linux/fs/nilfs2/alloc.c
Ryusuke Konishi f41e355f8b nilfs2: fix incorrect inode allocation from reserved inodes
If the bitmap block that manages the inode allocation status is corrupted,
nilfs_ifile_create_inode() may allocate a new inode from the reserved
inode area where it should not be allocated.

Previous fix commit d325dc6eb7 ("nilfs2: fix use-after-free bug of
struct nilfs_root"), fixed the problem that reserved inodes with inode
numbers less than NILFS_USER_INO (=11) were incorrectly reallocated due to
bitmap corruption, but since the start number of non-reserved inodes is
read from the super block and may change, in which case inode allocation
may occur from the extended reserved inode area.

If that happens, access to that inode will cause an IO error, causing the
file system to degrade to an error state.

Fix this potential issue by adding a wraparound option to the common
metadata object allocation routine and by modifying
nilfs_ifile_create_inode() to disable the option so that it only allocates
inodes with inode numbers greater than or equal to the inode number read
in "nilfs->ns_first_ino", regardless of the bitmap status of reserved
inodes.

Link: https://lkml.kernel.org/r/20240623051135.4180-4-konishi.ryusuke@gmail.com
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-07-03 19:30:16 -07:00

876 lines
25 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* NILFS dat/inode allocator
*
* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
*
* Originally written by Koji Sato.
* Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
*/
#include <linux/types.h>
#include <linux/buffer_head.h>
#include <linux/fs.h>
#include <linux/bitops.h>
#include <linux/slab.h>
#include "mdt.h"
#include "alloc.h"
/**
* nilfs_palloc_groups_per_desc_block - get the number of groups that a group
* descriptor block can maintain
* @inode: inode of metadata file using this allocator
*/
static inline unsigned long
nilfs_palloc_groups_per_desc_block(const struct inode *inode)
{
return i_blocksize(inode) /
sizeof(struct nilfs_palloc_group_desc);
}
/**
* nilfs_palloc_groups_count - get maximum number of groups
* @inode: inode of metadata file using this allocator
*/
static inline unsigned long
nilfs_palloc_groups_count(const struct inode *inode)
{
return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
}
/**
* nilfs_palloc_init_blockgroup - initialize private variables for allocator
* @inode: inode of metadata file using this allocator
* @entry_size: size of the persistent object
*/
int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
{
struct nilfs_mdt_info *mi = NILFS_MDT(inode);
mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
if (!mi->mi_bgl)
return -ENOMEM;
bgl_lock_init(mi->mi_bgl);
nilfs_mdt_set_entry_size(inode, entry_size, 0);
mi->mi_blocks_per_group =
DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
mi->mi_entries_per_block) + 1;
/*
* Number of blocks in a group including entry blocks
* and a bitmap block
*/
mi->mi_blocks_per_desc_block =
nilfs_palloc_groups_per_desc_block(inode) *
mi->mi_blocks_per_group + 1;
/*
* Number of blocks per descriptor including the
* descriptor block
*/
return 0;
}
/**
* nilfs_palloc_group - get group number and offset from an entry number
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
* @offset: pointer to store offset number in the group
*/
static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
unsigned long *offset)
{
__u64 group = nr;
*offset = do_div(group, nilfs_palloc_entries_per_group(inode));
return group;
}
/**
* nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
* @inode: inode of metadata file using this allocator
* @group: group number
*
* nilfs_palloc_desc_blkoff() returns block offset of the descriptor
* block which contains a descriptor of the specified group.
*/
static unsigned long
nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
{
unsigned long desc_block =
group / nilfs_palloc_groups_per_desc_block(inode);
return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
}
/**
* nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
* @inode: inode of metadata file using this allocator
* @group: group number
*
* nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
* block used to allocate/deallocate entries in the specified group.
