TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

hfsplus: use raw bio access for the volume headers

Browse Source 
The hfsplus backup volume header is located two blocks from the end of
the device.  In case of device sizes that are not 4k aligned this means
we can't access it using buffer_heads when using the default 4k block
size.

Switch to using raw bios to read/write all buffer headers.  We were not
relying on any caching behaviour of the buffer heads anyway.  Additionally
always read in the backup volume header during mount to verify that we
can actually read it.

Signed-off-by: Christoph Hellwig <hch@tuxera.com>
This commit is contained in:
Christoph Hellwig
2010-11-23 14:37:47 +01:00
committed by Christoph Hellwig
parent 3b5ce8ae31
commit 52399b171d
3 changed files with 130 additions and 87 deletions
Download Patch File Download Diff File Expand all files Collapse all files
fs/hfsplus/super.c
+22 -26
View File
@@ -157,45 +157,40 @@ int hfsplus_sync_fs(struct super_block *sb, int wait)
{
struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
struct hfsplus_vh *vhdr = sbi->s_vhdr;
int write_backup = 0;
int error, error2;
dprint(DBG_SUPER, "hfsplus_write_super\n");
mutex_lock(&sbi->vh_mutex);
mutex_lock(&sbi->alloc_mutex);
sb->s_dirt = 0;
mutex_lock(&sbi->vh_mutex);
mutex_lock(&sbi->alloc_mutex);
vhdr->free_blocks = cpu_to_be32(sbi->free_blocks);
vhdr->next_cnid = cpu_to_be32(sbi->next_cnid);
vhdr->folder_count = cpu_to_be32(sbi->folder_count);
vhdr->file_count = cpu_to_be32(sbi->file_count);
mark_buffer_dirty(sbi->s_vhbh);
if (test_and_clear_bit(HFSPLUS_SB_WRITEBACKUP, &sbi->flags)) {
if (sbi->sect_count) {
struct buffer_head *bh;
u32 block, offset;
block = sbi->blockoffset;
block += (sbi->sect_count - 2) >> (sb->s_blocksize_bits - 9);
offset = ((sbi->sect_count - 2) << 9) & (sb->s_blocksize - 1);
printk(KERN_DEBUG "hfs: backup: %u,%u,%u,%u\n",
sbi->blockoffset, sbi->sect_count,
block, offset);
bh = sb_bread(sb, block);
if (bh) {
vhdr = (struct hfsplus_vh *)(bh->b_data + offset);
if (be16_to_cpu(vhdr->signature) == HFSPLUS_VOLHEAD_SIG) {
memcpy(vhdr, sbi->s_vhdr, sizeof(*vhdr));
mark_buffer_dirty(bh);
brelse(bh);
} else
printk(KERN_WARNING "hfs: backup not found!\n");
}
}
memcpy(sbi->s_backup_vhdr, sbi->s_vhdr, sizeof(*sbi->s_vhdr));
write_backup = 1;
}
error = hfsplus_submit_bio(sb->s_bdev,
sbi->part_start + HFSPLUS_VOLHEAD_SECTOR,
sbi->s_vhdr, WRITE_SYNC);
if (!write_backup)
goto out;
error2 = hfsplus_submit_bio(sb->s_bdev,
sbi->part_start + sbi->sect_count - 2,
sbi->s_backup_vhdr, WRITE_SYNC);
if (!error)
error2 = error;
out:
mutex_unlock(&sbi->alloc_mutex);
mutex_unlock(&sbi->vh_mutex);
return 0;
return error;
}
static void hfsplus_write_super(struct super_block *sb)
@@ -229,7 +224,8 @@ static void hfsplus_put_super(struct super_block *sb)
hfs_btree_close(sbi->ext_tree);
iput(sbi->alloc_file);
iput(sbi->hidden_dir);
brelse(sbi->s_vhbh);
kfree(sbi->s_vhdr);
kfree(sbi->s_backup_vhdr);
unload_nls(sbi->nls);
kfree(sb->s_fs_info);
sb->s_fs_info = NULL;