- 根目录:
- fs
- affs
- file.c
/*
* linux/fs/affs/file.c
*
* (c) 1996 Hans-Joachim Widmaier - Rewritten
*
* (C) 1993 Ray Burr - Modified for Amiga FFS filesystem.
*
* (C) 1992 Eric Youngdale Modified for ISO 9660 filesystem.
*
* (C) 1991 Linus Torvalds - minix filesystem
*
* affs regular file handling primitives
*/
#include "affs.h"
#if PAGE_SIZE < 4096
#error PAGE_SIZE must be at least 4096
#endif
static int affs_grow_extcache(struct inode *inode, u32 lc_idx);
static struct buffer_head *affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext);
static inline struct buffer_head *affs_get_extblock(struct inode *inode, u32 ext);
static struct buffer_head *affs_get_extblock_slow(struct inode *inode, u32 ext);
static int affs_file_open(struct inode *inode, struct file *filp);
static int affs_file_release(struct inode *inode, struct file *filp);
const struct file_operations affs_file_operations = {
.llseek = generic_file_llseek,
.read = new_sync_read,
.read_iter = generic_file_read_iter,
.write = new_sync_write,
.write_iter = generic_file_write_iter,
.mmap = generic_file_mmap,
.open = affs_file_open,
.release = affs_file_release,
.fsync = affs_file_fsync,
.splice_read = generic_file_splice_read,
};
const struct inode_operations affs_file_inode_operations = {
.setattr = affs_notify_change,
};
static int
affs_file_open(struct inode *inode, struct file *filp)
{
pr_debug("open(%lu,%d)\n",
inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
atomic_inc(&AFFS_I(inode)->i_opencnt);
return 0;
}
static int
affs_file_release(struct inode *inode, struct file *filp)
{
pr_debug("release(%lu, %d)\n",
inode->i_ino, atomic_read(&AFFS_I(inode)->i_opencnt));
if (atomic_dec_and_test(&AFFS_I(inode)->i_opencnt)) {
mutex_lock(&inode->i_mutex);
if (inode->i_size != AFFS_I(inode)->mmu_private)
affs_truncate(inode);
affs_free_prealloc(inode);
mutex_unlock(&inode->i_mutex);
}
return 0;
}
static int
affs_grow_extcache(struct inode *inode, u32 lc_idx)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *bh;
u32 lc_max;
int i, j, key;
if (!AFFS_I(inode)->i_lc) {
char *ptr = (char *)get_zeroed_page(GFP_NOFS);
if (!ptr)
return -ENOMEM;
AFFS_I(inode)->i_lc = (u32 *)ptr;
AFFS_I(inode)->i_ac = (struct affs_ext_key *)(ptr + AFFS_CACHE_SIZE / 2);
}
lc_max = AFFS_LC_SIZE << AFFS_I(inode)->i_lc_shift;
if (AFFS_I(inode)->i_extcnt > lc_max) {
u32 lc_shift, lc_mask, tmp, off;
/* need to recalculate linear cache, start from old size */
lc_shift = AFFS_I(inode)->i_lc_shift;
tmp = (AFFS_I(inode)->i_extcnt / AFFS_LC_SIZE) >> lc_shift;
for (; tmp; tmp >>= 1)
lc_shift++;
lc_mask = (1 << lc_shift) - 1;
/* fix idx and old size to new shift */
lc_idx >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
AFFS_I(inode)->i_lc_size >>= (lc_shift - AFFS_I(inode)->i_lc_shift);
/* first shrink old cache to make more space */
off = 1 << (lc_shift - AFFS_I(inode)->i_lc_shift);
for (i = 1, j = off; j < AFFS_LC_SIZE; i++, j += off)
AFFS_I(inode)->i_ac[i] = AFFS_I(inode)->i_ac[j];
AFFS_I(inode)->i_lc_shift = lc_shift;
AFFS_I(inode)->i_lc_mask = lc_mask;
}
/* fill cache to the needed index */
i = AFFS_I(inode)->i_lc_size;
AFFS_I(inode)->i_lc_size = lc_idx + 1;
for (; i <= lc_idx; i++) {
if (!i) {
AFFS_I(inode)->i_lc[0] = inode->i_ino;
continue;
}
key = AFFS_I(inode)->i_lc[i - 1];
j = AFFS_I(inode)->i_lc_mask + 1;
// unlock cache
for (; j > 0; j--) {
bh = affs_bread(sb, key);
if (!bh)
goto err;
key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
affs_brelse(bh);
}
// lock cache
AFFS_I(inode)->i_lc[i] = key;
}
return 0;
err:
// lock cache
return -EIO;
}
static struct buffer_head *