*/
static unsigned long
nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
{
unsigned long desc_offset =
group % nilfs_palloc_groups_per_desc_block(inode);
return nilfs_palloc_desc_blkoff(inode, group) + 1 +
desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
}
/**
* nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
* @desc: pointer to descriptor structure for the group
* @lock: spin lock protecting @desc
*/
static unsigned long
nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
spinlock_t *lock)
{
unsigned long nfree;
spin_lock(lock);
nfree = le32_to_cpu(desc->pg_nfrees);
spin_unlock(lock);
return nfree;
}
/**
* nilfs_palloc_group_desc_add_entries - adjust count of free entries
* @desc: pointer to descriptor structure for the group
* @lock: spin lock protecting @desc
* @n: delta to be added
*/
static u32
nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
spinlock_t *lock, u32 n)
{
u32 nfree;
spin_lock(lock);
le32_add_cpu(&desc->pg_nfrees, n);
nfree = le32_to_cpu(desc->pg_nfrees);
spin_unlock(lock);
return nfree;
}
/**
* nilfs_palloc_entry_blkoff - get block offset of an entry block
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
*/
static unsigned long
nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
{
unsigned long group, group_offset;
group = nilfs_palloc_group(inode, nr, &group_offset);
return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
group_offset / NILFS_MDT(inode)->mi_entries_per_block;
}
/**
* nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
* @inode: inode of metadata file
* @bh: buffer head of the buffer to be initialized
* @kaddr: kernel address mapped for the page including the buffer
*/
static void nilfs_palloc_desc_block_init(struct inode *inode,
struct buffer_head *bh, void *kaddr)
{
struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
__le32 nfrees;
nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
while (n-- > 0) {
desc->pg_nfrees = nfrees;
desc++;
}
}
static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
int create,
void (*init_block)(struct inode *,
struct buffer_head *,
void *),
struct buffer_head **bhp,
struct nilfs_bh_assoc *prev,
spinlock_t *lock)
{
int ret;
spin_lock(lock);
if (prev->bh && blkoff == prev->blkoff &&
likely(buffer_uptodate(prev->bh))) {
get_bh(prev->bh);
*bhp = prev->bh;
spin_unlock(lock);
return 0;
}
spin_unlock(lock);
ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
if (!ret) {
spin_lock(lock);
/*
* The following code must be safe for change of the
* cache contents during the get block call.
*/
brelse(prev->bh);
get_bh(*bhp);
prev->bh = *bhp;
prev->blkoff = blkoff;
spin_unlock(lock);
}
return ret;
}
/**
* nilfs_palloc_delete_block - delete a block on the persistent allocator file
* @inode: inode of metadata file using this allocator
* @blkoff: block offset
* @prev: nilfs_bh_assoc struct of the last used buffer
* @lock: spin lock protecting @prev
*/
static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
struct nilfs_bh_assoc *prev,
spinlock_t *lock)
{
spin_lock(lock);
if (prev->bh && blkoff == prev->blkoff) {
brelse(prev->bh);
prev->bh = NULL;
}
spin_unlock(lock);
return nilfs_mdt_delete_block(inode, blkoff);
}
/**
* nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
* @inode: inode of metadata file using this allocator
* @group: group number
* @create: create flag
* @bhp: pointer to store the resultant buffer head
*/
static int nilfs_palloc_get_desc_block(struct inode *inode,
unsigned long group,
int create, struct buffer_head **bhp)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
return nilfs_palloc_get_block(inode,
nilfs_palloc_desc_blkoff(inode, group),
create, nilfs_palloc_desc_block_init,
bhp, &cache->prev_desc, &cache->lock);
}
/**
* nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
* @inode: inode of metadata file using this allocator
* @group: group number
* @create: create flag
* @bhp: pointer to store the resultant buffer head
*/
static int nilfs_palloc_get_bitmap_block(struct inode *inode,
unsigned long group,
int create, struct buffer_head **bhp)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
return nilfs_palloc_get_block(inode,
nilfs_palloc_bitmap_blkoff(inode, group),
create, NULL, bhp,
&cache->prev_bitmap, &cache->lock);
}
/**
* nilfs_palloc_delete_bitmap_block - delete a bitmap block
* @inode: inode of metadata file using this allocator
* @group: group number
*/
static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
unsigned long group)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
return nilfs_palloc_delete_block(inode,
nilfs_palloc_bitmap_blkoff(inode,
group),
&cache->prev_bitmap, &cache->lock);
}
/**
* nilfs_palloc_get_entry_block - get buffer head of an entry block
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
* @create: create flag
* @bhp: pointer to store the resultant buffer head
*/
int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
int create, struct buffer_head **bhp)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
return nilfs_palloc_get_block(inode,
nilfs_palloc_entry_blkoff(inode, nr),
create, NULL, bhp,
&cache->prev_entry, &cache->lock);
}
/**
* nilfs_palloc_delete_entry_block - delete an entry block
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry
*/
static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
return nilfs_palloc_delete_block(inode,
nilfs_palloc_entry_blkoff(inode, nr),
&cache->prev_entry, &cache->lock);
}
/**
* nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
* @inode: inode of metadata file using this allocator
