mirror of https://gitee.com/openkylin/linux.git
914 lines
26 KiB
C
914 lines
26 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* linux/fs/ext4/balloc.c
|
|
*
|
|
* Copyright (C) 1992, 1993, 1994, 1995
|
|
* Remy Card (card@masi.ibp.fr)
|
|
* Laboratoire MASI - Institut Blaise Pascal
|
|
* Universite Pierre et Marie Curie (Paris VI)
|
|
*
|
|
* Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993
|
|
* Big-endian to little-endian byte-swapping/bitmaps by
|
|
* David S. Miller (davem@caip.rutgers.edu), 1995
|
|
*/
|
|
|
|
#include <linux/time.h>
|
|
#include <linux/capability.h>
|
|
#include <linux/fs.h>
|
|
#include <linux/quotaops.h>
|
|
#include <linux/buffer_head.h>
|
|
#include "ext4.h"
|
|
#include "ext4_jbd2.h"
|
|
#include "mballoc.h"
|
|
|
|
#include <trace/events/ext4.h>
|
|
|
|
static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
|
|
ext4_group_t block_group);
|
|
/*
|
|
* balloc.c contains the blocks allocation and deallocation routines
|
|
*/
|
|
|
|
/*
|
|
* Calculate block group number for a given block number
|
|
*/
|
|
ext4_group_t ext4_get_group_number(struct super_block *sb,
|
|
ext4_fsblk_t block)
|
|
{
|
|
ext4_group_t group;
|
|
|
|
if (test_opt2(sb, STD_GROUP_SIZE))
|
|
group = (block -
|
|
le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) >>
|
|
(EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3);
|
|
else
|
|
ext4_get_group_no_and_offset(sb, block, &group, NULL);
|
|
return group;
|
|
}
|
|
|
|
/*
|
|
* Calculate the block group number and offset into the block/cluster
|
|
* allocation bitmap, given a block number
|
|
*/
|
|
void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr,
|
|
ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp)
|
|
{
|
|
struct ext4_super_block *es = EXT4_SB(sb)->s_es;
|
|
ext4_grpblk_t offset;
|
|
|
|
blocknr = blocknr - le32_to_cpu(es->s_first_data_block);
|
|
offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >>
|
|
EXT4_SB(sb)->s_cluster_bits;
|
|
if (offsetp)
|
|
*offsetp = offset;
|
|
if (blockgrpp)
|
|
*blockgrpp = blocknr;
|
|
|
|
}
|
|
|
|
/*
|
|
* Check whether the 'block' lives within the 'block_group'. Returns 1 if so
|
|
* and 0 otherwise.
|
|
*/
|
|
static inline int ext4_block_in_group(struct super_block *sb,
|
|
ext4_fsblk_t block,
|
|
ext4_group_t block_group)
|
|
{
|
|
ext4_group_t actual_group;
|
|
|
|
actual_group = ext4_get_group_number(sb, block);
|
|
return (actual_group == block_group) ? 1 : 0;
|
|
}
|
|
|
|
/* Return the number of clusters used for file system metadata; this
|
|
* represents the overhead needed by the file system.
|
|
*/
|
|
static unsigned ext4_num_overhead_clusters(struct super_block *sb,
|
|
ext4_group_t block_group,
|
|
struct ext4_group_desc *gdp)
|
|
{
|
|
unsigned num_clusters;
|
|
int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c;
|
|
ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group);
|
|
ext4_fsblk_t itbl_blk;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
|
|
/* This is the number of clusters used by the superblock,
|
|
* block group descriptors, and reserved block group
|
|
* descriptor blocks */
|
|
num_clusters = ext4_num_base_meta_clusters(sb, block_group);
|
|
|
|
/*
|
|
* For the allocation bitmaps and inode table, we first need
|
|
* to check to see if the block is in the block group. If it
|
|
* is, then check to see if the cluster is already accounted
|
|
* for in the clusters used for the base metadata cluster, or
|
|
* if we can increment the base metadata cluster to include
|
|
* that block. Otherwise, we will have to track the cluster
|
|
* used for the allocation bitmap or inode table explicitly.
|
|
* Normally all of these blocks are contiguous, so the special
|
|
* case handling shouldn't be necessary except for *very*
|
|
* unusual file system layouts.
