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super.c
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/*
* 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 = {
.shrink = ubifs_shrinker,
.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("inode is too large (%lld)",
(long long)inode->i_size);
return 1;
}
if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
ubifs_err("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 && (inode->i_mode & S_IFMT) != S_IFREG)
return 5;
if (!ubifs_compr_present(ui->compr_type)) {
ubifs_warn("inode %lu uses '%s' compression, but it was not "
"compiled in", inode->i_ino,
ubifs_compr_name(ui->compr_type));
}
err = dbg_check_dir_size(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 | S_NOATIME);
inode->i_nlink = le32_to_cpu(ino->nlink);
inode->i_uid = le32_to_cpu(ino->uid);
inode->i_gid = 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;
/* Disable read-ahead */
inode->i_mapping->backing_dev_info = &c->bdi;
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';
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("inode %lu validation failed, error %d", inode->i_ino, err);
dbg_dump_node(c, ino);
dbg_dump_inode(c, inode);
err = -EINVAL;
out_ino:
kfree(ino);
out:
ubifs_err("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);
INIT_LIST_HEAD(&inode->i_dentry);
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 pdflush 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("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(&inode->i_data, 0);
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("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->nospace = c->nospace_rp = 0;
smp_wmb();
}
done:
end_writeback(inode);
}
static void ubifs_dirty_inode(struct inode *inode)
{
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 vfsmount *mnt)
{
struct ubifs_info *c = mnt->mnt_sb->s_fs_info;
if (c->mount_opts.unmount_mode == 2)
seq_printf(s, ",fast_unmount");
else if (c->mount_opts.unmount_mode == 1)
seq_printf(s, ",norm_unmount");
if (c->mount_opts.bulk_read == 2)
seq_printf(s, ",bulk_read");
else if (c->mount_opts.bulk_read == 1)
seq_printf(s, ",no_bulk_read");
if (c->mount_opts.chk_data_crc == 2)
seq_printf(s, ",chk_data_crc");
else if (c->mount_opts.chk_data_crc == 1)
seq_printf(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("UBI volume is corrupted - read-only mode");
c->ro_media = 1;
}
if (c->di.ro_mode) {
ubifs_msg("read-only UBI device");
c->ro_media = 1;
}
if (c->vi.vol_type == UBI_STATIC_VOLUME) {
ubifs_msg("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->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;
if (c->leb_size < UBIFS_MIN_LEB_SZ) {
ubifs_err("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("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("bad min. I/O size %d", 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;
}
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) {
dbg_err("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) {
dbg_err("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->inode_budget'.
*/
c->page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
c->inode_budget = UBIFS_INO_NODE_SZ;
c->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->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("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 = kzalloc(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[BASEHD].wbuf.dtype = UBI_SHORTTERM;
/*
* Garbage Collector head likely contains long-term data and
* does not need to be synchronized by timer.
*/
c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM;
c->jheads[GCHD].wbuf.no_timer = 1;
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);
dbg_err("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 rb_node *this = c->buds.rb_node;
struct ubifs_bud *bud;
while (this) {
if (this->rb_left)
this = this->rb_left;
else if (this->rb_right)
this = this->rb_right;
else {
bud = rb_entry(this, struct ubifs_bud, rb);
this = rb_parent(this);
if (this) {
if (this->rb_left == &bud->rb)
this->rb_left = NULL;
else
this->rb_right = NULL;
}
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 = ubi_is_mapped(c->ubi, 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)
{
ubifs_msg("parse %s", 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;