affs_alloc_extblock(struct inode *inode, struct buffer_head *bh, u32 ext)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *new_bh;
u32 blocknr, tmp;
blocknr = affs_alloc_block(inode, bh->b_blocknr);
if (!blocknr)
return ERR_PTR(-ENOSPC);
new_bh = affs_getzeroblk(sb, blocknr);
if (!new_bh) {
affs_free_block(sb, blocknr);
return ERR_PTR(-EIO);
}
AFFS_HEAD(new_bh)->ptype = cpu_to_be32(T_LIST);
AFFS_HEAD(new_bh)->key = cpu_to_be32(blocknr);
AFFS_TAIL(sb, new_bh)->stype = cpu_to_be32(ST_FILE);
AFFS_TAIL(sb, new_bh)->parent = cpu_to_be32(inode->i_ino);
affs_fix_checksum(sb, new_bh);
mark_buffer_dirty_inode(new_bh, inode);
tmp = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
if (tmp)
affs_warning(sb, "alloc_ext", "previous extension set (%x)", tmp);
AFFS_TAIL(sb, bh)->extension = cpu_to_be32(blocknr);
affs_adjust_checksum(bh, blocknr - tmp);
mark_buffer_dirty_inode(bh, inode);
AFFS_I(inode)->i_extcnt++;
mark_inode_dirty(inode);
return new_bh;
}
static inline struct buffer_head *
affs_get_extblock(struct inode *inode, u32 ext)
{
/* inline the simplest case: same extended block as last time */
struct buffer_head *bh = AFFS_I(inode)->i_ext_bh;
if (ext == AFFS_I(inode)->i_ext_last)
get_bh(bh);
else
/* we have to do more (not inlined) */
bh = affs_get_extblock_slow(inode, ext);
return bh;
}
static struct buffer_head *
affs_get_extblock_slow(struct inode *inode, u32 ext)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *bh;
u32 ext_key;
u32 lc_idx, lc_off, ac_idx;
u32 tmp, idx;
if (ext == AFFS_I(inode)->i_ext_last + 1) {
/* read the next extended block from the current one */
bh = AFFS_I(inode)->i_ext_bh;
ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
if (ext < AFFS_I(inode)->i_extcnt)
goto read_ext;
if (ext > AFFS_I(inode)->i_extcnt)
BUG();
bh = affs_alloc_extblock(inode, bh, ext);
if (IS_ERR(bh))
return bh;
goto store_ext;
}
if (ext == 0) {
/* we seek back to the file header block */
ext_key = inode->i_ino;
goto read_ext;
}
if (ext >= AFFS_I(inode)->i_extcnt) {
struct buffer_head *prev_bh;
/* allocate a new extended block */
if (ext > AFFS_I(inode)->i_extcnt)
BUG();
/* get previous extended block */
prev_bh = affs_get_extblock(inode, ext - 1);
if (IS_ERR(prev_bh))
return prev_bh;
bh = affs_alloc_extblock(inode, prev_bh, ext);
affs_brelse(prev_bh);
if (IS_ERR(bh))
return bh;
goto store_ext;
}
again:
/* check if there is an extended cache and whether it's large enough */
lc_idx = ext >> AFFS_I(inode)->i_lc_shift;
lc_off = ext & AFFS_I(inode)->i_lc_mask;
if (lc_idx >= AFFS_I(inode)->i_lc_size) {
int err;
err = affs_grow_extcache(inode, lc_idx);
if (err)
return ERR_PTR(err);
goto again;
}
/* every n'th key we find in the linear cache */
if (!lc_off) {
ext_key = AFFS_I(inode)->i_lc[lc_idx];
goto read_ext;
}
/* maybe it's still in the associative cache */
ac_idx = (ext - lc_idx - 1) & AFFS_AC_MASK;
if (AFFS_I(inode)->i_ac[ac_idx].ext == ext) {
ext_key = AFFS_I(inode)->i_ac[ac_idx].key;
goto read_ext;
}
/* try to find one of the previous extended blocks */
tmp = ext;
idx = ac_idx;
while (--tmp, --lc_off > 0) {
idx = (idx - 1) & AFFS_AC_MASK;
if (AFFS_I(inode)->i_ac[idx].ext == tmp) {
ext_key = AFFS_I(inode)->i_ac[idx].key;
goto find_ext;
}
}
/* fall back to the linear cache */
ext_key = AFFS_I(inode)->i_lc[lc_idx];
find_ext:
/* read all extended blocks until we find the one we need */
//unlock cache
do {
bh = affs_bread(sb, ext_key);
if (!bh)
goto err_bread;
ext_key = be32_to_cpu(AFFS_TAIL(sb, bh)->extension);
affs_brelse(bh);
tmp++;
} while (tmp < ext);
//lock cache
/* store it in the associative cache */
// recalculate ac_idx?
