File-copy from v4.4.100
This is the result of 'cp' from a linux-stable tree with the 'v4.4.100'
tag checked out (commit 26d6298789e695c9f627ce49a7bbd2286405798a) on
git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Please refer to that tree for all history prior to this point.
Change-Id: I8a9ee2aea93cd29c52c847d0ce33091a73ae6afe
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
new file mode 100644
index 0000000..1fd90c0
--- /dev/null
+++ b/fs/ubifs/super.c
@@ -0,0 +1,2311 @@
+/*
+ * 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 initialization and VFS superblock operations. Some
+ * initialization stuff which is rather large and complex is placed at
+ * corresponding subsystems, but most of it is here.
+ */
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/ctype.h>
+#include <linux/kthread.h>
+#include <linux/parser.h>
+#include <linux/seq_file.h>
+#include <linux/mount.h>
+#include <linux/math64.h>
+#include <linux/writeback.h>
+#include "ubifs.h"
+
+/*
+ * Maximum amount of memory we may 'kmalloc()' without worrying that we are
+ * allocating too much.
+ */
+#define UBIFS_KMALLOC_OK (128*1024)
+
+/* Slab cache for UBIFS inodes */
+struct kmem_cache *ubifs_inode_slab;
+
+/* UBIFS TNC shrinker description */
+static struct shrinker ubifs_shrinker_info = {
+ .scan_objects = ubifs_shrink_scan,
+ .count_objects = ubifs_shrink_count,
+ .seeks = DEFAULT_SEEKS,
+};
+
+/**
+ * validate_inode - validate inode.
+ * @c: UBIFS file-system description object
+ * @inode: the inode to validate
+ *
+ * This is a helper function for 'ubifs_iget()' which validates various fields
+ * of a newly built inode to make sure they contain sane values and prevent
+ * possible vulnerabilities. Returns zero if the inode is all right and
+ * a non-zero error code if not.
+ */
+static int validate_inode(struct ubifs_info *c, const struct inode *inode)
+{
+ int err;
+ const struct ubifs_inode *ui = ubifs_inode(inode);
+
+ if (inode->i_size > c->max_inode_sz) {
+ ubifs_err(c, "inode is too large (%lld)",
+ (long long)inode->i_size);
+ return 1;
+ }
+
+ if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
+ ubifs_err(c, "unknown compression type %d", ui->compr_type);
+ return 2;
+ }
+
+ if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
+ return 3;
+
+ if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
+ return 4;
+
+ if (ui->xattr && !S_ISREG(inode->i_mode))
+ return 5;
+
+ if (!ubifs_compr_present(ui->compr_type)) {
+ ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
+ inode->i_ino, ubifs_compr_name(ui->compr_type));
+ }
+
+ err = dbg_check_dir(c, inode);
+ return err;
+}
+
+struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
+{
+ int err;
+ union ubifs_key key;
+ struct ubifs_ino_node *ino;
+ struct ubifs_info *c = sb->s_fs_info;
+ struct inode *inode;
+ struct ubifs_inode *ui;
+
+ dbg_gen("inode %lu", inum);
+
+ inode = iget_locked(sb, inum);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+ if (!(inode->i_state & I_NEW))
+ return inode;
+ ui = ubifs_inode(inode);
+
+ ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
+ if (!ino) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ ino_key_init(c, &key, inode->i_ino);
+
+ err = ubifs_tnc_lookup(c, &key, ino);
+ if (err)
+ goto out_ino;
+
+ inode->i_flags |= S_NOCMTIME;
+#ifndef CONFIG_UBIFS_ATIME_SUPPORT
+ inode->i_flags |= S_NOATIME;
+#endif
+ set_nlink(inode, le32_to_cpu(ino->nlink));
+ i_uid_write(inode, le32_to_cpu(ino->uid));
+ i_gid_write(inode, le32_to_cpu(ino->gid));
+ inode->i_atime.tv_sec = (int64_t)le64_to_cpu(ino->atime_sec);
+ inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
+ inode->i_mtime.tv_sec = (int64_t)le64_to_cpu(ino->mtime_sec);
+ inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
+ inode->i_ctime.tv_sec = (int64_t)le64_to_cpu(ino->ctime_sec);
+ inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
+ inode->i_mode = le32_to_cpu(ino->mode);
+ inode->i_size = le64_to_cpu(ino->size);
+
+ ui->data_len = le32_to_cpu(ino->data_len);
+ ui->flags = le32_to_cpu(ino->flags);
+ ui->compr_type = le16_to_cpu(ino->compr_type);
+ ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
+ ui->xattr_cnt = le32_to_cpu(ino->xattr_cnt);
+ ui->xattr_size = le32_to_cpu(ino->xattr_size);
+ ui->xattr_names = le32_to_cpu(ino->xattr_names);
+ ui->synced_i_size = ui->ui_size = inode->i_size;
+
+ ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
+
+ err = validate_inode(c, inode);
+ if (err)
+ goto out_invalid;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_mapping->a_ops = &ubifs_file_address_operations;
+ inode->i_op = &ubifs_file_inode_operations;
+ inode->i_fop = &ubifs_file_operations;
+ if (ui->xattr) {
+ ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_ino;
+ }
+ memcpy(ui->data, ino->data, ui->data_len);
+ ((char *)ui->data)[ui->data_len] = '\0';
+ } else if (ui->data_len != 0) {
+ err = 10;
+ goto out_invalid;
+ }
+ break;
+ case S_IFDIR:
+ inode->i_op = &ubifs_dir_inode_operations;
+ inode->i_fop = &ubifs_dir_operations;
+ if (ui->data_len != 0) {
+ err = 11;
+ goto out_invalid;
+ }
+ break;
+ case S_IFLNK:
+ inode->i_op = &ubifs_symlink_inode_operations;
+ if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
+ err = 12;
+ goto out_invalid;
+ }
+ ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_ino;
+ }
+ memcpy(ui->data, ino->data, ui->data_len);
+ ((char *)ui->data)[ui->data_len] = '\0';
+ inode->i_link = ui->data;
+ break;
+ case S_IFBLK:
+ case S_IFCHR:
+ {
+ dev_t rdev;
+ union ubifs_dev_desc *dev;
+
+ ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_ino;
+ }
+
+ dev = (union ubifs_dev_desc *)ino->data;
+ if (ui->data_len == sizeof(dev->new))
+ rdev = new_decode_dev(le32_to_cpu(dev->new));
+ else if (ui->data_len == sizeof(dev->huge))
+ rdev = huge_decode_dev(le64_to_cpu(dev->huge));
+ else {
+ err = 13;
+ goto out_invalid;
+ }
+ memcpy(ui->data, ino->data, ui->data_len);
+ inode->i_op = &ubifs_file_inode_operations;
+ init_special_inode(inode, inode->i_mode, rdev);
+ break;
+ }
+ case S_IFSOCK:
+ case S_IFIFO:
+ inode->i_op = &ubifs_file_inode_operations;
+ init_special_inode(inode, inode->i_mode, 0);
+ if (ui->data_len != 0) {
+ err = 14;
+ goto out_invalid;
+ }
+ break;
+ default:
+ err = 15;
+ goto out_invalid;
+ }
+
+ kfree(ino);
+ ubifs_set_inode_flags(inode);
+ unlock_new_inode(inode);
+ return inode;
+
+out_invalid:
+ ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
+ ubifs_dump_node(c, ino);
+ ubifs_dump_inode(c, inode);
+ err = -EINVAL;
+out_ino:
+ kfree(ino);
+out:
+ ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
+ iget_failed(inode);
+ return ERR_PTR(err);
+}
+
+static struct inode *ubifs_alloc_inode(struct super_block *sb)
+{
+ struct ubifs_inode *ui;
+
+ ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
+ if (!ui)
+ return NULL;
+
+ memset((void *)ui + sizeof(struct inode), 0,
+ sizeof(struct ubifs_inode) - sizeof(struct inode));
+ mutex_init(&ui->ui_mutex);
+ spin_lock_init(&ui->ui_lock);
+ return &ui->vfs_inode;
+};
+
+static void ubifs_i_callback(struct rcu_head *head)
+{
+ struct inode *inode = container_of(head, struct inode, i_rcu);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ kmem_cache_free(ubifs_inode_slab, ui);
+}
+
+static void ubifs_destroy_inode(struct inode *inode)
+{
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ kfree(ui->data);
+ call_rcu(&inode->i_rcu, ubifs_i_callback);
+}
+
+/*
+ * Note, Linux write-back code calls this without 'i_mutex'.
+ */
+static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
+{
+ int err = 0;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ ubifs_assert(!ui->xattr);
+ if (is_bad_inode(inode))
+ return 0;
+
+ mutex_lock(&ui->ui_mutex);
+ /*
+ * Due to races between write-back forced by budgeting
+ * (see 'sync_some_inodes()') and background write-back, the inode may
+ * have already been synchronized, do not do this again. This might
+ * also happen if it was synchronized in an VFS operation, e.g.
