![Linus Torvalds](/assets/img/avatar_default.png)
In particular, s_freeing_list needs to be initialized early, since it is used on some of the error paths when mounts fail. The mapping inode, for example, would be initialized and then free'd on an error path before s_freeing_list was initialized, but the inode drop operation needs the s_freeing_list to be set up. Normally you'd never see this, because not only is logfs fairly rare, but a successful mount will never have any issues. Reported-by: werner <w.landgraf@ru.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
672 lines
17 KiB
C
672 lines
17 KiB
C
/*
|
|
* fs/logfs/super.c
|
|
*
|
|
* As should be obvious for Linux kernel code, license is GPLv2
|
|
*
|
|
* Copyright (c) 2005-2008 Joern Engel <joern@logfs.org>
|
|
*
|
|
* Generally contains mount/umount code and also serves as a dump area for
|
|
* any functions that don't fit elsewhere and neither justify a file of their
|
|
* own.
|
|
*/
|
|
#include "logfs.h"
|
|
#include <linux/bio.h>
|
|
#include <linux/slab.h>
|
|
#include <linux/blkdev.h>
|
|
#include <linux/mtd/mtd.h>
|
|
#include <linux/statfs.h>
|
|
#include <linux/buffer_head.h>
|
|
|
|
static DEFINE_MUTEX(emergency_mutex);
|
|
static struct page *emergency_page;
|
|
|
|
struct page *emergency_read_begin(struct address_space *mapping, pgoff_t index)
|
|
{
|
|
filler_t *filler = (filler_t *)mapping->a_ops->readpage;
|
|
struct page *page;
|
|
int err;
|
|
|
|
page = read_cache_page(mapping, index, filler, NULL);
|
|
if (page)
|
|
return page;
|
|
|
|
/* No more pages available, switch to emergency page */
|
|
printk(KERN_INFO"Logfs: Using emergency page\n");
|
|
mutex_lock(&emergency_mutex);
|
|
err = filler(NULL, emergency_page);
|
|
if (err) {
|
|
mutex_unlock(&emergency_mutex);
|
|
printk(KERN_EMERG"Logfs: Error reading emergency page\n");
|
|
return ERR_PTR(err);
|
|
}
|
|
return emergency_page;
|
|
}
|
|
|
|
void emergency_read_end(struct page *page)
|
|
{
|
|
if (page == emergency_page)
|
|
mutex_unlock(&emergency_mutex);
|
|
else
|
|
page_cache_release(page);
|
|
}
|
|
|
|
static void dump_segfile(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct logfs_segment_entry se;
|
|
u32 segno;
|
|
|
|
for (segno = 0; segno < super->s_no_segs; segno++) {
|
|
logfs_get_segment_entry(sb, segno, &se);
|
|
printk("%3x: %6x %8x", segno, be32_to_cpu(se.ec_level),
|
|
be32_to_cpu(se.valid));
|
|
if (++segno < super->s_no_segs) {
|
|
logfs_get_segment_entry(sb, segno, &se);
|
|
printk(" %6x %8x", be32_to_cpu(se.ec_level),
|
|
be32_to_cpu(se.valid));
|
|
}
|
|
if (++segno < super->s_no_segs) {
|
|
logfs_get_segment_entry(sb, segno, &se);
|
|
printk(" %6x %8x", be32_to_cpu(se.ec_level),
|
|
be32_to_cpu(se.valid));
|
|
}
|
|
if (++segno < super->s_no_segs) {
|
|
logfs_get_segment_entry(sb, segno, &se);
|
|
printk(" %6x %8x", be32_to_cpu(se.ec_level),
|
|
be32_to_cpu(se.valid));
|
|
}
|
|
printk("\n");
|
|
}
|
|
}
|
|
|
|
/*
|
|
* logfs_crash_dump - dump debug information to device
|
|
*
|
|
* The LogFS superblock only occupies part of a segment. This function will
|
|
* write as much debug information as it can gather into the spare space.
|
|
*/
|
|
void logfs_crash_dump(struct super_block *sb)
|
|
{
|
|
dump_segfile(sb);
|
|
}
|
|
|
|
/*
|
|
* TODO: move to lib/string.c
|
|
*/
|
|
/**
|
|
* memchr_inv - Find a character in an area of memory.