AFFS_I(inode)->i_ac[ac_idx].ext = ext;
AFFS_I(inode)->i_ac[ac_idx].key = ext_key;
read_ext:
/* finally read the right extended block */
//unlock cache
bh = affs_bread(sb, ext_key);
if (!bh)
goto err_bread;
//lock cache
store_ext:
/* release old cached extended block and store the new one */
affs_brelse(AFFS_I(inode)->i_ext_bh);
AFFS_I(inode)->i_ext_last = ext;
AFFS_I(inode)->i_ext_bh = bh;
get_bh(bh);
return bh;
err_bread:
affs_brelse(bh);
return ERR_PTR(-EIO);
}
static int
affs_get_block(struct inode *inode, sector_t block, struct buffer_head *bh_result, int create)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *ext_bh;
u32 ext;
pr_debug("%s(%u, %lu)\n",
__func__, (u32)inode->i_ino, (unsigned long)block);
BUG_ON(block > (sector_t)0x7fffffffUL);
if (block >= AFFS_I(inode)->i_blkcnt) {
if (block > AFFS_I(inode)->i_blkcnt || !create)
goto err_big;
} else
create = 0;
//lock cache
affs_lock_ext(inode);
ext = (u32)block / AFFS_SB(sb)->s_hashsize;
block -= ext * AFFS_SB(sb)->s_hashsize;
ext_bh = affs_get_extblock(inode, ext);
if (IS_ERR(ext_bh))
goto err_ext;
map_bh(bh_result, sb, (sector_t)be32_to_cpu(AFFS_BLOCK(sb, ext_bh, block)));
if (create) {
u32 blocknr = affs_alloc_block(inode, ext_bh->b_blocknr);
if (!blocknr)
goto err_alloc;
set_buffer_new(bh_result);
AFFS_I(inode)->mmu_private += AFFS_SB(sb)->s_data_blksize;
AFFS_I(inode)->i_blkcnt++;
/* store new block */
if (bh_result->b_blocknr)
affs_warning(sb, "get_block", "block already set (%x)", bh_result->b_blocknr);
AFFS_BLOCK(sb, ext_bh, block) = cpu_to_be32(blocknr);
AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(block + 1);
affs_adjust_checksum(ext_bh, blocknr - bh_result->b_blocknr + 1);
bh_result->b_blocknr = blocknr;
if (!block) {
/* insert first block into header block */
u32 tmp = be32_to_cpu(AFFS_HEAD(ext_bh)->first_data);
if (tmp)
affs_warning(sb, "get_block", "first block already set (%d)", tmp);
AFFS_HEAD(ext_bh)->first_data = cpu_to_be32(blocknr);
affs_adjust_checksum(ext_bh, blocknr - tmp);
}
}
affs_brelse(ext_bh);
//unlock cache
affs_unlock_ext(inode);
return 0;
err_big:
affs_error(inode->i_sb,"get_block","strange block request %d", block);
return -EIO;
err_ext:
// unlock cache
affs_unlock_ext(inode);
return PTR_ERR(ext_bh);
err_alloc:
brelse(ext_bh);
clear_buffer_mapped(bh_result);
bh_result->b_bdev = NULL;
// unlock cache
affs_unlock_ext(inode);
return -ENOSPC;
}
static int affs_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, affs_get_block, wbc);
}
static int affs_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page, affs_get_block);
}
static void affs_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
affs_truncate(inode);
}
}
static int affs_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
*pagep = NULL;
ret = cont_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
affs_get_block,
&AFFS_I(mapping->host)->mmu_private);
