/* * 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> #include <crypto/hash.h> #include <crypto/algapi.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; u8 hash[UBIFS_HASH_ARR_SZ]; unsigned int deletion:1; unsigned long long sqnum; struct list_head list; union ubifs_key key; union { struct fscrypt_name 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); } /** * inode_still_linked - check whether inode in question will be re-linked. * @c: UBIFS file-system description object * @rino: replay entry to test * * O_TMPFILE files can be re-linked, this means link count goes from 0 to 1. * This case needs special care, otherwise all references to the inode will * be removed upon the first replay entry of an inode with link count 0 * is found. */ static bool inode_still_linked(struct ubifs_info *c, struct replay_entry *rino) { struct replay_entry *r; ubifs_assert(c, rino->deletion); ubifs_assert(c, key_type(c, &rino->key) == UBIFS_INO_KEY); /* * Find the most recent entry for the inode behind @rino and check * whether it is a deletion. */ list_for_each_entry_reverse(r, &c->replay_list, list) { ubifs_assert(c, r->sqnum >= rino->sqnum); if (key_inum(c, &r->key) == key_inum(c, &rino->key)) return r->deletion == 0; } ubifs_assert(c, 0); return false; } /** * 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); 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->hash, &r->nm); } else { if (r->deletion) switch (key_type(c, &r->key)) { case UBIFS_INO_KEY: { ino_t inum = key_inum(c, &r->key); if (inode_still_linked(c, r)) { err = 0; break; } 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, r->hash); 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 * @b: 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 ubifs_info *c = priv; 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(c, 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(fname_name(&r->nm)); 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, const u8 *hash, 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; ubifs_copy_hash(c, hash, r->hash); 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, const u8 *hash, 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; ubifs_copy_hash(c, hash, r->hash); r->deletion = !!deletion; r->sqnum = sqnum; key_copy(c, key, &r->key); fname_len(&r->nm) = nlen; memcpy(nbuf, name, nlen); nbuf[nlen] = '\0'; fname_name(&r->nm) = 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 || (key_type == UBIFS_XENT_KEY && 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; } /* authenticate_sleb_hash and authenticate_sleb_hmac are split out for stack usage */ static int authenticate_sleb_hash(struct ubifs_info *c, struct shash_desc *log_hash, u8 *hash) { SHASH_DESC_ON_STACK(hash_desc, c->hash_tfm); hash_desc->tfm = c->hash_tfm; ubifs_shash_copy_state(c, log_hash, hash_desc); return crypto_shash_final(hash_desc, hash); } static int authenticate_sleb_hmac(struct ubifs_info *c, u8 *hash, u8 *hmac) { SHASH_DESC_ON_STACK(hmac_desc, c->hmac_tfm); hmac_desc->tfm = c->hmac_tfm; return crypto_shash_digest(hmac_desc, hash, c->hash_len, hmac); } /** * authenticate_sleb - authenticate one scan LEB * @c: UBIFS file-system description object * @sleb: the scan LEB to authenticate * @log_hash: * @is_last: if true, this is is the last LEB * * This function iterates over the buds of a single LEB authenticating all buds * with the authentication nodes on this LEB. Authentication nodes are written * after some buds and contain a HMAC covering the authentication node itself * and the buds between the last authentication node and the current * authentication node. It can happen that the last buds cannot be authenticated * because a powercut happened when some nodes were written but not the * corresponding authentication node. This function returns the number of nodes * that could be authenticated or a negative error code. */ static int authenticate_sleb(struct ubifs_info *c, struct ubifs_scan_leb *sleb, struct shash_desc *log_hash, int is_last) { int n_not_auth = 0; struct ubifs_scan_node *snod; int n_nodes = 0; int err; u8 *hash, *hmac; if (!ubifs_authenticated(c)) return sleb->nodes_cnt; hash = kmalloc(crypto_shash_descsize(c->hash_tfm), GFP_NOFS); hmac = kmalloc(c->hmac_desc_len, GFP_NOFS); if (!hash || !hmac) { err = -ENOMEM; goto out; } list_for_each_entry(snod, &sleb->nodes, list) { n_nodes++; if (snod->type == UBIFS_AUTH_NODE) { struct ubifs_auth_node *auth = snod->node; err = authenticate_sleb_hash(c, log_hash, hash); if (err) goto out; err = authenticate_sleb_hmac(c, hash, hmac); if (err) goto out; err = ubifs_check_hmac(c, auth->hmac, hmac); if (err) { err = -EPERM; goto out; } n_not_auth = 0; } else { err = crypto_shash_update(log_hash, snod->node, snod->len); if (err) goto out; n_not_auth++; } } /* * A powercut can happen when some nodes were written, but not yet * the corresponding authentication node. This may only happen on * the last bud though. */ if (n_not_auth) { if (is_last) { dbg_mnt("%d unauthenticated nodes found on LEB %d, Ignoring them", n_not_auth, sleb->lnum); err = 0; } else { dbg_mnt("%d unauthenticated nodes found on non-last LEB %d", n_not_auth, sleb->lnum); err = -EPERM; } } else { err = 0; } out: kfree(hash); kfree(hmac); return err ? err : n_nodes - n_not_auth; } /** * 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; int n_nodes, n = 0; 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); n_nodes = authenticate_sleb(c, sleb, b->bud->log_hash, is_last); if (n_nodes < 0) { err = n_nodes; goto out; } ubifs_shash_copy_state(c, b->bud->log_hash, c->jheads[b->bud->jhead].log_hash); /* * 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) { u8 hash[UBIFS_HASH_ARR_SZ]; int deletion = 0; cond_resched(); if (snod->sqnum >= SQNUM_WATERMARK) { ubifs_err(c, "file system's life ended"); goto out_dump; } ubifs_node_calc_hash(c, snod->node, hash); 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, hash, &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, hash, &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, hash, &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, hash, &key, snod->sqnum, 1, &used, old_size, new_size); break; } case UBIFS_AUTH_NODE: 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; n++; if (n == n_nodes) break; } ubifs_assert(c, ubifs_search_bud(c, lnum)); ubifs_assert(c, sleb->endpt - offs >= used); ubifs_assert(c, 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(c, 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; int err; 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) { err = -ENOMEM; goto out; } bud->lnum = lnum; bud->start = offs; bud->jhead = jhead; bud->log_hash = ubifs_hash_get_desc(c); if (IS_ERR(bud->log_hash)) { err = PTR_ERR(bud->log_hash); goto out; } ubifs_shash_copy_state(c, c->log_hash, bud->log_hash); ubifs_add_bud(c, bud); b->bud = bud; b->sqnum = sqnum; list_add_tail(&b->list, &c->replay_buds); return 0; out: kfree(bud); kfree(b); return err; } /** * 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); err = ubifs_shash_init(c, c->log_hash); if (err) goto out; err = ubifs_shash_update(c, c->log_hash, node, UBIFS_CS_NODE_SZ); if (err < 0) goto out; } 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 = ubifs_shash_update(c, c->log_hash, ref, UBIFS_REF_NODE_SZ); if (err) goto out; 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 * something 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, 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; }