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Message-Id: <1210070159-22794-9-git-send-email-Artem.Bityutskiy@nokia.com>
Date: Tue, 6 May 2008 13:35:39 +0300
From: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
To: LKML <linux-kernel@...r.kernel.org>
Cc: Adrian Hunter <ext-adrian.hunter@...ia.com>,
Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Subject: [PATCH take 2 08/28] UBIFS: add superblock and master node
This patch contains the superblock and master node implementations.
The UBIFS superblock is read-only and contains only static data like
the default compression type. The superblock sits at the fixed
position and may be changed only with user-space tools. The master
node contains dynamic information like the position of the root
indexing node of the UBIFS indexing B-tree, and so on. The master
node is updated out-of-place.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@...ia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@...ia.com>
---
fs/ubifs/master.c | 387 +++++++++++++++++++++++++++++++++
fs/ubifs/sb.c | 612 +++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 999 insertions(+), 0 deletions(-)
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
new file mode 100644
index 0000000..d9dfc95
--- /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)
+{
+ unsigned 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 = c->main_lebs * (unsigned long long)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;
+}
diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
new file mode 100644
index 0000000..2fe4c7c
--- /dev/null
+++ b/fs/ubifs/sb.c
@@ -0,0 +1,612 @@
+/*
+ * 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 UBIFS superblock. The superblock is stored at the first
+ * LEB of the volume and is never changed by UBIFS. Only user-space tools may
+ * change it. The superblock node mostly contains geometry information.
+ */
+
+#include "ubifs.h"
+
+/*
+ * Default journal size in logical eraseblocks as a percent of total
+ * flash size.
+ */
+#define DEFAULT_JRN_PERCENT 5
+
+/* Default maximum journal size in bytes */
+#define DEFAULT_MAX_JRN (32*1024*1024)
+
+/* Default indexing tree fanout */
+#define DEFAULT_FANOUT 8
+
+/* Default number of LEBs for orphan information */
+#ifdef CONFIG_UBIFS_FS_DEBUG
+#define DEFAULT_ORPHAN_LEBS 2 /* 2 is better for testing */
+#else
+#define DEFAULT_ORPHAN_LEBS 1
+#endif
+
+/* Default number of journal heads */
+#define DEFAULT_JHEADS_CNT 1
+
+/* Default positions of different LEBs in the main area */
+#define DEFAULT_IDX_LEB 0
+#define DEFAULT_DATA_LEB 1
+#define DEFAULT_GC_LEB 2
+
+/* Default number of LEB numbers in LPT's save table */
+#define DEFAULT_LSAVE_CNT 256
+
+/* Default reserved pool size as a percent of maximum free space */
+#define DEFAULT_RP_PERCENT 5
+
+/* The default maximum size of reserved pool in bytes */
+#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
+
+/* Default UBIFS compressor */
+#define DEFAULT_COMPRESSOR UBIFS_COMPR_LZO
+
+/* Default time granularity in nanoseconds */
+#define DEFAULT_TIME_GRAN 1000000000
+
+/**
+ * create_default_filesystem - format empty UBI volume.
+ * @c: UBIFS file-system description object
+ *
+ * This function creates default empty file-system. Returns zero in case of
+ * success and a negative error code in case of failure.
+ */
+static int create_default_filesystem(struct ubifs_info *c)
+{
+ struct ubifs_sb_node *sup;
+ struct ubifs_mst_node *mst;
+ struct ubifs_idx_node *idx;
+ struct ubifs_branch *br;
+ struct ubifs_ino_node *ino;
+ struct ubifs_cs_node *cs;
+ union ubifs_key key;
+ int err, tmp, jrn_lebs, log_lebs, max_buds, main_lebs, main_first;
+ int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
+ uint64_t tmp64, main_bytes;
+
+ /* Some functions called from here depend on the @c->key_len filed */
+ c->key_len = UBIFS_SK_LEN;
+
+ /*
+ * First of all, we have to calculate default file-system geometry -
+ * log size, journal size, etc.
