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inode.c
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/*
* inode.c
*
* PURPOSE
* Inode handling routines for the OSTA-UDF(tm) filesystem.
*
* COPYRIGHT
* This file is distributed under the terms of the GNU General Public
* License (GPL). Copies of the GPL can be obtained from:
* ftp://prep.ai.mit.edu/pub/gnu/GPL
* Each contributing author retains all rights to their own work.
*
* (C) 1998 Dave Boynton
* (C) 1998-2004 Ben Fennema
* (C) 1999-2000 Stelias Computing Inc
*
* HISTORY
*
* 10/04/98 dgb Added rudimentary directory functions
* 10/07/98 Fully working udf_block_map! It works!
* 11/25/98 bmap altered to better support extents
* 12/06/98 blf partition support in udf_iget, udf_block_map
* and udf_read_inode
* 12/12/98 rewrote udf_block_map to handle next extents and descs across
* block boundaries (which is not actually allowed)
* 12/20/98 added support for strategy 4096
* 03/07/99 rewrote udf_block_map (again)
* New funcs, inode_bmap, udf_next_aext
* 04/19/99 Support for writing device EA's for major/minor #
*/
#include "udfdecl.h"
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/pagemap.h>
#include <linux/writeback.h>
#include <linux/slab.h>
#include <linux/crc-itu-t.h>
#include <linux/mpage.h>
#include <linux/uio.h>
#include <linux/bio.h>
#include "udf_i.h"
#include "udf_sb.h"
MODULE_AUTHOR("Ben Fennema");
MODULE_DESCRIPTION("Universal Disk Format Filesystem");
MODULE_LICENSE("GPL");
#define EXTENT_MERGE_SIZE 5
static umode_t udf_convert_permissions(struct fileEntry *);
static int udf_update_inode(struct inode *, int);
static int udf_sync_inode(struct inode *inode);
static int udf_alloc_i_data(struct inode *inode, size_t size);
static sector_t inode_getblk(struct inode *, sector_t, int *, int *);
static int8_t udf_insert_aext(struct inode *, struct extent_position,
struct kernel_lb_addr, uint32_t);
static void udf_split_extents(struct inode *, int *, int, int,
struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_prealloc_extents(struct inode *, int, int,
struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_merge_extents(struct inode *,
struct kernel_long_ad[EXTENT_MERGE_SIZE], int *);
static void udf_update_extents(struct inode *,
struct kernel_long_ad[EXTENT_MERGE_SIZE], int, int,
struct extent_position *);
static int udf_get_block(struct inode *, sector_t, struct buffer_head *, int);
static void __udf_clear_extent_cache(struct inode *inode)
{
struct udf_inode_info *iinfo = UDF_I(inode);
if (iinfo->cached_extent.lstart != -1) {
brelse(iinfo->cached_extent.epos.bh);
iinfo->cached_extent.lstart = -1;
}
}
/* Invalidate extent cache */
static void udf_clear_extent_cache(struct inode *inode)
{
struct udf_inode_info *iinfo = UDF_I(inode);
spin_lock(&iinfo->i_extent_cache_lock);
__udf_clear_extent_cache(inode);
spin_unlock(&iinfo->i_extent_cache_lock);
}
/* Return contents of extent cache */
static int udf_read_extent_cache(struct inode *inode, loff_t bcount,
loff_t *lbcount, struct extent_position *pos)
{
struct udf_inode_info *iinfo = UDF_I(inode);
int ret = 0;
spin_lock(&iinfo->i_extent_cache_lock);
if ((iinfo->cached_extent.lstart <= bcount) &&
(iinfo->cached_extent.lstart != -1)) {
/* Cache hit */
*lbcount = iinfo->cached_extent.lstart;
memcpy(pos, &iinfo->cached_extent.epos,
sizeof(struct extent_position));
if (pos->bh)
get_bh(pos->bh);
ret = 1;
}
spin_unlock(&iinfo->i_extent_cache_lock);
return ret;
}
/* Add extent to extent cache */