+ * 'ubifs_link()'.
+ */
+ if (!ui->dirty) {
+ mutex_unlock(&ui->ui_mutex);
+ return 0;
+ }
+
+ /*
+ * As an optimization, do not write orphan inodes to the media just
+ * because this is not needed.
+ */
+ dbg_gen("inode %lu, mode %#x, nlink %u",
+ inode->i_ino, (int)inode->i_mode, inode->i_nlink);
+ if (inode->i_nlink) {
+ err = ubifs_jnl_write_inode(c, inode);
+ if (err)
+ ubifs_err(c, "can't write inode %lu, error %d",
+ inode->i_ino, err);
+ else
+ err = dbg_check_inode_size(c, inode, ui->ui_size);
+ }
+
+ ui->dirty = 0;
+ mutex_unlock(&ui->ui_mutex);
+ ubifs_release_dirty_inode_budget(c, ui);
+ return err;
+}
+
+static void ubifs_evict_inode(struct inode *inode)
+{
+ int err;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ if (ui->xattr)
+ /*
+ * Extended attribute inode deletions are fully handled in
+ * 'ubifs_removexattr()'. These inodes are special and have
+ * limited usage, so there is nothing to do here.
+ */
+ goto out;
+
+ dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
+ ubifs_assert(!atomic_read(&inode->i_count));
+
+ truncate_inode_pages_final(&inode->i_data);
+
+ if (inode->i_nlink)
+ goto done;
+
+ if (is_bad_inode(inode))
+ goto out;
+
+ ui->ui_size = inode->i_size = 0;
+ err = ubifs_jnl_delete_inode(c, inode);
+ if (err)
+ /*
+ * Worst case we have a lost orphan inode wasting space, so a
+ * simple error message is OK here.
+ */
+ ubifs_err(c, "can't delete inode %lu, error %d",
+ inode->i_ino, err);
+
+out:
+ if (ui->dirty)
+ ubifs_release_dirty_inode_budget(c, ui);
+ else {
+ /* We've deleted something - clean the "no space" flags */
+ c->bi.nospace = c->bi.nospace_rp = 0;
+ smp_wmb();
+ }
+done:
+ clear_inode(inode);
+}
+
+static void ubifs_dirty_inode(struct inode *inode, int flags)
+{
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ ubifs_assert(mutex_is_locked(&ui->ui_mutex));
+ if (!ui->dirty) {
+ ui->dirty = 1;
+ dbg_gen("inode %lu", inode->i_ino);
+ }
+}
+
+static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
+{
+ struct ubifs_info *c = dentry->d_sb->s_fs_info;
+ unsigned long long free;
+ __le32 *uuid = (__le32 *)c->uuid;
+
+ free = ubifs_get_free_space(c);
+ dbg_gen("free space %lld bytes (%lld blocks)",
+ free, free >> UBIFS_BLOCK_SHIFT);
+
+ buf->f_type = UBIFS_SUPER_MAGIC;
+ buf->f_bsize = UBIFS_BLOCK_SIZE;
+ buf->f_blocks = c->block_cnt;
+ buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
+ if (free > c->report_rp_size)
+ buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
+ else
+ buf->f_bavail = 0;
+ buf->f_files = 0;
+ buf->f_ffree = 0;
+ buf->f_namelen = UBIFS_MAX_NLEN;
+ buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
+ buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
+ ubifs_assert(buf->f_bfree <= c->block_cnt);
+ return 0;
+}
+
+static int ubifs_show_options(struct seq_file *s, struct dentry *root)
+{
+ struct ubifs_info *c = root->d_sb->s_fs_info;
+
+ if (c->mount_opts.unmount_mode == 2)
+ seq_puts(s, ",fast_unmount");
+ else if (c->mount_opts.unmount_mode == 1)
+ seq_puts(s, ",norm_unmount");
+
+ if (c->mount_opts.bulk_read == 2)
+ seq_puts(s, ",bulk_read");
+ else if (c->mount_opts.bulk_read == 1)
+ seq_puts(s, ",no_bulk_read");
+
+ if (c->mount_opts.chk_data_crc == 2)
+ seq_puts(s, ",chk_data_crc");
+ else if (c->mount_opts.chk_data_crc == 1)
+ seq_puts(s, ",no_chk_data_crc");
+
+ if (c->mount_opts.override_compr) {
+ seq_printf(s, ",compr=%s",
+ ubifs_compr_name(c->mount_opts.compr_type));
+ }
+
+ return 0;
+}
+
+static int ubifs_sync_fs(struct super_block *sb, int wait)
+{
+ int i, err;
+ struct ubifs_info *c = sb->s_fs_info;
+
+ /*
+ * Zero @wait is just an advisory thing to help the file system shove
+ * lots of data into the queues, and there will be the second
+ * '->sync_fs()' call, with non-zero @wait.
+ */
+ if (!wait)
+ return 0;
+
+ /*
+ * Synchronize write buffers, because 'ubifs_run_commit()' does not
+ * do this if it waits for an already running commit.
+ */
+ for (i = 0; i < c->jhead_cnt; i++) {
+ err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
+ if (err)
+ return err;
+ }
+
+ /*
+ * Strictly speaking, it is not necessary to commit the journal here,
+ * synchronizing write-buffers would be enough. But committing makes
+ * UBIFS free space predictions much more accurate, so we want to let
+ * the user be able to get more accurate results of 'statfs()' after
+ * they synchronize the file system.
+ */
+ err = ubifs_run_commit(c);
+ if (err)
+ return err;
+
+ return ubi_sync(c->vi.ubi_num);
+}
+
+/**
+ * init_constants_early - initialize UBIFS constants.
+ * @c: UBIFS file-system description object
+ *
+ * This function initialize UBIFS constants which do not need the superblock to
+ * be read. It also checks that the UBI volume satisfies basic UBIFS
+ * requirements. Returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+static int init_constants_early(struct ubifs_info *c)
+{
+ if (c->vi.corrupted) {
+ ubifs_warn(c, "UBI volume is corrupted - read-only mode");
+ c->ro_media = 1;
+ }
+
+ if (c->di.ro_mode) {
+ ubifs_msg(c, "read-only UBI device");
+ c->ro_media = 1;
+ }
+
+ if (c->vi.vol_type == UBI_STATIC_VOLUME) {
+ ubifs_msg(c, "static UBI volume - read-only mode");
+ c->ro_media = 1;
+ }
+
+ c->leb_cnt = c->vi.size;
+ c->leb_size = c->vi.usable_leb_size;
+ c->leb_start = c->di.leb_start;
+ c->half_leb_size = c->leb_size / 2;
+ c->min_io_size = c->di.min_io_size;
+ c->min_io_shift = fls(c->min_io_size) - 1;
+ c->max_write_size = c->di.max_write_size;
+ c->max_write_shift = fls(c->max_write_size) - 1;
+
+ if (c->leb_size < UBIFS_MIN_LEB_SZ) {
+ ubifs_err(c, "too small LEBs (%d bytes), min. is %d bytes",
+ c->leb_size, UBIFS_MIN_LEB_SZ);
+ return -EINVAL;
+ }
+
+ if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
+ ubifs_err(c, "too few LEBs (%d), min. is %d",
+ c->leb_cnt, UBIFS_MIN_LEB_CNT);
+ return -EINVAL;
+ }
+
+ if (!is_power_of_2(c->min_io_size)) {
+ ubifs_err(c, "bad min. I/O size %d", c->min_io_size);
+ return -EINVAL;
+ }
+
+ /*
+ * Maximum write size has to be greater or equivalent to min. I/O
+ * size, and be multiple of min. I/O size.
+ */
+ if (c->max_write_size < c->min_io_size ||
+ c->max_write_size % c->min_io_size ||
+ !is_power_of_2(c->max_write_size)) {
+ ubifs_err(c, "bad write buffer size %d for %d min. I/O unit",
+ c->max_write_size, c->min_io_size);
+ return -EINVAL;
+ }
+
+ /*
+ * UBIFS aligns all node to 8-byte boundary, so to make function in
+ * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
+ * less than 8.
+ */
+ if (c->min_io_size < 8) {
+ c->min_io_size = 8;
+ c->min_io_shift = 3;
+ if (c->max_write_size < c->min_io_size) {
+ c->max_write_size = c->min_io_size;
+ c->max_write_shift = c->min_io_shift;
+ }
+ }
+
+ c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
+ c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
+
+ /*
+ * Initialize node length ranges which are mostly needed for node
+ * length validation.