+ */
+ c->max_leb_cnt = c->leb_cnt;
+ if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JRN_PERCENT)
+ /* We can first multiply then divide and have no overflow */
+ jrn_lebs = c->leb_cnt * DEFAULT_JRN_PERCENT / 100;
+ else
+ jrn_lebs = (c->leb_cnt / 100) * DEFAULT_JRN_PERCENT;
+
+ if (jrn_lebs < UBIFS_MIN_JRN_LEBS)
+ jrn_lebs = UBIFS_MIN_JRN_LEBS;
+ if (jrn_lebs * c->leb_size > DEFAULT_MAX_JRN)
+ jrn_lebs = DEFAULT_MAX_JRN / c->leb_size;
+
+ /*
+ * The log should be large enough to fit reference nodes for all bud
+ * LEBs. Because buds do not have to start from the beginning of LEBs
+ * (half of the LEB may contain committed data), the log should
+ * generally be larger, make it twice as large.
+ */
+ tmp = 2 * (c->ref_node_alsz * jrn_lebs) + c->leb_size - 1;
+ log_lebs = tmp / c->leb_size;
+ /* Plus one LEB reserved for commit */
+ log_lebs += 1;
+ /* And some extra space to allow writes while committing */
+ log_lebs += 1;
+
+ max_buds = jrn_lebs - log_lebs;
+ if (max_buds < UBIFS_MIN_BUD_LEBS)
+ max_buds = UBIFS_MIN_BUD_LEBS;
+
+ /*
+ * Orphan nodes are stored in a separate area. One node can store a lot
+ * of orphan inode numbers, but when new orphan comes we just add a new
+ * orphan node. At some point the nodes are consolidated into one
+ * orphan node.
+ */
+ orph_lebs = DEFAULT_ORPHAN_LEBS;
+
+ main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
+ main_lebs -= orph_lebs;
+
+ lpt_first = UBIFS_LOG_LNUM + log_lebs;
+ c->lsave_cnt = DEFAULT_LSAVE_CNT;
+ err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
+ &big_lpt);
+ if (err)
+ return err;
+
+ dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
+ lpt_first + lpt_lebs - 1);
+
+ main_first = c->leb_cnt - main_lebs;
+
+ /* Create default superblock */
+ tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
+ sup = kzalloc(tmp, GFP_KERNEL);
+ if (!sup)
+ return -ENOMEM;
+
+ tmp64 = (uint64_t)max_buds * c->leb_size;
+ if (big_lpt)
+ sup_flags |= UBIFS_FLG_BIGLPT;
+
+ sup->ch.node_type = UBIFS_SB_NODE;
+ sup->key_hash = UBIFS_KEY_HASH_R5;
+ sup->flags = cpu_to_le32(sup_flags);
+ sup->min_io_size = cpu_to_le32(c->min_io_size);
+ sup->leb_size = cpu_to_le32(c->leb_size);
+ sup->leb_cnt = cpu_to_le32(c->leb_cnt);
+ sup->max_leb_cnt = cpu_to_le32(c->max_leb_cnt);
+ sup->max_bud_bytes = cpu_to_le64(tmp64);
+ sup->log_lebs = cpu_to_le32(log_lebs);
+ sup->lpt_lebs = cpu_to_le32(lpt_lebs);
+ sup->orph_lebs = cpu_to_le32(orph_lebs);
+ sup->jhead_cnt = cpu_to_le32(DEFAULT_JHEADS_CNT);
+ sup->fanout = cpu_to_le32(DEFAULT_FANOUT);
+ sup->lsave_cnt = cpu_to_le32(c->lsave_cnt);
+ sup->fmt_vers = cpu_to_le32(UBIFS_FORMAT_VERSION);
+ sup->default_compr = cpu_to_le16(DEFAULT_COMPRESSOR);
+ sup->time_gran = cpu_to_le32(DEFAULT_TIME_GRAN);
+
+ main_bytes = (uint64_t)main_lebs * c->leb_size;
+ tmp64 = main_bytes * DEFAULT_RP_PERCENT;
+ do_div(tmp64, 100);
+ if (tmp64 > DEFAULT_MAX_RP_SIZE)
+ tmp64 = DEFAULT_MAX_RP_SIZE;
+ sup->rp_size = cpu_to_le64(tmp64);
+
+ err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
+ kfree(sup);
+ if (err)
+ return err;
+
+ dbg_gen("default superblock created at LEB 0:0");
+
+ /* Create default master node */
+ mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
+ if (!mst)
+ return -ENOMEM;
+
+ mst->ch.node_type = UBIFS_MST_NODE;
+ mst->log_lnum = cpu_to_le32(UBIFS_LOG_LNUM);
+ mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
+ mst->cmt_no = cpu_to_le64(0);
+ mst->root_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
+ mst->root_offs = cpu_to_le32(0);
+ tmp = ubifs_idx_node_sz(c, 1);
+ mst->root_len = cpu_to_le32(tmp);
+ mst->gc_lnum = cpu_to_le32(main_first + DEFAULT_GC_LEB);
