = '\0'; + r->nm.name = nbuf; + r->flags = (deletion ? REPLAY_DELETION : 0); + key_copy(c, key, &r->key); + + ubifs_assert(!*p); + rb_link_node(&r->rb, parent, p); + rb_insert_color(&r->rb, &c->replay_tree); + 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("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("bad key type %d", key_type); + return -EINVAL; + } + + return 0; +} + +/** + * replay_bud - replay a bud logical eraseblock. + * @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 + * @free: amount of free space in the bud is returned here + * @dirty: amount of dirty space from padding and deletion nodes is returned + * here + * + * This function returns zero in case of success and a negative error code in + * case of failure. + */ +static int replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead, + int *free, int *dirty) +{ + int err = 0, used = 0; + struct ubifs_scan_leb *sleb; + struct ubifs_scan_node *snod; + struct ubifs_bud *bud; + + dbg_mnt("replay bud LEB %d, head %d", lnum, jhead); + if (c->need_recovery) + sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, jhead != GCHD); + else + sleb = ubifs_scan(c, lnum, offs, c->sbuf); + 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("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("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("unexpected node type %d in bud LEB %d:%d", + snod->type, lnum, snod->offs); + err = -EINVAL; + goto out_dump; + } + if (err) + goto out; + } + + bud = ubifs_search_bud(c, lnum); + if (!bud) + BUG(); + + ubifs_assert(sleb->endpt - offs >= used); + ubifs_assert(sleb->endpt % c->min_io_size == 0); + + if (sleb->endpt + c->min_io_size <= c->leb_size && + !(c->vfs_sb->s_flags & MS_RDONLY)) + err = ubifs_wbuf_seek_nolock(&c->jheads[jhead].wbuf, lnum, + sleb->endpt, UBI_SHORTTERM); + + *dirty = sleb->endpt - offs - used; + *free = c->leb_size - sleb->endpt; + +out: + ubifs_scan_destroy(sleb); + return err; + +out_dump: + ubifs_err("bad node is at LEB %d:%d", lnum, snod->offs); + dbg_dump_node(c, snod->node); + ubifs_scan_destroy(sleb); + return -EINVAL; +} + +/** + * insert_ref_node - insert a reference node to the replay tree. + * @c: UBIFS file-system description object + * @lnum: node logical eraseblock number + * @offs: node offset + * @sqnum: sequence number + * @free: amount of free space in bud + * @dirty: amount of dirty space from padding and deletion nodes + * + * This function inserts a reference node to the replay tree and returns zero + * in case of success ort a negative error code in case of failure. + */ +static int insert_ref_node(struct ubifs_info *c, int lnum, int offs, + unsigned long long sqnum, int free, int dirty) +{ + struct rb_node **p = &c->replay_tree.rb_node, *parent = NULL; + struct replay_entry *r; + + dbg_mnt("add ref LEB %d:%d", lnum, offs); + while (*p) { + parent = *p; + r = rb_entry(parent, struct replay_entry, rb); + if (sqnum < r->sqnum) { + p = &(*p)->rb_left; + continue; + } else if (sqnum > r->sqnum) { + p = &(*p)->rb_right; + continue; + } + ubifs_err("duplicate sqnum in replay tree"); + return -EINVAL; + } + + r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL); + if (!r) + return -ENOMEM; + + r->lnum = lnum; + r->offs = offs; + r->sqnum = sqnum; + r->flags = REPLAY_REF; + r->free = free; + r->dirty = dirty; + + rb_link_node(&r->rb, parent, p); + rb_insert_color(&r->rb, &c->replay_tree); + return 0; +} + +/** + * 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, uninitialized_var(free), uninitialized_var(dirty); + + list_for_each_entry(b, &c->replay_buds, list) { + err = replay_bud(c, b->bud->lnum, b->bud->start, b->bud->jhead, + &free, &dirty); + if (err) + return err; + err = insert_ref_node(c, b->bud->lnum, b->bud->start, b->sqnum, + free, dirty); + if (err) + return err; + } + + 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("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); + if (IS_ERR(sleb)) { + if (c->need_recovery) + 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) { + dbg_err("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) { + dbg_err("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 unmaps 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) { + dbg_err("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("file system's life ended"); + goto out_dump; + } + + if (snod->sqnum < c->cs_sqnum) { + dbg_err("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("unexpected node in log"); + goto out_dump; + } + break; + default: + ubifs_err("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("log error detected while replying the log at LEB %d:%d", + lnum, offs + snod->offs); + dbg_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, i, lnum, offs, free; + void *sbuf = NULL; + + 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("bad index head LEB %d:%d", c->ihead_lnum, + c->ihead_offs); + return -EINVAL; + } + + sbuf = vmalloc(c->leb_size); + if (!sbuf) + return -ENOMEM; + + dbg_mnt("start replaying the journal"); + + c->replaying = 1; + + lnum = c->ltail_lnum = c->lhead_lnum; + offs = c->lhead_offs; + + for (i = 0; i < c->log_lebs; i++, lnum++) { + if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) { + /* + * The log is logically circular, we reached the last + * LEB, switch to the first one. + */ + lnum = UBIFS_LOG_LNUM; + offs = 0; + } + err = replay_log_leb(c, lnum, offs, sbuf); + if (err == 1) + /* We hit the end of the log */ + break; + if (err) + goto out; + offs = 0; + } + + err = replay_buds(c); + if (err) + goto out; + + err = apply_replay_tree(c); + if (err) + goto out; + + 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, + c->highest_inum); +out: + destroy_replay_tree(c); + destroy_bud_list(c); + vfree(sbuf); + c->replaying = 0; + return err; +} |