+ */
+ c->ranges[UBIFS_PAD_NODE].len = UBIFS_PAD_NODE_SZ;
+ c->ranges[UBIFS_SB_NODE].len = UBIFS_SB_NODE_SZ;
+ c->ranges[UBIFS_MST_NODE].len = UBIFS_MST_NODE_SZ;
+ c->ranges[UBIFS_REF_NODE].len = UBIFS_REF_NODE_SZ;
+ c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
+ c->ranges[UBIFS_CS_NODE].len = UBIFS_CS_NODE_SZ;
+
+ c->ranges[UBIFS_INO_NODE].min_len = UBIFS_INO_NODE_SZ;
+ c->ranges[UBIFS_INO_NODE].max_len = UBIFS_MAX_INO_NODE_SZ;
+ c->ranges[UBIFS_ORPH_NODE].min_len =
+ UBIFS_ORPH_NODE_SZ + sizeof(__le64);
+ c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
+ c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
+ c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
+ c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
+ c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
+ c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
+ c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
+ /*
+ * Minimum indexing node size is amended later when superblock is
+ * read and the key length is known.
+ */
+ c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
+ /*
+ * Maximum indexing node size is amended later when superblock is
+ * read and the fanout is known.
+ */
+ c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
+
+ /*
+ * Initialize dead and dark LEB space watermarks. See gc.c for comments
+ * about these values.
+ */
+ c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
+ c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
+
+ /*
+ * Calculate how many bytes would be wasted at the end of LEB if it was
+ * fully filled with data nodes of maximum size. This is used in
+ * calculations when reporting free space.
+ */
+ c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
+
+ /* Buffer size for bulk-reads */
+ c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
+ if (c->max_bu_buf_len > c->leb_size)
+ c->max_bu_buf_len = c->leb_size;
+ return 0;
+}
+
+/**
+ * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB the write-buffer was synchronized to
+ * @free: how many free bytes left in this LEB
+ * @pad: how many bytes were padded
+ *
+ * This is a callback function which is called by the I/O unit when the
+ * write-buffer is synchronized. We need this to correctly maintain space
+ * accounting in bud logical eraseblocks. This function returns zero in case of
+ * success and a negative error code in case of failure.
+ *
+ * This function actually belongs to the journal, but we keep it here because
+ * we want to keep it static.
+ */
+static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
+{
+ return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
+}
+
+/*
+ * init_constants_sb - initialize UBIFS constants.
+ * @c: UBIFS file-system description object
+ *
+ * This is a helper function which initializes various UBIFS constants after
+ * the superblock has been read. It also checks various UBIFS parameters and
+ * makes sure they are all right. Returns zero in case of success and a
+ * negative error code in case of failure.
+ */
+static int init_constants_sb(struct ubifs_info *c)
+{
+ int tmp, err;
+ long long tmp64;
+
+ c->main_bytes = (long long)c->main_lebs * c->leb_size;
+ c->max_znode_sz = sizeof(struct ubifs_znode) +
+ c->fanout * sizeof(struct ubifs_zbranch);
+
+ tmp = ubifs_idx_node_sz(c, 1);
+ c->ranges[UBIFS_IDX_NODE].min_len = tmp;
+ c->min_idx_node_sz = ALIGN(tmp, 8);
+
+ tmp = ubifs_idx_node_sz(c, c->fanout);
+ c->ranges[UBIFS_IDX_NODE].max_len = tmp;
+ c->max_idx_node_sz = ALIGN(tmp, 8);
+
+ /* Make sure LEB size is large enough to fit full commit */
+ tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
+ tmp = ALIGN(tmp, c->min_io_size);
+ if (tmp > c->leb_size) {
+ ubifs_err(c, "too small LEB size %d, at least %d needed",
+ c->leb_size, tmp);
+ return -EINVAL;
+ }
+
+ /*
+ * Make sure that the log is large enough to fit reference nodes for
+ * all buds plus one reserved LEB.
+ */
+ tmp64 = c->max_bud_bytes + c->leb_size - 1;
+ c->max_bud_cnt = div_u64(tmp64, c->leb_size);
+ tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
+ tmp /= c->leb_size;
+ tmp += 1;
+ if (c->log_lebs < tmp) {
+ ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
+ c->log_lebs, tmp);
+ return -EINVAL;
+ }
+
+ /*
+ * When budgeting we assume worst-case scenarios when the pages are not
+ * be compressed and direntries are of the maximum size.
+ *
+ * Note, data, which may be stored in inodes is budgeted separately, so
+ * it is not included into 'c->bi.inode_budget'.
+ */
+ c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
+ c->bi.inode_budget = UBIFS_INO_NODE_SZ;
+ c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
+
+ /*
+ * When the amount of flash space used by buds becomes
+ * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
+ * The writers are unblocked when the commit is finished. To avoid
+ * writers to be blocked UBIFS initiates background commit in advance,
+ * when number of bud bytes becomes above the limit defined below.
+ */
+ c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
+
+ /*
+ * Ensure minimum journal size. All the bytes in the journal heads are
+ * considered to be used, when calculating the current journal usage.
+ * Consequently, if the journal is too small, UBIFS will treat it as
+ * always full.
+ */
+ tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
+ if (c->bg_bud_bytes < tmp64)
+ c->bg_bud_bytes = tmp64;
+ if (c->max_bud_bytes < tmp64 + c->leb_size)
+ c->max_bud_bytes = tmp64 + c->leb_size;
+
+ err = ubifs_calc_lpt_geom(c);
+ if (err)
+ return err;
+
+ /* Initialize effective LEB size used in budgeting calculations */
+ c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
+ return 0;
+}
+
+/*
+ * init_constants_master - initialize UBIFS constants.
+ * @c: UBIFS file-system description object
+ *
+ * This is a helper function which initializes various UBIFS constants after
+ * the master node has been read. It also checks various UBIFS parameters and
+ * makes sure they are all right.
+ */
+static void init_constants_master(struct ubifs_info *c)
+{
+ long long tmp64;
+
+ c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+ c->report_rp_size = ubifs_reported_space(c, c->rp_size);
+
+ /*
+ * Calculate total amount of FS blocks. This number is not used
+ * internally because it does not make much sense for UBIFS, but it is
+ * necessary to report something for the 'statfs()' call.
+ *
+ * Subtract the LEB reserved for GC, the LEB which is reserved for
+ * deletions, minimum LEBs for the index, and assume only one journal
+ * head is available.
+ */
+ tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
+ tmp64 *= (long long)c->leb_size - c->leb_overhead;
+ tmp64 = ubifs_reported_space(c, tmp64);
+ c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
+}
+
+/**
+ * take_gc_lnum - reserve GC LEB.
+ * @c: UBIFS file-system description object
+ *
+ * This function ensures that the LEB reserved for garbage collection is marked
+ * as "taken" in lprops. We also have to set free space to LEB size and dirty
+ * space to zero, because lprops may contain out-of-date information if the
+ * file-system was un-mounted before it has been committed. This function
+ * returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int take_gc_lnum(struct ubifs_info *c)
+{
+ int err;
+
+ if (c->gc_lnum == -1) {
+ ubifs_err(c, "no LEB for GC");
+ return -EINVAL;
+ }
+
+ /* And we have to tell lprops that this LEB is taken */
+ err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
+ LPROPS_TAKEN, 0, 0);
+ return err;
+}
+
+/**
+ * alloc_wbufs - allocate write-buffers.
+ * @c: UBIFS file-system description object
+ *
+ * This helper function allocates and initializes UBIFS write-buffers. Returns
+ * zero in case of success and %-ENOMEM in case of failure.
+ */
+static int alloc_wbufs(struct ubifs_info *c)
+{
+ int i, err;
+
+ c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
+ GFP_KERNEL);
+ if (!c->jheads)
+ return -ENOMEM;
+
+ /* Initialize journal heads */
+ for (i = 0; i < c->jhead_cnt; i++) {
+ INIT_LIST_HEAD(&c->jheads[i].buds_list);
+ err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
+ if (err)
+ return err;
+
+ c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
+ c->jheads[i].wbuf.jhead = i;
+ c->jheads[i].grouped = 1;
+ }
+
+ /*
+ * Garbage Collector head does not need to be synchronized by timer.
+ * Also GC head nodes are not grouped.
+ */
+ c->jheads[GCHD].wbuf.no_timer = 1;
+ c->jheads[GCHD].grouped = 0;
+
+ return 0;
+}
+
+/**
+ * free_wbufs - free write-buffers.
+ * @c: UBIFS file-system description object
+ */
+static void free_wbufs(struct ubifs_info *c)
+{
+ int i;
+
+ if (c->jheads) {
+ for (i = 0; i < c->jhead_cnt; i++) {
+ kfree(c->jheads[i].wbuf.buf);
+ kfree(c->jheads[i].wbuf.inodes);
+ }
+ kfree(c->jheads);
+ c->jheads = NULL;
+ }
+}
+
+/**
+ * free_orphans - free orphans.