|
|
*/
|
|
if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) {
|
|
block_cluster = EXT4_B2C(sbi,
|
|
ext4_block_bitmap(sb, gdp) - start);
|
|
if (block_cluster < num_clusters)
|
|
block_cluster = -1;
|
|
else if (block_cluster == num_clusters) {
|
|
num_clusters++;
|
|
block_cluster = -1;
|
|
}
|
|
}
|
|
|
|
if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) {
|
|
inode_cluster = EXT4_B2C(sbi,
|
|
ext4_inode_bitmap(sb, gdp) - start);
|
|
if (inode_cluster < num_clusters)
|
|
inode_cluster = -1;
|
|
else if (inode_cluster == num_clusters) {
|
|
num_clusters++;
|
|
inode_cluster = -1;
|
|
}
|
|
}
|
|
|
|
itbl_blk = ext4_inode_table(sb, gdp);
|
|
for (i = 0; i < sbi->s_itb_per_group; i++) {
|
|
if (ext4_block_in_group(sb, itbl_blk + i, block_group)) {
|
|
c = EXT4_B2C(sbi, itbl_blk + i - start);
|
|
if ((c < num_clusters) || (c == inode_cluster) ||
|
|
(c == block_cluster) || (c == itbl_cluster))
|
|
continue;
|
|
if (c == num_clusters) {
|
|
num_clusters++;
|
|
continue;
|
|
}
|
|
num_clusters++;
|
|
itbl_cluster = c;
|
|
}
|
|
}
|
|
|
|
if (block_cluster != -1)
|
|
num_clusters++;
|
|
if (inode_cluster != -1)
|
|
num_clusters++;
|
|
|
|
return num_clusters;
|
|
}
|
|
|
|
static unsigned int num_clusters_in_group(struct super_block *sb,
|
|
ext4_group_t block_group)
|
|
{
|
|
unsigned int blocks;
|
|
|
|
if (block_group == ext4_get_groups_count(sb) - 1) {
|
|
/*
|
|
* Even though mke2fs always initializes the first and
|
|
* last group, just in case some other tool was used,
|
|
* we need to make sure we calculate the right free
|
|
* blocks.
|
|
*/
|
|
blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) -
|
|
ext4_group_first_block_no(sb, block_group);
|
|
} else
|
|
blocks = EXT4_BLOCKS_PER_GROUP(sb);
|
|
return EXT4_NUM_B2C(EXT4_SB(sb), blocks);
|
|
}
|
|
|
|
/* Initializes an uninitialized block bitmap */
|
|
static int ext4_init_block_bitmap(struct super_block *sb,
|
|
struct buffer_head *bh,
|
|
ext4_group_t block_group,
|
|
struct ext4_group_desc *gdp)
|
|
{
|
|
unsigned int bit, bit_max;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
ext4_fsblk_t start, tmp;
|
|
|
|
J_ASSERT_BH(bh, buffer_locked(bh));
|
|
|
|
/* If checksum is bad mark all blocks used to prevent allocation
|
|
* essentially implementing a per-group read-only flag. */
|
|
if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) {
|
|
ext4_mark_group_bitmap_corrupted(sb, block_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT |
|
|
EXT4_GROUP_INFO_IBITMAP_CORRUPT);
|
|
return -EFSBADCRC;
|
|
}
|
|
memset(bh->b_data, 0, sb->s_blocksize);
|
|
|
|
bit_max = ext4_num_base_meta_clusters(sb, block_group);
|
|
if ((bit_max >> 3) >= bh->b_size)
|
|
return -EFSCORRUPTED;
|
|
|
|
for (bit = 0; bit < bit_max; bit++)
|
|
ext4_set_bit(bit, bh->b_data);
|
|
|
|
start = ext4_group_first_block_no(sb, block_group);
|
|
|
|
/* Set bits for block and inode bitmaps, and inode table */
|
|
tmp = ext4_block_bitmap(sb, gdp);
|
|
if (ext4_block_in_group(sb, tmp, block_group))
|
|
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
|
|
|
|
tmp = ext4_inode_bitmap(sb, gdp);
|
|
if (ext4_block_in_group(sb, tmp, block_group))
|
|
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
|
|
|
|
tmp = ext4_inode_table(sb, gdp);
|
|
for (; tmp < ext4_inode_table(sb, gdp) +
|
|
sbi->s_itb_per_group; tmp++) {
|
|
if (ext4_block_in_group(sb, tmp, block_group))
|
|
ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data);
|
|
}
|
|
|
|
/*
|
|
* Also if the number of blocks within the group is less than
|
|
* the blocksize * 8 ( which is the size of bitmap ), set rest
|
|
* of the block bitmap to 1
|
|
*/
|
|
ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group),
|
|
sb->s_blocksize * 8, bh->b_data);
|
|
return 0;
|
|
}
|
|
|
|
/* Return the number of free blocks in a block group. It is used when
|
|
* the block bitmap is uninitialized, so we can't just count the bits
|
|
* in the bitmap. */
|
|
unsigned ext4_free_clusters_after_init(struct super_block *sb,
|
|
ext4_group_t block_group,
|
|
struct ext4_group_desc *gdp)
|
|
{
|
|
return num_clusters_in_group(sb, block_group) -
|
|
ext4_num_overhead_clusters(sb, block_group, gdp);
|
|
}
|
|
|
|
/*
|
|
* The free blocks are managed by bitmaps. A file system contains several
|
|
* blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap
|
|
* block for inodes, N blocks for the inode table and data blocks.