* @group: group number
* @bh: buffer head of the buffer storing the group descriptor block
* @kaddr: kernel address mapped for the page including the buffer
*/
static struct nilfs_palloc_group_desc *
nilfs_palloc_block_get_group_desc(const struct inode *inode,
unsigned long group,
const struct buffer_head *bh, void *kaddr)
{
return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
group % nilfs_palloc_groups_per_desc_block(inode);
}
/**
* nilfs_palloc_block_get_entry - get kernel address of an entry
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
* @bh: buffer head of the buffer storing the entry block
* @kaddr: kernel address mapped for the page including the buffer
*/
void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
const struct buffer_head *bh, void *kaddr)
{
unsigned long entry_offset, group_offset;
nilfs_palloc_group(inode, nr, &group_offset);
entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
return kaddr + bh_offset(bh) +
entry_offset * NILFS_MDT(inode)->mi_entry_size;
}
/**
* nilfs_palloc_find_available_slot - find available slot in a group
* @bitmap: bitmap of the group
* @target: offset number of an entry in the group (start point)
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
* @wrap: whether to wrap around
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
unsigned int bsize,
spinlock_t *lock, bool wrap)
{
int pos, end = bsize;
if (likely(target < bsize)) {
pos = target;
do {
pos = nilfs_find_next_zero_bit(bitmap, end, pos);
if (pos >= end)
break;
if (!nilfs_set_bit_atomic(lock, pos, bitmap))
return pos;
} while (++pos < end);
end = target;
}
if (!wrap)
return -ENOSPC;
/* wrap around */
for (pos = 0; pos < end; pos++) {
pos = nilfs_find_next_zero_bit(bitmap, end, pos);
if (pos >= end)
break;
if (!nilfs_set_bit_atomic(lock, pos, bitmap))
return pos;
}
return -ENOSPC;
}
/**
* nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
* in a group descriptor block
* @inode: inode of metadata file using this allocator
* @curr: current group number
* @max: maximum number of groups
*/
static unsigned long
nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
unsigned long curr, unsigned long max)
{
return min_t(unsigned long,
nilfs_palloc_groups_per_desc_block(inode) -
curr % nilfs_palloc_groups_per_desc_block(inode),
max - curr + 1);
}
/**
* nilfs_palloc_count_desc_blocks - count descriptor blocks number
* @inode: inode of metadata file using this allocator
* @desc_blocks: descriptor blocks number [out]
*/
static int nilfs_palloc_count_desc_blocks(struct inode *inode,
unsigned long *desc_blocks)
{
__u64 blknum;
int ret;
ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
if (likely(!ret))
*desc_blocks = DIV_ROUND_UP(
(unsigned long)blknum,
NILFS_MDT(inode)->mi_blocks_per_desc_block);
return ret;
}
/**
* nilfs_palloc_mdt_file_can_grow - check potential opportunity for
* MDT file growing
* @inode: inode of metadata file using this allocator
* @desc_blocks: known current descriptor blocks count
*/
static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
unsigned long desc_blocks)
{
return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
nilfs_palloc_groups_count(inode);
}
/**
* nilfs_palloc_count_max_entries - count max number of entries that can be
* described by descriptor blocks count
* @inode: inode of metadata file using this allocator
* @nused: current number of used entries
* @nmaxp: max number of entries [out]
*/
int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
{
unsigned long desc_blocks = 0;
u64 entries_per_desc_block, nmax;
int err;
err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
if (unlikely(err))
return err;
entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
nilfs_palloc_groups_per_desc_block(inode);
nmax = entries_per_desc_block * desc_blocks;
if (nused == nmax &&
nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
nmax += entries_per_desc_block;
if (nused > nmax)
return -ERANGE;
*nmaxp = nmax;
return 0;
}
/**
* nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
* @wrap: whether to wrap around
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req, bool wrap)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, maxgroup, ngroups;
unsigned long group_offset, maxgroup_offset;
unsigned long n, entries_per_group;
unsigned long i, j;
spinlock_t *lock;
int pos, ret;
ngroups = nilfs_palloc_groups_count(inode);
maxgroup = ngroups - 1;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
entries_per_group = nilfs_palloc_entries_per_group(inode);
for (i = 0; i < ngroups; i += n) {
if (group >= ngroups && wrap) {
/* wrap around */
group = 0;
maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
&maxgroup_offset) - 1;
}
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
desc_kaddr = kmap_local_page(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
maxgroup);
for (j = 0; j < n; j++, desc++, group++, group_offset = 0) {
lock = nilfs_mdt_bgl_lock(inode, group);
if (nilfs_palloc_group_desc_nfrees(desc, lock) == 0)
continue;
kunmap_local(desc_kaddr);
ret = nilfs_palloc_get_bitmap_block(inode, group, 1,
&bitmap_bh);
if (unlikely(ret < 0)) {
brelse(desc_bh);
return ret;
}
desc_kaddr = kmap_local_page(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
pos = nilfs_palloc_find_available_slot(
bitmap, group_offset, entries_per_group, lock,
wrap);
/*
* Since the search for a free slot in the second and
* subsequent bitmap blocks always starts from the
* beginning, the wrap flag only has an effect on the
* first search.
