diff options
Diffstat (limited to 'fs/ubifs/lpt_commit.c')
| -rw-r--r-- | fs/ubifs/lpt_commit.c | 2037 |
1 files changed, 2037 insertions, 0 deletions
diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c new file mode 100644 index 000000000..ce89bdc3e --- /dev/null +++ b/fs/ubifs/lpt_commit.c @@ -0,0 +1,2037 @@ +/* + * This file is part of UBIFS. + * + * Copyright (C) 2006-2008 Nokia Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Authors: Adrian Hunter + * Artem Bityutskiy (Битюцкий Артём) + */ + +/* + * This file implements commit-related functionality of the LEB properties + * subsystem. + */ + +#include <linux/crc16.h> +#include <linux/slab.h> +#include <linux/random.h> +#include "ubifs.h" + +static int dbg_populate_lsave(struct ubifs_info *c); + +/** + * first_dirty_cnode - find first dirty cnode. + * @c: UBIFS file-system description object + * @nnode: nnode at which to start + * + * This function returns the first dirty cnode or %NULL if there is not one. + */ +static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode) +{ + ubifs_assert(nnode); + while (1) { + int i, cont = 0; + + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + struct ubifs_cnode *cnode; + + cnode = nnode->nbranch[i].cnode; + if (cnode && + test_bit(DIRTY_CNODE, &cnode->flags)) { + if (cnode->level == 0) + return cnode; + nnode = (struct ubifs_nnode *)cnode; + cont = 1; + break; + } + } + if (!cont) + return (struct ubifs_cnode *)nnode; + } +} + +/** + * next_dirty_cnode - find next dirty cnode. + * @cnode: cnode from which to begin searching + * + * This function returns the next dirty cnode or %NULL if there is not one. + */ +static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode) +{ + struct ubifs_nnode *nnode; + int i; + + ubifs_assert(cnode); + nnode = cnode->parent; + if (!nnode) + return NULL; + for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) { + cnode = nnode->nbranch[i].cnode; + if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) { + if (cnode->level == 0) + return cnode; /* cnode is a pnode */ + /* cnode is a nnode */ + return first_dirty_cnode((struct ubifs_nnode *)cnode); + } + } + return (struct ubifs_cnode *)nnode; +} + +/** + * get_cnodes_to_commit - create list of dirty cnodes to commit. + * @c: UBIFS file-system description object + * + * This function returns the number of cnodes to commit. + */ +static int get_cnodes_to_commit(struct ubifs_info *c) +{ + struct ubifs_cnode *cnode, *cnext; + int cnt = 0; + + if (!c->nroot) + return 0; + + if (!test_bit(DIRTY_CNODE, &c->nroot->flags)) + return 0; + + c->lpt_cnext = first_dirty_cnode(c->nroot); + cnode = c->lpt_cnext; + if (!cnode) + return 0; + cnt += 1; + while (1) { + ubifs_assert(!test_bit(COW_CNODE, &cnode->flags)); + __set_bit(COW_CNODE, &cnode->flags); + cnext = next_dirty_cnode(cnode); + if (!cnext) { + cnode->cnext = c->lpt_cnext; + break; + } + cnode->cnext = cnext; + cnode = cnext; + cnt += 1; + } + dbg_cmt("committing %d cnodes", cnt); + dbg_lp("committing %d cnodes", cnt); + ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt); + return cnt; +} + +/** + * upd_ltab - update LPT LEB properties. + * @c: UBIFS file-system description object + * @lnum: LEB number + * @free: amount of free space + * @dirty: amount of dirty space to add + */ +static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty) +{ + dbg_lp("LEB %d free %d dirty %d to %d +%d", + lnum, c->ltab[lnum - c->lpt_first].free, + c->ltab[lnum - c->lpt_first].dirty, free, dirty); + ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last); + c->ltab[lnum - c->lpt_first].free = free; + c->ltab[lnum - c->lpt_first].dirty += dirty; +} + +/** + * alloc_lpt_leb - allocate an LPT LEB that is empty. + * @c: UBIFS file-system description object + * @lnum: LEB number is passed and returned here + * + * This function finds the next empty LEB in the ltab starting from @lnum. If a + * an empty LEB is found it is returned in @lnum and the function returns %0. + * Otherwise the function returns -ENOSPC. Note however, that LPT is designed + * never to run out of space. + */ +static int alloc_lpt_leb(struct ubifs_info *c, int *lnum) +{ + int i, n; + + n = *lnum - c->lpt_first + 1; + for (i = n; i < c->lpt_lebs; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (c->ltab[i].free == c->leb_size) { + c->ltab[i].cmt = 1; + *lnum = i + c->lpt_first; + return 0; + } + } + + for (i = 0; i < n; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (c->ltab[i].free == c->leb_size) { + c->ltab[i].cmt = 1; + *lnum = i + c->lpt_first; + return 0; + } + } + return -ENOSPC; +} + +/** + * layout_cnodes - layout cnodes for commit. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int layout_cnodes(struct ubifs_info *c) +{ + int lnum, offs, len, alen, done_lsave, done_ltab, err; + struct ubifs_cnode *cnode; + + err = dbg_chk_lpt_sz(c, 0, 0); + if (err) + return err; + cnode = c->lpt_cnext; + if (!cnode) + return 0; + lnum = c->nhead_lnum; + offs = c->nhead_offs; + /* Try to place lsave and ltab nicely */ + done_lsave = !c->big_lpt; + done_ltab = 0; + if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + if (offs + c->ltab_sz <= c->leb_size) { + done_ltab = 1; + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + do { + if (cnode->level) { + len = c->nnode_sz; + c->dirty_nn_cnt -= 1; + } else { + len = c->pnode_sz; + c->dirty_pn_cnt -= 1; + } + while (offs + len > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + /* Try to place lsave and ltab nicely */ + if (!done_lsave) { + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + continue; + } + if (!done_ltab) { + done_ltab = 1; + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + continue; + } + break; + } + if (cnode->parent) { + cnode->parent->nbranch[cnode->iip].lnum = lnum; + cnode->parent->nbranch[cnode->iip].offs = offs; + } else { + c->lpt_lnum = lnum; + c->lpt_offs = offs; + } + offs += len; + dbg_chk_lpt_sz(c, 1, len); + cnode = cnode->cnext; + } while (cnode && cnode != c->lpt_cnext); + + /* Make sure to place LPT's save table */ + if (!done_lsave) { + if (offs + c->lsave_sz > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + } + done_lsave = 1; + c->lsave_lnum = lnum; + c->lsave_offs = offs; + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + /* Make sure to place LPT's own lprops table */ + if (!done_ltab) { + if (offs + c->ltab_sz > c->leb_size) { + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = alloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + } + c->ltab_lnum = lnum; + c->ltab_offs = offs; + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + alen = ALIGN(offs, c->min_io_size); + upd_ltab(c, lnum, c->leb_size - alen, alen - offs); + dbg_chk_lpt_sz(c, 4, alen - offs); + err = dbg_chk_lpt_sz(c, 3, alen); + if (err) + return err; + return 0; + +no_space: + ubifs_err(c, "LPT out of space at LEB %d:%d needing %d, done_ltab %d, done_lsave %d", + lnum, offs, len, done_ltab, done_lsave); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return err; +} + +/** + * realloc_lpt_leb - allocate an LPT LEB that is empty. + * @c: UBIFS file-system description object + * @lnum: LEB number is passed and returned here + * + * This function duplicates exactly the results of the function alloc_lpt_leb. + * It is used during end commit to reallocate the same LEB numbers that were + * allocated by alloc_lpt_leb during start commit. + * + * This function finds the next LEB that was allocated by the alloc_lpt_leb + * function starting from @lnum. If a LEB is found it is returned in @lnum and + * the function returns %0. Otherwise the function returns -ENOSPC. + * Note however, that LPT is designed never to run out of space. + */ +static int realloc_lpt_leb(struct ubifs_info *c, int *lnum) +{ + int i, n; + + n = *lnum - c->lpt_first + 1; + for (i = n; i < c->lpt_lebs; i++) + if (c->ltab[i].cmt) { + c->ltab[i].cmt = 0; + *lnum = i + c->lpt_first; + return 0; + } + + for (i = 0; i < n; i++) + if (c->ltab[i].cmt) { + c->ltab[i].cmt = 0; + *lnum = i + c->lpt_first; + return 0; + } + return -ENOSPC; +} + +/** + * write_cnodes - write cnodes for commit. + * @c: UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +static int write_cnodes(struct ubifs_info *c) +{ + int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave; + struct ubifs_cnode *cnode; + void *buf = c->lpt_buf; + + cnode = c->lpt_cnext; + if (!cnode) + return 0; + lnum = c->nhead_lnum; + offs = c->nhead_offs; + from = offs; + /* Ensure empty LEB is unmapped */ + if (offs == 0) { + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + /* Try to place lsave and ltab nicely */ + done_lsave = !c->big_lpt; + done_ltab = 0; + if (!done_lsave && offs + c->lsave_sz <= c->leb_size) { + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + if (offs + c->ltab_sz <= c->leb_size) { + done_ltab = 1; + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + /* Loop for each cnode */ + do { + if (cnode->level) + len = c->nnode_sz; + else + len = c->pnode_sz; + while (offs + len > c->leb_size) { + wlen = offs - from; + if (wlen) { + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, + alen); + if (err) + return err; + } + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + /* Try to place lsave and ltab nicely */ + if (!done_lsave) { + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + continue; + } + if (!done_ltab) { + done_ltab = 1; + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + continue; + } + break; + } + if (cnode->level) + ubifs_pack_nnode(c, buf + offs, + (struct ubifs_nnode *)cnode); + else + ubifs_pack_pnode(c, buf + offs, + (struct ubifs_pnode *)cnode); + /* + * The reason for the barriers is the same as in case of TNC. + * See comment in 'write_index()'. 'dirty_cow_nnode()' and + * 'dirty_cow_pnode()' are the functions for which this is + * important. + */ + clear_bit(DIRTY_CNODE, &cnode->flags); + smp_mb__before_atomic(); + clear_bit(COW_CNODE, &cnode->flags); + smp_mb__after_atomic(); + offs += len; + dbg_chk_lpt_sz(c, 1, len); + cnode = cnode->cnext; + } while (cnode && cnode != c->lpt_cnext); + + /* Make sure to place LPT's save table */ + if (!done_lsave) { + if (offs + c->lsave_sz > c->leb_size) { + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + done_lsave = 1; + ubifs_pack_lsave(c, buf + offs, c->lsave); + offs += c->lsave_sz; + dbg_chk_lpt_sz(c, 1, c->lsave_sz); + } + + /* Make sure to place LPT's own lprops table */ + if (!done_ltab) { + if (offs + c->ltab_sz > c->leb_size) { + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + dbg_chk_lpt_sz(c, 2, c->leb_size - offs); + err = realloc_lpt_leb(c, &lnum); + if (err) + goto no_space; + offs = from = 0; + ubifs_assert(lnum >= c->lpt_first && + lnum <= c->lpt_last); + err = ubifs_leb_unmap(c, lnum); + if (err) + return err; + } + ubifs_pack_ltab(c, buf + offs, c->ltab_cmt); + offs += c->ltab_sz; + dbg_chk_lpt_sz(c, 1, c->ltab_sz); + } + + /* Write remaining data in buffer */ + wlen = offs - from; + alen = ALIGN(wlen, c->min_io_size); + memset(buf + offs, 0xff, alen - wlen); + err = ubifs_leb_write(c, lnum, buf + from, from, alen); + if (err) + return err; + + dbg_chk_lpt_sz(c, 4, alen - wlen); + err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size)); + if (err) + return err; + + c->nhead_lnum = lnum; + c->nhead_offs = ALIGN(offs, c->min_io_size); + + dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs); + dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs); + dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs); + if (c->big_lpt) + dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs); + + return 0; + +no_space: + ubifs_err(c, "LPT out of space mismatch at LEB %d:%d needing %d, done_ltab %d, done_lsave %d", + lnum, offs, len, done_ltab, done_lsave); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return err; +} + +/** + * next_pnode_to_dirty - find next pnode to dirty. + * @c: UBIFS file-system description object + * @pnode: pnode + * + * This function returns the next pnode to dirty or %NULL if there are no more + * pnodes. Note that pnodes that have never been written (lnum == 0) are + * skipped. + */ +static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c, + struct ubifs_pnode *pnode) +{ + struct ubifs_nnode *nnode; + int iip; + + /* Try to go right */ + nnode = pnode->parent; + for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + return ubifs_get_pnode(c, nnode, iip); + } + + /* Go up while can't go right */ + do { + iip = nnode->iip + 1; + nnode = nnode->parent; + if (!nnode) + return NULL; + for (; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + break; + } + } while (iip >= UBIFS_LPT_FANOUT); + + /* Go right */ + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return (void *)nnode; + + /* Go down to level 1 */ + while (nnode->level > 1) { + for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) { + if (nnode->nbranch[iip].lnum) + break; + } + if (iip >= UBIFS_LPT_FANOUT) { + /* + * Should not happen, but we need to keep going + * if it does. + */ + iip = 0; + } + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return (void *)nnode; + } + + for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) + if (nnode->nbranch[iip].lnum) + break; + if (iip >= UBIFS_LPT_FANOUT) + /* Should not happen, but we need to keep going if it does */ + iip = 0; + return ubifs_get_pnode(c, nnode, iip); +} + +/** + * pnode_lookup - lookup a pnode in the LPT. + * @c: UBIFS file-system description object + * @i: pnode number (0 to main_lebs - 1) + * + * This function returns a pointer to the pnode on success or a negative + * error code on failure. + */ +static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i) +{ + int err, h, iip, shft; + struct ubifs_nnode *nnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + i <<= UBIFS_LPT_FANOUT_SHIFT; + nnode = c->nroot; + shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT; + for (h = 1; h < c->lpt_hght; h++) { + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + shft -= UBIFS_LPT_FANOUT_SHIFT; + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return ERR_CAST(nnode); + } + iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1)); + return ubifs_get_pnode(c, nnode, iip); +} + +/** + * add_pnode_dirt - add dirty space to LPT LEB properties. + * @c: UBIFS file-system description object + * @pnode: pnode for which to add dirt + */ +static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum, + c->pnode_sz); +} + +/** + * do_make_pnode_dirty - mark a pnode dirty. + * @c: UBIFS file-system description object + * @pnode: pnode to mark dirty + */ +static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode) +{ + /* Assumes cnext list is empty i.e. not called during commit */ + if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) { + struct ubifs_nnode *nnode; + + c->dirty_pn_cnt += 1; + add_pnode_dirt(c, pnode); + /* Mark parent and ancestors dirty too */ + nnode = pnode->parent; + while (nnode) { + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + nnode = nnode->parent; + } else + break; + } + } +} + +/** + * make_tree_dirty - mark the entire LEB properties tree dirty. + * @c: UBIFS file-system description object + * + * This function is used by the "small" LPT model to cause the entire LEB + * properties tree to be written. The "small" LPT model does not use LPT + * garbage collection because it is more efficient to write the entire tree + * (because it is small). + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_tree_dirty(struct ubifs_info *c) +{ + struct ubifs_pnode *pnode; + + pnode = pnode_lookup(c, 0); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + + while (pnode) { + do_make_pnode_dirty(c, pnode); + pnode = next_pnode_to_dirty(c, pnode); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + } + return 0; +} + +/** + * need_write_all - determine if the LPT area is running out of free space. + * @c: UBIFS file-system description object + * + * This function returns %1 if the LPT area is running out of free space and %0 + * if it is not. + */ +static int need_write_all(struct ubifs_info *c) +{ + long long free = 0; + int i; + + for (i = 0; i < c->lpt_lebs; i++) { + if (i + c->lpt_first == c->nhead_lnum) + free += c->leb_size - c->nhead_offs; + else if (c->ltab[i].free == c->leb_size) + free += c->leb_size; + else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size) + free += c->leb_size; + } + /* Less than twice the size left */ + if (free <= c->lpt_sz * 2) + return 1; + return 0; +} + +/** + * lpt_tgc_start - start trivial garbage collection of LPT LEBs. + * @c: UBIFS file-system description object + * + * LPT trivial garbage collection is where a LPT LEB contains only dirty and + * free space and so may be reused as soon as the next commit is completed. + * This function is called during start commit to mark LPT LEBs for trivial GC. + */ +static void lpt_tgc_start(struct ubifs_info *c) +{ + int i; + + for (i = 0; i < c->lpt_lebs; i++) { + if (i + c->lpt_first == c->nhead_lnum) + continue; + if (c->ltab[i].dirty > 0 && + c->ltab[i].free + c->ltab[i].dirty == c->leb_size) { + c->ltab[i].tgc = 1; + c->ltab[i].free = c->leb_size; + c->ltab[i].dirty = 0; + dbg_lp("LEB %d", i + c->lpt_first); + } + } +} + +/** + * lpt_tgc_end - end trivial garbage collection of LPT LEBs. + * @c: UBIFS file-system description object + * + * LPT trivial garbage collection is where a LPT LEB contains only dirty and + * free space and so may be reused as soon as the next commit is completed. + * This function is called after the commit is completed (master node has been + * written) and un-maps LPT LEBs that were marked for trivial GC. + */ +static int lpt_tgc_end(struct ubifs_info *c) +{ + int i, err; + + for (i = 0; i < c->lpt_lebs; i++) + if (c->ltab[i].tgc) { + err = ubifs_leb_unmap(c, i + c->lpt_first); + if (err) + return err; + c->ltab[i].tgc = 0; + dbg_lp("LEB %d", i + c->lpt_first); + } + return 