|
|
*
|
|
* The file system contains group descriptors which are located after the
|
|
* super block. Each descriptor contains the number of the bitmap block and
|
|
* the free blocks count in the block. The descriptors are loaded in memory
|
|
* when a file system is mounted (see ext4_fill_super).
|
|
*/
|
|
|
|
/**
|
|
* ext4_get_group_desc() -- load group descriptor from disk
|
|
* @sb: super block
|
|
* @block_group: given block group
|
|
* @bh: pointer to the buffer head to store the block
|
|
* group descriptor
|
|
*/
|
|
struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb,
|
|
ext4_group_t block_group,
|
|
struct buffer_head **bh)
|
|
{
|
|
unsigned int group_desc;
|
|
unsigned int offset;
|
|
ext4_group_t ngroups = ext4_get_groups_count(sb);
|
|
struct ext4_group_desc *desc;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct buffer_head *bh_p;
|
|
|
|
if (block_group >= ngroups) {
|
|
ext4_error(sb, "block_group >= groups_count - block_group = %u,"
|
|
" groups_count = %u", block_group, ngroups);
|
|
|
|
return NULL;
|
|
}
|
|
|
|
group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb);
|
|
offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1);
|
|
bh_p = sbi_array_rcu_deref(sbi, s_group_desc, group_desc);
|
|
/*
|
|
* sbi_array_rcu_deref returns with rcu unlocked, this is ok since
|
|
* the pointer being dereferenced won't be dereferenced again. By
|
|
* looking at the usage in add_new_gdb() the value isn't modified,
|
|
* just the pointer, and so it remains valid.
|
|
*/
|
|
if (!bh_p) {
|
|
ext4_error(sb, "Group descriptor not loaded - "
|
|
"block_group = %u, group_desc = %u, desc = %u",
|
|
block_group, group_desc, offset);
|
|
return NULL;
|
|
}
|
|
|
|
desc = (struct ext4_group_desc *)(
|
|
(__u8 *)bh_p->b_data +
|
|
offset * EXT4_DESC_SIZE(sb));
|
|
if (bh)
|
|
*bh = bh_p;
|
|
return desc;
|
|
}
|
|
|
|
/*
|
|
* Return the block number which was discovered to be invalid, or 0 if
|
|
* the block bitmap is valid.
|
|
*/
|
|
static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb,
|
|
struct ext4_group_desc *desc,
|
|
ext4_group_t block_group,
|
|
struct buffer_head *bh)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
ext4_grpblk_t offset;
|
|
ext4_grpblk_t next_zero_bit;
|
|
ext4_grpblk_t max_bit = EXT4_CLUSTERS_PER_GROUP(sb);
|
|
ext4_fsblk_t blk;
|
|
ext4_fsblk_t group_first_block;
|
|
|
|
if (ext4_has_feature_flex_bg(sb)) {
|
|
/* with FLEX_BG, the inode/block bitmaps and itable
|
|
* blocks may not be in the group at all
|
|
* so the bitmap validation will be skipped for those groups
|
|
* or it has to also read the block group where the bitmaps
|
|
* are located to verify they are set.
