diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ubifs/tnc_commit.c | 1102 |
1 files changed, 0 insertions, 1102 deletions
diff --git a/fs/ubifs/tnc_commit.c b/fs/ubifs/tnc_commit.c deleted file mode 100644 index 8ac76b1..0000000 --- a/fs/ubifs/tnc_commit.c +++ /dev/null @@ -1,1102 +0,0 @@ -/* - * 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 TNC functions for committing */ - -#include "ubifs.h" - -/** - * make_idx_node - make an index node for fill-the-gaps method of TNC commit. - * @c: UBIFS file-system description object - * @idx: buffer in which to place new index node - * @znode: znode from which to make new index node - * @lnum: LEB number where new index node will be written - * @offs: offset where new index node will be written - * @len: length of new index node - */ -static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx, - struct ubifs_znode *znode, int lnum, int offs, int len) -{ - struct ubifs_znode *zp; - int i, err; - - /* Make index node */ - idx->ch.node_type = UBIFS_IDX_NODE; - idx->child_cnt = cpu_to_le16(znode->child_cnt); - idx->level = cpu_to_le16(znode->level); - for (i = 0; i < znode->child_cnt; i++) { - struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); - struct ubifs_zbranch *zbr = &znode->zbranch[i]; - - key_write_idx(c, &zbr->key, &br->key); - br->lnum = cpu_to_le32(zbr->lnum); - br->offs = cpu_to_le32(zbr->offs); - br->len = cpu_to_le32(zbr->len); - if (!zbr->lnum || !zbr->len) { - ubifs_err("bad ref in znode"); - dbg_dump_znode(c, znode); - if (zbr->znode) - dbg_dump_znode(c, zbr->znode); - } - } - ubifs_prepare_node(c, idx, len, 0); - -#ifdef CONFIG_UBIFS_FS_DEBUG - znode->lnum = lnum; - znode->offs = offs; - znode->len = len; -#endif - - err = insert_old_idx_znode(c, znode); - - /* Update the parent */ - zp = znode->parent; - if (zp) { - struct ubifs_zbranch *zbr; - - zbr = &zp->zbranch[znode->iip]; - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - } else { - c->zroot.lnum = lnum; - c->zroot.offs = offs; - c->zroot.len = len; - } - c->calc_idx_sz += ALIGN(len, 8); - - atomic_long_dec(&c->dirty_zn_cnt); - - ubifs_assert(ubifs_zn_dirty(znode)); - ubifs_assert(test_bit(COW_ZNODE, &znode->flags)); - - __clear_bit(DIRTY_ZNODE, &znode->flags); - __clear_bit(COW_ZNODE, &znode->flags); - - return err; -} - -/** - * fill_gap - make index nodes in gaps in dirty index LEBs. - * @c: UBIFS file-system description object - * @lnum: LEB number that gap appears in - * @gap_start: offset of start of gap - * @gap_end: offset of end of gap - * @dirt: adds dirty space to this - * - * This function returns the number of index nodes written into the gap. - */ -static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end, - int *dirt) -{ - int len, gap_remains, gap_pos, written, pad_len; - - ubifs_assert((gap_start & 7) == 0); - ubifs_assert((gap_end & 7) == 0); - ubifs_assert(gap_end >= gap_start); - - gap_remains = gap_end - gap_start; - if (!gap_remains) - return 0; - gap_pos = gap_start; - written = 0; - while (c->enext) { - len = ubifs_idx_node_sz(c, c->enext->child_cnt); - if (len < gap_remains) { - struct ubifs_znode *znode = c->enext; - const int alen = ALIGN(len, 8); - int err; - - ubifs_assert(alen <= gap_remains); - err = make_idx_node(c, c->ileb_buf + gap_pos, znode, - lnum, gap_pos, len); - if (err) - return err; - gap_remains -= alen; - gap_pos += alen; - c->enext = znode->cnext; - if (c->enext == c->cnext) - c->enext = NULL; - written += 1; - } else - break; - } - if (gap_end == c->leb_size) { - c->ileb_len = ALIGN(gap_pos, c->min_io_size); - /* Pad to end of min_io_size */ - pad_len = c->ileb_len - gap_pos; - } else - /* Pad to end of gap */ - pad_len = gap_remains; - dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d", - lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len); - ubifs_pad(c, c->ileb_buf + gap_pos, pad_len); - *dirt += pad_len; - return written; -} - -/** - * find_old_idx - find an index node obsoleted since the last commit start. - * @c: UBIFS file-system description object - * @lnum: LEB number of obsoleted index node - * @offs: offset of obsoleted index node - * - * Returns %1 if found and %0 otherwise. - */ -static int find_old_idx(struct ubifs_info *c, int lnum, int offs) -{ - struct ubifs_old_idx *o; - struct rb_node *p; - - p = c->old_idx.rb_node; - while (p) { - o = rb_entry(p, struct ubifs_old_idx, rb); - if (lnum < o->lnum) - p = p->rb_left; - else if (lnum > o->lnum) - p = p->rb_right; - else if (offs < o->offs) - p = p->rb_left; - else if (offs > o->offs) - p = p->rb_right; - else - return 1; - } - return 0; -} - -/** - * is_idx_node_in_use - determine if an index node can be overwritten. - * @c: UBIFS file-system description object - * @key: key of index node - * @level: index node level - * @lnum: LEB number of index node - * @offs: offset of index node - * - * If @key / @lnum / @offs identify an index node that was not part of the old - * index, then this function returns %0 (obsolete). Else if the index node was - * part of the old index but is now dirty %1 is returned, else if it is clean %2 - * is returned. A negative error code is returned on failure. - */ -static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key, - int level, int lnum, int offs) -{ - int ret; - - ret = is_idx_node_in_tnc(c, key, level, lnum, offs); - if (ret < 0) - return ret; /* Error code */ - if (ret == 0) - if (find_old_idx(c, lnum, offs)) - return 1; - return ret; -} - -/** - * layout_leb_in_gaps - layout index nodes using in-the-gaps method. - * @c: UBIFS file-system description object - * @p: return LEB number here - * - * This function lays out new index nodes for dirty znodes using in-the-gaps - * method of TNC commit. - * This function merely puts the next znode into the next gap, making no attempt - * to try to maximise the number of znodes that fit. - * This function returns the number of index nodes written into the gaps, or a - * negative error code on failure. - */ -static int layout_leb_in_gaps(struct ubifs_info *c, int *p) -{ - struct ubifs_scan_leb *sleb; - struct ubifs_scan_node *snod; - int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written; - - tot_written = 0; - /* Get an index LEB with lots of obsolete index nodes */ - lnum = ubifs_find_dirty_idx_leb(c); - if (lnum < 0) - /* - * There also may be dirt in the index head that could be - * filled, however we do not check there at present. - */ - return lnum; /* Error code */ - *p = lnum; - dbg_gc("LEB %d", lnum); - /* - * Scan the index LEB. We use the generic scan for this even though - * it is more comprehensive and less efficient than is needed for this - * purpose. - */ - sleb = ubifs_scan(c, lnum, 0, c->ileb_buf); - c->ileb_len = 0; - if (IS_ERR(sleb)) - return PTR_ERR(sleb); - gap_start = 0; - list_for_each_entry(snod, &sleb->nodes, list) { - struct ubifs_idx_node *idx; - int in_use, level; - - ubifs_assert(snod->type == UBIFS_IDX_NODE); - idx = snod->node; - key_read(c, ubifs_idx_key(c, idx), &snod->key); - level = le16_to_cpu(idx->level); - /* Determine if the index node is in use (not obsolete) */ - in_use = is_idx_node_in_use(c, &snod->key, level, lnum, - snod->offs); - if (in_use < 0) { - ubifs_scan_destroy(sleb); - return in_use; /* Error code */ - } - if (in_use) { - if (in_use == 1) - dirt += ALIGN(snod->len, 8); - /* - * The obsolete index nodes form gaps that can be - * overwritten. This gap has ended because we have - * found an index node that is still in use - * i.e. not obsolete - */ - gap_end = snod->offs; - /* Try to fill gap */ - written = fill_gap(c, lnum, gap_start, gap_end, &dirt); - if (written < 0) { - ubifs_scan_destroy(sleb); - return written; /* Error code */ - } - tot_written += written; - gap_start = ALIGN(snod->offs + snod->len, 8); - } - } - ubifs_scan_destroy(sleb); - c->ileb_len = c->leb_size; - gap_end = c->leb_size; - /* Try to fill gap */ - written = fill_gap(c, lnum, gap_start, gap_end, &dirt); - if (written < 0) - return written; /* Error code */ - tot_written += written; - if (tot_written == 0) { - struct ubifs_lprops lp; - - dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); - err = ubifs_read_one_lp(c, lnum, &lp); - if (err) - return err; - if (lp.free == c->leb_size) { - /* - * We must have snatched this LEB from the idx_gc list - * so we need to correct the free and dirty space. - */ - err = ubifs_change_one_lp(c, lnum, - c->leb_size - c->ileb_len, - dirt, 0, 0, 0); - if (err) - return err; - } - return 0; - } - err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt, - 0, 0, 0); - if (err) - return err; - err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len, - UBI_SHORTTERM); - if (err) - return err; - dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written); - return tot_written; -} - -/** - * get_leb_cnt - calculate the number of empty LEBs needed to commit. - * @c: UBIFS file-system description object - * @cnt: number of znodes to commit - * - * This function returns the number of empty LEBs needed to commit @cnt znodes - * to the current index head. The number is not exact and may be more than - * needed. - */ -static int get_leb_cnt(struct ubifs_info *c, int cnt) -{ - int d; - - /* Assume maximum index node size (i.e. overestimate space needed) */ - cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz; - if (cnt < 0) - cnt = 0; - d = c->leb_size / c->max_idx_node_sz; - return DIV_ROUND_UP(cnt, d); -} - -/** - * layout_in_gaps - in-the-gaps method of committing TNC. - * @c: UBIFS file-system description object - * @cnt: number of dirty znodes to commit. - * - * This function lays out new index nodes for dirty znodes using in-the-gaps - * method of TNC commit. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int layout_in_gaps(struct ubifs_info *c, int cnt) -{ - int err, leb_needed_cnt, written, *p; - - dbg_gc("%d znodes to write", cnt); - - c->gap_lebs = kmalloc(sizeof(int) * (c->lst.idx_lebs + 1), GFP_NOFS); - if (!c->gap_lebs) - return -ENOMEM; - - p = c->gap_lebs; - do { - ubifs_assert(p < c->gap_lebs + sizeof(int) * c->lst.idx_lebs); - written = layout_leb_in_gaps(c, p); - if (written < 0) { - err = written; - if (err != -ENOSPC) { - kfree(c->gap_lebs); - c->gap_lebs = NULL; - return err; - } - if (!dbg_force_in_the_gaps_enabled) { - /* - * Do not print scary warnings if the debugging - * option which forces in-the-gaps is enabled. - */ - ubifs_err("out of space"); - spin_lock(&c->space_lock); - dbg_dump_budg(c); - spin_unlock(&c->space_lock); - dbg_dump_lprops(c); - } - /* Try to commit anyway */ - err = 0; - break; - } - p++; - cnt -= written; - leb_needed_cnt = get_leb_cnt(c, cnt); - dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt, - leb_needed_cnt, c->ileb_cnt); - } while (leb_needed_cnt > c->ileb_cnt); - - *p = -1; - return 0; -} - -/** - * layout_in_empty_space - layout index nodes in empty space. - * @c: UBIFS file-system description object - * - * This function lays out new index nodes for dirty znodes using empty LEBs. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int layout_in_empty_space(struct ubifs_info *c) -{ - struct ubifs_znode *znode, *cnext, *zp; - int lnum, offs, len, next_len, buf_len, buf_offs, used, avail; - int wlen, blen, err; - - cnext = c->enext; - if (!cnext) - return 0; - - lnum = c->ihead_lnum; - buf_offs = c->ihead_offs; - - buf_len = ubifs_idx_node_sz(c, c->fanout); - buf_len = ALIGN(buf_len, c->min_io_size); - used = 0; - avail = buf_len; - - /* Ensure there is enough room for first write */ - next_len = ubifs_idx_node_sz(c, cnext->child_cnt); - if (buf_offs + next_len > c->leb_size) - lnum = -1; - - while (1) { - znode = cnext; - - len = ubifs_idx_node_sz(c, znode->child_cnt); - - /* Determine the index node position */ - if (lnum == -1) { - if (c->ileb_nxt >= c->ileb_cnt) { - ubifs_err("out of space"); - return -ENOSPC; - } - lnum = c->ilebs[c->ileb_nxt++]; - buf_offs = 0; - used = 0; - avail = buf_len; - } - - offs = buf_offs + used; - -#ifdef CONFIG_UBIFS_FS_DEBUG - znode->lnum = lnum; - znode->offs = offs; - znode->len = len; -#endif - - /* Update the parent */ - zp = znode->parent; - if (zp) { - struct ubifs_zbranch *zbr; - int i; - - i = znode->iip; - zbr = &zp->zbranch[i]; - zbr->lnum = lnum; - zbr->offs = offs; - zbr->len = len; - } else { - c->zroot.lnum = lnum; - c->zroot.offs = offs; - c->zroot.len = len; - } - c->calc_idx_sz += ALIGN(len, 8); - - /* - * Once lprops is updated, we can decrease the dirty znode count - * but it is easier to just do it here. - */ - atomic_long_dec(&c->dirty_zn_cnt); - - /* - * Calculate the next index node length to see if there is - * enough room for it - */ - cnext = znode->cnext; - if (cnext == c->cnext) - next_len = 0; - else - next_len = ubifs_idx_node_sz(c, cnext->child_cnt); - - if (c->min_io_size == 1) { - buf_offs += ALIGN(len, 8); - if (next_len) { - if (buf_offs + next_len <= c->leb_size) - continue; - err = ubifs_update_one_lp(c, lnum, 0, - c->leb_size - buf_offs, 0, 0); - if (err) - return err; - lnum = -1; - continue; - } - err = ubifs_update_one_lp(c, lnum, - c->leb_size - buf_offs, 0, 0, 0); - if (err) - return err; - break; - } - - /* Update buffer positions */ - wlen = used + len; - used += ALIGN(len, 8); - avail -= ALIGN(len, 8); - - if (next_len != 0 && - buf_offs + used + next_len <= c->leb_size && - avail > 0) - continue; - - if (avail <= 0 && next_len && - buf_offs + used + next_len <= c->leb_size) - blen = buf_len; - else - blen = ALIGN(wlen, c->min_io_size); - - /* The buffer is full or there are no more znodes to do */ - buf_offs += blen; - if (next_len) { - if (buf_offs + next_len > c->leb_size) { - err = ubifs_update_one_lp(c, lnum, - c->leb_size - buf_offs, blen - used, - 0, 0); - if (err) - return err; - lnum = -1; - } - used -= blen; - if (used < 0) - used = 0; - avail = buf_len - used; - continue; - } - err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs, - blen - used, 0, 0); - if (err) - return err; - break; - } - -#ifdef CONFIG_UBIFS_FS_DEBUG - c->new_ihead_lnum = lnum; - c->new_ihead_offs = buf_offs; -#endif - - return 0; -} - -/** - * layout_commit - determine positions of index nodes to commit. - * @c: UBIFS file-system description object - * @no_space: indicates that insufficient empty LEBs were allocated - * @cnt: number of znodes to commit - * - * Calculate and update the positions of index nodes to commit. If there were - * an insufficient number of empty LEBs allocated, then index nodes are placed - * into the gaps created by obsolete index nodes in non-empty index LEBs. For - * this purpose, an obsolete index node is one that was not in the index as at - * the end of the last commit. To write "in-the-gaps" requires that those index - * LEBs are updated atomically in-place. - */ -static int layout_commit(struct ubifs_info *c, int no_space, int cnt) -{ - int err; - - if (no_space) { - err = layout_in_gaps(c, cnt); - if (err) - return err; - } - err = layout_in_empty_space(c); - return err; -} - -/** - * find_first_dirty - find first dirty znode. - * @znode: znode to begin searching from - */ -static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode) -{ - int i, cont; - - if (!znode) - return NULL; - - while (1) { - if (znode->level == 0) { - if (ubifs_zn_dirty(znode)) - return znode; - return NULL; - } - cont = 0; - for (i = 0; i < znode->child_cnt; i++) { - struct ubifs_zbranch *zbr = &znode->zbranch[i]; - - if (zbr->znode && ubifs_zn_dirty(zbr->znode)) { - znode = zbr->znode; - cont = 1; - break; - } - } - if (!cont) { - if (ubifs_zn_dirty(znode)) - return znode; - return NULL; - } - } -} - -/** - * find_next_dirty - find next dirty znode. - * @znode: znode to begin searching from - */ -static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode) -{ - int n = znode->iip + 1; - - znode = znode->parent; - if (!znode) - return NULL; - for (; n < znode->child_cnt; n++) { - struct ubifs_zbranch *zbr = &znode->zbranch[n]; - - if (zbr->znode && ubifs_zn_dirty(zbr->znode)) - return find_first_dirty(zbr->znode); - } - return znode; -} - -/** - * get_znodes_to_commit - create list of dirty znodes to commit. - * @c: UBIFS file-system description object - * - * This function returns the number of znodes to commit. - */ -static int get_znodes_to_commit(struct ubifs_info *c) -{ - struct ubifs_znode *znode, *cnext; - int cnt = 0; - - c->cnext = find_first_dirty(c->zroot.znode); - znode = c->enext = c->cnext; - if (!znode) { - dbg_cmt("no znodes to commit"); - return 0; - } - cnt += 1; - while (1) { - ubifs_assert(!test_bit(COW_ZNODE, &znode->flags)); - __set_bit(COW_ZNODE, &znode->flags); - znode->alt = 0; - cnext = find_next_dirty(znode); - if (!cnext) { - znode->cnext = c->cnext; - break; - } - znode->cnext = cnext; - znode = cnext; - cnt += 1; - } - dbg_cmt("committing %d znodes", cnt); - ubifs_assert(cnt == atomic_long_read(&c->dirty_zn_cnt)); - return cnt; -} - -/** - * alloc_idx_lebs - allocate empty LEBs to be used to commit. - * @c: UBIFS file-system description object - * @cnt: number of znodes to commit - * - * This function returns %-ENOSPC if it cannot allocate a sufficient number of - * empty LEBs. %0 is returned on success, otherwise a negative error code - * is returned. - */ -static int alloc_idx_lebs(struct ubifs_info *c, int cnt) -{ - int i, leb_cnt, lnum; - - c->ileb_cnt = 0; - c->ileb_nxt = 0; - leb_cnt = get_leb_cnt(c, cnt); - dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt); - if (!leb_cnt) - return 0; - c->ilebs = kmalloc(leb_cnt * sizeof(int), GFP_NOFS); - if (!c->ilebs) - return -ENOMEM; - for (i = 0; i < leb_cnt; i++) { - lnum = ubifs_find_free_leb_for_idx(c); - if (lnum < 0) - return lnum; - c->ilebs[c->ileb_cnt++] = lnum; - dbg_cmt("LEB %d", lnum); - } - if (dbg_force_in_the_gaps()) - return -ENOSPC; - return 0; -} - -/** - * free_unused_idx_lebs - free unused LEBs that were allocated for the commit. - * @c: UBIFS file-system description object - * - * It is possible that we allocate more empty LEBs for the commit than we need. - * This functions frees the surplus. - * - * This function returns %0 on success and a negative error code on failure. - */ -static int free_unused_idx_lebs(struct ubifs_info *c) -{ - int i, err = 0, lnum, er; - - for (i = c->ileb_nxt; i < c->ileb_cnt; i++) { - lnum = c->ilebs[i]; - dbg_cmt("LEB %d", lnum); - er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, - LPROPS_INDEX | LPROPS_TAKEN, 0); - if (!err) - err = er; - } - return err; -} - -/** - * free_idx_lebs - free unused LEBs after commit end. - * @c: UBIFS file-system description object - * - * This function returns %0 on success and a negative error code on failure. - */ -static int free_idx_lebs(struct ubifs_info *c) -{ - int err; - - err = free_unused_idx_lebs(c); - kfree(c->ilebs); - c->ilebs = NULL; - return err; -} - -/** - * ubifs_tnc_start_commit - start TNC commit. - * @c: UBIFS file-system description object - * @zroot: new index root position is returned here - * - * This function prepares the list of indexing nodes to commit and lays out - * their positions on flash. If there is not enough free space it uses the - * in-gap commit method. Returns zero in case of success and a negative error - * code in case of failure. - */ -int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot) -{ - int err = 0, cnt; - - mutex_lock(&c->tnc_mutex); - err = dbg_check_tnc(c, 1); - if (err) - goto out; - cnt = get_znodes_to_commit(c); - if (cnt != 0) { - int no_space = 0; - - err = alloc_idx_lebs(c, cnt); - if (err == -ENOSPC) - no_space = 1; - else if (err) - goto out_free; - err = layout_commit(c, no_space, cnt); - if (err) - goto out_free; - ubifs_assert(atomic_long_read(&c->dirty_zn_cnt) == 0); - err = free_unused_idx_lebs(c); - if (err) - goto out; - } - destroy_old_idx(c); - memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch)); - - err = ubifs_save_dirty_idx_lnums(c); - if (err) - goto out; - - spin_lock(&c->space_lock); - /* - * Although we have not finished committing yet, update size of the - * committed index ('c->old_idx_sz') and zero out the index growth - * budget. It is OK to do this now, because we've reserved all the - * space which is needed to commit the index, and it is save for the - * budgeting subsystem to assume the index is already committed, - * even though it is not. - */ - c->old_idx_sz = c->calc_idx_sz; - c->budg_uncommitted_idx = 0; - spin_unlock(&c->space_lock); - mutex_unlock(&c->tnc_mutex); - - dbg_cmt("number of index LEBs %d", c->lst.idx_lebs); - dbg_cmt("size of index %llu", c->calc_idx_sz); - return err; - -out_free: - free_idx_lebs(c); -out: - mutex_unlock(&c->tnc_mutex); - return err; -} - -/** - * write_index - write index nodes. - * @c: UBIFS file-system description object - * - * This function writes the index nodes whose positions were laid out in the - * layout_in_empty_space function. - */ -static int write_index(struct ubifs_info *c) -{ - struct ubifs_idx_node *idx; - struct ubifs_znode *znode, *cnext; - int i, lnum, offs, len, next_len, buf_len, buf_offs, used; - int avail, wlen, err, lnum_pos = 0; - - cnext = c->enext; - if (!cnext) - return 0; - - /* - * Always write index nodes to the index head so that index nodes and - * other types of nodes are never mixed in the same erase block. - */ - lnum = c->ihead_lnum; - buf_offs = c->ihead_offs; - - /* Allocate commit buffer */ - buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size); - used = 0; - avail = buf_len; - - /* Ensure there is enough room for first write */ - next_len = ubifs_idx_node_sz(c, cnext->child_cnt); - if (buf_offs + next_len > c->leb_size) { - err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0, - LPROPS_TAKEN); - if (err) - return err; - lnum = -1; - } - - while (1) { - cond_resched(); - - znode = cnext; - idx = c->cbuf + used; - - /* Make index node */ - idx->ch.node_type = UBIFS_IDX_NODE; - idx->child_cnt = cpu_to_le16(znode->child_cnt); - idx->level = cpu_to_le16(znode->level); - for (i = 0; i < znode->child_cnt; i++) { - struct ubifs_branch *br = ubifs_idx_branch(c, idx, i); - struct ubifs_zbranch *zbr = &znode->zbranch[i]; - - key_write_idx(c, &zbr->key, &br->key); - br->lnum = cpu_to_le32(zbr->lnum); - br->offs = cpu_to_le32(zbr->offs); - br->len = cpu_to_le32(zbr->len); - if (!zbr->lnum || !zbr->len) { - ubifs_err("bad ref in znode"); - dbg_dump_znode(c, znode); - if (zbr->znode) - dbg_dump_znode(c, zbr->znode); - } - } - len = ubifs_idx_node_sz(c, znode->child_cnt); - ubifs_prepare_node(c, idx, len, 0); - - /* Determine the index node position */ - if (lnum == -1) { - lnum = c->ilebs[lnum_pos++]; - buf_offs = 0; - used = 0; - avail = buf_len; - } - offs = buf_offs + used; - -#ifdef CONFIG_UBIFS_FS_DEBUG - if (lnum != znode->lnum || offs != znode->offs || - len != znode->len) { - ubifs_err("inconsistent znode posn"); - return -EINVAL; - } -#endif - - /* Grab some stuff from znode while we still can */ - cnext = znode->cnext; - - ubifs_assert(ubifs_zn_dirty(znode)); - ubifs_assert(test_bit(COW_ZNODE, &znode->flags)); - - /* - * It is important that other threads should see %DIRTY_ZNODE - * flag cleared before %COW_ZNODE. Specifically, it matters in - * the 'dirty_cow_znode()' function. This is the reason for the - * first barrier. Also, we want the bit changes to be seen to - * other threads ASAP, to avoid unnecesarry copying, which is - * the reason for the second barrier. - */ - clear_bit(DIRTY_ZNODE, &znode->flags); - smp_mb__before_clear_bit(); - clear_bit(COW_ZNODE, &znode->flags); - smp_mb__after_clear_bit(); - - /* Do not access znode from this point on */ - - /* Update buffer positions */ - wlen = used + len; - used += ALIGN(len, 8); - avail -= ALIGN(len, 8); - - /* - * Calculate the next index node length to see if there is - * enough room for it - */ - if (cnext == c->cnext) - next_len = 0; - else - next_len = ubifs_idx_node_sz(c, cnext->child_cnt); - - if (c->min_io_size == 1) { - /* - * Write the prepared index node immediately if there is - * no minimum IO size - */ - err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, - wlen, UBI_SHORTTERM); - if (err) - return err; - buf_offs += ALIGN(wlen, 8); - if (next_len) { - used = 0; - avail = buf_len; - if (buf_offs + next_len > c->leb_size) { - err = ubifs_update_one_lp(c, lnum, - LPROPS_NC, 0, 0, LPROPS_TAKEN); - if (err) - return err; - lnum = -1; - } - continue; - } - } else { - int blen, nxt_offs = buf_offs + used + next_len; - - if (next_len && nxt_offs <= c->leb_size) { - if (avail > 0) - continue; - else - blen = buf_len; - } else { - wlen = ALIGN(wlen, 8); - blen = ALIGN(wlen, c->min_io_size); - ubifs_pad(c, c->cbuf + wlen, blen - wlen); - } - /* - * The buffer is full or there are no more znodes - * to do - */ - err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs, - blen, UBI_SHORTTERM); - if (err) - return err; - buf_offs += blen; - if (next_len) { - if (nxt_offs > c->leb_size) { - err = ubifs_update_one_lp(c, lnum, - LPROPS_NC, 0, 0, LPROPS_TAKEN); - if (err) - return err; - lnum = -1; - } - used -= blen; - if (used < 0) - used = 0; - avail = buf_len - used; - memmove(c->cbuf, c->cbuf + blen, used); - continue; - } - } - break; - } - -#ifdef CONFIG_UBIFS_FS_DEBUG - if (lnum != c->new_ihead_lnum || buf_offs != c->new_ihead_offs) { - ubifs_err("inconsistent ihead"); - return -EINVAL; - } -#endif - - c->ihead_lnum = lnum; - c->ihead_offs = buf_offs; - - return 0; -} - -/** - * free_obsolete_znodes - free obsolete znodes. - * @c: UBIFS file-system description object - * - * At the end of commit end, obsolete znodes are freed. - */ -static void free_obsolete_znodes(struct ubifs_info *c) -{ - struct ubifs_znode *znode, *cnext; - - cnext = c->cnext; - do { - znode = cnext; - cnext = znode->cnext; - if (test_bit(OBSOLETE_ZNODE, &znode->flags)) - kfree(znode); - else { - znode->cnext = NULL; - atomic_long_inc(&c->clean_zn_cnt); - atomic_long_inc(&ubifs_clean_zn_cnt); - } - } while (cnext != c->cnext); -} - -/** - * return_gap_lebs - return LEBs used by the in-gap commit method. - * @c: UBIFS file-system description object - * - * This function clears the "taken" flag for the LEBs which were used by the - * "commit in-the-gaps" method. - */ -static int return_gap_lebs(struct ubifs_info *c) -{ - int *p, err; - - if (!c->gap_lebs) - return 0; - - dbg_cmt(""); - for (p = c->gap_lebs; *p != -1; p++) { - err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0, - LPROPS_TAKEN, 0); - if (err) - return err; - } - - kfree(c->gap_lebs); - c->gap_lebs = NULL; - return 0; -} - -/** - * ubifs_tnc_end_commit - update the TNC for commit end. - * @c: UBIFS file-system description object - * - * Write the dirty znodes. - */ -int ubifs_tnc_end_commit(struct ubifs_info *c) -{ - int err; - - if (!c->cnext) - return 0; - - err = return_gap_lebs(c); - if (err) - return err; - - err = write_index(c); - if (err) - return err; - - mutex_lock(&c->tnc_mutex); - - dbg_cmt("TNC height is %d", c->zroot.znode->level + 1); - - free_obsolete_znodes(c); - - c->cnext = NULL; - kfree(c->ilebs); - c->ilebs = NULL; - - mutex_unlock(&c->tnc_mutex); - - return 0; -} |