UBIFS: add new flash file system

This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.html

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>

1 files changed, 387 insertions, 0 deletions

diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
new file mode 100644
index 000000000000..71d5493bf565
--- /dev/null
+++ b/fs/ubifs/master.c
@@ -0,0 +1,387 @@
+/*
+ * 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: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/* This file implements reading and writing the master node */
+
+#include "ubifs.h"
+
+/**
+ * scan_for_master - search the valid master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function scans the master node LEBs and search for the latest master
+ * node. Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int scan_for_master(struct ubifs_info *c)
+{
+        struct ubifs_scan_leb *sleb;
+        struct ubifs_scan_node *snod;
+        int lnum, offs = 0, nodes_cnt;
+
+        lnum = UBIFS_MST_LNUM;
+
+        sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+        if (IS_ERR(sleb))
+                return PTR_ERR(sleb);
+        nodes_cnt = sleb->nodes_cnt;
+        if (nodes_cnt > 0) {
+                snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
+                                  list);
+                if (snod->type != UBIFS_MST_NODE)
+                        goto out;
+                memcpy(c->mst_node, snod->node, snod->len);
+                offs = snod->offs;
+        }
+        ubifs_scan_destroy(sleb);
+
+        lnum += 1;
+
+        sleb = ubifs_scan(c, lnum, 0, c->sbuf);
+        if (IS_ERR(sleb))
+                return PTR_ERR(sleb);
+        if (sleb->nodes_cnt != nodes_cnt)
+                goto out;
+        if (!sleb->nodes_cnt)
+                goto out;
+        snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
+        if (snod->type != UBIFS_MST_NODE)
+                goto out;
+        if (snod->offs != offs)
+                goto out;
+        if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
+                   (void *)snod->node + UBIFS_CH_SZ,
+                   UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
+                goto out;
+        c->mst_offs = offs;
+        ubifs_scan_destroy(sleb);
+        return 0;
+
+out:
+        ubifs_scan_destroy(sleb);
+        return -EINVAL;
+}
+
+/**
+ * validate_master - validate master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function validates data which was read from master node. Returns zero
+ * if the data is all right and %-EINVAL if not.
+ */
+static int validate_master(const struct ubifs_info *c)
+{
+        long long main_sz;
+        int err;
+
+        if (c->max_sqnum >= SQNUM_WATERMARK) {
+                err = 1;
+                goto out;
+        }
+
+        if (c->cmt_no >= c->max_sqnum) {
+                err = 2;
+                goto out;
+        }
+
+        if (c->highest_inum >= INUM_WATERMARK) {
+                err = 3;
+                goto out;
+        }
+
+        if (c->lhead_lnum < UBIFS_LOG_LNUM ||
+            c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
+            c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
+            c->lhead_offs & (c->min_io_size - 1)) {
+                err = 4;
+                goto out;
+        }
+
+        if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
+            c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
+                err = 5;
+                goto out;
+        }
+
+        if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
+            c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
+                err = 6;
+                goto out;
+        }
+
+        if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
+                err = 7;
+                goto out;
+        }
+
+        if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
+            c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
+            c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
+                err = 8;
+                goto out;
+        }
+
+        main_sz = (long long)c->main_lebs * c->leb_size;
+        if (c->old_idx_sz & 7 || c->old_idx_sz >= main_sz) {
+                err = 9;
+                goto out;
+        }
+
+        if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
+            c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
+                err = 10;
+                goto out;
+        }
+
+        if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
+            c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
+            c->nhead_offs > c->leb_size) {
+                err = 11;
+                goto out;
+        }
+
+        if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
+            c->ltab_offs < 0 ||
+            c->ltab_offs + c->ltab_sz > c->leb_size) {
+                err = 12;
+                goto out;
+        }
+
+        if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
+            c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
+            c->lsave_offs + c->lsave_sz > c->leb_size)) {
+                err = 13;
+                goto out;
+        }
+
+        if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
+                err = 14;
+                goto out;
+        }
+
+        if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
+                err = 15;
+                goto out;
+        }
+
+        if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
+                err = 16;
+                goto out;
+        }
+
+        if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
+            c->lst.total_free & 7) {
+                err = 17;
+                goto out;
+        }
+
+        if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
+                err = 18;
+                goto out;
+        }
+
+        if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
+                err = 19;
+                goto out;
+        }
+
+        if (c->lst.total_free + c->lst.total_dirty +
+            c->lst.total_used > main_sz) {
+                err = 20;
+                goto out;
+        }
+
+        if (c->lst.total_dead + c->lst.total_dark +
+            c->lst.total_used + c->old_idx_sz > main_sz) {
+                err = 21;
+                goto out;
+        }
+