|
|
*/
|
|
return 0;
|
|
}
|
|
group_first_block = ext4_group_first_block_no(sb, block_group);
|
|
|
|
/* check whether block bitmap block number is set */
|
|
blk = ext4_block_bitmap(sb, desc);
|
|
offset = blk - group_first_block;
|
|
if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
|
|
!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
|
|
/* bad block bitmap */
|
|
return blk;
|
|
|
|
/* check whether the inode bitmap block number is set */
|
|
blk = ext4_inode_bitmap(sb, desc);
|
|
offset = blk - group_first_block;
|
|
if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
|
|
!ext4_test_bit(EXT4_B2C(sbi, offset), bh->b_data))
|
|
/* bad block bitmap */
|
|
return blk;
|
|
|
|
/* check whether the inode table block number is set */
|
|
blk = ext4_inode_table(sb, desc);
|
|
offset = blk - group_first_block;
|
|
if (offset < 0 || EXT4_B2C(sbi, offset) >= max_bit ||
|
|
EXT4_B2C(sbi, offset + sbi->s_itb_per_group) >= max_bit)
|
|
return blk;
|
|
next_zero_bit = ext4_find_next_zero_bit(bh->b_data,
|
|
EXT4_B2C(sbi, offset + sbi->s_itb_per_group),
|
|
EXT4_B2C(sbi, offset));
|
|
if (next_zero_bit <
|
|
EXT4_B2C(sbi, offset + sbi->s_itb_per_group))
|
|
/* bad bitmap for inode tables */
|
|
return blk;
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_validate_block_bitmap(struct super_block *sb,
|
|
struct ext4_group_desc *desc,
|
|
ext4_group_t block_group,
|
|
struct buffer_head *bh)
|
|
{
|
|
ext4_fsblk_t blk;
|
|
struct ext4_group_info *grp = ext4_get_group_info(sb, block_group);
|
|
|
|
if (buffer_verified(bh))
|
|
return 0;
|
|
if (EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
|
|
return -EFSCORRUPTED;
|
|
|
|
ext4_lock_group(sb, block_group);
|
|
if (buffer_verified(bh))
|
|
goto verified;
|
|
if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group,
|
|
desc, bh) ||
|
|
ext4_simulate_fail(sb, EXT4_SIM_BBITMAP_CRC))) {
|
|
ext4_unlock_group(sb, block_group);
|
|
ext4_error(sb, "bg %u: bad block bitmap checksum", block_group);
|
|
ext4_mark_group_bitmap_corrupted(sb, block_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
return -EFSBADCRC;
|
|
}
|
|
blk = ext4_valid_block_bitmap(sb, desc, block_group, bh);
|
|
if (unlikely(blk != 0)) {
|
|
ext4_unlock_group(sb, block_group);
|
|
ext4_error(sb, "bg %u: block %llu: invalid block bitmap",
|
|
block_group, blk);
|
|
ext4_mark_group_bitmap_corrupted(sb, block_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
return -EFSCORRUPTED;
|
|
}
|
|
set_buffer_verified(bh);
|
|
verified:
|
|
ext4_unlock_group(sb, block_group);
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* ext4_read_block_bitmap_nowait()
|
|
* @sb: super block
|
|
* @block_group: given block group
|
|
*
|
|
* Read the bitmap for a given block_group,and validate the
|
|
* bits for block/inode/inode tables are set in the bitmaps
|
|
*
|
|
* Return buffer_head on success or NULL in case of failure.