0; +} + +/** + * populate_lsave - fill the lsave array with important LEB numbers. + * @c: the UBIFS file-system description object + * + * This function is only called for the "big" model. It records a small number + * of LEB numbers of important LEBs. Important LEBs are ones that are (from + * most important to least important): empty, freeable, freeable index, dirty + * index, dirty or free. Upon mount, we read this list of LEB numbers and bring + * their pnodes into memory. That will stop us from having to scan the LPT + * straight away. For the "small" model we assume that scanning the LPT is no + * big deal. + */ +static void populate_lsave(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + int i, cnt = 0; + + ubifs_assert(c->big_lpt); + if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { + c->lpt_drty_flgs |= LSAVE_DIRTY; + ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); + } + + if (dbg_populate_lsave(c)) + return; + + list_for_each_entry(lprops, &c->empty_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + list_for_each_entry(lprops, &c->freeable_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + list_for_each_entry(lprops, &c->frdi_idx_list, list) { + c->lsave[cnt++] = lprops->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + heap = &c->lpt_heap[LPROPS_FREE - 1]; + for (i = 0; i < heap->cnt; i++) { + c->lsave[cnt++] = heap->arr[i]->lnum; + if (cnt >= c->lsave_cnt) + return; + } + /* Fill it up completely */ + while (cnt < c->lsave_cnt) + c->lsave[cnt++] = c->main_first; +} + +/** + * nnode_lookup - lookup a nnode in the LPT. + * @c: UBIFS file-system description object + * @i: nnode number + * + * This function returns a pointer to the nnode on success or a negative + * error code on failure. + */ +static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i) +{ + int err, iip; + struct ubifs_nnode *nnode; + + if (!c->nroot) { + err = ubifs_read_nnode(c, NULL, 0); + if (err) + return ERR_PTR(err); + } + nnode = c->nroot; + while (1) { + iip = i & (UBIFS_LPT_FANOUT - 1); + i >>= UBIFS_LPT_FANOUT_SHIFT; + if (!i) + break; + nnode = ubifs_get_nnode(c, nnode, iip); + if (IS_ERR(nnode)) + return nnode; + } + return nnode; +} + +/** + * make_nnode_dirty - find a nnode and, if found, make it dirty. + * @c: UBIFS file-system description object + * @node_num: nnode number of nnode to make dirty + * @lnum: LEB number where nnode was written + * @offs: offset where nnode was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum, + int offs) +{ + struct ubifs_nnode *nnode; + + nnode = nnode_lookup(c, node_num); + if (IS_ERR(nnode)) + return PTR_ERR(nnode); + if (nnode->parent) { + struct ubifs_nbranch *branch; + + branch = &nnode->parent->nbranch[nnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + return 0; /* nnode is obsolete */ + } else if (c->lpt_lnum != lnum || c->lpt_offs != offs) + return 0; /* nnode is obsolete */ + /* Assumes cnext list is empty i.e. not called during commit */ + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + /* Mark parent and ancestors dirty too */ + nnode = nnode->parent; + while (nnode) { + if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) { + c->dirty_nn_cnt += 1; + ubifs_add_nnode_dirt(c, nnode); + nnode = nnode->parent; + } else + break; + } + } + return 0; +} + +/** + * make_pnode_dirty - find a pnode and, if found, make it dirty. + * @c: UBIFS file-system description object + * @node_num: pnode number of pnode to make dirty + * @lnum: LEB number where pnode was written + * @offs: offset where pnode was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum, + int offs) +{ + struct ubifs_pnode *pnode; + struct ubifs_nbranch *branch; + + pnode = pnode_lookup(c, node_num); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + branch = &pnode->parent->nbranch[pnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + return 0; + do_make_pnode_dirty(c, pnode); + return 0; +} + +/** + * make_ltab_dirty - make ltab node dirty. + * @c: UBIFS file-system description object + * @lnum: LEB number where ltab was written + * @offs: offset where ltab was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->ltab_lnum || offs != c->ltab_offs) + return 0; /* This ltab node is obsolete */ + if (!(c->lpt_drty_flgs & LTAB_DIRTY)) { + c->lpt_drty_flgs |= LTAB_DIRTY; + ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz); + } + return 0; +} + +/** + * make_lsave_dirty - make lsave node dirty. + * @c: UBIFS file-system description object + * @lnum: LEB number where lsave was written + * @offs: offset where lsave was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->lsave_lnum || offs != c->lsave_offs) + return 0; /* This lsave node is obsolete */ + if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) { + c->lpt_drty_flgs |= LSAVE_DIRTY; + ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz); + } + return 0; +} + +/** + * make_node_dirty - make node dirty. + * @c: UBIFS file-system description object + * @node_type: LPT node type + * @node_num: node number + * @lnum: LEB number where node was written + * @offs: offset where node was written + * + * This function is used by LPT garbage collection. LPT garbage collection is + * used only for the "big" LPT model (c->big_lpt == 1). Garbage collection + * simply involves marking all the nodes in the LEB being garbage-collected as + * dirty. The dirty nodes are written next commit, after which the LEB is free + * to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num, + int lnum, int offs) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return make_nnode_dirty(c, node_num, lnum, offs); + case UBIFS_LPT_PNODE: + return make_pnode_dirty(c, node_num, lnum, offs); + case UBIFS_LPT_LTAB: + return make_ltab_dirty(c, lnum, offs); + case UBIFS_LPT_LSAVE: + return make_lsave_dirty(c, lnum, offs); + } + return -EINVAL; +} + +/** + * get_lpt_node_len - return the length of a node based on its type. + * @c: UBIFS file-system