static void udf_update_extent_cache(struct inode *inode, loff_t estart,
struct extent_position *pos, int next_epos)
{
struct udf_inode_info *iinfo = UDF_I(inode);
spin_lock(&iinfo->i_extent_cache_lock);
/* Invalidate previously cached extent */
__udf_clear_extent_cache(inode);
if (pos->bh)
get_bh(pos->bh);
memcpy(&iinfo->cached_extent.epos, pos,
sizeof(struct extent_position));
iinfo->cached_extent.lstart = estart;
if (next_epos)
switch (iinfo->i_alloc_type) {
case ICBTAG_FLAG_AD_SHORT:
iinfo->cached_extent.epos.offset -=
sizeof(struct short_ad);
break;
case ICBTAG_FLAG_AD_LONG:
iinfo->cached_extent.epos.offset -=
sizeof(struct long_ad);
}
spin_unlock(&iinfo->i_extent_cache_lock);
}
void udf_evict_inode(struct inode *inode)
{
struct udf_inode_info *iinfo = UDF_I(inode);
int want_delete = 0;
if (!inode->i_nlink && !is_bad_inode(inode)) {
want_delete = 1;
udf_setsize(inode, 0);
udf_update_inode(inode, IS_SYNC(inode));
}
truncate_inode_pages_final(&inode->i_data);
invalidate_inode_buffers(inode);
clear_inode(inode);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB &&
inode->i_size != iinfo->i_lenExtents) {
udf_warn(inode->i_sb, "Inode %lu (mode %o) has inode size %llu different from extent length %llu. Filesystem need not be standards compliant.\n",
inode->i_ino, inode->i_mode,
(unsigned long long)inode->i_size,
(unsigned long long)iinfo->i_lenExtents);
}
kfree(iinfo->i_ext.i_data);
iinfo->i_ext.i_data = NULL;
udf_clear_extent_cache(inode);
if (want_delete) {
udf_free_inode(inode);
}
}
static void udf_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
struct udf_inode_info *iinfo = UDF_I(inode);
loff_t isize = inode->i_size;
if (to > isize) {
truncate_pagecache(inode, isize);
if (iinfo->i_alloc_type != ICBTAG_FLAG_AD_IN_ICB) {
down_write(&iinfo->i_data_sem);
udf_clear_extent_cache(inode);
udf_truncate_extents(inode);
up_write(&iinfo->i_data_sem);
}
}
}
static int udf_writepage(struct page *page, struct writeback_control *wbc)
{
return block_write_full_page(page, udf_get_block, wbc);
}
static int udf_writepages(struct address_space *mapping,
struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, udf_get_block);
}
static int udf_readpage(struct file *file, struct page *page)
{
return mpage_readpage(page, udf_get_block);
}
static int udf_readpages(struct file *file, struct address_space *mapping,
struct list_head *pages, unsigned nr_pages)
{
return mpage_readpages(mapping, pages, nr_pages, udf_get_block);
}
static int udf_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
ret = block_write_begin(mapping, pos, len, flags, pagep, udf_get_block);
if (unlikely(ret))
udf_write_failed(mapping, pos + len);
return ret;
}
static ssize_t udf_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
ssize_t ret;
ret = blockdev_direct_IO(iocb, inode, iter, udf_get_block);
if (unlikely(ret < 0 && iov_iter_rw(iter) == WRITE))
udf_write_failed(mapping, iocb->ki_pos + count);
return ret;
}
static sector_t udf_bmap(struct address_space *mapping, sector_t block)
{
return generic_block_bmap(mapping, block, udf_get_block);
}
const struct address_space_operations udf_aops = {
.readpage = udf_readpage,
.readpages = udf_readpages,
.writepage = udf_writepage,
.writepages = udf_writepages,
.write_begin = udf_write_begin,
.write_end = generic_write_end,
.direct_IO = udf_direct_IO,
.bmap = udf_bmap,
};
/*
* Expand file stored in ICB to a normal one-block-file
*
* This function requires i_data_sem for writing and releases it.