+ * @c: UBIFS file-system description object
+ */
+static void free_orphans(struct ubifs_info *c)
+{
+ struct ubifs_orphan *orph;
+
+ while (c->orph_dnext) {
+ orph = c->orph_dnext;
+ c->orph_dnext = orph->dnext;
+ list_del(&orph->list);
+ kfree(orph);
+ }
+
+ while (!list_empty(&c->orph_list)) {
+ orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
+ list_del(&orph->list);
+ kfree(orph);
+ ubifs_err(c, "orphan list not empty at unmount");
+ }
+
+ vfree(c->orph_buf);
+ c->orph_buf = NULL;
+}
+
+/**
+ * free_buds - free per-bud objects.
+ * @c: UBIFS file-system description object
+ */
+static void free_buds(struct ubifs_info *c)
+{
+ struct ubifs_bud *bud, *n;
+
+ rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
+ kfree(bud);
+}
+
+/**
+ * check_volume_empty - check if the UBI volume is empty.
+ * @c: UBIFS file-system description object
+ *
+ * This function checks if the UBIFS volume is empty by looking if its LEBs are
+ * mapped or not. The result of checking is stored in the @c->empty variable.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int check_volume_empty(struct ubifs_info *c)
+{
+ int lnum, err;
+
+ c->empty = 1;
+ for (lnum = 0; lnum < c->leb_cnt; lnum++) {
+ err = ubifs_is_mapped(c, lnum);
+ if (unlikely(err < 0))
+ return err;
+ if (err == 1) {
+ c->empty = 0;
+ break;
+ }
+
+ cond_resched();
+ }
+
+ return 0;
+}
+
+/*
+ * UBIFS mount options.
+ *
+ * Opt_fast_unmount: do not run a journal commit before un-mounting
+ * Opt_norm_unmount: run a journal commit before un-mounting
+ * Opt_bulk_read: enable bulk-reads
+ * Opt_no_bulk_read: disable bulk-reads
+ * Opt_chk_data_crc: check CRCs when reading data nodes
+ * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
+ * Opt_override_compr: override default compressor
+ * Opt_err: just end of array marker
+ */
+enum {
+ Opt_fast_unmount,
+ Opt_norm_unmount,
+ Opt_bulk_read,
+ Opt_no_bulk_read,
+ Opt_chk_data_crc,
+ Opt_no_chk_data_crc,
+ Opt_override_compr,
+ Opt_err,
+};
+
+static const match_table_t tokens = {
+ {Opt_fast_unmount, "fast_unmount"},
+ {Opt_norm_unmount, "norm_unmount"},
+ {Opt_bulk_read, "bulk_read"},
+ {Opt_no_bulk_read, "no_bulk_read"},
+ {Opt_chk_data_crc, "chk_data_crc"},
+ {Opt_no_chk_data_crc, "no_chk_data_crc"},
+ {Opt_override_compr, "compr=%s"},
+ {Opt_err, NULL},
+};
+
+/**
+ * parse_standard_option - parse a standard mount option.
+ * @option: the option to parse
+ *
+ * Normally, standard mount options like "sync" are passed to file-systems as
+ * flags. However, when a "rootflags=" kernel boot parameter is used, they may
+ * be present in the options string. This function tries to deal with this
+ * situation and parse standard options. Returns 0 if the option was not
+ * recognized, and the corresponding integer flag if it was.
+ *
+ * UBIFS is only interested in the "sync" option, so do not check for anything
+ * else.
+ */
+static int parse_standard_option(const char *option)
+{
+
+ pr_notice("UBIFS: parse %s\n", option);
+ if (!strcmp(option, "sync"))
+ return MS_SYNCHRONOUS;
+ return 0;
+}
+
+/**
+ * ubifs_parse_options - parse mount parameters.
+ * @c: UBIFS file-system description object
+ * @options: parameters to parse
+ * @is_remount: non-zero if this is FS re-mount
+ *
+ * This function parses UBIFS mount options and returns zero in case success
+ * and a negative error code in case of failure.
+ */
+static int ubifs_parse_options(struct ubifs_info *c, char *options,
+ int is_remount)
+{
+ char *p;
+ substring_t args[MAX_OPT_ARGS];
+
+ if (!options)
+ return 0;
+
+ while ((p = strsep(&options, ","))) {
+ int token;
+
+ if (!*p)
+ continue;
+
+ token = match_token(p, tokens, args);
+ switch (token) {
+ /*
+ * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
+ * We accept them in order to be backward-compatible. But this
+ * should be removed at some point.
+ */
+ case Opt_fast_unmount:
+ c->mount_opts.unmount_mode = 2;
+ break;
+ case Opt_norm_unmount:
+ c->mount_opts.unmount_mode = 1;
+ break;
+ case Opt_bulk_read:
+ c->mount_opts.bulk_read = 2;
+ c->bulk_read = 1;
+ break;
+ case Opt_no_bulk_read:
+ c->mount_opts.bulk_read = 1;
+ c->bulk_read = 0;
+ break;
+ case Opt_chk_data_crc:
+ c->mount_opts.chk_data_crc = 2;
+ c->no_chk_data_crc = 0;
+ break;
+ case Opt_no_chk_data_crc:
+ c->mount_opts.chk_data_crc = 1;
+ c->no_chk_data_crc = 1;
+ break;
+ case Opt_override_compr:
+ {
+ char *name = match_strdup(&args[0]);
+
+ if (!name)
+ return -ENOMEM;
+ if (!strcmp(name, "none"))
+ c->mount_opts.compr_type = UBIFS_COMPR_NONE;
+ else if (!strcmp(name, "lzo"))
+ c->mount_opts.compr_type = UBIFS_COMPR_LZO;
+ else if (!strcmp(name, "zlib"))
+ c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
+ else {
+ ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
+ kfree(name);
+ return -EINVAL;
+ }
+ kfree(name);
+ c->mount_opts.override_compr = 1;
+ c->default_compr = c->mount_opts.compr_type;
+ break;
+ }
+ default:
+ {
+ unsigned long flag;
+ struct super_block *sb = c->vfs_sb;
+
+ flag = parse_standard_option(p);
+ if (!flag) {
+ ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
+ p);
+ return -EINVAL;
+ }
+ sb->s_flags |= flag;
+ break;
+ }
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * destroy_journal - destroy journal data structures.
+ * @c: UBIFS file-system description object
+ *
+ * This function destroys journal data structures including those that may have
+ * been created by recovery functions.
+ */
+static void destroy_journal(struct ubifs_info *c)
+{
+ while (!list_empty(&c->unclean_leb_list)) {
+ struct ubifs_unclean_leb *ucleb;
+
+ ucleb = list_entry(c->unclean_leb_list.next,
+ struct ubifs_unclean_leb, list);
+ list_del(&ucleb->list);
+ kfree(ucleb);
+ }
+ while (!list_empty(&c->old_buds)) {
+ struct ubifs_bud *bud;
+
+ bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
+ list_del(&bud->list);
+ kfree(bud);
+ }
+ ubifs_destroy_idx_gc(c);
+ ubifs_destroy_size_tree(c);
+ ubifs_tnc_close(c);
+ free_buds(c);
+}
+
+/**
+ * bu_init - initialize bulk-read information.
+ * @c: UBIFS file-system description object
+ */
+static void bu_init(struct ubifs_info *c)
+{
+ ubifs_assert(c->bulk_read == 1);
+
+ if (c->bu.buf)
+ return; /* Already initialized */
+
+again:
+ c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
+ if (!c->bu.buf) {
+ if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
+ c->max_bu_buf_len = UBIFS_KMALLOC_OK;
+ goto again;
+ }
+
+ /* Just disable bulk-read */
+ ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
+ c->max_bu_buf_len);
+ c->mount_opts.bulk_read = 1;
+ c->bulk_read = 0;
+ return;
+ }
+}
+
+/**
+ * check_free_space - check if there is enough free space to mount.
+ * @c: UBIFS file-system description object
+ *
+ * This function makes sure UBIFS has enough free space to be mounted in
+ * read/write mode. UBIFS must always have some free space to allow deletions.
+ */
+static int check_free_space(struct ubifs_info *c)
+{
+ ubifs_assert(c->dark_wm > 0);
+ if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
+ ubifs_err(c, "insufficient free space to mount in R/W mode");
+ ubifs_dump_budg(c, &c->bi);
+ ubifs_dump_lprops(c);
+ return -ENOSPC;
+ }
+ return 0;
+}
+
+/**
+ * mount_ubifs - mount UBIFS file-system.
+ * @c: UBIFS file-system description object
+ *
+ * This function mounts UBIFS file system. Returns zero in case of success and
+ * a negative error code in case of failure.
+ */
+static int mount_ubifs(struct ubifs_info *c)
+{
+ int err;
+ long long x, y;
+ size_t sz;
+
+ c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
+ /* Suppress error messages while probing if MS_SILENT is set */
+ c->probing = !!(c->vfs_sb->s_flags & MS_SILENT);
+
+ err = init_constants_early(c);
+ if (err)
+ return err;
+
+ err = ubifs_debugging_init(c);
+ if (err)
+ return err;
+
+ err = check_volume_empty(c);
+ if (err)
+ goto out_free;
+
+ if (c->empty && (c->ro_mount || c->ro_media)) {
+ /*
+ * This UBI volume is empty, and read-only, or the file system
+ * is mounted read-only - we cannot format it.