|
|
*/
|
|
struct buffer_head *
|
|
ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group)
|
|
{
|
|
struct ext4_group_desc *desc;
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct buffer_head *bh;
|
|
ext4_fsblk_t bitmap_blk;
|
|
int err;
|
|
|
|
desc = ext4_get_group_desc(sb, block_group, NULL);
|
|
if (!desc)
|
|
return ERR_PTR(-EFSCORRUPTED);
|
|
bitmap_blk = ext4_block_bitmap(sb, desc);
|
|
if ((bitmap_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
|
|
(bitmap_blk >= ext4_blocks_count(sbi->s_es))) {
|
|
ext4_error(sb, "Invalid block bitmap block %llu in "
|
|
"block_group %u", bitmap_blk, block_group);
|
|
ext4_mark_group_bitmap_corrupted(sb, block_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
return ERR_PTR(-EFSCORRUPTED);
|
|
}
|
|
bh = sb_getblk(sb, bitmap_blk);
|
|
if (unlikely(!bh)) {
|
|
ext4_warning(sb, "Cannot get buffer for block bitmap - "
|
|
"block_group = %u, block_bitmap = %llu",
|
|
block_group, bitmap_blk);
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
if (bitmap_uptodate(bh))
|
|
goto verify;
|
|
|
|
lock_buffer(bh);
|
|
if (bitmap_uptodate(bh)) {
|
|
unlock_buffer(bh);
|
|
goto verify;
|
|
}
|
|
ext4_lock_group(sb, block_group);
|
|
if (ext4_has_group_desc_csum(sb) &&
|
|
(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
|
|
if (block_group == 0) {
|
|
ext4_unlock_group(sb, block_group);
|
|
unlock_buffer(bh);
|
|
ext4_error(sb, "Block bitmap for bg 0 marked "
|
|
"uninitialized");
|
|
err = -EFSCORRUPTED;
|
|
goto out;
|
|
}
|
|
err = ext4_init_block_bitmap(sb, bh, block_group, desc);
|
|
set_bitmap_uptodate(bh);
|
|
set_buffer_uptodate(bh);
|
|
set_buffer_verified(bh);
|
|
ext4_unlock_group(sb, block_group);
|
|
unlock_buffer(bh);
|
|
if (err) {
|
|
ext4_error(sb, "Failed to init block bitmap for group "
|
|
"%u: %d", block_group, err);
|
|
goto out;
|
|
}
|
|
goto verify;
|
|
}
|
|
ext4_unlock_group(sb, block_group);
|
|
if (buffer_uptodate(bh)) {
|
|
/*
|
|
* if not uninit if bh is uptodate,
|
|
* bitmap is also uptodate
|
|
*/
|
|
set_bitmap_uptodate(bh);
|
|
unlock_buffer(bh);
|
|
goto verify;
|
|
}
|
|
/*
|
|
* submit the buffer_head for reading
|
|
*/
|
|
set_buffer_new(bh);
|
|
trace_ext4_read_block_bitmap_load(sb, block_group);
|
|
bh->b_end_io = ext4_end_bitmap_read;
|
|
get_bh(bh);
|
|
submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
|
|
return bh;
|
|
verify:
|
|
err = ext4_validate_block_bitmap(sb, desc, block_group, bh);
|
|
if (err)
|
|
goto out;
|
|
return bh;
|
|
out:
|
|
put_bh(bh);
|
|
return ERR_PTR(err);
|
|
}
|
|
|
|
/* Returns 0 on success, 1 on error */
|
|
int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group,
|
|
struct buffer_head *bh)
|
|
{
|
|
struct ext4_group_desc *desc;
|
|
|
|
if (!buffer_new(bh))
|
|
return 0;
|
|
desc = ext4_get_group_desc(sb, block_group, NULL);
|
|
if (!desc)
|
|
return -EFSCORRUPTED;
|
|
wait_on_buffer(bh);
|
|
ext4_simulate_fail_bh(sb, bh, EXT4_SIM_BBITMAP_EIO);
|
|
if (!buffer_uptodate(bh)) {
|
|
ext4_set_errno(sb, EIO);
|
|
ext4_error(sb, "Cannot read block bitmap - "
|
|
"block_group = %u, block_bitmap = %llu",
|
|
block_group, (unsigned long long) bh->b_blocknr);
|
|
ext4_mark_group_bitmap_corrupted(sb, block_group,
|
|
EXT4_GROUP_INFO_BBITMAP_CORRUPT);
|
|
return -EIO;
|
|
}
|
|
clear_buffer_new(bh);
|
|
/* Panic or remount fs read-only if block bitmap is invalid */
|
|
return ext4_validate_block_bitmap(sb, desc, block_group, bh);
|
|
}
|
|
|
|
struct buffer_head *
|
|
ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group)
|
|
{
|
|
struct buffer_head *bh;
|
|
int err;
|
|
|
|
bh = ext4_read_block_bitmap_nowait(sb, block_group);
|
|
if (IS_ERR(bh))
|
|
return bh;
|
|
err = ext4_wait_block_bitmap(sb, block_group, bh);
|
|
if (err) {
|
|
put_bh(bh);
|
|
return ERR_PTR(err);
|
|
}
|
|
return bh;
|
|
}
|
|
|
|
/**
|
|
* ext4_has_free_clusters()
|
|
* @sbi: in-core super block structure.