* This function requires i_mutex held
*/
int udf_expand_file_adinicb(struct inode *inode)
{
struct page *page;
char *kaddr;
struct udf_inode_info *iinfo = UDF_I(inode);
int err;
struct writeback_control udf_wbc = {
.sync_mode = WB_SYNC_NONE,
.nr_to_write = 1,
};
WARN_ON_ONCE(!inode_is_locked(inode));
if (!iinfo->i_lenAlloc) {
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
else
iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
/* from now on we have normal address_space methods */
inode->i_data.a_ops = &udf_aops;
up_write(&iinfo->i_data_sem);
mark_inode_dirty(inode);
return 0;
}
/*
* Release i_data_sem so that we can lock a page - page lock ranks
* above i_data_sem. i_mutex still protects us against file changes.
*/
up_write(&iinfo->i_data_sem);
page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS);
if (!page)
return -ENOMEM;
if (!PageUptodate(page)) {
kaddr = kmap(page);
memset(kaddr + iinfo->i_lenAlloc, 0x00,
PAGE_SIZE - iinfo->i_lenAlloc);
memcpy(kaddr, iinfo->i_ext.i_data + iinfo->i_lenEAttr,
iinfo->i_lenAlloc);
flush_dcache_page(page);
SetPageUptodate(page);
kunmap(page);
}
down_write(&iinfo->i_data_sem);
memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr, 0x00,
iinfo->i_lenAlloc);
iinfo->i_lenAlloc = 0;
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
iinfo->i_alloc_type = ICBTAG_FLAG_AD_SHORT;
else
iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG;
/* from now on we have normal address_space methods */
inode->i_data.a_ops = &udf_aops;
up_write(&iinfo->i_data_sem);
err = inode->i_data.a_ops->writepage(page, &udf_wbc);
if (err) {
/* Restore everything back so that we don't lose data... */
lock_page(page);
kaddr = kmap(page);
down_write(&iinfo->i_data_sem);
memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr,
inode->i_size);
kunmap(page);
unlock_page(page);
iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
inode->i_data.a_ops = &udf_adinicb_aops;
up_write(&iinfo->i_data_sem);
}
put_page(page);
mark_inode_dirty(inode);
return err;
}
struct buffer_head *udf_expand_dir_adinicb(struct inode *inode, int *block,
int *err)
{
int newblock;
struct buffer_head *dbh = NULL;
struct kernel_lb_addr eloc;
uint8_t alloctype;
struct extent_position epos;
struct udf_fileident_bh sfibh, dfibh;
loff_t f_pos = udf_ext0_offset(inode);
int size = udf_ext0_offset(inode) + inode->i_size;
struct fileIdentDesc cfi, *sfi, *dfi;
struct udf_inode_info *iinfo = UDF_I(inode);
if (UDF_QUERY_FLAG(inode->i_sb, UDF_FLAG_USE_SHORT_AD))
alloctype = ICBTAG_FLAG_AD_SHORT;
else
alloctype = ICBTAG_FLAG_AD_LONG;
if (!inode->i_size) {
iinfo->i_alloc_type = alloctype;
mark_inode_dirty(inode);
return NULL;
}
/* alloc block, and copy data to it */
*block = udf_new_block(inode->i_sb, inode,
iinfo->i_location.partitionReferenceNum,
iinfo->i_location.logicalBlockNum, err);
if (!(*block))
return NULL;
newblock = udf_get_pblock(inode->i_sb, *block,
iinfo->i_location.partitionReferenceNum,
0);
if (!newblock)
return NULL;
dbh = udf_tgetblk(inode->i_sb, newblock);
if (!dbh)
return NULL;
lock_buffer(dbh);
memset(dbh->b_data, 0x00, inode->i_sb->s_blocksize);
set_buffer_uptodate(dbh);
unlock_buffer(dbh);
mark_buffer_dirty_inode(dbh, inode);