*/
kunmap_local(bitmap_kaddr);
if (pos >= 0)
goto found;
brelse(bitmap_bh);
}
kunmap_local(desc_kaddr);
brelse(desc_bh);
}
/* no entries left */
return -ENOSPC;
found:
/* found a free entry */
nilfs_palloc_group_desc_add_entries(desc, lock, -1);
req->pr_entry_nr = entries_per_group * group + pos;
kunmap_local(desc_kaddr);
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
return 0;
}
/**
* nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
*/
void nilfs_palloc_commit_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
mark_buffer_dirty(req->pr_bitmap_bh);
mark_buffer_dirty(req->pr_desc_bh);
nilfs_mdt_mark_dirty(inode);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
}
/**
* nilfs_palloc_commit_free_entry - finish deallocating a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the removal
*/
void nilfs_palloc_commit_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct nilfs_palloc_group_desc *desc;
unsigned long group, group_offset;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
spinlock_t *lock;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(inode, group,
req->pr_desc_bh, desc_kaddr);
bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
lock = nilfs_mdt_bgl_lock(inode, group);
if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
nilfs_warn(inode->i_sb,
"%s (ino=%lu): entry number %llu already freed",
__func__, inode->i_ino,
(unsigned long long)req->pr_entry_nr);
else
nilfs_palloc_group_desc_add_entries(desc, lock, 1);
kunmap_local(bitmap_kaddr);
kunmap_local(desc_kaddr);
mark_buffer_dirty(req->pr_desc_bh);
mark_buffer_dirty(req->pr_bitmap_bh);
nilfs_mdt_mark_dirty(inode);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
}
/**
* nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
*/
void nilfs_palloc_abort_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct nilfs_palloc_group_desc *desc;
void *desc_kaddr, *bitmap_kaddr;
unsigned char *bitmap;
unsigned long group, group_offset;
spinlock_t *lock;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(inode, group,
req->pr_desc_bh, desc_kaddr);
bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
lock = nilfs_mdt_bgl_lock(inode, group);
if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
nilfs_warn(inode->i_sb,
"%s (ino=%lu): entry number %llu already freed",
__func__, inode->i_ino,
(unsigned long long)req->pr_entry_nr);
else
nilfs_palloc_group_desc_add_entries(desc, lock, 1);
kunmap_local(bitmap_kaddr);
kunmap_local(desc_kaddr);
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
req->pr_entry_nr = 0;
req->pr_bitmap_bh = NULL;
req->pr_desc_bh = NULL;
}
/**
* nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the removal
*/
int nilfs_palloc_prepare_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
struct buffer_head *desc_bh, *bitmap_bh;
unsigned long group, group_offset;
int ret;
group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
if (ret < 0)
return ret;
ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
if (ret < 0) {
brelse(desc_bh);
return ret;
}
req->pr_desc_bh = desc_bh;
req->pr_bitmap_bh = bitmap_bh;
return 0;
}
/**
* nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the removal
*/
void nilfs_palloc_abort_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
{
brelse(req->pr_bitmap_bh);
brelse(req->pr_desc_bh);
req->pr_entry_nr = 0;
req->pr_bitmap_bh = NULL;
req->pr_desc_bh = NULL;
}
/**
* nilfs_palloc_freev - deallocate a set of persistent objects
* @inode: inode of metadata file using this allocator