if (unlikely(ret))
affs_write_failed(mapping, pos + len);
return ret;
}
static sector_t _affs_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping,block,affs_get_block);
}
const struct address_space_operations affs_aops = {
.readpage = affs_readpage,
.writepage = affs_writepage,
.write_begin = affs_write_begin,
.write_end = generic_write_end,
.bmap = _affs_bmap
};
static inline struct buffer_head *
affs_bread_ino(struct inode *inode, int block, int create)
{
struct buffer_head *bh, tmp_bh;
int err;
tmp_bh.b_state = 0;
err = affs_get_block(inode, block, &tmp_bh, create);
if (!err) {
bh = affs_bread(inode->i_sb, tmp_bh.b_blocknr);
if (bh) {
bh->b_state |= tmp_bh.b_state;
return bh;
}
err = -EIO;
}
return ERR_PTR(err);
}
static inline struct buffer_head *
affs_getzeroblk_ino(struct inode *inode, int block)
{
struct buffer_head *bh, tmp_bh;
int err;
tmp_bh.b_state = 0;
err = affs_get_block(inode, block, &tmp_bh, 1);
if (!err) {
bh = affs_getzeroblk(inode->i_sb, tmp_bh.b_blocknr);
if (bh) {
bh->b_state |= tmp_bh.b_state;
return bh;
}
err = -EIO;
}
return ERR_PTR(err);
}
static inline struct buffer_head *
affs_getemptyblk_ino(struct inode *inode, int block)
{
struct buffer_head *bh, tmp_bh;
int err;
tmp_bh.b_state = 0;
err = affs_get_block(inode, block, &tmp_bh, 1);
if (!err) {
bh = affs_getemptyblk(inode->i_sb, tmp_bh.b_blocknr);
if (bh) {
bh->b_state |= tmp_bh.b_state;
return bh;
}
err = -EIO;
}
return ERR_PTR(err);
}
static int
affs_do_readpage_ofs(struct page *page, unsigned to)
{
struct inode *inode = page->mapping->host;
struct super_block *sb = inode->i_sb;
struct buffer_head *bh;
char *data;
unsigned pos = 0;
u32 bidx, boff, bsize;
u32 tmp;
pr_debug("%s(%u, %ld, 0, %d)\n", __func__, (u32)inode->i_ino,
page->index, to);
BUG_ON(to > PAGE_CACHE_SIZE);
kmap(page);
data = page_address(page);
bsize = AFFS_SB(sb)->s_data_blksize;
tmp = page->index << PAGE_CACHE_SHIFT;
bidx = tmp / bsize;
boff = tmp % bsize;
while (pos < to) {
bh = affs_bread_ino(inode, bidx, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
tmp = min(bsize - boff, to - pos);
BUG_ON(pos + tmp > to || tmp > bsize);
memcpy(data + pos, AFFS_DATA(bh) + boff, tmp);
affs_brelse(bh);
bidx++;
pos += tmp;
boff = 0;
}
flush_dcache_page(page);
kunmap(page);
return 0;
}
static int
affs_extent_file_ofs(struct inode *inode, u32 newsize)
{
struct super_block *sb = inode->i_sb;
struct buffer_head *bh, *prev_bh;
u32 bidx, boff;
u32 size, bsize;
u32 tmp;
pr_debug("%s(%u, %d)\n", __func__, (u32)inode->i_ino, newsize);
bsize = AFFS_SB(sb)->s_data_blksize;
bh = NULL;
size = AFFS_I(inode)->mmu_private;
bidx = size / bsize;
boff = size % bsize;
if (boff) {
bh = affs_bread_ino(inode, bidx, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
tmp = min(bsize - boff, newsize - size);
BUG_ON(boff + tmp > bsize || tmp > bsize);
memset(AFFS_DATA(bh) + boff, 0, tmp);