|
|
* @nclusters: number of needed blocks
|
|
* @flags: flags from ext4_mb_new_blocks()
|
|
*
|
|
* Check if filesystem has nclusters free & available for allocation.
|
|
* On success return 1, return 0 on failure.
|
|
*/
|
|
static int ext4_has_free_clusters(struct ext4_sb_info *sbi,
|
|
s64 nclusters, unsigned int flags)
|
|
{
|
|
s64 free_clusters, dirty_clusters, rsv, resv_clusters;
|
|
struct percpu_counter *fcc = &sbi->s_freeclusters_counter;
|
|
struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter;
|
|
|
|
free_clusters = percpu_counter_read_positive(fcc);
|
|
dirty_clusters = percpu_counter_read_positive(dcc);
|
|
resv_clusters = atomic64_read(&sbi->s_resv_clusters);
|
|
|
|
/*
|
|
* r_blocks_count should always be multiple of the cluster ratio so
|
|
* we are safe to do a plane bit shift only.
|
|
*/
|
|
rsv = (ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits) +
|
|
resv_clusters;
|
|
|
|
if (free_clusters - (nclusters + rsv + dirty_clusters) <
|
|
EXT4_FREECLUSTERS_WATERMARK) {
|
|
free_clusters = percpu_counter_sum_positive(fcc);
|
|
dirty_clusters = percpu_counter_sum_positive(dcc);
|
|
}
|
|
/* Check whether we have space after accounting for current
|
|
* dirty clusters & root reserved clusters.
|
|
*/
|
|
if (free_clusters >= (rsv + nclusters + dirty_clusters))
|
|
return 1;
|
|
|
|
/* Hm, nope. Are (enough) root reserved clusters available? */
|
|
if (uid_eq(sbi->s_resuid, current_fsuid()) ||
|
|
(!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) ||
|
|
capable(CAP_SYS_RESOURCE) ||
|
|
(flags & EXT4_MB_USE_ROOT_BLOCKS)) {
|
|
|
|
if (free_clusters >= (nclusters + dirty_clusters +
|
|
resv_clusters))
|
|
return 1;
|
|
}
|
|
/* No free blocks. Let's see if we can dip into reserved pool */
|
|
if (flags & EXT4_MB_USE_RESERVED) {
|
|
if (free_clusters >= (nclusters + dirty_clusters))
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
|
|
s64 nclusters, unsigned int flags)
|
|
{
|
|
if (ext4_has_free_clusters(sbi, nclusters, flags)) {
|
|
percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
|
|
return 0;
|
|
} else
|
|
return -ENOSPC;
|
|
}
|
|
|
|
/**
|
|
* ext4_should_retry_alloc() - check if a block allocation should be retried
|
|
* @sb: super block
|
|
* @retries: number of attemps has been made
|
|
*
|
|
* ext4_should_retry_alloc() is called when ENOSPC is returned, and if
|
|
* it is profitable to retry the operation, this function will wait
|
|
* for the current or committing transaction to complete, and then
|
|
* return TRUE. We will only retry once.
|
|
*/
|
|
int ext4_should_retry_alloc(struct super_block *sb, int *retries)
|
|
{
|
|
if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
|
|
(*retries)++ > 1 ||
|
|
!EXT4_SB(sb)->s_journal)
|
|
return 0;
|
|
|
|
smp_mb();
|
|
if (EXT4_SB(sb)->s_mb_free_pending == 0)
|
|
return 0;
|
|
|
|
jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
|
|
jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks
|
|
*
|
|
* @handle: handle to this transaction
|
|
* @inode: file inode
|
|
* @goal: given target block(filesystem wide)
|
|
* @count: pointer to total number of clusters needed
|
|
* @errp: error code
|
|
*
|
|
* Return 1st allocated block number on success, *count stores total account
|
|
* error stores in errp pointer
|
|
*/
|
|
ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
|
|
ext4_fsblk_t goal, unsigned int flags,
|
|
unsigned long *count, int *errp)
|
|
{
|
|
struct ext4_allocation_request ar;
|
|
ext4_fsblk_t ret;
|
|
|
|
memset(&ar, 0, sizeof(ar));
|
|
/* Fill with neighbour allocated blocks */
|
|
ar.inode = inode;
|
|
ar.goal = goal;
|
|
ar.len = count ? *count : 1;
|
|
ar.flags = flags;
|
|
|
|
ret = ext4_mb_new_blocks(handle, &ar, errp);
|
|
if (count)
|
|
*count = ar.len;
|
|
/*
|
|
* Account for the allocated meta blocks. We will never
|
|
* fail EDQUOT for metdata, but we do account for it.