+ */
+ ubifs_err(c, "can't format empty UBI volume: read-only %s",
+ c->ro_media ? "UBI volume" : "mount");
+ err = -EROFS;
+ goto out_free;
+ }
+
+ if (c->ro_media && !c->ro_mount) {
+ ubifs_err(c, "cannot mount read-write - read-only media");
+ err = -EROFS;
+ goto out_free;
+ }
+
+ /*
+ * The requirement for the buffer is that it should fit indexing B-tree
+ * height amount of integers. We assume the height if the TNC tree will
+ * never exceed 64.
+ */
+ err = -ENOMEM;
+ c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
+ if (!c->bottom_up_buf)
+ goto out_free;
+
+ c->sbuf = vmalloc(c->leb_size);
+ if (!c->sbuf)
+ goto out_free;
+
+ if (!c->ro_mount) {
+ c->ileb_buf = vmalloc(c->leb_size);
+ if (!c->ileb_buf)
+ goto out_free;
+ }
+
+ if (c->bulk_read == 1)
+ bu_init(c);
+
+ if (!c->ro_mount) {
+ c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
+ GFP_KERNEL);
+ if (!c->write_reserve_buf)
+ goto out_free;
+ }
+
+ c->mounting = 1;
+
+ err = ubifs_read_superblock(c);
+ if (err)
+ goto out_free;
+
+ c->probing = 0;
+
+ /*
+ * Make sure the compressor which is set as default in the superblock
+ * or overridden by mount options is actually compiled in.
+ */
+ if (!ubifs_compr_present(c->default_compr)) {
+ ubifs_err(c, "'compressor \"%s\" is not compiled in",
+ ubifs_compr_name(c->default_compr));
+ err = -ENOTSUPP;
+ goto out_free;
+ }
+
+ err = init_constants_sb(c);
+ if (err)
+ goto out_free;
+
+ sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
+ sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
+ c->cbuf = kmalloc(sz, GFP_NOFS);
+ if (!c->cbuf) {
+ err = -ENOMEM;
+ goto out_free;
+ }
+
+ err = alloc_wbufs(c);
+ if (err)
+ goto out_cbuf;
+
+ sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
+ if (!c->ro_mount) {
+ /* Create background thread */
+ c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+ if (IS_ERR(c->bgt)) {
+ err = PTR_ERR(c->bgt);
+ c->bgt = NULL;
+ ubifs_err(c, "cannot spawn \"%s\", error %d",
+ c->bgt_name, err);
+ goto out_wbufs;
+ }
+ wake_up_process(c->bgt);
+ }
+
+ err = ubifs_read_master(c);
+ if (err)
+ goto out_master;
+
+ init_constants_master(c);
+
+ if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
+ ubifs_msg(c, "recovery needed");
+ c->need_recovery = 1;
+ }
+
+ if (c->need_recovery && !c->ro_mount) {
+ err = ubifs_recover_inl_heads(c, c->sbuf);
+ if (err)
+ goto out_master;
+ }
+
+ err = ubifs_lpt_init(c, 1, !c->ro_mount);
+ if (err)
+ goto out_master;
+
+ if (!c->ro_mount && c->space_fixup) {
+ err = ubifs_fixup_free_space(c);
+ if (err)
+ goto out_lpt;
+ }
+
+ if (!c->ro_mount && !c->need_recovery) {
+ /*
+ * Set the "dirty" flag so that if we reboot uncleanly we
+ * will notice this immediately on the next mount.
+ */
+ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
+ err = ubifs_write_master(c);
+ if (err)
+ goto out_lpt;
+ }
+
+ err = dbg_check_idx_size(c, c->bi.old_idx_sz);
+ if (err)
+ goto out_lpt;
+
+ err = ubifs_replay_journal(c);
+ if (err)
+ goto out_journal;
+
+ /* Calculate 'min_idx_lebs' after journal replay */
+ c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
+
+ err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
+ if (err)
+ goto out_orphans;
+
+ if (!c->ro_mount) {
+ int lnum;
+
+ err = check_free_space(c);
+ if (err)
+ goto out_orphans;
+
+ /* Check for enough log space */
+ lnum = c->lhead_lnum + 1;
+ if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
+ lnum = UBIFS_LOG_LNUM;
+ if (lnum == c->ltail_lnum) {
+ err = ubifs_consolidate_log(c);
+ if (err)
+ goto out_orphans;
+ }
+
+ if (c->need_recovery) {
+ err = ubifs_recover_size(c);
+ if (err)
+ goto out_orphans;
+ err = ubifs_rcvry_gc_commit(c);
+ if (err)
+ goto out_orphans;
+ } else {
+ err = take_gc_lnum(c);
+ if (err)
+ goto out_orphans;
+
+ /*
+ * GC LEB may contain garbage if there was an unclean
+ * reboot, and it should be un-mapped.
+ */
+ err = ubifs_leb_unmap(c, c->gc_lnum);
+ if (err)
+ goto out_orphans;
+ }
+
+ err = dbg_check_lprops(c);
+ if (err)
+ goto out_orphans;
+ } else if (c->need_recovery) {
+ err = ubifs_recover_size(c);
+ if (err)
+ goto out_orphans;
+ } else {
+ /*
+ * Even if we mount read-only, we have to set space in GC LEB
+ * to proper value because this affects UBIFS free space
+ * reporting. We do not want to have a situation when
+ * re-mounting from R/O to R/W changes amount of free space.
+ */
+ err = take_gc_lnum(c);
+ if (err)
+ goto out_orphans;
+ }
+
+ spin_lock(&ubifs_infos_lock);
+ list_add_tail(&c->infos_list, &ubifs_infos);
+ spin_unlock(&ubifs_infos_lock);
+
+ if (c->need_recovery) {
+ if (c->ro_mount)
+ ubifs_msg(c, "recovery deferred");
+ else {
+ c->need_recovery = 0;
+ ubifs_msg(c, "recovery completed");
+ /*
+ * GC LEB has to be empty and taken at this point. But
+ * the journal head LEBs may also be accounted as
+ * "empty taken" if they are empty.
+ */
+ ubifs_assert(c->lst.taken_empty_lebs > 0);
+ }
+ } else
+ ubifs_assert(c->lst.taken_empty_lebs > 0);
+
+ err = dbg_check_filesystem(c);
+ if (err)
+ goto out_infos;
+
+ err = dbg_debugfs_init_fs(c);
+ if (err)
+ goto out_infos;
+
+ c->mounting = 0;
+
+ ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
+ c->vi.ubi_num, c->vi.vol_id, c->vi.name,
+ c->ro_mount ? ", R/O mode" : "");
+ x = (long long)c->main_lebs * c->leb_size;
+ y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
+ ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
+ c->leb_size, c->leb_size >> 10, c->min_io_size,
+ c->max_write_size);
+ ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
+ x, x >> 20, c->main_lebs,
+ y, y >> 20, c->log_lebs + c->max_bud_cnt);
+ ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
+ c->report_rp_size, c->report_rp_size >> 10);
+ ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
+ c->fmt_version, c->ro_compat_version,
+ UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
+ c->big_lpt ? ", big LPT model" : ", small LPT model");
+
+ dbg_gen("default compressor: %s", ubifs_compr_name(c->default_compr));
+ dbg_gen("data journal heads: %d",
+ c->jhead_cnt - NONDATA_JHEADS_CNT);
+ dbg_gen("log LEBs: %d (%d - %d)",
+ c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
+ dbg_gen("LPT area LEBs: %d (%d - %d)",
+ c->lpt_lebs, c->lpt_first, c->lpt_last);
+ dbg_gen("orphan area LEBs: %d (%d - %d)",
+ c->orph_lebs, c->orph_first, c->orph_last);
+ dbg_gen("main area LEBs: %d (%d - %d)",
+ c->main_lebs, c->main_first, c->leb_cnt - 1);
+ dbg_gen("index LEBs: %d", c->lst.idx_lebs);
+ dbg_gen("total index bytes: %lld (%lld KiB, %lld MiB)",
+ c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
+ c->bi.old_idx_sz >> 20);
+ dbg_gen("key hash type: %d", c->key_hash_type);
+ dbg_gen("tree fanout: %d", c->fanout);
+ dbg_gen("reserved GC LEB: %d", c->gc_lnum);
+ dbg_gen("max. znode size %d", c->max_znode_sz);
+ dbg_gen("max. index node size %d", c->max_idx_node_sz);
+ dbg_gen("node sizes: data %zu, inode %zu, dentry %zu",
+ UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
+ dbg_gen("node sizes: trun %zu, sb %zu, master %zu",
+ UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
+ dbg_gen("node sizes: ref %zu, cmt. start %zu, orph %zu",
+ UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
+ dbg_gen("max. node sizes: data %zu, inode %zu dentry %zu, idx %d",
+ UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
+ UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
+ dbg_gen("dead watermark: %d", c->dead_wm);
+ dbg_gen("dark watermark: %d", c->dark_wm);
+ dbg_gen("LEB overhead: %d", c->leb_overhead);
+ x = (long long)c->main_lebs * c->dark_wm;
+ dbg_gen("max. dark space: %lld (%lld KiB, %lld MiB)",
+ x, x >> 10, x >> 20);
+ dbg_gen("maximum bud bytes: %lld (%lld KiB, %lld MiB)",
+ c->max_bud_bytes, c->max_bud_bytes >> 10,
+ c->max_bud_bytes >> 20);
+ dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
+ c->bg_bud_bytes, c->bg_bud_bytes >> 10,
+ c->bg_bud_bytes >> 20);
+ dbg_gen("current bud bytes %lld (%lld KiB, %lld MiB)",
+ c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
+ dbg_gen("max. seq. number: %llu", c->max_sqnum);
+ dbg_gen("commit number: %llu", c->cmt_no);
+
+ return 0;
+
+out_infos:
+ spin_lock(&ubifs_infos_lock);
+ list_del(&c->infos_list);
+ spin_unlock(&ubifs_infos_lock);
+out_orphans:
+ free_orphans(c);
+out_journal:
+ destroy_journal(c);
+out_lpt:
+ ubifs_lpt_free(c, 0);
+out_master:
+ kfree(c->mst_node);
+ kfree(c->rcvrd_mst_node);
+ if (c->bgt)
+ kthread_stop(c->bgt);
+out_wbufs:
+ free_wbufs(c);
+out_cbuf:
+ kfree(c->cbuf);
+out_free:
+ kfree(c->write_reserve_buf);
+ kfree(c->bu.buf);
+ vfree(c->ileb_buf);
+ vfree(c->sbuf);
+ kfree(c->bottom_up_buf);
+ ubifs_debugging_exit(c);
+ return err;
+}
+
+/**
+ * ubifs_umount - un-mount UBIFS file-system.