be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
affs_fix_checksum(sb, bh);
mark_buffer_dirty_inode(bh, inode);
size += tmp;
bidx++;
} else if (bidx) {
bh = affs_bread_ino(inode, bidx - 1, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
}
while (size < newsize) {
prev_bh = bh;
bh = affs_getzeroblk_ino(inode, bidx);
if (IS_ERR(bh))
goto out;
tmp = min(bsize, newsize - size);
BUG_ON(tmp > bsize);
AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
affs_fix_checksum(sb, bh);
bh->b_state &= ~(1UL << BH_New);
mark_buffer_dirty_inode(bh, inode);
if (prev_bh) {
u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp_next)
affs_warning(sb, "extent_file_ofs",
"next block already set for %d (%d)",
bidx, tmp_next);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
mark_buffer_dirty_inode(prev_bh, inode);
affs_brelse(prev_bh);
}
size += bsize;
bidx++;
}
affs_brelse(bh);
inode->i_size = AFFS_I(inode)->mmu_private = newsize;
return 0;
out:
inode->i_size = AFFS_I(inode)->mmu_private = newsize;
return PTR_ERR(bh);
}
static int
affs_readpage_ofs(struct file *file, struct page *page)
{
struct inode *inode = page->mapping->host;
u32 to;
int err;
pr_debug("%s(%u, %ld)\n", __func__, (u32)inode->i_ino, page->index);
to = PAGE_CACHE_SIZE;
if (((page->index + 1) << PAGE_CACHE_SHIFT) > inode->i_size) {
to = inode->i_size & ~PAGE_CACHE_MASK;
memset(page_address(page) + to, 0, PAGE_CACHE_SIZE - to);
}
err = affs_do_readpage_ofs(page, to);
if (!err)
SetPageUptodate(page);
unlock_page(page);
return err;
}
static int affs_write_begin_ofs(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
struct inode *inode = mapping->host;
struct page *page;
pgoff_t index;
int err = 0;
pr_debug("%s(%u, %llu, %llu)\n", __func__, (u32)inode->i_ino,
(unsigned long long)pos, (unsigned long long)pos + len);
if (pos > AFFS_I(inode)->mmu_private) {
/* XXX: this probably leaves a too-big i_size in case of
* failure. Should really be updating i_size at write_end time
*/
err = affs_extent_file_ofs(inode, pos);
if (err)
return err;
}
index = pos >> PAGE_CACHE_SHIFT;
page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
*pagep = page;
if (PageUptodate(page))
return 0;
/* XXX: inefficient but safe in the face of short writes */
err = affs_do_readpage_ofs(page, PAGE_CACHE_SIZE);
if (err) {
unlock_page(page);
page_cache_release(page);
}
return err;
}
static int affs_write_end_ofs(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
struct inode *inode = mapping->host;
struct super_block *sb = inode->i_sb;
struct buffer_head *bh, *prev_bh;
char *data;
u32 bidx, boff, bsize;
unsigned from, to;
u32 tmp;
int written;
from = pos & (PAGE_CACHE_SIZE - 1);
to = pos + len;
/*
* XXX: not sure if this can handle short copies (len < copied), but
* we don't have to, because the page should always be uptodate here,
* due to write_begin.