|
|
*/
|
|
if (!(*errp) && (flags & EXT4_MB_DELALLOC_RESERVED)) {
|
|
dquot_alloc_block_nofail(inode,
|
|
EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/**
|
|
* ext4_count_free_clusters() -- count filesystem free clusters
|
|
* @sb: superblock
|
|
*
|
|
* Adds up the number of free clusters from each block group.
|
|
*/
|
|
ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb)
|
|
{
|
|
ext4_fsblk_t desc_count;
|
|
struct ext4_group_desc *gdp;
|
|
ext4_group_t i;
|
|
ext4_group_t ngroups = ext4_get_groups_count(sb);
|
|
struct ext4_group_info *grp;
|
|
#ifdef EXT4FS_DEBUG
|
|
struct ext4_super_block *es;
|
|
ext4_fsblk_t bitmap_count;
|
|
unsigned int x;
|
|
struct buffer_head *bitmap_bh = NULL;
|
|
|
|
es = EXT4_SB(sb)->s_es;
|
|
desc_count = 0;
|
|
bitmap_count = 0;
|
|
gdp = NULL;
|
|
|
|
for (i = 0; i < ngroups; i++) {
|
|
gdp = ext4_get_group_desc(sb, i, NULL);
|
|
if (!gdp)
|
|
continue;
|
|
grp = NULL;
|
|
if (EXT4_SB(sb)->s_group_info)
|
|
grp = ext4_get_group_info(sb, i);
|
|
if (!grp || !EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
|
|
desc_count += ext4_free_group_clusters(sb, gdp);
|
|
brelse(bitmap_bh);
|
|
bitmap_bh = ext4_read_block_bitmap(sb, i);
|
|
if (IS_ERR(bitmap_bh)) {
|
|
bitmap_bh = NULL;
|
|
continue;
|
|
}
|
|
|
|
x = ext4_count_free(bitmap_bh->b_data,
|
|
EXT4_CLUSTERS_PER_GROUP(sb) / 8);
|
|
printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n",
|
|
i, ext4_free_group_clusters(sb, gdp), x);
|
|
bitmap_count += x;
|
|
}
|
|
brelse(bitmap_bh);
|
|
printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu"
|
|
", computed = %llu, %llu\n",
|
|
EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)),
|
|
desc_count, bitmap_count);
|
|
return bitmap_count;
|
|
#else
|
|
desc_count = 0;
|
|
for (i = 0; i < ngroups; i++) {
|
|
gdp = ext4_get_group_desc(sb, i, NULL);
|
|
if (!gdp)
|
|
continue;
|
|
grp = NULL;
|
|
if (EXT4_SB(sb)->s_group_info)
|
|
grp = ext4_get_group_info(sb, i);
|
|
if (!grp || !EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
|
|
desc_count += ext4_free_group_clusters(sb, gdp);
|
|
}
|
|
|
|
return desc_count;
|
|
#endif
|
|
}
|
|
|
|
static inline int test_root(ext4_group_t a, int b)
|
|
{
|
|
while (1) {
|
|
if (a < b)
|
|
return 0;
|
|
if (a == b)
|
|
return 1;
|
|
if ((a % b) != 0)
|
|
return 0;
|
|
a = a / b;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ext4_bg_has_super - number of blocks used by the superblock in group
|
|
* @sb: superblock for filesystem
|
|
* @group: group number to check
|
|
*
|
|
* Return the number of blocks used by the superblock (primary or backup)
|
|
* in this group. Currently this will be only 0 or 1.
