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linux-next/fs/affs/file.c
Josef Bacik 02c24a8218 fs: push i_mutex and filemap_write_and_wait down into ->fsync() handlers
Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,

Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: Josef Bacik <josef@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:47:59 -04:00

943 lines
24 KiB
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 = do_sync_read,
.aio_read = generic_file_aio_read,
.write = do_sync_write,
.aio_write = generic_file_aio_write,
.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 = {
.truncate = affs_truncate,
.setattr = affs_notify_change,
};
static int
affs_file_open(struct inode *inode, struct file *filp)
{
pr_debug("AFFS: 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("AFFS: 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("AFFS: get_block(%u, %lu)\n", (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 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)) {
loff_t isize = mapping->host->i_size;
if (pos + len > isize)
vmtruncate(mapping->host, isize);
}
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 file *file, struct page *page, unsigned from, unsigned to)
{
struct inode *inode = page->mapping->host;
struct super_block *sb = inode->i_sb;
struct buffer_head *bh;
char *data;
u32 bidx, boff, bsize;
u32 tmp;
pr_debug("AFFS: read_page(%u, %ld, %d, %d)\n", (u32)inode->i_ino, page->index, from, to);
BUG_ON(from > to || to > PAGE_CACHE_SIZE);
kmap(page);
data = page_address(page);
bsize = AFFS_SB(sb)->s_data_blksize;
tmp = (page->index << PAGE_CACHE_SHIFT) + from;
bidx = tmp / bsize;
boff = tmp % bsize;
while (from < to) {
bh = affs_bread_ino(inode, bidx, 0);
if (IS_ERR(bh))
return PTR_ERR(bh);
tmp = min(bsize - boff, to - from);
BUG_ON(from + tmp > to || tmp > bsize);
memcpy(data + from, AFFS_DATA(bh) + boff, tmp);
affs_brelse(bh);
bidx++;
from += 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("AFFS: extent_file(%u, %d)\n", (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 = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp)
affs_warning(sb, "extent_file_ofs", "next block already set for %d (%d)", bidx, tmp);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
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("AFFS: read_page(%u, %ld)\n", (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(file, page, 0, 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("AFFS: write_begin(%u, %llu, %llu)\n", (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(file, page, 0, 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("AFFS: write_begin(%u, %llu, %llu)\n", (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 = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp)
affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
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 = be32_to_cpu(AFFS_DATA_HEAD(prev_bh)->next);
if (tmp)
affs_warning(sb, "commit_write_ofs", "next block already set for %d (%d)", bidx, tmp);
AFFS_DATA_HEAD(prev_bh)->next = cpu_to_be32(bh->b_blocknr);
affs_adjust_checksum(prev_bh, bh->b_blocknr - tmp);
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("AFFS: 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("AFFS: 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;
u32 size = inode->i_size;
int res;
res = mapping->a_ops->write_begin(NULL, mapping, size, 0, 0, &page, &fsdata);
if (!res)
res = mapping->a_ops->write_end(NULL, mapping, size, 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;
}