+        if (c->lst.total_dead < 0 ||
+            c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
+            c->lst.total_dead & 7) {
+                err = 22;
+                goto out;
+        }
+
+        if (c->lst.total_dark < 0 ||
+            c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
+            c->lst.total_dark & 7) {
+                err = 23;
+                goto out;
+        }
+
+        return 0;
+
+out:
+        ubifs_err("bad master node at offset %d error %d", c->mst_offs, err);
+        dbg_dump_node(c, c->mst_node);
+        return -EINVAL;
+}
+
+/**
+ * ubifs_read_master - read master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function finds and reads the master node during file-system mount. If
+ * the flash is empty, it creates default master node as well. Returns zero in
+ * case of success and a negative error code in case of failure.
+ */
+int ubifs_read_master(struct ubifs_info *c)
+{
+        int err, old_leb_cnt;
+
+        c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
+        if (!c->mst_node)
+                return -ENOMEM;
+
+        err = scan_for_master(c);
+        if (err) {
+                err = ubifs_recover_master_node(c);
+                if (err)
+                        /*
+                         * Note, we do not free 'c->mst_node' here because the
+                         * unmount routine will take care of this.
+                         */
+                        return err;
+        }
+
+        /* Make sure that the recovery flag is clear */
+        c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
+
+        c->max_sqnum       = le64_to_cpu(c->mst_node->ch.sqnum);
+        c->highest_inum    = le64_to_cpu(c->mst_node->highest_inum);
+        c->cmt_no          = le64_to_cpu(c->mst_node->cmt_no);
+        c->zroot.lnum      = le32_to_cpu(c->mst_node->root_lnum);
+        c->zroot.offs      = le32_to_cpu(c->mst_node->root_offs);
+        c->zroot.len       = le32_to_cpu(c->mst_node->root_len);
+        c->lhead_lnum      = le32_to_cpu(c->mst_node->log_lnum);
+        c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
+        c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
+        c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
+        c->old_idx_sz      = le64_to_cpu(c->mst_node->index_size);
+        c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
+        c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
+        c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
+        c->nhead_offs      = le32_to_cpu(c->mst_node->nhead_offs);
+        c->ltab_lnum       = le32_to_cpu(c->mst_node->ltab_lnum);
+        c->ltab_offs       = le32_to_cpu(c->mst_node->ltab_offs);
+        c->lsave_lnum      = le32_to_cpu(c->mst_node->lsave_lnum);
+        c->lsave_offs      = le32_to_cpu(c->mst_node->lsave_offs);
+        c->lscan_lnum      = le32_to_cpu(c->mst_node->lscan_lnum);
+        c->lst.empty_lebs  = le32_to_cpu(c->mst_node->empty_lebs);
+        c->lst.idx_lebs    = le32_to_cpu(c->mst_node->idx_lebs);
+        old_leb_cnt        = le32_to_cpu(c->mst_node->leb_cnt);
+        c->lst.total_free  = le64_to_cpu(c->mst_node->total_free);
+        c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
+        c->lst.total_used  = le64_to_cpu(c->mst_node->total_used);
+        c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
+        c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);
+
+        c->calc_idx_sz = c->old_idx_sz;
+
+        if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
+                c->no_orphs = 1;
+
+        if (old_leb_cnt != c->leb_cnt) {
+                /* The file system has been resized */
+                int growth = c->leb_cnt - old_leb_cnt;
+
+                if (c->leb_cnt < old_leb_cnt ||
+                    c->leb_cnt < UBIFS_MIN_LEB_CNT) {
+                        ubifs_err("bad leb_cnt on master node");
+                        dbg_dump_node(c, c->mst_node);
+                        return -EINVAL;
+                }
+
+                dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
+                        old_leb_cnt, c->leb_cnt);
+                c->lst.empty_lebs += growth;
+                c->lst.total_free += growth * (long long)c->leb_size;
+                c->lst.total_dark += growth * (long long)c->dark_wm;
+
+                /*
+                 * Reflect changes back onto the master node. N.B. the master
+                 * node gets written immediately whenever mounting (or
+                 * remounting) in read-write mode, so we do not need to write it
+                 * here.
+                 */
+                c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
+                c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
+                c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
+                c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
+        }
+
+        err = validate_master(c);
+        if (err)
+                return err;
+
+        err = dbg_old_index_check_init(c, &c->zroot);
+
+        return err;
+}
+
+/**
+ * ubifs_write_master - write master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function writes the master node. The caller has to take the
+ * @c->mst_mutex lock before calling this function. Returns zero in case of
+ * success and a negative error code in case of failure. The master node is
+ * written twice to enable recovery.
+ */
+int ubifs_write_master(struct ubifs_info *c)
+{
+        int err, lnum, offs, len;
+
+        if (c->ro_media)
+                return -EINVAL;
+
+        lnum = UBIFS_MST_LNUM;
+        offs = c->mst_offs + c->mst_node_alsz;
+        len = UBIFS_MST_NODE_SZ;
+
+        if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
+                err = ubifs_leb_unmap(c, lnum);
+                if (err)
+                        return err;
+                offs = 0;
+        }
+
+        c->mst_offs = offs;
+        c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
+
+        err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
+        if (err)
+                return err;
+
+        lnum += 1;
+
+        if (offs == 0) {
+                err = ubifs_leb_unmap(c, lnum);
+                if (err)
+                        return err;
+        }
+        err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
+
+        return err;
+}