*/
pr_debug("%s(%u, %llu, %llu)\n",
__func__, (u32)inode->i_ino, (unsigned long long)pos,
(unsigned long long)pos + len);
bsize = AFFS_SB(sb)->s_data_blksize;
data = page_address(page);
bh = NULL;
written = 0;
tmp = (page->index << PAGE_CACHE_SHIFT) + from;
bidx = tmp / bsize;
boff = tmp % bsize;
if (boff) {
bh = affs_bread_ino(inode, bidx, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
tmp = min(bsize - boff, to - from);
BUG_ON(boff + tmp > bsize || tmp > bsize);
memcpy(AFFS_DATA(bh) + boff, data + from, tmp);
be32_add_cpu(&AFFS_DATA_HEAD(bh)->size, tmp);
affs_fix_checksum(sb, bh);
mark_buffer_dirty_inode(bh, inode);
written += tmp;
from += tmp;
bidx++;
} else if (bidx) {
bh = affs_bread_ino(inode, bidx - 1, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
}
while (from + bsize <= to) {
prev_bh = bh;
bh = affs_getemptyblk_ino(inode, bidx);
if (IS_ERR(bh))
goto out;
memcpy(AFFS_DATA(bh), data + from, bsize);
if (buffer_new(bh)) {
AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
AFFS_DATA_HEAD(bh)->size = cpu_to_be32(bsize);
AFFS_DATA_HEAD(bh)->next = 0;
bh->b_state &= ~(1UL << BH_New);
if (prev_bh) {
u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp_next)
affs_warning(sb, "commit_write_ofs",
"next block already set for %d (%d)",
bidx, tmp_next);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
mark_buffer_dirty_inode(prev_bh, inode);
}
}
affs_brelse(prev_bh);
affs_fix_checksum(sb, bh);
mark_buffer_dirty_inode(bh, inode);
written += bsize;
from += bsize;
bidx++;
}
if (from < to) {
prev_bh = bh;
bh = affs_bread_ino(inode, bidx, 1);
if (IS_ERR(bh))
goto out;
tmp = min(bsize, to - from);
BUG_ON(tmp > bsize);
memcpy(AFFS_DATA(bh), data + from, tmp);
if (buffer_new(bh)) {
AFFS_DATA_HEAD(bh)->ptype = cpu_to_be32(T_DATA);
AFFS_DATA_HEAD(bh)->key = cpu_to_be32(inode->i_ino);
AFFS_DATA_HEAD(bh)->sequence = cpu_to_be32(bidx);
AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
AFFS_DATA_HEAD(bh)->next = 0;
bh->b_state &= ~(1UL << BH_New);
if (prev_bh) {
u32 tmp_next = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp_next)
affs_warning(sb, "commit_write_ofs",
"next block already set for %d (%d)",
bidx, tmp_next);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp_next);
mark_buffer_dirty_inode(prev_bh, inode);
}
} else if (be32_to_cpu(AFFS_DATA_HEAD(bh)->size) < tmp)
AFFS_DATA_HEAD(bh)->size = cpu_to_be32(tmp);
affs_brelse(prev_bh);
affs_fix_checksum(sb, bh);
mark_buffer_dirty_inode(bh, inode);
written += tmp;
from += tmp;
bidx++;
}
SetPageUptodate(page);
done:
affs_brelse(bh);
tmp = (page->index << PAGE_CACHE_SHIFT) + from;
if (tmp > inode->i_size)
inode->i_size = AFFS_I(inode)->mmu_private = tmp;
unlock_page(page);
page_cache_release(page);
return written;
out:
bh = prev_bh;
if (!written)
written = PTR_ERR(bh);
goto done;
}
const struct address_space_operations affs_aops_ofs = {
.readpage = affs_readpage_ofs,
//.writepage = affs_writepage_ofs,
.write_begin = affs_write_begin_ofs,
.write_end = affs_write_end_ofs
};
/* Free any preallocated blocks. */
void
affs_free_prealloc(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
pr_debug("free_prealloc(ino=%lu)\n", inode->i_ino);
while (AFFS_I(inode)->i_pa_cnt) {
AFFS_I(inode)->i_pa_cnt--;
affs_free_block(sb, ++AFFS_I(inode)->i_lastalloc);
}
}
/* Truncate (or enlarge) a file to the requested size. */
void
affs_truncate(struct inode *inode)
{