|
|
* @s: The memory area
|
|
* @c: The byte to search for
|
|
* @n: The size of the area.
|
|
*
|
|
* returns the address of the first character other than @c, or %NULL
|
|
* if the whole buffer contains just @c.
|
|
*/
|
|
void *memchr_inv(const void *s, int c, size_t n)
|
|
{
|
|
const unsigned char *p = s;
|
|
while (n-- != 0)
|
|
if ((unsigned char)c != *p++)
|
|
return (void *)(p - 1);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* FIXME: There should be a reserve for root, similar to ext2.
|
|
*/
|
|
int logfs_statfs(struct dentry *dentry, struct kstatfs *stats)
|
|
{
|
|
struct super_block *sb = dentry->d_sb;
|
|
struct logfs_super *super = logfs_super(sb);
|
|
|
|
stats->f_type = LOGFS_MAGIC_U32;
|
|
stats->f_bsize = sb->s_blocksize;
|
|
stats->f_blocks = super->s_size >> LOGFS_BLOCK_BITS >> 3;
|
|
stats->f_bfree = super->s_free_bytes >> sb->s_blocksize_bits;
|
|
stats->f_bavail = super->s_free_bytes >> sb->s_blocksize_bits;
|
|
stats->f_files = 0;
|
|
stats->f_ffree = 0;
|
|
stats->f_namelen = LOGFS_MAX_NAMELEN;
|
|
return 0;
|
|
}
|
|
|
|
static int logfs_sb_set(struct super_block *sb, void *_super)
|
|
{
|
|
struct logfs_super *super = _super;
|
|
|
|
sb->s_fs_info = super;
|
|
sb->s_mtd = super->s_mtd;
|
|
sb->s_bdev = super->s_bdev;
|
|
#ifdef CONFIG_BLOCK
|
|
if (sb->s_bdev)
|
|
sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info;
|
|
#endif
|
|
#ifdef CONFIG_MTD
|
|
if (sb->s_mtd)
|
|
sb->s_bdi = sb->s_mtd->backing_dev_info;
|
|
#endif
|
|
return 0;
|
|
}
|
|
|
|
static int logfs_sb_test(struct super_block *sb, void *_super)
|
|
{
|
|
struct logfs_super *super = _super;
|
|
struct mtd_info *mtd = super->s_mtd;
|
|
|
|
if (mtd && sb->s_mtd == mtd)
|
|
return 1;
|
|
if (super->s_bdev && sb->s_bdev == super->s_bdev)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static void set_segment_header(struct logfs_segment_header *sh, u8 type,
|
|
u8 level, u32 segno, u32 ec)
|
|
{
|
|
sh->pad = 0;
|
|
sh->type = type;
|
|
sh->level = level;
|
|
sh->segno = cpu_to_be32(segno);
|
|
sh->ec = cpu_to_be32(ec);
|
|
sh->gec = cpu_to_be64(segno);
|
|
sh->crc = logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4);
|
|
}
|
|
|
|
static void logfs_write_ds(struct super_block *sb, struct logfs_disk_super *ds,
|
|
u32 segno, u32 ec)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct logfs_segment_header *sh = &ds->ds_sh;
|
|
int i;
|
|
|
|
memset(ds, 0, sizeof(*ds));
|
|
set_segment_header(sh, SEG_SUPER, 0, segno, ec);
|
|
|
|
ds->ds_ifile_levels = super->s_ifile_levels;
|
|
ds->ds_iblock_levels = super->s_iblock_levels;
|
|
ds->ds_data_levels = super->s_data_levels; /* XXX: Remove */
|
|
ds->ds_segment_shift = super->s_segshift;
|
|
ds->ds_block_shift = sb->s_blocksize_bits;
|
|
ds->ds_write_shift = super->s_writeshift;
|
|
ds->ds_filesystem_size = cpu_to_be64(super->s_size);
|
|
ds->ds_segment_size = cpu_to_be32(super->s_segsize);
|
|
ds->ds_bad_seg_reserve = cpu_to_be32(super->s_bad_seg_reserve);
|
|
ds->ds_feature_incompat = cpu_to_be64(super->s_feature_incompat);
|
|
ds->ds_feature_ro_compat= cpu_to_be64(super->s_feature_ro_compat);
|
|
ds->ds_feature_compat = cpu_to_be64(super->s_feature_compat);
|
|
ds->ds_feature_flags = cpu_to_be64(super->s_feature_flags);
|
|
ds->ds_root_reserve = cpu_to_be64(super->s_root_reserve);
|
|
ds->ds_speed_reserve = cpu_to_be64(super->s_speed_reserve);
|
|
journal_for_each(i)