sfibh.soffset = sfibh.eoffset =
f_pos & (inode->i_sb->s_blocksize - 1);
sfibh.sbh = sfibh.ebh = NULL;
dfibh.soffset = dfibh.eoffset = 0;
dfibh.sbh = dfibh.ebh = dbh;
while (f_pos < size) {
iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
sfi = udf_fileident_read(inode, &f_pos, &sfibh, &cfi, NULL,
NULL, NULL, NULL);
if (!sfi) {
brelse(dbh);
return NULL;
}
iinfo->i_alloc_type = alloctype;
sfi->descTag.tagLocation = cpu_to_le32(*block);
dfibh.soffset = dfibh.eoffset;
dfibh.eoffset += (sfibh.eoffset - sfibh.soffset);
dfi = (struct fileIdentDesc *)(dbh->b_data + dfibh.soffset);
if (udf_write_fi(inode, sfi, dfi, &dfibh, sfi->impUse,
sfi->fileIdent +
le16_to_cpu(sfi->lengthOfImpUse))) {
iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB;
brelse(dbh);
return NULL;
}
}
mark_buffer_dirty_inode(dbh, inode);
memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr, 0,
iinfo->i_lenAlloc);
iinfo->i_lenAlloc = 0;
eloc.logicalBlockNum = *block;
eloc.partitionReferenceNum =
iinfo->i_location.partitionReferenceNum;
iinfo->i_lenExtents = inode->i_size;
epos.bh = NULL;
epos.block = iinfo->i_location;
epos.offset = udf_file_entry_alloc_offset(inode);
udf_add_aext(inode, &epos, &eloc, inode->i_size, 0);
/* UniqueID stuff */
brelse(epos.bh);
mark_inode_dirty(inode);
return dbh;
}
static int udf_get_block(struct inode *inode, sector_t block,
struct buffer_head *bh_result, int create)
{
int err, new;
sector_t phys = 0;
struct udf_inode_info *iinfo;
if (!create) {
phys = udf_block_map(inode, block);
if (phys)
map_bh(bh_result, inode->i_sb, phys);
return 0;
}
err = -EIO;
new = 0;
iinfo = UDF_I(inode);
down_write(&iinfo->i_data_sem);
if (block == iinfo->i_next_alloc_block + 1) {
iinfo->i_next_alloc_block++;
iinfo->i_next_alloc_goal++;
}
udf_clear_extent_cache(inode);
phys = inode_getblk(inode, block, &err, &new);
if (!phys)
goto abort;
if (new)
set_buffer_new(bh_result);
map_bh(bh_result, inode->i_sb, phys);
abort:
up_write(&iinfo->i_data_sem);
return err;
}
static struct buffer_head *udf_getblk(struct inode *inode, long block,
int create, int *err)
{
struct buffer_head *bh;
struct buffer_head dummy;
dummy.b_state = 0;
dummy.b_blocknr = -1000;
*err = udf_get_block(inode, block, &dummy, create);
if (!*err && buffer_mapped(&dummy)) {
bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
if (buffer_new(&dummy)) {
lock_buffer(bh);
memset(bh->b_data, 0x00, inode->i_sb->s_blocksize);
set_buffer_uptodate(bh);
unlock_buffer(bh);
mark_buffer_dirty_inode(bh, inode);
}
return bh;
}
return NULL;
}
/* Extend the file by 'blocks' blocks, return the number of extents added */
static int udf_do_extend_file(struct inode *inode,
struct extent_position *last_pos,
struct kernel_long_ad *last_ext,
sector_t blocks)
{
sector_t add;
int count = 0, fake = !(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
struct super_block *sb = inode->i_sb;
struct kernel_lb_addr prealloc_loc = {};
int prealloc_len = 0;
struct udf_inode_info *iinfo;
int err;
/* The previous extent is fake and we should not extend by anything
* - there's nothing to do... */
if (!blocks && fake)
return 0;
iinfo = UDF_I(inode);
/* Round the last extent up to a multiple of block size */