|
|
*/
|
|
int ext4_bg_has_super(struct super_block *sb, ext4_group_t group)
|
|
{
|
|
struct ext4_super_block *es = EXT4_SB(sb)->s_es;
|
|
|
|
if (group == 0)
|
|
return 1;
|
|
if (ext4_has_feature_sparse_super2(sb)) {
|
|
if (group == le32_to_cpu(es->s_backup_bgs[0]) ||
|
|
group == le32_to_cpu(es->s_backup_bgs[1]))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
if ((group <= 1) || !ext4_has_feature_sparse_super(sb))
|
|
return 1;
|
|
if (!(group & 1))
|
|
return 0;
|
|
if (test_root(group, 3) || (test_root(group, 5)) ||
|
|
test_root(group, 7))
|
|
return 1;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb,
|
|
ext4_group_t group)
|
|
{
|
|
unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
|
|
ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb);
|
|
ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1;
|
|
|
|
if (group == first || group == first + 1 || group == last)
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb,
|
|
ext4_group_t group)
|
|
{
|
|
if (!ext4_bg_has_super(sb, group))
|
|
return 0;
|
|
|
|
if (ext4_has_feature_meta_bg(sb))
|
|
return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
|
|
else
|
|
return EXT4_SB(sb)->s_gdb_count;
|
|
}
|
|
|
|
/**
|
|
* ext4_bg_num_gdb - number of blocks used by the group table in group
|
|
* @sb: superblock for filesystem
|
|
* @group: group number to check
|
|
*
|
|
* Return the number of blocks used by the group descriptor table
|
|
* (primary or backup) in this group. In the future there may be a
|
|
* different number of descriptor blocks in each group.
|
|
*/
|
|
unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group)
|
|
{
|
|
unsigned long first_meta_bg =
|
|
le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg);
|
|
unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb);
|
|
|
|
if (!ext4_has_feature_meta_bg(sb) || metagroup < first_meta_bg)
|
|
return ext4_bg_num_gdb_nometa(sb, group);
|
|
|
|
return ext4_bg_num_gdb_meta(sb,group);
|
|
|
|
}
|
|
|
|
/*
|
|
* This function returns the number of file system metadata clusters at
|
|
* the beginning of a block group, including the reserved gdt blocks.
|
|
*/
|
|
static unsigned ext4_num_base_meta_clusters(struct super_block *sb,
|
|
ext4_group_t block_group)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
unsigned num;
|
|
|
|
/* Check for superblock and gdt backups in this group */
|
|
num = ext4_bg_has_super(sb, block_group);
|
|
|
|
if (!ext4_has_feature_meta_bg(sb) ||
|
|
block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) *
|
|
sbi->s_desc_per_block) {
|
|
if (num) {
|
|
num += ext4_bg_num_gdb(sb, block_group);
|
|
num += le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks);
|
|
}
|
|
} else { /* For META_BG_BLOCK_GROUPS */
|
|
num += ext4_bg_num_gdb(sb, block_group);
|
|
}
|
|
return EXT4_NUM_B2C(sbi, num);
|
|
}
|
|
/**
|
|
* ext4_inode_to_goal_block - return a hint for block allocation
|
|
* @inode: inode for block allocation
|
|
*
|
|
* Return the ideal location to start allocating blocks for a
|
|
* newly created inode.
|
|
*/
|
|
ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode)
|
|
{
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
ext4_group_t block_group;
|
|
ext4_grpblk_t colour;
|
|
int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb));
|
|
ext4_fsblk_t bg_start;
|
|
ext4_fsblk_t last_block;
|
|
|
|
block_group = ei->i_block_group;
|
|
if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) {
|
|
/*
|
|
* If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME
|
|
* block groups per flexgroup, reserve the first block
|
|
* group for directories and special files. Regular
|
|
* files will start at the second block group. This
|
|
* tends to speed up directory access and improves
|
|
* fsck times.
|
|
*/
|
|
block_group &= ~(flex_size-1);
|
|
if (S_ISREG(inode->i_mode))
|
|
block_group++;
|
|
}
|
|
bg_start = ext4_group_first_block_no(inode->i_sb, block_group);
|
|
last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1;
|
|
|
|
/*
|
|
* If we are doing delayed allocation, we don't need take
|
|
* colour into account.
|
|
*/
|
|
if (test_opt(inode->i_sb, DELALLOC))
|
|
return bg_start;
|
|
|
|
if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block)
|
|
colour = (current->pid % 16) *
|
|
(EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16);
|
|
else
|
|
colour = (current->pid % 16) * ((last_block - bg_start) / 16);
|
|
return bg_start + colour;
|
|
}
|
|
|