+ * @c: UBIFS file-system description object
+ *
+ * Note, this function is called to free allocated resourced when un-mounting,
+ * as well as free resources when an error occurred while we were half way
+ * through mounting (error path cleanup function). So it has to make sure the
+ * resource was actually allocated before freeing it.
+ */
+static void ubifs_umount(struct ubifs_info *c)
+{
+ dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
+ c->vi.vol_id);
+
+ dbg_debugfs_exit_fs(c);
+ spin_lock(&ubifs_infos_lock);
+ list_del(&c->infos_list);
+ spin_unlock(&ubifs_infos_lock);
+
+ if (c->bgt)
+ kthread_stop(c->bgt);
+
+ destroy_journal(c);
+ free_wbufs(c);
+ free_orphans(c);
+ ubifs_lpt_free(c, 0);
+
+ kfree(c->cbuf);
+ kfree(c->rcvrd_mst_node);
+ kfree(c->mst_node);
+ kfree(c->write_reserve_buf);
+ kfree(c->bu.buf);
+ vfree(c->ileb_buf);
+ vfree(c->sbuf);
+ kfree(c->bottom_up_buf);
+ ubifs_debugging_exit(c);
+}
+
+/**
+ * ubifs_remount_rw - re-mount in read-write mode.
+ * @c: UBIFS file-system description object
+ *
+ * UBIFS avoids allocating many unnecessary resources when mounted in read-only
+ * mode. This function allocates the needed resources and re-mounts UBIFS in
+ * read-write mode.
+ */
+static int ubifs_remount_rw(struct ubifs_info *c)
+{
+ int err, lnum;
+
+ if (c->rw_incompat) {
+ ubifs_err(c, "the file-system is not R/W-compatible");
+ ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
+ c->fmt_version, c->ro_compat_version,
+ UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
+ return -EROFS;
+ }
+
+ mutex_lock(&c->umount_mutex);
+ dbg_save_space_info(c);
+ c->remounting_rw = 1;
+ c->ro_mount = 0;
+
+ if (c->space_fixup) {
+ err = ubifs_fixup_free_space(c);
+ if (err)
+ goto out;
+ }
+
+ err = check_free_space(c);
+ if (err)
+ goto out;
+
+ if (c->old_leb_cnt != c->leb_cnt) {
+ struct ubifs_sb_node *sup;
+
+ sup = ubifs_read_sb_node(c);
+ if (IS_ERR(sup)) {
+ err = PTR_ERR(sup);
+ goto out;
+ }
+ sup->leb_cnt = cpu_to_le32(c->leb_cnt);
+ err = ubifs_write_sb_node(c, sup);
+ kfree(sup);
+ if (err)
+ goto out;
+ }
+
+ if (c->need_recovery) {
+ ubifs_msg(c, "completing deferred recovery");
+ err = ubifs_write_rcvrd_mst_node(c);
+ if (err)
+ goto out;
+ err = ubifs_recover_size(c);
+ if (err)
+ goto out;
+ err = ubifs_clean_lebs(c, c->sbuf);
+ if (err)
+ goto out;
+ err = ubifs_recover_inl_heads(c, c->sbuf);
+ if (err)
+ goto out;
+ } else {
+ /* A readonly mount is not allowed to have orphans */
+ ubifs_assert(c->tot_orphans == 0);
+ err = ubifs_clear_orphans(c);
+ if (err)
+ goto out;
+ }
+
+ if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
+ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
+ err = ubifs_write_master(c);
+ if (err)
+ goto out;
+ }
+
+ c->ileb_buf = vmalloc(c->leb_size);
+ if (!c->ileb_buf) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
+ if (!c->write_reserve_buf) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = ubifs_lpt_init(c, 0, 1);
+ if (err)
+ goto out;
+
+ /* Create background thread */
+ c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
+ if (IS_ERR(c->bgt)) {
+ err = PTR_ERR(c->bgt);
+ c->bgt = NULL;
+ ubifs_err(c, "cannot spawn \"%s\", error %d",
+ c->bgt_name, err);
+ goto out;
+ }
+ wake_up_process(c->bgt);
+
+ c->orph_buf = vmalloc(c->leb_size);
+ if (!c->orph_buf) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ /* Check for enough log space */
+ lnum = c->lhead_lnum + 1;
+ if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
+ lnum = UBIFS_LOG_LNUM;
+ if (lnum == c->ltail_lnum) {
+ err = ubifs_consolidate_log(c);
+ if (err)
+ goto out;
+ }
+
+ if (c->need_recovery)
+ err = ubifs_rcvry_gc_commit(c);
+ else
+ err = ubifs_leb_unmap(c, c->gc_lnum);
+ if (err)
+ goto out;
+
+ dbg_gen("re-mounted read-write");
+ c->remounting_rw = 0;
+
+ if (c->need_recovery) {
+ c->need_recovery = 0;
+ ubifs_msg(c, "deferred recovery completed");
+ } else {
+ /*
+ * Do not run the debugging space check if the were doing
+ * recovery, because when we saved the information we had the
+ * file-system in a state where the TNC and lprops has been
+ * modified in memory, but all the I/O operations (including a
+ * commit) were deferred. So the file-system was in
+ * "non-committed" state. Now the file-system is in committed
+ * state, and of course the amount of free space will change
+ * because, for example, the old index size was imprecise.
+ */
+ err = dbg_check_space_info(c);
+ }
+
+ mutex_unlock(&c->umount_mutex);
+ return err;
+
+out:
+ c->ro_mount = 1;
+ vfree(c->orph_buf);
+ c->orph_buf = NULL;
+ if (c->bgt) {
+ kthread_stop(c->bgt);
+ c->bgt = NULL;
+ }
+ free_wbufs(c);
+ kfree(c->write_reserve_buf);
+ c->write_reserve_buf = NULL;
+ vfree(c->ileb_buf);
+ c->ileb_buf = NULL;
+ ubifs_lpt_free(c, 1);
+ c->remounting_rw = 0;
+ mutex_unlock(&c->umount_mutex);
+ return err;
+}
+
+/**
+ * ubifs_remount_ro - re-mount in read-only mode.
+ * @c: UBIFS file-system description object
+ *
+ * We assume VFS has stopped writing. Possibly the background thread could be
+ * running a commit, however kthread_stop will wait in that case.