+ mst->ihead_lnum = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
+ mst->ihead_offs = cpu_to_le32(ALIGN(tmp, c->min_io_size));
+ mst->index_size = cpu_to_le64(ALIGN(tmp, 8));
+ mst->lpt_lnum = cpu_to_le32(c->lpt_lnum);
+ mst->lpt_offs = cpu_to_le32(c->lpt_offs);
+ mst->nhead_lnum = cpu_to_le32(c->nhead_lnum);
+ mst->nhead_offs = cpu_to_le32(c->nhead_offs);
+ mst->ltab_lnum = cpu_to_le32(c->ltab_lnum);
+ mst->ltab_offs = cpu_to_le32(c->ltab_offs);
+ mst->lsave_lnum = cpu_to_le32(c->lsave_lnum);
+ mst->lsave_offs = cpu_to_le32(c->lsave_offs);
+ mst->lscan_lnum = cpu_to_le32(main_first);
+ mst->empty_lebs = cpu_to_le32(main_lebs - 2);
+ mst->idx_lebs = cpu_to_le32(1);
+ mst->leb_cnt = cpu_to_le32(c->leb_cnt);
+
+ /* Calculate lprops statistics */
+ tmp64 = main_bytes;
+ tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
+ tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
+ mst->total_free = cpu_to_le64(tmp64);
+
+ tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
+ ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
+ UBIFS_INO_NODE_SZ;
+ tmp64 += ino_waste;
+ tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
+ mst->total_dirty = cpu_to_le64(tmp64);
+
+ /* The indexing LEB does not contribute to dark space */
+ tmp64 = (c->main_lebs - 1) * c->dark_wm;
+ mst->total_dark = cpu_to_le64(tmp64);
+
+ mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
+
+ err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
+ UBI_UNKNOWN);
+ if (err) {
+ kfree(mst);
+ return err;
+ }
+ err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0,
+ UBI_UNKNOWN);
+ kfree(mst);
+ if (err)
+ return err;
+
+ dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
+
+ /* Create the root indexing node */
+ tmp = ubifs_idx_node_sz(c, 1);
+ idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
+ if (!idx)
+ return -ENOMEM;
+
+ c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
+ c->key_hash = key_r5_hash;
+
+ idx->ch.node_type = UBIFS_IDX_NODE;
+ idx->child_cnt = cpu_to_le16(1);
+ ino_key_init(c, &key, UBIFS_ROOT_INO);
+ br = ubifs_idx_branch(c, idx, 0);
+ key_write_idx(c, &key, &br->key);
+ br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
+ br->len = cpu_to_le32(UBIFS_INO_NODE_SZ);
+ err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0,
+ UBI_UNKNOWN);
+ kfree(idx);
+ if (err)
+ return err;
+
+ dbg_gen("default root indexing node created LEB %d:0",
+ main_first + DEFAULT_IDX_LEB);
+
+ /* Create default root inode */
+ tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
+ ino = kzalloc(tmp, GFP_KERNEL);
+ if (!ino)
+ return -ENOMEM;
+
+ ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
+ ino->ch.node_type = UBIFS_INO_NODE;
+ ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
+ ino->nlink = cpu_to_le32(2);
+ tmp = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
+ ino->atime_sec = tmp;
+ ino->ctime_sec = tmp;
+ ino->mtime_sec = tmp;
+ ino->atime_nsec = 0;
+ ino->ctime_nsec = 0;
+ ino->mtime_nsec = 0;
+ ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
+ ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
+
+ /* Set compression enabled by default */
+ ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
+
+ err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
+ main_first + DEFAULT_DATA_LEB, 0,
+ UBI_UNKNOWN);
+ kfree(ino);
+ if (err)
+ return err;
+
+ dbg_gen("root inode created at LEB %d:0",
+ main_first + DEFAULT_DATA_LEB);
+
+ /*
+ * The first node in the log has to be the commit start node. This is
+ * always the case during normal file-system operation. Write a fake
+ * commit start node to the log.