|
|
ds->ds_journal_seg[i] = cpu_to_be32(super->s_journal_seg[i]);
|
|
ds->ds_magic = cpu_to_be64(LOGFS_MAGIC);
|
|
ds->ds_crc = logfs_crc32(ds, sizeof(*ds),
|
|
LOGFS_SEGMENT_HEADERSIZE + 12);
|
|
}
|
|
|
|
static int write_one_sb(struct super_block *sb,
|
|
struct page *(*find_sb)(struct super_block *sb, u64 *ofs))
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct logfs_disk_super *ds;
|
|
struct logfs_segment_entry se;
|
|
struct page *page;
|
|
u64 ofs;
|
|
u32 ec, segno;
|
|
int err;
|
|
|
|
page = find_sb(sb, &ofs);
|
|
if (!page)
|
|
return -EIO;
|
|
ds = page_address(page);
|
|
segno = seg_no(sb, ofs);
|
|
logfs_get_segment_entry(sb, segno, &se);
|
|
ec = be32_to_cpu(se.ec_level) >> 4;
|
|
ec++;
|
|
logfs_set_segment_erased(sb, segno, ec, 0);
|
|
logfs_write_ds(sb, ds, segno, ec);
|
|
err = super->s_devops->write_sb(sb, page);
|
|
page_cache_release(page);
|
|
return err;
|
|
}
|
|
|
|
int logfs_write_sb(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
int err;
|
|
|
|
/* First superblock */
|
|
err = write_one_sb(sb, super->s_devops->find_first_sb);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Last superblock */
|
|
err = write_one_sb(sb, super->s_devops->find_last_sb);
|
|
if (err)
|
|
return err;
|
|
return 0;
|
|
}
|
|
|
|
static int ds_cmp(const void *ds0, const void *ds1)
|
|
{
|
|
size_t len = sizeof(struct logfs_disk_super);
|
|
|
|
/* We know the segment headers differ, so ignore them */
|
|
len -= LOGFS_SEGMENT_HEADERSIZE;
|
|
ds0 += LOGFS_SEGMENT_HEADERSIZE;
|
|
ds1 += LOGFS_SEGMENT_HEADERSIZE;
|
|
return memcmp(ds0, ds1, len);
|
|
}
|
|
|
|
static int logfs_recover_sb(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct logfs_disk_super _ds0, *ds0 = &_ds0;
|
|
struct logfs_disk_super _ds1, *ds1 = &_ds1;
|
|
int err, valid0, valid1;
|
|
|
|
/* read first superblock */
|
|
err = wbuf_read(sb, super->s_sb_ofs[0], sizeof(*ds0), ds0);
|
|
if (err)
|
|
return err;
|
|
/* read last superblock */
|
|
err = wbuf_read(sb, super->s_sb_ofs[1], sizeof(*ds1), ds1);
|
|
if (err)
|
|
return err;
|
|
valid0 = logfs_check_ds(ds0) == 0;
|
|
valid1 = logfs_check_ds(ds1) == 0;
|
|
|
|
if (!valid0 && valid1) {
|
|
printk(KERN_INFO"First superblock is invalid - fixing.\n");
|
|
return write_one_sb(sb, super->s_devops->find_first_sb);
|
|
}
|
|
if (valid0 && !valid1) {
|
|
printk(KERN_INFO"Last superblock is invalid - fixing.\n");
|
|
return write_one_sb(sb, super->s_devops->find_last_sb);
|
|
}
|
|
if (valid0 && valid1 && ds_cmp(ds0, ds1)) {
|
|
printk(KERN_INFO"Superblocks don't match - fixing.\n");
|
|
return logfs_write_sb(sb);
|
|
}
|
|
/* If neither is valid now, something's wrong. Didn't we properly
|
|
* check them before?!? */
|
|
BUG_ON(!valid0 && !valid1);
|
|
return 0;
|
|
}
|
|
|
|
static int logfs_make_writeable(struct super_block *sb)
|
|
{
|
|
int err;
|
|
|
|
err = logfs_open_segfile(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Repair any broken superblock copies */
|
|
err = logfs_recover_sb(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Check areas for trailing unaccounted data */
|
|
err = logfs_check_areas(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
/* Do one GC pass before any data gets dirtied */
|
|
logfs_gc_pass(sb);
|
|
|
|
/* after all initializations are done, replay the journal
|
|
* for rw-mounts, if necessary */
|
|
err = logfs_replay_journal(sb);