+ */
+static void ubifs_remount_ro(struct ubifs_info *c)
+{
+ int i, err;
+
+ ubifs_assert(!c->need_recovery);
+ ubifs_assert(!c->ro_mount);
+
+ mutex_lock(&c->umount_mutex);
+ if (c->bgt) {
+ kthread_stop(c->bgt);
+ c->bgt = NULL;
+ }
+
+ dbg_save_space_info(c);
+
+ for (i = 0; i < c->jhead_cnt; i++)
+ ubifs_wbuf_sync(&c->jheads[i].wbuf);
+
+ c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
+ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+ c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
+ err = ubifs_write_master(c);
+ if (err)
+ ubifs_ro_mode(c, err);
+
+ vfree(c->orph_buf);
+ c->orph_buf = NULL;
+ kfree(c->write_reserve_buf);
+ c->write_reserve_buf = NULL;
+ vfree(c->ileb_buf);
+ c->ileb_buf = NULL;
+ ubifs_lpt_free(c, 1);
+ c->ro_mount = 1;
+ err = dbg_check_space_info(c);
+ if (err)
+ ubifs_ro_mode(c, err);
+ mutex_unlock(&c->umount_mutex);
+}
+
+static void ubifs_put_super(struct super_block *sb)
+{
+ int i;
+ struct ubifs_info *c = sb->s_fs_info;
+
+ ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
+
+ /*
+ * The following asserts are only valid if there has not been a failure
+ * of the media. For example, there will be dirty inodes if we failed
+ * to write them back because of I/O errors.
+ */
+ if (!c->ro_error) {
+ ubifs_assert(c->bi.idx_growth == 0);
+ ubifs_assert(c->bi.dd_growth == 0);
+ ubifs_assert(c->bi.data_growth == 0);
+ }
+
+ /*
+ * The 'c->umount_lock' prevents races between UBIFS memory shrinker
+ * and file system un-mount. Namely, it prevents the shrinker from
+ * picking this superblock for shrinking - it will be just skipped if
+ * the mutex is locked.
+ */
+ mutex_lock(&c->umount_mutex);
+ if (!c->ro_mount) {
+ /*
+ * First of all kill the background thread to make sure it does
+ * not interfere with un-mounting and freeing resources.
+ */
+ if (c->bgt) {
+ kthread_stop(c->bgt);
+ c->bgt = NULL;
+ }
+
+ /*
+ * On fatal errors c->ro_error is set to 1, in which case we do
+ * not write the master node.
+ */
+ if (!c->ro_error) {
+ int err;
+
+ /* Synchronize write-buffers */
+ for (i = 0; i < c->jhead_cnt; i++)
+ ubifs_wbuf_sync(&c->jheads[i].wbuf);
+
+ /*
+ * We are being cleanly unmounted which means the
+ * orphans were killed - indicate this in the master
+ * node. Also save the reserved GC LEB number.
+ */
+ c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
+ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
+ c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
+ err = ubifs_write_master(c);
+ if (err)
+ /*
+ * Recovery will attempt to fix the master area
+ * next mount, so we just print a message and
+ * continue to unmount normally.
+ */
+ ubifs_err(c, "failed to write master node, error %d",
+ err);
+ } else {
+ for (i = 0; i < c->jhead_cnt; i++)
+ /* Make sure write-buffer timers are canceled */
+ hrtimer_cancel(&c->jheads[i].wbuf.timer);
+ }
+ }
+
+ ubifs_umount(c);
+ bdi_destroy(&c->bdi);
+ ubi_close_volume(c->ubi);
+ mutex_unlock(&c->umount_mutex);
+}
+
+static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
+{
+ int err;
+ struct ubifs_info *c = sb->s_fs_info;
+
+ sync_filesystem(sb);
+ dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
+
+ err = ubifs_parse_options(c, data, 1);
+ if (err) {
+ ubifs_err(c, "invalid or unknown remount parameter");
+ return err;
+ }
+
+ if (c->ro_mount && !(*flags & MS_RDONLY)) {
+ if (c->ro_error) {
+ ubifs_msg(c, "cannot re-mount R/W due to prior errors");
+ return -EROFS;
+ }
+ if (c->ro_media) {
+ ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
+ return -EROFS;
+ }
+ err = ubifs_remount_rw(c);
+ if (err)
+ return err;
+ } else if (!c->ro_mount && (*flags & MS_RDONLY)) {
+ if (c->ro_error) {
+ ubifs_msg(c, "cannot re-mount R/O due to prior errors");
+ return -EROFS;
+ }
+ ubifs_remount_ro(c);
+ }
+
+ if (c->bulk_read == 1)
+ bu_init(c);
+ else {
+ dbg_gen("disable bulk-read");
+ kfree(c->bu.buf);
+ c->bu.buf = NULL;
+ }
+
+ ubifs_assert(c->lst.taken_empty_lebs > 0);
+ return 0;
+}
+
+const struct super_operations ubifs_super_operations = {
+ .alloc_inode = ubifs_alloc_inode,
+ .destroy_inode = ubifs_destroy_inode,
+ .put_super = ubifs_put_super,
+ .write_inode = ubifs_write_inode,
+ .evict_inode = ubifs_evict_inode,
+ .statfs = ubifs_statfs,
+ .dirty_inode = ubifs_dirty_inode,
+ .remount_fs = ubifs_remount_fs,
+ .show_options = ubifs_show_options,
+ .sync_fs = ubifs_sync_fs,
+};
+
+/**
+ * open_ubi - parse UBI device name string and open the UBI device.
+ * @name: UBI volume name
+ * @mode: UBI volume open mode
+ *
+ * The primary method of mounting UBIFS is by specifying the UBI volume
+ * character device node path. However, UBIFS may also be mounted withoug any
+ * character device node using one of the following methods:
+ *
+ * o ubiX_Y - mount UBI device number X, volume Y;
+ * o ubiY - mount UBI device number 0, volume Y;
+ * o ubiX:NAME - mount UBI device X, volume with name NAME;
+ * o ubi:NAME - mount UBI device 0, volume with name NAME.
+ *
+ * Alternative '!' separator may be used instead of ':' (because some shells
+ * like busybox may interpret ':' as an NFS host name separator). This function
+ * returns UBI volume description object in case of success and a negative
+ * error code in case of failure.
+ */
+static struct ubi_volume_desc *open_ubi(const char *name, int mode)
+{
+ struct ubi_volume_desc *ubi;
+ int dev, vol;
+ char *endptr;
+
+ /* First, try to open using the device node path method */
+ ubi = ubi_open_volume_path(name, mode);
+ if (!IS_ERR(ubi))
+ return ubi;
+
+ /* Try the "nodev" method */
+ if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
+ return ERR_PTR(-EINVAL);
+
+ /* ubi:NAME method */
+ if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
+ return ubi_open_volume_nm(0, name + 4, mode);
+
+ if (!isdigit(name[3]))
+ return ERR_PTR(-EINVAL);
+
+ dev = simple_strtoul(name + 3, &endptr, 0);
+
+ /* ubiY method */
+ if (*endptr == '\0')
+ return ubi_open_volume(0, dev, mode);
+
+ /* ubiX_Y method */
+ if (*endptr == '_' && isdigit(endptr[1])) {
+ vol = simple_strtoul(endptr + 1, &endptr, 0);
+ if (*endptr != '\0')
+ return ERR_PTR(-EINVAL);
+ return ubi_open_volume(dev, vol, mode);
+ }
+
+ /* ubiX:NAME method */
+ if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
+ return ubi_open_volume_nm(dev, ++endptr, mode);
+
+ return ERR_PTR(-EINVAL);
+}
+
+static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
+{
+ struct ubifs_info *c;
+
+ c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
+ if (c) {
+ spin_lock_init(&c->cnt_lock);
+ spin_lock_init(&c->cs_lock);
+ spin_lock_init(&c->buds_lock);
+ spin_lock_init(&c->space_lock);
+ spin_lock_init(&c->orphan_lock);
+ init_rwsem(&c->commit_sem);
+ mutex_init(&c->lp_mutex);
+ mutex_init(&c->tnc_mutex);
+ mutex_init(&c->log_mutex);
+ mutex_init(&c->umount_mutex);
+ mutex_init(&c->bu_mutex);
+ mutex_init(&c->write_reserve_mutex);
+ init_waitqueue_head(&c->cmt_wq);
+ c->buds = RB_ROOT;
+ c->old_idx = RB_ROOT;
+ c->size_tree = RB_ROOT;
+ c->orph_tree = RB_ROOT;
+ INIT_LIST_HEAD(&c->infos_list);
+ INIT_LIST_HEAD(&c->idx_gc);
+ INIT_LIST_HEAD(&c->replay_list);
+ INIT_LIST_HEAD(&c->replay_buds);
+ INIT_LIST_HEAD(&c->uncat_list);
+ INIT_LIST_HEAD(&c->empty_list);
+ INIT_LIST_HEAD(&c->freeable_list);
+ INIT_LIST_HEAD(&c->frdi_idx_list);
+ INIT_LIST_HEAD(&c->unclean_leb_list);
+ INIT_LIST_HEAD(&c->old_buds);
+ INIT_LIST_HEAD(&c->orph_list);
+ INIT_LIST_HEAD(&c->orph_new);
+ c->no_chk_data_crc = 1;
+
+ c->highest_inum = UBIFS_FIRST_INO;
+ c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
+
+ ubi_get_volume_info(ubi, &c->vi);
+ ubi_get_device_info(c->vi.ubi_num, &c->di);
+ }
+ return c;
+}
+
+static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
+{
+ struct ubifs_info *c = sb->s_fs_info;
+ struct inode *root;
+ int err;
+
+ c->vfs_sb = sb;
+ /* Re-open the UBI device in read-write mode */
+ c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
+ if (IS_ERR(c->ubi)) {
+ err = PTR_ERR(c->ubi);
+ goto out;
+ }
+
+ /*
+ * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
+ * UBIFS, I/O is not deferred, it is done immediately in readpage,
+ * which means the user would have to wait not just for their own I/O
+ * but the read-ahead I/O as well i.e. completely pointless.