+ */
+ tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
+ cs = kzalloc(tmp, GFP_KERNEL);
+ if (!cs)
+ return -ENOMEM;
+
+ cs->ch.node_type = UBIFS_CS_NODE;
+ err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
+ 0, UBI_UNKNOWN);
+ kfree(cs);
+
+ ubifs_msg("default file-system created");
+ return 0;
+}
+
+/**
+ * validate_sb - validate superblock node.
+ * @c: UBIFS file-system description object
+ * @sup: superblock node
+ *
+ * This function validates superblock node @sup. Since most of data was read
+ * from the superblock and stored in @c, the function validates fields in @c
+ * instead. Returns zero in case of success and %-EINVAL in case of validation
+ * failure.
+ */
+static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
+{
+ long long max_bytes;
+ int err = 1;
+
+ if (!c->key_hash) {
+ err = 2;
+ goto failed;
+ }
+
+ if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
+ err = 3;
+ goto failed;
+ }
+
+ if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
+ ubifs_err("min. I/O unit mismatch: %d in superblock, %d real",
+ le32_to_cpu(sup->min_io_size), c->min_io_size);
+ goto failed;
+ }
+
+ if (le32_to_cpu(sup->leb_size) != c->leb_size) {
+ ubifs_err("LEB size mismatch: %d in superblock, %d real",
+ le32_to_cpu(sup->leb_size), c->leb_size);
+ goto failed;
+ }
+
+ if (c->leb_cnt < UBIFS_MIN_LEB_CNT || c->leb_cnt > c->vi.size) {
+ ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, "
+ "%d minimum required", c->leb_cnt, c->vi.size,
+ UBIFS_MIN_LEB_CNT);
+ goto failed;
+ }
+
+ if (c->max_leb_cnt < c->leb_cnt) {
+ ubifs_err("max. LEB count %d less than LEB count %d",
+ c->max_leb_cnt, c->leb_cnt);
+ goto failed;
+ }
+
+ if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
+ c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
+ c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
+ c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
+ err = 6;
+ goto failed;
+ }
+
+ if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
+ err = 7;
+ goto failed;
+ }
+
+ if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS ||
+ c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) {
+ err = 8;
+ goto failed;
+ }
+
+ if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
+ c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
+ err = 9;
+ goto failed;
+ }
+
+ if (c->fanout < UBIFS_MIN_FANOUT ||
+ ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
+ err = 10;
+ goto failed;
+ }
+
+ if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
+ c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
+ c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
+ err = 11;
+ goto failed;
+ }
+
+ if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
+ c->orph_lebs + c->main_lebs != c->leb_cnt) {
+ err = 12;
+ goto failed;
+ }
+
+ if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
+ err = 13;
+ goto failed;
+ }
+
+ max_bytes = c->main_lebs * (long long)c->leb_size;
+ if (c->rp_size < 0 || max_bytes < c->rp_size) {
+ err = 14;
+ goto failed;
+ }
+
+ if (le32_to_cpu(sup->time_gran) > 1000000000 ||
+ le32_to_cpu(sup->time_gran) < 1) {
+ err = 15;
+ goto failed;
+ }
+
+ return 0;
+
+failed:
+ ubifs_err("bad superblock, error %d", err);
+ dbg_dump_node(c, sup);
+ return -EINVAL;
+}
+
+/**
+ * ubifs_read_sb_node - read superblock node.
+ * @c: UBIFS file-system description object
+ *
+ * This function returns a pointer to the superblock node or a negative error
+ * code.
+ */
+struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
+{
+ struct ubifs_sb_node *sup;
+ int err;
+
+ sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
+ if (!sup)
+ return ERR_PTR(-ENOMEM);
+
+ err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
+ UBIFS_SB_LNUM, 0);
+ if (err) {
+ kfree(sup);
+ return ERR_PTR(err);
+ }
+
+ return sup;
+}
+
+/**
+ * ubifs_write_sb_node - write superblock node.
+ * @c: UBIFS file-system description object
+ * @sup: superblock node read with 'ubifs_read_sb_node()'
+ *
+ * This function returns %0 on success and a negative error code on failure.