|
|
if (err)
|
|
return err;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int logfs_get_sb_final(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct inode *rootdir;
|
|
int err;
|
|
|
|
/* root dir */
|
|
rootdir = logfs_iget(sb, LOGFS_INO_ROOT);
|
|
if (IS_ERR(rootdir))
|
|
goto fail;
|
|
|
|
sb->s_root = d_alloc_root(rootdir);
|
|
if (!sb->s_root) {
|
|
iput(rootdir);
|
|
goto fail;
|
|
}
|
|
|
|
/* at that point we know that ->put_super() will be called */
|
|
super->s_erase_page = alloc_pages(GFP_KERNEL, 0);
|
|
if (!super->s_erase_page)
|
|
return -ENOMEM;
|
|
memset(page_address(super->s_erase_page), 0xFF, PAGE_SIZE);
|
|
|
|
/* FIXME: check for read-only mounts */
|
|
err = logfs_make_writeable(sb);
|
|
if (err) {
|
|
__free_page(super->s_erase_page);
|
|
return err;
|
|
}
|
|
|
|
log_super("LogFS: Finished mounting\n");
|
|
return 0;
|
|
|
|
fail:
|
|
iput(super->s_master_inode);
|
|
iput(super->s_segfile_inode);
|
|
iput(super->s_mapping_inode);
|
|
return -EIO;
|
|
}
|
|
|
|
int logfs_check_ds(struct logfs_disk_super *ds)
|
|
{
|
|
struct logfs_segment_header *sh = &ds->ds_sh;
|
|
|
|
if (ds->ds_magic != cpu_to_be64(LOGFS_MAGIC))
|
|
return -EINVAL;
|
|
if (sh->crc != logfs_crc32(sh, LOGFS_SEGMENT_HEADERSIZE, 4))
|
|
return -EINVAL;
|
|
if (ds->ds_crc != logfs_crc32(ds, sizeof(*ds),
|
|
LOGFS_SEGMENT_HEADERSIZE + 12))
|
|
return -EINVAL;
|
|
return 0;
|
|
}
|
|
|
|
static struct page *find_super_block(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct page *first, *last;
|
|
|
|
first = super->s_devops->find_first_sb(sb, &super->s_sb_ofs[0]);
|
|
if (!first || IS_ERR(first))
|
|
return NULL;
|
|
last = super->s_devops->find_last_sb(sb, &super->s_sb_ofs[1]);
|
|
if (!last || IS_ERR(last)) {
|
|
page_cache_release(first);
|
|
return NULL;
|
|
}
|
|
|
|
if (!logfs_check_ds(page_address(first))) {
|
|
page_cache_release(last);
|
|
return first;
|
|
}
|
|
|
|
/* First one didn't work, try the second superblock */
|
|
if (!logfs_check_ds(page_address(last))) {
|
|
page_cache_release(first);
|
|
return last;
|
|
}
|
|
|
|
/* Neither worked, sorry folks */
|
|
page_cache_release(first);
|
|
page_cache_release(last);
|
|
return NULL;
|
|
}
|
|
|
|
static int __logfs_read_sb(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
struct page *page;
|
|
struct logfs_disk_super *ds;
|
|
int i;
|
|
|
|
page = find_super_block(sb);
|
|
if (!page)
|
|
return -EINVAL;
|
|
|
|
ds = page_address(page);
|
|
super->s_size = be64_to_cpu(ds->ds_filesystem_size);
|
|
super->s_root_reserve = be64_to_cpu(ds->ds_root_reserve);
|
|
super->s_speed_reserve = be64_to_cpu(ds->ds_speed_reserve);
|
|
super->s_bad_seg_reserve = be32_to_cpu(ds->ds_bad_seg_reserve);
|
|
super->s_segsize = 1 << ds->ds_segment_shift;
|
|
super->s_segmask = (1 << ds->ds_segment_shift) - 1;
|
|
super->s_segshift = ds->ds_segment_shift;
|
|
sb->s_blocksize = 1 << ds->ds_block_shift;
|
|
sb->s_blocksize_bits = ds->ds_block_shift;
|
|
super->s_writesize = 1 << ds->ds_write_shift;
|
|
super->s_writeshift = ds->ds_write_shift;
|
|
super->s_no_segs = super->s_size >> super->s_segshift;
|
|
super->s_no_blocks = super->s_segsize >> sb->s_blocksize_bits;
|
|
super->s_feature_incompat = be64_to_cpu(ds->ds_feature_incompat);
|
|
super->s_feature_ro_compat = be64_to_cpu(ds->ds_feature_ro_compat);
|
|
super->s_feature_compat = be64_to_cpu(ds->ds_feature_compat);