struct super_block *sb = inode->i_sb;
u32 ext, ext_key;
u32 last_blk, blkcnt, blk;
u32 size;
struct buffer_head *ext_bh;
int i;
pr_debug("truncate(inode=%d, oldsize=%u, newsize=%u)\n",
(u32)inode->i_ino, (u32)AFFS_I(inode)->mmu_private, (u32)inode->i_size);
last_blk = 0;
ext = 0;
if (inode->i_size) {
last_blk = ((u32)inode->i_size - 1) / AFFS_SB(sb)->s_data_blksize;
ext = last_blk / AFFS_SB(sb)->s_hashsize;
}
if (inode->i_size > AFFS_I(inode)->mmu_private) {
struct address_space *mapping = inode->i_mapping;
struct page *page;
void *fsdata;
loff_t isize = inode->i_size;
int res;
res = mapping->a_ops->write_begin(NULL, mapping, isize, 0, 0, &page, &fsdata);
if (!res)
res = mapping->a_ops->write_end(NULL, mapping, isize, 0, 0, page, fsdata);
else
inode->i_size = AFFS_I(inode)->mmu_private;
mark_inode_dirty(inode);
return;
} else if (inode->i_size == AFFS_I(inode)->mmu_private)
return;
// lock cache
ext_bh = affs_get_extblock(inode, ext);
if (IS_ERR(ext_bh)) {
affs_warning(sb, "truncate", "unexpected read error for ext block %u (%d)",
ext, PTR_ERR(ext_bh));
return;
}
if (AFFS_I(inode)->i_lc) {
/* clear linear cache */
i = (ext + 1) >> AFFS_I(inode)->i_lc_shift;
if (AFFS_I(inode)->i_lc_size > i) {
AFFS_I(inode)->i_lc_size = i;
for (; i < AFFS_LC_SIZE; i++)
AFFS_I(inode)->i_lc[i] = 0;
}
/* clear associative cache */
for (i = 0; i < AFFS_AC_SIZE; i++)
if (AFFS_I(inode)->i_ac[i].ext >= ext)
AFFS_I(inode)->i_ac[i].ext = 0;
}
ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
blkcnt = AFFS_I(inode)->i_blkcnt;
i = 0;
blk = last_blk;
if (inode->i_size) {
i = last_blk % AFFS_SB(sb)->s_hashsize + 1;
blk++;
} else
AFFS_HEAD(ext_bh)->first_data = 0;
AFFS_HEAD(ext_bh)->block_count = cpu_to_be32(i);
size = AFFS_SB(sb)->s_hashsize;
if (size > blkcnt - blk + i)
size = blkcnt - blk + i;
for (; i < size; i++, blk++) {
affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
AFFS_BLOCK(sb, ext_bh, i) = 0;
}
AFFS_TAIL(sb, ext_bh)->extension = 0;
affs_fix_checksum(sb, ext_bh);
mark_buffer_dirty_inode(ext_bh, inode);
affs_brelse(ext_bh);
if (inode->i_size) {
AFFS_I(inode)->i_blkcnt = last_blk + 1;
AFFS_I(inode)->i_extcnt = ext + 1;
if (AFFS_SB(sb)->s_flags & SF_OFS) {
struct buffer_head *bh = affs_bread_ino(inode, last_blk, 0);
u32 tmp;
if (IS_ERR(bh)) {
affs_warning(sb, "truncate", "unexpected read error for last block %u (%d)",
ext, PTR_ERR(bh));
return;
}
tmp = be32_to_cpu(AFFS_DATA_HEAD(bh)->next);
AFFS_DATA_HEAD(bh)->next = 0;
affs_adjust_checksum(bh, -tmp);
affs_brelse(bh);
}
} else {
AFFS_I(inode)->i_blkcnt = 0;
AFFS_I(inode)->i_extcnt = 1;
}
AFFS_I(inode)->mmu_private = inode->i_size;
// unlock cache
while (ext_key) {
ext_bh = affs_bread(sb, ext_key);
size = AFFS_SB(sb)->s_hashsize;
if (size > blkcnt - blk)
size = blkcnt - blk;
for (i = 0; i < size; i++, blk++)
affs_free_block(sb, be32_to_cpu(AFFS_BLOCK(sb, ext_bh, i)));
affs_free_block(sb, ext_key);
ext_key = be32_to_cpu(AFFS_TAIL(sb, ext_bh)->extension);
affs_brelse(ext_bh);
}
affs_free_prealloc(inode);
}
int affs_file_fsync(struct file *filp, loff_t start, loff_t end, int datasync)
{
struct inode *inode = filp->f_mapping->host;
int ret, err;
err = filemap_write_and_wait_range(inode->i_mapping, start, end);
if (err)
return err;
mutex_lock(&inode->i_mutex);
ret = write_inode_now(inode, 0);
err = sync_blockdev(inode->i_sb->s_bdev);
if (!ret)
ret = err;
mutex_unlock(&inode->i_mutex);
return ret;
}