if (last_ext->extLength & (sb->s_blocksize - 1)) {
last_ext->extLength =
(last_ext->extLength & UDF_EXTENT_FLAG_MASK) |
(((last_ext->extLength & UDF_EXTENT_LENGTH_MASK) +
sb->s_blocksize - 1) & ~(sb->s_blocksize - 1));
iinfo->i_lenExtents =
(iinfo->i_lenExtents + sb->s_blocksize - 1) &
~(sb->s_blocksize - 1);
}
/* Last extent are just preallocated blocks? */
if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
EXT_NOT_RECORDED_ALLOCATED) {
/* Save the extent so that we can reattach it to the end */
prealloc_loc = last_ext->extLocation;
prealloc_len = last_ext->extLength;
/* Mark the extent as a hole */
last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
(last_ext->extLength & UDF_EXTENT_LENGTH_MASK);
last_ext->extLocation.logicalBlockNum = 0;
last_ext->extLocation.partitionReferenceNum = 0;
}
/* Can we merge with the previous extent? */
if ((last_ext->extLength & UDF_EXTENT_FLAG_MASK) ==
EXT_NOT_RECORDED_NOT_ALLOCATED) {
add = ((1 << 30) - sb->s_blocksize -
(last_ext->extLength & UDF_EXTENT_LENGTH_MASK)) >>
sb->s_blocksize_bits;
if (add > blocks)
add = blocks;
blocks -= add;
last_ext->extLength += add << sb->s_blocksize_bits;
}
if (fake) {
udf_add_aext(inode, last_pos, &last_ext->extLocation,
last_ext->extLength, 1);
count++;
} else {
struct kernel_lb_addr tmploc;
uint32_t tmplen;
udf_write_aext(inode, last_pos, &last_ext->extLocation,
last_ext->extLength, 1);
/*
* We've rewritten the last extent but there may be empty
* indirect extent after it - enter it.
*/
udf_next_aext(inode, last_pos, &tmploc, &tmplen, 0);
}
/* Managed to do everything necessary? */
if (!blocks)
goto out;
/* All further extents will be NOT_RECORDED_NOT_ALLOCATED */
last_ext->extLocation.logicalBlockNum = 0;
last_ext->extLocation.partitionReferenceNum = 0;
add = (1 << (30-sb->s_blocksize_bits)) - 1;
last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
(add << sb->s_blocksize_bits);
/* Create enough extents to cover the whole hole */
while (blocks > add) {
blocks -= add;
err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
last_ext->extLength, 1);
if (err)
return err;
count++;
}
if (blocks) {
last_ext->extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
(blocks << sb->s_blocksize_bits);
err = udf_add_aext(inode, last_pos, &last_ext->extLocation,
last_ext->extLength, 1);
if (err)
return err;
count++;
}
out:
/* Do we have some preallocated blocks saved? */
if (prealloc_len) {
err = udf_add_aext(inode, last_pos, &prealloc_loc,
prealloc_len, 1);
if (err)
return err;
last_ext->extLocation = prealloc_loc;
last_ext->extLength = prealloc_len;
count++;
}
/* last_pos should point to the last written extent... */
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
last_pos->offset -= sizeof(struct short_ad);
else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
last_pos->offset -= sizeof(struct long_ad);
else
return -EIO;
return count;
}
static int udf_extend_file(struct inode *inode, loff_t newsize)
{
struct extent_position epos;
struct kernel_lb_addr eloc;
uint32_t elen;
int8_t etype;
struct super_block *sb = inode->i_sb;
sector_t first_block = newsize >> sb->s_blocksize_bits, offset;
int adsize;
struct udf_inode_info *iinfo = UDF_I(inode);
struct kernel_long_ad extent;