|
|
super->s_feature_flags = be64_to_cpu(ds->ds_feature_flags);
|
|
|
|
journal_for_each(i)
|
|
super->s_journal_seg[i] = be32_to_cpu(ds->ds_journal_seg[i]);
|
|
|
|
super->s_ifile_levels = ds->ds_ifile_levels;
|
|
super->s_iblock_levels = ds->ds_iblock_levels;
|
|
super->s_data_levels = ds->ds_data_levels;
|
|
super->s_total_levels = super->s_ifile_levels + super->s_iblock_levels
|
|
+ super->s_data_levels;
|
|
page_cache_release(page);
|
|
return 0;
|
|
}
|
|
|
|
static int logfs_read_sb(struct super_block *sb, int read_only)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
int ret;
|
|
|
|
super->s_btree_pool = mempool_create(32, btree_alloc, btree_free, NULL);
|
|
if (!super->s_btree_pool)
|
|
return -ENOMEM;
|
|
|
|
btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool);
|
|
btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool);
|
|
btree_init_mempool32(&super->s_shadow_tree.segment_map,
|
|
super->s_btree_pool);
|
|
|
|
ret = logfs_init_mapping(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = __logfs_read_sb(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
if (super->s_feature_incompat & ~LOGFS_FEATURES_INCOMPAT)
|
|
return -EIO;
|
|
if ((super->s_feature_ro_compat & ~LOGFS_FEATURES_RO_COMPAT) &&
|
|
!read_only)
|
|
return -EIO;
|
|
|
|
ret = logfs_init_rw(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = logfs_init_areas(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = logfs_init_gc(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = logfs_init_journal(sb);
|
|
if (ret)
|
|
return ret;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void logfs_kill_sb(struct super_block *sb)
|
|
{
|
|
struct logfs_super *super = logfs_super(sb);
|
|
|
|
log_super("LogFS: Start unmounting\n");
|
|
/* Alias entries slow down mount, so evict as many as possible */
|
|
sync_filesystem(sb);
|
|
logfs_write_anchor(sb);
|
|
|
|
/*
|
|
* From this point on alias entries are simply dropped - and any
|
|
* writes to the object store are considered bugs.
|
|
*/
|
|
super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN;
|
|
log_super("LogFS: Now in shutdown\n");
|
|
generic_shutdown_super(sb);
|
|
|
|
BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes);
|
|
|
|
logfs_cleanup_gc(sb);
|
|
logfs_cleanup_journal(sb);
|
|
logfs_cleanup_areas(sb);
|
|
logfs_cleanup_rw(sb);
|
|
if (super->s_erase_page)
|
|
__free_page(super->s_erase_page);
|
|
super->s_devops->put_device(super);
|
|
logfs_mempool_destroy(super->s_btree_pool);
|
|
logfs_mempool_destroy(super->s_alias_pool);
|
|
kfree(super);
|
|
log_super("LogFS: Finished unmounting\n");
|
|
}
|
|
|
|
static struct dentry *logfs_get_sb_device(struct logfs_super *super,
|
|
struct file_system_type *type, int flags)
|
|
{
|
|
struct super_block *sb;
|
|
int err = -ENOMEM;
|
|
static int mount_count;
|
|
|
|
log_super("LogFS: Start mount %x\n", mount_count++);
|
|
|
|
err = -EINVAL;
|
|
sb = sget(type, logfs_sb_test, logfs_sb_set, super);
|
|
if (IS_ERR(sb)) {
|
|
super->s_devops->put_device(super);
|
|
kfree(super);
|
|
return ERR_CAST(sb);
|
|
}
|
|
|
|
if (sb->s_root) {
|
|
/* Device is already in use */
|
|
super->s_devops->put_device(super);
|
|
kfree(super);
|
|
return dget(sb->s_root);
|
|
}
|
|
|
|
/*
|
|
* sb->s_maxbytes is limited to 8TB. On 32bit systems, the page cache
|
|
* only covers 16TB and the upper 8TB are used for indirect blocks.