* @entry_nrs: array of entry numbers to be deallocated
* @nitems: number of entries stored in @entry_nrs
*/
int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
{
struct buffer_head *desc_bh, *bitmap_bh;
struct nilfs_palloc_group_desc *desc;
unsigned char *bitmap;
void *desc_kaddr, *bitmap_kaddr;
unsigned long group, group_offset;
__u64 group_min_nr, last_nrs[8];
const unsigned long epg = nilfs_palloc_entries_per_group(inode);
const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
unsigned int entry_start, end, pos;
spinlock_t *lock;
int i, j, k, ret;
u32 nfree;
for (i = 0; i < nitems; i = j) {
int change_group = false;
int nempties = 0, n = 0;
group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
if (ret < 0)
return ret;
ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
&bitmap_bh);
if (ret < 0) {
brelse(desc_bh);
return ret;
}
/* Get the first entry number of the group */
group_min_nr = (__u64)group * epg;
bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);
bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
lock = nilfs_mdt_bgl_lock(inode, group);
j = i;
entry_start = rounddown(group_offset, epb);
do {
if (!nilfs_clear_bit_atomic(lock, group_offset,
bitmap)) {
nilfs_warn(inode->i_sb,
"%s (ino=%lu): entry number %llu already freed",
__func__, inode->i_ino,
(unsigned long long)entry_nrs[j]);
} else {
n++;
}
j++;
if (j >= nitems || entry_nrs[j] < group_min_nr ||
entry_nrs[j] >= group_min_nr + epg) {
change_group = true;
} else {
group_offset = entry_nrs[j] - group_min_nr;
if (group_offset >= entry_start &&
group_offset < entry_start + epb) {
/* This entry is in the same block */
continue;
}
}
/* Test if the entry block is empty or not */
end = entry_start + epb;
pos = nilfs_find_next_bit(bitmap, end, entry_start);
if (pos >= end) {
last_nrs[nempties++] = entry_nrs[j - 1];
if (nempties >= ARRAY_SIZE(last_nrs))
break;
}
if (change_group)
break;
/* Go on to the next entry block */
entry_start = rounddown(group_offset, epb);
} while (true);
kunmap_local(bitmap_kaddr);
mark_buffer_dirty(bitmap_bh);
brelse(bitmap_bh);
for (k = 0; k < nempties; k++) {
ret = nilfs_palloc_delete_entry_block(inode,
last_nrs[k]);
if (ret && ret != -ENOENT)
nilfs_warn(inode->i_sb,
"error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
ret, (unsigned long long)last_nrs[k],
inode->i_ino);
}
desc_kaddr = kmap_local_page(desc_bh->b_page);
desc = nilfs_palloc_block_get_group_desc(
inode, group, desc_bh, desc_kaddr);
nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
kunmap_local(desc_kaddr);
mark_buffer_dirty(desc_bh);
nilfs_mdt_mark_dirty(inode);
brelse(desc_bh);
if (nfree == nilfs_palloc_entries_per_group(inode)) {
ret = nilfs_palloc_delete_bitmap_block(inode, group);
if (ret && ret != -ENOENT)
nilfs_warn(inode->i_sb,
"error %d deleting bitmap block of group=%lu, ino=%lu",
ret, group, inode->i_ino);
}
}
return 0;
}
void nilfs_palloc_setup_cache(struct inode *inode,
struct nilfs_palloc_cache *cache)
{
NILFS_MDT(inode)->mi_palloc_cache = cache;
spin_lock_init(&cache->lock);
}
void nilfs_palloc_clear_cache(struct inode *inode)
{
struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
spin_lock(&cache->lock);
brelse(cache->prev_desc.bh);
brelse(cache->prev_bitmap.bh);
brelse(cache->prev_entry.bh);
cache->prev_desc.bh = NULL;
cache->prev_bitmap.bh = NULL;
cache->prev_entry.bh = NULL;
spin_unlock(&cache->lock);
}
void nilfs_palloc_destroy_cache(struct inode *inode)
{
nilfs_palloc_clear_cache(inode);
NILFS_MDT(inode)->mi_palloc_cache = NULL;
}