description object + * @node_type: LPT node type + */ +static int get_lpt_node_len(const struct ubifs_info *c, int node_type) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return c->nnode_sz; + case UBIFS_LPT_PNODE: + return c->pnode_sz; + case UBIFS_LPT_LTAB: + return c->ltab_sz; + case UBIFS_LPT_LSAVE: + return c->lsave_sz; + } + return 0; +} + +/** + * get_pad_len - return the length of padding in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer + * @len: length of buffer + */ +static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len) +{ + int offs, pad_len; + + if (c->min_io_size == 1) + return 0; + offs = c->leb_size - len; + pad_len = ALIGN(offs, c->min_io_size) - offs; + return pad_len; +} + +/** + * get_lpt_node_type - return type (and node number) of a node in a buffer. + * @c: UBIFS file-system description object + * @buf: buffer + * @node_num: node number is returned here + */ +static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf, + int *node_num) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int pos = 0, node_type; + + node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS); + *node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits); + return node_type; +} + +/** + * is_a_node - determine if a buffer contains a node. + * @c: UBIFS file-system description object + * @buf: buffer + * @len: length of buffer + * + * This function returns %1 if the buffer contains a node or %0 if it does not. + */ +static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len) +{ + uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES; + int pos = 0, node_type, node_len; + uint16_t crc, calc_crc; + + if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8) + return 0; + node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS); + if (node_type == UBIFS_LPT_NOT_A_NODE) + return 0; + node_len = get_lpt_node_len(c, node_type); + if (!node_len || node_len > len) + return 0; + pos = 0; + addr = buf; + crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS); + calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES, + node_len - UBIFS_LPT_CRC_BYTES); + if (crc != calc_crc) + return 0; + return 1; +} + +/** + * lpt_gc_lnum - garbage collect a LPT LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to garbage collect + * + * LPT garbage collection is used only for the "big" LPT model + * (c->big_lpt == 1). Garbage collection simply involves marking all the nodes + * in the LEB being garbage-collected as dirty. The dirty nodes are written + * next commit, after which the LEB is free to be reused. + * + * This function returns %0 on success and a negative error code on failure. + */ +static int lpt_gc_lnum(struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, node_type, node_num, node_len, offs; + void *buf = c->lpt_buf; + + dbg_lp("LEB %d", lnum); + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + return err; + + while (1) { + if (!is_a_node(c, buf, len)) { + int pad_len; + + pad_len = get_pad_len(c, buf, len); + if (pad_len) { + buf += pad_len; + len -= pad_len; + continue; + } + return 0; + } + node_type = get_lpt_node_type(c, buf, &node_num); + node_len = get_lpt_node_len(c, node_type); + offs = c->leb_size - len; + ubifs_assert(node_len != 0); + mutex_lock(&c->lp_mutex); + err = make_node_dirty(c, node_type, node_num, lnum, offs); + mutex_unlock(&c->lp_mutex); + if (err) + return err; + buf += node_len; + len -= node_len; + } + return 0; +} + +/** + * lpt_gc - LPT garbage collection. + * @c: UBIFS file-system description object + * + * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'. + * Returns %0 on success and a negative error code on failure. + */ +static int lpt_gc(struct ubifs_info *c) +{ + int i, lnum = -1, dirty = 0; + + mutex_lock(&c->lp_mutex); + for (i = 0; i < c->lpt_lebs; i++) { + ubifs_assert(!c->ltab[i].tgc); + if (i + c->lpt_first == c->nhead_lnum || + c->ltab[i].free + c->ltab[i].dirty == c->leb_size) + continue; + if (c->ltab[i].dirty > dirty) { + dirty = c->ltab[i].dirty; + lnum = i + c->lpt_first; + } + } + mutex_unlock(&c->lp_mutex); + if (lnum == -1) + return -ENOSPC; + return lpt_gc_lnum(c, lnum); +} + +/** + * ubifs_lpt_start_commit - UBIFS commit starts. + * @c: the UBIFS file-system description object + * + * This function has to be called when UBIFS starts the commit operation. + * This function "freezes" all currently dirty LEB properties and does not + * change them anymore. Further changes are saved and tracked separately + * because they are not part of this commit. This function returns zero in case + * of success and a negative error code in case of failure. + */ +int ubifs_lpt_start_commit(struct ubifs_info *c) +{ + int err, cnt; + + dbg_lp(""); + + mutex_lock(&c->lp_mutex); + err = dbg_chk_lpt_free_spc(c); + if (err) + goto out; + err = dbg_check_ltab(c); + if (err) + goto out; + + if (c->check_lpt_free) { + /* + * We ensure there is enough free space in + * ubifs_lpt_post_commit() by marking nodes dirty. That + * information is lost when we unmount, so we also need + * to check free space once after mounting also. + */ + c->check_lpt_free = 0; + while (need_write_all(c)) { + mutex_unlock(&c->lp_mutex); + err = lpt_gc(c); + if (err) + return err; + mutex_lock(&c->lp_mutex); + } + } + + lpt_tgc_start(c); + + if (!c->dirty_pn_cnt) { + dbg_cmt("no cnodes to commit"); + err = 0; + goto out; + } + + if (!c->big_lpt && need_write_all(c)) { + /* If needed, write everything */ + err = make_tree_dirty(c); + if (err) + goto out; + lpt_tgc_start(c); + } + + if (c->big_lpt) + populate_lsave(c); + + cnt = get_cnodes_to_commit(c); + ubifs_assert(cnt != 0); + + err = layout_cnodes(c); + if (err) + goto out; + + /* Copy the LPT's own lprops for end commit to write */ + memcpy(c->ltab_cmt, c->ltab, + sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs); + c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY); + +out: + mutex_unlock(&c->lp_mutex); + return