|
|
* On 64bit system we could bump up the limit, but that would make
|
|
* the filesystem incompatible with 32bit systems.
|
|
*/
|
|
sb->s_maxbytes = (1ull << 43) - 1;
|
|
sb->s_op = &logfs_super_operations;
|
|
sb->s_flags = flags | MS_NOATIME;
|
|
|
|
err = logfs_read_sb(sb, sb->s_flags & MS_RDONLY);
|
|
if (err)
|
|
goto err1;
|
|
|
|
sb->s_flags |= MS_ACTIVE;
|
|
err = logfs_get_sb_final(sb);
|
|
if (err) {
|
|
deactivate_locked_super(sb);
|
|
return ERR_PTR(err);
|
|
}
|
|
return dget(sb->s_root);
|
|
|
|
err1:
|
|
/* no ->s_root, no ->put_super() */
|
|
iput(super->s_master_inode);
|
|
iput(super->s_segfile_inode);
|
|
iput(super->s_mapping_inode);
|
|
deactivate_locked_super(sb);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
static struct dentry *logfs_mount(struct file_system_type *type, int flags,
|
|
const char *devname, void *data)
|
|
{
|
|
ulong mtdnr;
|
|
struct logfs_super *super;
|
|
int err;
|
|
|
|
super = kzalloc(sizeof(*super), GFP_KERNEL);
|
|
if (!super)
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
mutex_init(&super->s_dirop_mutex);
|
|
mutex_init(&super->s_object_alias_mutex);
|
|
INIT_LIST_HEAD(&super->s_freeing_list);
|
|
|
|
if (!devname)
|
|
err = logfs_get_sb_bdev(super, type, devname);
|
|
else if (strncmp(devname, "mtd", 3))
|
|
err = logfs_get_sb_bdev(super, type, devname);
|
|
else {
|
|
char *garbage;
|
|
mtdnr = simple_strtoul(devname+3, &garbage, 0);
|
|
if (*garbage)
|
|
err = -EINVAL;
|
|
else
|
|
err = logfs_get_sb_mtd(super, mtdnr);
|
|
}
|
|
|
|
if (err) {
|
|
kfree(super);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
return logfs_get_sb_device(super, type, flags);
|
|
}
|
|
|
|
static struct file_system_type logfs_fs_type = {
|
|
.owner = THIS_MODULE,
|
|
.name = "logfs",
|
|
.mount = logfs_mount,
|
|
.kill_sb = logfs_kill_sb,
|
|
.fs_flags = FS_REQUIRES_DEV,
|
|
|
|
};
|
|
|
|
static int __init logfs_init(void)
|
|
{
|
|
int ret;
|
|
|
|
emergency_page = alloc_pages(GFP_KERNEL, 0);
|
|
if (!emergency_page)
|
|
return -ENOMEM;
|
|
|
|
ret = logfs_compr_init();
|
|
if (ret)
|
|
goto out1;
|
|
|
|
ret = logfs_init_inode_cache();
|
|
if (ret)
|
|
goto out2;
|
|
|
|
return register_filesystem(&logfs_fs_type);
|
|
out2:
|
|
logfs_compr_exit();
|
|
out1:
|
|
__free_pages(emergency_page, 0);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit logfs_exit(void)
|
|
{
|
|
unregister_filesystem(&logfs_fs_type);
|
|
logfs_destroy_inode_cache();
|
|
logfs_compr_exit();
|
|
__free_pages(emergency_page, 0);
|
|
}
|
|
|
|
module_init(logfs_init);
|
|
module_exit(logfs_exit);
|
|
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_AUTHOR("Joern Engel <joern@logfs.org>");
|
|
MODULE_DESCRIPTION("scalable flash filesystem");
|