int err;
if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_SHORT)
adsize = sizeof(struct short_ad);
else if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_LONG)
adsize = sizeof(struct long_ad);
else
BUG();
etype = inode_bmap(inode, first_block, &epos, &eloc, &elen, &offset);
/* File has extent covering the new size (could happen when extending
* inside a block)? */
if (etype != -1)
return 0;
if (newsize & (sb->s_blocksize - 1))
offset++;
/* Extended file just to the boundary of the last file block? */
if (offset == 0)
return 0;
/* Truncate is extending the file by 'offset' blocks */
if ((!epos.bh && epos.offset == udf_file_entry_alloc_offset(inode)) ||
(epos.bh && epos.offset == sizeof(struct allocExtDesc))) {
/* File has no extents at all or has empty last
* indirect extent! Create a fake extent... */
extent.extLocation.logicalBlockNum = 0;
extent.extLocation.partitionReferenceNum = 0;
extent.extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
} else {
epos.offset -= adsize;
etype = udf_next_aext(inode, &epos, &extent.extLocation,
&extent.extLength, 0);
extent.extLength |= etype << 30;
}
err = udf_do_extend_file(inode, &epos, &extent, offset);
if (err < 0)
goto out;
err = 0;
iinfo->i_lenExtents = newsize;
out:
brelse(epos.bh);
return err;
}
static sector_t inode_getblk(struct inode *inode, sector_t block,
int *err, int *new)
{
struct kernel_long_ad laarr[EXTENT_MERGE_SIZE];
struct extent_position prev_epos, cur_epos, next_epos;
int count = 0, startnum = 0, endnum = 0;
uint32_t elen = 0, tmpelen;
struct kernel_lb_addr eloc, tmpeloc;
int c = 1;
loff_t lbcount = 0, b_off = 0;
uint32_t newblocknum, newblock;
sector_t offset = 0;
int8_t etype;
struct udf_inode_info *iinfo = UDF_I(inode);
int goal = 0, pgoal = iinfo->i_location.logicalBlockNum;
int lastblock = 0;
bool isBeyondEOF;
*err = 0;
*new = 0;
prev_epos.offset = udf_file_entry_alloc_offset(inode);
prev_epos.block = iinfo->i_location;
prev_epos.bh = NULL;
cur_epos = next_epos = prev_epos;
b_off = (loff_t)block << inode->i_sb->s_blocksize_bits;
/* find the extent which contains the block we are looking for.
alternate between laarr[0] and laarr[1] for locations of the
current extent, and the previous extent */
do {
if (prev_epos.bh != cur_epos.bh) {
brelse(prev_epos.bh);
get_bh(cur_epos.bh);
prev_epos.bh = cur_epos.bh;
}
if (cur_epos.bh != next_epos.bh) {
brelse(cur_epos.bh);
get_bh(next_epos.bh);
cur_epos.bh = next_epos.bh;
}
lbcount += elen;
prev_epos.block = cur_epos.block;
cur_epos.block = next_epos.block;
prev_epos.offset = cur_epos.offset;
cur_epos.offset = next_epos.offset;
etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 1);
if (etype == -1)
break;
c = !c;
laarr[c].extLength = (etype << 30) | elen;
laarr[c].extLocation = eloc;
if (etype != (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
pgoal = eloc.logicalBlockNum +
((elen + inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits);
count++;
} while (lbcount + elen <= b_off);
b_off -= lbcount;
offset = b_off >> inode->i_sb->s_blocksize_bits;
/*
* Move prev_epos and cur_epos into indirect extent if we are at
* the pointer to it
*/
udf_next_aext(inode, &prev_epos, &tmpeloc, &tmpelen, 0);