+ *
+ * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
+ */
+ c->bdi.name = "ubifs",
+ c->bdi.capabilities = 0;
+ err = bdi_init(&c->bdi);
+ if (err)
+ goto out_close;
+ err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
+ c->vi.ubi_num, c->vi.vol_id);
+ if (err)
+ goto out_bdi;
+
+ err = ubifs_parse_options(c, data, 0);
+ if (err)
+ goto out_bdi;
+
+ sb->s_bdi = &c->bdi;
+ sb->s_fs_info = c;
+ sb->s_magic = UBIFS_SUPER_MAGIC;
+ sb->s_blocksize = UBIFS_BLOCK_SIZE;
+ sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
+ sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
+ if (c->max_inode_sz > MAX_LFS_FILESIZE)
+ sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
+ sb->s_op = &ubifs_super_operations;
+
+ mutex_lock(&c->umount_mutex);
+ err = mount_ubifs(c);
+ if (err) {
+ ubifs_assert(err < 0);
+ goto out_unlock;
+ }
+
+ /* Read the root inode */
+ root = ubifs_iget(sb, UBIFS_ROOT_INO);
+ if (IS_ERR(root)) {
+ err = PTR_ERR(root);
+ goto out_umount;
+ }
+
+ sb->s_root = d_make_root(root);
+ if (!sb->s_root) {
+ err = -ENOMEM;
+ goto out_umount;
+ }
+
+ mutex_unlock(&c->umount_mutex);
+ return 0;
+
+out_umount:
+ ubifs_umount(c);
+out_unlock:
+ mutex_unlock(&c->umount_mutex);
+out_bdi:
+ bdi_destroy(&c->bdi);
+out_close:
+ ubi_close_volume(c->ubi);
+out:
+ return err;
+}
+
+static int sb_test(struct super_block *sb, void *data)
+{
+ struct ubifs_info *c1 = data;
+ struct ubifs_info *c = sb->s_fs_info;
+
+ return c->vi.cdev == c1->vi.cdev;
+}
+
+static int sb_set(struct super_block *sb, void *data)
+{
+ sb->s_fs_info = data;
+ return set_anon_super(sb, NULL);
+}
+
+static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
+ const char *name, void *data)
+{
+ struct ubi_volume_desc *ubi;
+ struct ubifs_info *c;
+ struct super_block *sb;
+ int err;
+
+ dbg_gen("name %s, flags %#x", name, flags);
+
+ /*
+ * Get UBI device number and volume ID. Mount it read-only so far
+ * because this might be a new mount point, and UBI allows only one
+ * read-write user at a time.
+ */
+ ubi = open_ubi(name, UBI_READONLY);
+ if (IS_ERR(ubi)) {
+ pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
+ current->pid, name, (int)PTR_ERR(ubi));
+ return ERR_CAST(ubi);
+ }
+
+ c = alloc_ubifs_info(ubi);
+ if (!c) {
+ err = -ENOMEM;
+ goto out_close;
+ }
+
+ dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
+
+ sb = sget(fs_type, sb_test, sb_set, flags, c);
+ if (IS_ERR(sb)) {
+ err = PTR_ERR(sb);
+ kfree(c);
+ goto out_close;
+ }
+
+ if (sb->s_root) {
+ struct ubifs_info *c1 = sb->s_fs_info;
+ kfree(c);
+ /* A new mount point for already mounted UBIFS */
+ dbg_gen("this ubi volume is already mounted");
+ if (!!(flags & MS_RDONLY) != c1->ro_mount) {
+ err = -EBUSY;
+ goto out_deact;
+ }
+ } else {
+ err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
+ if (err)
+ goto out_deact;
+ /* We do not support atime */
+ sb->s_flags |= MS_ACTIVE;
+#ifndef CONFIG_UBIFS_ATIME_SUPPORT
+ sb->s_flags |= MS_NOATIME;
+#else
+ ubifs_msg(c, "full atime support is enabled.");
+#endif
+ }
+
+ /* 'fill_super()' opens ubi again so we must close it here */
+ ubi_close_volume(ubi);
+
+ return dget(sb->s_root);
+
+out_deact:
+ deactivate_locked_super(sb);
+out_close:
+ ubi_close_volume(ubi);
+ return ERR_PTR(err);
+}
+
+static void kill_ubifs_super(struct super_block *s)
+{
+ struct ubifs_info *c = s->s_fs_info;
+ kill_anon_super(s);
+ kfree(c);
+}
+
+static struct file_system_type ubifs_fs_type = {
+ .name = "ubifs",
+ .owner = THIS_MODULE,
+ .mount = ubifs_mount,
+ .kill_sb = kill_ubifs_super,
+};
+MODULE_ALIAS_FS("ubifs");
+
+/*
+ * Inode slab cache constructor.
+ */
+static void inode_slab_ctor(void *obj)
+{
+ struct ubifs_inode *ui = obj;
+ inode_init_once(&ui->vfs_inode);
+}
+
+static int __init ubifs_init(void)
+{
+ int err;
+
+ BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
+
+ /* Make sure node sizes are 8-byte aligned */
+ BUILD_BUG_ON(UBIFS_CH_SZ & 7);
+ BUILD_BUG_ON(UBIFS_INO_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_SB_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_MST_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_REF_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_CS_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
+
+ BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ & 7);
+ BUILD_BUG_ON(UBIFS_MAX_NODE_SZ & 7);
+ BUILD_BUG_ON(MIN_WRITE_SZ & 7);
+
+ /* Check min. node size */
+ BUILD_BUG_ON(UBIFS_INO_NODE_SZ < MIN_WRITE_SZ);
+ BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
+ BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
+ BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
+
+ BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
+ BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
+ BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
+ BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ > UBIFS_MAX_NODE_SZ);
+
+ /* Defined node sizes */
+ BUILD_BUG_ON(UBIFS_SB_NODE_SZ != 4096);
+ BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
+ BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
+ BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
+
+ /*
+ * We use 2 bit wide bit-fields to store compression type, which should
+ * be amended if more compressors are added. The bit-fields are:
+ * @compr_type in 'struct ubifs_inode', @default_compr in
+ * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
+ */
+ BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
+
+ /*
+ * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
+ * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
+ */
+ if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
+ pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
+ current->pid, (unsigned int)PAGE_CACHE_SIZE);
+ return -EINVAL;
+ }
+
+ ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
+ sizeof(struct ubifs_inode), 0,
+ SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
+ &inode_slab_ctor);
+ if (!ubifs_inode_slab)
+ return -ENOMEM;
+
+ err = register_shrinker(&ubifs_shrinker_info);
+ if (err)
+ goto out_slab;
+
+ err = ubifs_compressors_init();
+ if (err)
+ goto out_shrinker;
+
+ err = dbg_debugfs_init();
+ if (err)
+ goto out_compr;
+
+ err = register_filesystem(&ubifs_fs_type);
+ if (err) {
+ pr_err("UBIFS error (pid %d): cannot register file system, error %d",
+ current->pid, err);
+ goto out_dbg;
+ }
+ return 0;
+
+out_dbg:
+ dbg_debugfs_exit();
+out_compr:
+ ubifs_compressors_exit();
+out_shrinker:
+ unregister_shrinker(&ubifs_shrinker_info);
+out_slab:
+ kmem_cache_destroy(ubifs_inode_slab);
+ return err;
+}
+/* late_initcall to let compressors initialize first */
+late_initcall(ubifs_init);
+
+static void __exit ubifs_exit(void)
+{
+ ubifs_assert(list_empty(&ubifs_infos));
+ ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
+
+ dbg_debugfs_exit();
+ ubifs_compressors_exit();
+ unregister_shrinker(&ubifs_shrinker_info);
+
+ /*
+ * Make sure all delayed rcu free inodes are flushed before we
+ * destroy cache.
+ */
+ rcu_barrier();
+ kmem_cache_destroy(ubifs_inode_slab);
+ unregister_filesystem(&ubifs_fs_type);
+}
+module_exit(ubifs_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_VERSION(__stringify(UBIFS_VERSION));
+MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
+MODULE_DESCRIPTION("UBIFS - UBI File System");