err; +} + +/** + * free_obsolete_cnodes - free obsolete cnodes for commit end. + * @c: UBIFS file-system description object + */ +static void free_obsolete_cnodes(struct ubifs_info *c) +{ + struct ubifs_cnode *cnode, *cnext; + + cnext = c->lpt_cnext; + if (!cnext) + return; + do { + cnode = cnext; + cnext = cnode->cnext; + if (test_bit(OBSOLETE_CNODE, &cnode->flags)) + kfree(cnode); + else + cnode->cnext = NULL; + } while (cnext != c->lpt_cnext); + c->lpt_cnext = NULL; +} + +/** + * ubifs_lpt_end_commit - finish the commit operation. + * @c: the UBIFS file-system description object + * + * This function has to be called when the commit operation finishes. It + * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to + * the media. Returns zero in case of success and a negative error code in case + * of failure. + */ +int ubifs_lpt_end_commit(struct ubifs_info *c) +{ + int err; + + dbg_lp(""); + + if (!c->lpt_cnext) + return 0; + + err = write_cnodes(c); + if (err) + return err; + + mutex_lock(&c->lp_mutex); + free_obsolete_cnodes(c); + mutex_unlock(&c->lp_mutex); + + return 0; +} + +/** + * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC. + * @c: UBIFS file-system description object + * + * LPT trivial GC is completed after a commit. Also LPT GC is done after a + * commit for the "big" LPT model. + */ +int ubifs_lpt_post_commit(struct ubifs_info *c) +{ + int err; + + mutex_lock(&c->lp_mutex); + err = lpt_tgc_end(c); + if (err) + goto out; + if (c->big_lpt) + while (need_write_all(c)) { + mutex_unlock(&c->lp_mutex); + err = lpt_gc(c); + if (err) + return err; + mutex_lock(&c->lp_mutex); + } +out: + mutex_unlock(&c->lp_mutex); + return err; +} + +/** + * first_nnode - find the first nnode in memory. + * @c: UBIFS file-system description object + * @hght: height of tree where nnode found is returned here + * + * This function returns a pointer to the nnode found or %NULL if no nnode is + * found. This function is a helper to 'ubifs_lpt_free()'. + */ +static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght) +{ + struct ubifs_nnode *nnode; + int h, i, found; + + nnode = c->nroot; + *hght = 0; + if (!nnode) + return NULL; + for (h = 1; h < c->lpt_hght; h++) { + found = 0; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (nnode->nbranch[i].nnode) { + found = 1; + nnode = nnode->nbranch[i].nnode; + *hght = h; + break; + } + } + if (!found) + break; + } + return nnode; +} + +/** + * next_nnode - find the next nnode in memory. + * @c: UBIFS file-system description object + * @nnode: nnode from which to start. + * @hght: height of tree where nnode is, is passed and returned here + * + * This function returns a pointer to the nnode found or %NULL if no nnode is + * found. This function is a helper to 'ubifs_lpt_free()'. + */ +static struct ubifs_nnode *next_nnode(struct ubifs_info *c, + struct ubifs_nnode *nnode, int *hght) +{ + struct ubifs_nnode *parent; + int iip, h, i, found; + + parent = nnode->parent; + if (!parent) + return NULL; + if (nnode->iip == UBIFS_LPT_FANOUT - 1) { + *hght -= 1; + return parent; + } + for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) { + nnode = parent->nbranch[iip].nnode; + if (nnode) + break; + } + if (!nnode) { + *hght -= 1; + return parent; + } + for (h = *hght + 1; h < c->lpt_hght; h++) { + found = 0; + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + if (nnode->nbranch[i].nnode) { + found = 1; + nnode = nnode->nbranch[i].nnode; + *hght = h; + break; + } + } + if (!found) + break; + } + return nnode; +} + +/** + * ubifs_lpt_free - free resources owned by the LPT. + * @c: UBIFS file-system description object + * @wr_only: free only resources used for writing + */ +void ubifs_lpt_free(struct ubifs_info *c, int wr_only) +{ + struct ubifs_nnode *nnode; + int i, hght; + + /* Free write-only things first */ + + free_obsolete_cnodes(c); /* Leftover from a failed commit */ + + vfree(c->ltab_cmt); + c->ltab_cmt = NULL; + vfree(c->lpt_buf); + c->lpt_buf = NULL; + kfree(c->lsave); + c->lsave = NULL; + + if (wr_only) + return; + + /* Now free the rest */ + + nnode = first_nnode(c, &hght); + while (nnode) { + for (i = 0; i < UBIFS_LPT_FANOUT; i++) + kfree(nnode->nbranch[i].nnode); + nnode = next_nnode(c, nnode, &hght); + } + for (i = 0; i < LPROPS_HEAP_CNT; i++) + kfree(c->lpt_heap[i].arr); + kfree(c->dirty_idx.arr); + kfree(c->nroot); + vfree(c->ltab); + kfree(c->lpt_nod_buf); +} + +/* + * Everything below is related to debugging. + */ + +/** + * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes. + * @buf: buffer + * @len: buffer length + */ +static int dbg_is_all_ff(uint8_t *buf, int len) +{ + int i; + + for (i = 0; i < len; i++) + if (buf[i] != 0xff) + return 0; + return 1; +} + +/** + * dbg_is_nnode_dirty - determine if a nnode is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where nnode was written + * @offs: offset where nnode was written + */ +static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs) +{ + struct ubifs_nnode *nnode; + int hght; + + /* Entire tree is in memory so first_nnode / next_nnode are OK */ + nnode = first_nnode(c, &hght); + for (; nnode; nnode = next_nnode(c, nnode, &hght)) { + struct ubifs_nbranch *branch; + + cond_resched(); + if (nnode->parent) { + branch = &nnode->parent->nbranch[nnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &nnode->flags)) + return 1; + return 0; + } else { + if (c->lpt_lnum != lnum || c->lpt_offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &nnode->flags)) + return 1; + return 0; + } + } + return 1; +} + +/** + * dbg_is_pnode_dirty - determine if a pnode is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where pnode was written + * @offs: offset where pnode was written + */ +static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs) +{ + int i, cnt; + + cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); + for (i = 0; i < cnt; i++) { + struct ubifs_pnode *pnode; + struct ubifs_nbranch *branch; + + cond_resched(); + pnode = pnode_lookup(c, i); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + branch = &pnode->parent->nbranch[pnode->iip]; + if (branch->lnum != lnum || branch->offs != offs) + continue; + if (test_bit(DIRTY_CNODE, &pnode->flags)) + return 1; + return 0; + } + return 1; +} + +/** + * dbg_is_ltab_dirty - determine if a ltab node is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where ltab node was written + * @offs: offset where ltab node was written + */ +static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->ltab_lnum || offs != c->ltab_offs) + return 1; + return (c->lpt_drty_flgs & LTAB_DIRTY) != 0; +} + +/** + * dbg_is_lsave_dirty - determine if a lsave node is dirty. + * @c: the UBIFS file-system description object + * @lnum: LEB number where lsave node was written + * @offs: offset where lsave node was written + */ +static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs) +{ + if (lnum != c->lsave_lnum || offs != c->lsave_offs) + return 1; + return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0; +} + +/** + * dbg_is_node_dirty - determine if a node is dirty. + * @c: the UBIFS file-system description object + * @node_type: node type + * @lnum: LEB number where node was written + * @offs: offset where node was written + */ +static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum, + int offs) +{ + switch (node_type) { + case UBIFS_LPT_NNODE: + return dbg_is_nnode_dirty(c, lnum, offs); + case UBIFS_LPT_PNODE: + return dbg_is_pnode_dirty(c, lnum, offs); + case UBIFS_LPT_LTAB: + return dbg_is_ltab_dirty(c, lnum, offs); + case UBIFS_LPT_LSAVE: + return dbg_is_lsave_dirty(c, lnum, offs); + } + return 1; +} + +/** + * dbg_check_ltab_lnum - check the ltab for a LPT LEB number. + * @c: the UBIFS file-system description object + * @lnum: LEB number where node was written + * @offs: offset where node was written + * + * This function returns %0 on success and a negative error code on failure. + */ +static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len; + int ret; + void *buf, *p; + + if (!dbg_is_chk_lprops(c)) + return 0; + + buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL); + if (!buf) { + ubifs_err(c, "cannot allocate memory for ltab checking"); + return 0; + } + + dbg_lp("LEB %d", lnum); + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + goto out; + + while (1) { + if (!is_a_node(c, p, len)) { + int i, pad_len; + + pad_len = get_pad_len(c, p, len); + if (pad_len) { + p += pad_len; + len -= pad_len; + dirty += pad_len; + continue; + } + if (!dbg_is_all_ff(p, len)) { + ubifs_err(c, "invalid empty space in LEB %d at %d", + lnum, c->leb_size - len); + err = -EINVAL; + } + i = lnum - c->lpt_first; + if (len != c->ltab[i].free) { + ubifs_err(c, "invalid free space in LEB %d (free %d, expected %d)", + lnum, len, c->ltab[i].free); + err = -EINVAL; + } + if (dirty != c->ltab[i].dirty) { + ubifs_err(c, "invalid dirty space in LEB %d (dirty %d, expected %d)", + lnum, dirty, c->ltab[i].dirty); + err = -EINVAL; + } + goto out; + } + node_type = get_lpt_node_type(c, p, &node_num); + node_len = get_lpt_node_len(c, node_type); + ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len); + if (ret == 1) + dirty += node_len; + p += node_len; + len -= node_len; + } + + err = 0; +out: + vfree(buf); + return err; +} + +/** + * dbg_check_ltab - check the free and dirty space in the ltab. + * @c: the UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_check_ltab(struct ubifs_info *c) +{ + int lnum, err, i, cnt; + + if (!dbg_is_chk_lprops(c)) + return 0; + + /* Bring the entire tree into memory */ + cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT); + for (i = 0; i < cnt; i++) { + struct ubifs_pnode *pnode; + + pnode = pnode_lookup(c, i); + if (IS_ERR(pnode)) + return PTR_ERR(pnode); + cond_resched(); + } + + /* Check nodes */ + err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0); + if (err) + return err; + + /* Check each LEB */ + for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) { + err = dbg_check_ltab_lnum(c, lnum); + if (err) { + ubifs_err(c, "failed at LEB %d", lnum); + return err; + } + } + + dbg_lp("succeeded"); + return 0; +} + +/** + * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT. + * @c: the UBIFS file-system description object + * + * This function returns %0 on success and a negative error code on failure. + */ +int dbg_chk_lpt_free_spc(struct ubifs_info *c) +{ + long long free = 0; + int i; + + if (!dbg_is_chk_lprops(c)) + return 0; + + for (i = 0; i < c->lpt_lebs; i++) { + if (c->ltab[i].tgc || c->ltab[i].cmt) + continue; + if (i + c->lpt_first == c->nhead_lnum) + free += c->leb_size - c->nhead_offs; + else if (c->ltab[i].free == c->leb_size) + free += c->leb_size; + } + if (free < c->lpt_sz) { + ubifs_err(c, "LPT space error: free %lld lpt_sz %lld", + free, c->lpt_sz); + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + return -EINVAL; + } + return 0; +} + +/** + * dbg_chk_lpt_sz - check LPT does not write more than LPT size. + * @c: the UBIFS file-system description object + * @action: what to do + * @len: length written + * + * This function returns %0 on success and a negative error code on failure. + * The @action argument may be one of: + * o %0 - LPT debugging checking starts, initialize debugging variables; + * o %1 - wrote an LPT node, increase LPT size by @len bytes; + * o %2 - switched to a different LEB and wasted @len bytes; + * o %3 - check that we've written the right number of bytes. + * o %4 - wasted @len bytes; + */ +int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len) +{ + struct ubifs_debug_info *d = c->dbg; + long long chk_lpt_sz, lpt_sz; + int err = 0; + + if (!dbg_is_chk_lprops(c)) + return 0; + + switch (action) { + case 0: + d->chk_lpt_sz = 0; + d->chk_lpt_sz2 = 0; + d->chk_lpt_lebs = 0; + d->chk_lpt_wastage = 0; + if (c->dirty_pn_cnt > c->pnode_cnt) { + ubifs_err(c, "dirty pnodes %d exceed max %d", + c->dirty_pn_cnt, c->pnode_cnt); + err = -EINVAL; + } + if (c->dirty_nn_cnt > c->nnode_cnt) { + ubifs_err(c, "dirty nnodes %d exceed max %d", + c->dirty_nn_cnt, c->nnode_cnt); + err = -EINVAL; + } + return err; + case 1: + d->chk_lpt_sz += len; + return 0; + case 2: + d->chk_lpt_sz += len; + d->chk_lpt_wastage += len; + d->chk_lpt_lebs += 1; + return 0; + case 3: + chk_lpt_sz = c->leb_size; + chk_lpt_sz *= d->chk_lpt_lebs; + chk_lpt_sz += len - c->nhead_offs; + if (d->chk_lpt_sz != chk_lpt_sz) { + ubifs_err(c, "LPT wrote %lld but space used was %lld", + d->chk_lpt_sz, chk_lpt_sz); + err = -EINVAL; + } + if (d->chk_lpt_sz > c->lpt_sz) { + ubifs_err(c, "LPT wrote %lld but lpt_sz is %lld", + d->chk_lpt_sz, c->lpt_sz); + err = -EINVAL; + } + if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) { + ubifs_err(c, "LPT layout size %lld but wrote %lld", + d->chk_lpt_sz, d->chk_lpt_sz2); + err = -EINVAL; + } + if (d->chk_lpt_sz2 && d->new_nhead_offs != len) { + ubifs_err(c, "LPT new nhead offs: expected %d was %d", + d->new_nhead_offs, len); + err = -EINVAL; + } + lpt_sz = (long long)c->pnode_cnt * c->pnode_sz; + lpt_sz += (long long)c->nnode_cnt * c->nnode_sz; + lpt_sz += c->ltab_sz; + if (c->big_lpt) + lpt_sz += c->lsave_sz; + if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) { + ubifs_err(c, "LPT chk_lpt_sz %lld + waste %lld exceeds %lld", + d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz); + err = -EINVAL; + } + if (err) { + ubifs_dump_lpt_info(c); + ubifs_dump_lpt_lebs(c); + dump_stack(); + } + d->chk_lpt_sz2 = d->chk_lpt_sz; + d->chk_lpt_sz = 0; + d->chk_lpt_wastage = 0; + d->chk_lpt_lebs = 0; + d->new_nhead_offs = len; + return err; + case 4: + d->chk_lpt_sz += len; + d->chk_lpt_wastage += len; + return 0; + default: + return -EINVAL; + } +} + +/** + * ubifs_dump_lpt_leb - dump an LPT LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to dump + * + * This function dumps an LEB from LPT area. Nodes in this area are very + * different to nodes in the main area (e.g., they do not have common headers, + * they do not have 8-byte alignments, etc), so we have a separate function to + * dump LPT area LEBs. Note, LPT has to be locked by the caller. + */ +static void dump_lpt_leb(const struct ubifs_info *c, int lnum) +{ + int err, len = c->leb_size, node_type, node_num, node_len, offs; + void *buf, *p; + + pr_err("(pid %d) start dumping LEB %d\n", current->pid, lnum); + buf = p = __vmalloc(c->leb_size, GFP_NOFS, PAGE_KERNEL); + if (!buf) { + ubifs_err(c, "cannot allocate memory to dump LPT"); + return; + } + + err = ubifs_leb_read(c, lnum, buf, 0, c->leb_size, 1); + if (err) + goto out; + + while (1) { + offs = c->leb_size - len; + if (!is_a_node(c, p, len)) { + int pad_len; + + pad_len = get_pad_len(c, p, len); + if (pad_len) { + pr_err("LEB %d:%d, pad %d bytes\n", + lnum, offs, pad_len); + p += pad_len; + len -= pad_len; + continue; + } + if (len) + pr_err("LEB %d:%d, free %d bytes\n", + lnum, offs, len); + break; + } + + node_type = get_lpt_node_type(c, p, &node_num); + switch (node_type) { + case UBIFS_LPT_PNODE: + { + node_len = c->pnode_sz; + if (c->big_lpt) + pr_err("LEB %d:%d, pnode num %d\n", + lnum, offs, node_num); + else + pr_err("LEB %d:%d, pnode\n", lnum, offs); + break; + } + case UBIFS_LPT_NNODE: + { + int i; + struct ubifs_nnode nnode; + + node_len = c->nnode_sz; + if (c->big_lpt) + pr_err("LEB %d:%d, nnode num %d, ", + lnum, offs, node_num); + else + pr_err("LEB %d:%d, nnode, ", + lnum, offs); + err = ubifs_unpack_nnode(c, p, &nnode); + if (err) { + pr_err("failed to unpack_node, error %d\n", + err); + break; + } + for (i = 0; i < UBIFS_LPT_FANOUT; i++) { + pr_cont("%d:%d", nnode.nbranch[i].lnum, + nnode.nbranch[i].offs); + if (i != UBIFS_LPT_FANOUT - 1) + pr_cont(", "); + } + pr_cont("\n"); + break; + } + case UBIFS_LPT_LTAB: + node_len = c->ltab_sz; + pr_err("LEB %d:%d, ltab\n", lnum, offs); + break; + case UBIFS_LPT_LSAVE: + node_len = c->lsave_sz; + pr_err("LEB %d:%d, lsave len\n", lnum, offs); + break; + default: + ubifs_err(c, "LPT node type %d not recognized", node_type); + goto out; + } + + p += node_len; + len -= node_len; + } + + pr_err("(pid %d) finish dumping LEB %d\n", current->pid, lnum); +out: + vfree(buf); + return; +} + +/** + * ubifs_dump_lpt_lebs - dump LPT lebs. + * @c: UBIFS file-system description object + * + * This function dumps all LPT LEBs. The caller has to make sure the LPT is + * locked. + */ +void ubifs_dump_lpt_lebs(const struct ubifs_info *c) +{ + int i; + + pr_err("(pid %d) start dumping all LPT LEBs\n", current->pid); + for (i = 0; i < c->lpt_lebs; i++) + dump_lpt_leb(c, i + c->lpt_first); + pr_err("(pid %d) finish dumping all LPT LEBs\n", current->pid); +} + +/** + * dbg_populate_lsave - debugging version of 'populate_lsave()' + * @c: UBIFS file-system description object + * + * This is a debugging version for 'populate_lsave()' which populates lsave + * with random LEBs instead of useful LEBs, which is good for test coverage. + * Returns zero if lsave has not been populated (this debugging feature is + * disabled) an non-zero if lsave has been populated. + */ +static int dbg_populate_lsave(struct ubifs_info *c) +{ + struct ubifs_lprops *lprops; + struct ubifs_lpt_heap *heap; + int i; + + if (!dbg_is_chk_gen(c)) + return 0; + if (prandom_u32() & 3) + return 0; + + for (i = 0; i < c->lsave_cnt; i++) + c->lsave[i] = c->main_first; + + list_for_each_entry(lprops, &c->empty_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + list_for_each_entry(lprops, &c->freeable_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + list_for_each_entry(lprops, &c->frdi_idx_list, list) + c->lsave[prandom_u32() % c->lsave_cnt] = lprops->lnum; + + heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + heap = &c->lpt_heap[LPROPS_DIRTY - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + heap = &c->lpt_heap[LPROPS_FREE - 1]; + for (i = 0; i < heap->cnt; i++) + c->lsave[prandom_u32() % c->lsave_cnt] = heap->arr[i]->lnum; + + return 1; +} |