+ */
+int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
+{
+ int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
+
+ ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
+ return ubi_leb_change(c->ubi, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM);
+}
+
+/**
+ * ubifs_read_superblock - read superblock.
+ * @c: UBIFS file-system description object
+ *
+ * This function finds, reads and checks the superblock. If an empty UBI volume
+ * is being mounted, this function creates default superblock. Returns zero in
+ * case of success, and a negative error code in case of failure.
+ */
+int ubifs_read_superblock(struct ubifs_info *c)
+{
+ int err, sup_flags;
+ struct ubifs_sb_node *sup;
+
+ if (c->empty) {
+ err = create_default_filesystem(c);
+ if (err)
+ return err;
+ }
+
+ sup = ubifs_read_sb_node(c);
+ if (IS_ERR(sup))
+ return PTR_ERR(sup);
+
+ /*
+ * The software supports all previous versions but not future versions,
+ * due to the unavailability of time-travelling equipment.
+ */
+ c->fmt_vers = le32_to_cpu(sup->fmt_vers);
+ if (c->fmt_vers > UBIFS_FORMAT_VERSION) {
+ ubifs_err("on-flash format version is %d, but software only "
+ "supports up to version %d", c->fmt_vers,
+ UBIFS_FORMAT_VERSION);
+ err = -EINVAL;
+ goto out;
+ }
+
+ if (c->fmt_vers == 1) {
+ ubifs_err("this on-flash format is not supported");
+ err = -EINVAL;
+ goto out;
+ }
+
+ switch (sup->key_hash) {
+ case UBIFS_KEY_HASH_R5:
+ c->key_hash = key_r5_hash;
+ c->key_hash_type = UBIFS_KEY_HASH_R5;
+ break;
+
+ case UBIFS_KEY_HASH_TEST:
+ c->key_hash = key_test_hash;
+ c->key_hash_type = UBIFS_KEY_HASH_TEST;
+ break;
+ };
+
+ c->key_fmt = sup->key_fmt;
+
+ switch (c->key_fmt) {
+ case UBIFS_SIMPLE_KEY_FMT:
+ c->key_len = UBIFS_SK_LEN;
+ break;
+ default:
+ ubifs_err("unsupported key format");
+ err = -EINVAL;
+ goto out;
+ }
+
+ c->leb_cnt = le32_to_cpu(sup->leb_cnt);
+ c->max_leb_cnt = le32_to_cpu(sup->max_leb_cnt);
+ c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
+ c->log_lebs = le32_to_cpu(sup->log_lebs);
+ c->lpt_lebs = le32_to_cpu(sup->lpt_lebs);
+ c->orph_lebs = le32_to_cpu(sup->orph_lebs);
+ c->jhead_cnt = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
+ c->fanout = le32_to_cpu(sup->fanout);
+ c->lsave_cnt = le32_to_cpu(sup->lsave_cnt);
+ c->default_compr = le16_to_cpu(sup->default_compr);
+ c->rp_size = le64_to_cpu(sup->rp_size);
+ c->rp_uid = le32_to_cpu(sup->rp_uid);
+ c->rp_gid = le32_to_cpu(sup->rp_gid);
+ sup_flags = le32_to_cpu(sup->flags);
+
+ c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
+
+ c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
+
+ /* Automatically increase file system size to the maximum size */
+ c->old_leb_cnt = c->leb_cnt;
+ if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
+ c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
+ if (c->vfs_sb->s_flags & MS_RDONLY)
+ dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
+ c->old_leb_cnt, c->leb_cnt);
+ else {
+ dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
+ c->old_leb_cnt, c->leb_cnt);
+ sup->leb_cnt = cpu_to_le32(c->leb_cnt);
+ err = ubifs_write_sb_node(c, sup);
+ if (err)
+ goto out;
+ c->old_leb_cnt = c->leb_cnt;
+ }
+ }
+
+ c->log_bytes = (long long)c->log_lebs * c->leb_size;
+ c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
+ c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
+ c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
+ c->orph_first = c->lpt_last + 1;
+ c->orph_last = c->orph_first + c->orph_lebs - 1;
+ c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
+ c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
+ c->main_first = c->leb_cnt - c->main_lebs;
+ c->report_rp_size = ubifs_reported_space(c, c->rp_size);
+
+ err = validate_sb(c, sup);
+out:
+ kfree(sup);
+ return err;
+}
--
1.5.4.1
--
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