udf_next_aext(inode, &cur_epos, &tmpeloc, &tmpelen, 0);
/* if the extent is allocated and recorded, return the block
if the extent is not a multiple of the blocksize, round up */
if (etype == (EXT_RECORDED_ALLOCATED >> 30)) {
if (elen & (inode->i_sb->s_blocksize - 1)) {
elen = EXT_RECORDED_ALLOCATED |
((elen + inode->i_sb->s_blocksize - 1) &
~(inode->i_sb->s_blocksize - 1));
udf_write_aext(inode, &cur_epos, &eloc, elen, 1);
}
brelse(prev_epos.bh);
brelse(cur_epos.bh);
brelse(next_epos.bh);
newblock = udf_get_lb_pblock(inode->i_sb, &eloc, offset);
return newblock;
}
/* Are we beyond EOF? */
if (etype == -1) {
int ret;
isBeyondEOF = true;
if (count) {
if (c)
laarr[0] = laarr[1];
startnum = 1;
} else {
/* Create a fake extent when there's not one */
memset(&laarr[0].extLocation, 0x00,
sizeof(struct kernel_lb_addr));
laarr[0].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED;
/* Will udf_do_extend_file() create real extent from
a fake one? */
startnum = (offset > 0);
}
/* Create extents for the hole between EOF and offset */
ret = udf_do_extend_file(inode, &prev_epos, laarr, offset);
if (ret < 0) {
brelse(prev_epos.bh);
brelse(cur_epos.bh);
brelse(next_epos.bh);
*err = ret;
return 0;
}
c = 0;
offset = 0;
count += ret;
/* We are not covered by a preallocated extent? */
if ((laarr[0].extLength & UDF_EXTENT_FLAG_MASK) !=
EXT_NOT_RECORDED_ALLOCATED) {
/* Is there any real extent? - otherwise we overwrite
* the fake one... */
if (count)
c = !c;
laarr[c].extLength = EXT_NOT_RECORDED_NOT_ALLOCATED |
inode->i_sb->s_blocksize;
memset(&laarr[c].extLocation, 0x00,
sizeof(struct kernel_lb_addr));
count++;
}
endnum = c + 1;
lastblock = 1;
} else {
isBeyondEOF = false;
endnum = startnum = ((count > 2) ? 2 : count);
/* if the current extent is in position 0,
swap it with the previous */
if (!c && count != 1) {
laarr[2] = laarr[0];
laarr[0] = laarr[1];
laarr[1] = laarr[2];
c = 1;
}
/* if the current block is located in an extent,
read the next extent */
etype = udf_next_aext(inode, &next_epos, &eloc, &elen, 0);
if (etype != -1) {
laarr[c + 1].extLength = (etype << 30) | elen;
laarr[c + 1].extLocation = eloc;
count++;
startnum++;
endnum++;
} else
lastblock = 1;
}
/* if the current extent is not recorded but allocated, get the
* block in the extent corresponding to the requested block */
if ((laarr[c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30))
newblocknum = laarr[c].extLocation.logicalBlockNum + offset;
else { /* otherwise, allocate a new block */
if (iinfo->i_next_alloc_block == block)
goal = iinfo->i_next_alloc_goal;
if (!goal) {
if (!(goal = pgoal)) /* XXX: what was intended here? */
goal = iinfo->i_location.logicalBlockNum + 1;
}
newblocknum = udf_new_block(inode->i_sb, inode,
iinfo->i_location.partitionReferenceNum,
goal, err);
if (!newblocknum) {
brelse(prev_epos.bh);
brelse(cur_epos.bh);
brelse(next_epos.bh);
*err = -ENOSPC;
return 0;
}
if (isBeyondEOF)
iinfo->i_lenExtents += inode->i_sb->s_blocksize;
}
/* if the extent the requsted block is located in contains multiple
* blocks, split the extent into at most three extents. blocks prior
* to requested block, requested block, and blocks after requested
* block */
udf_split_extents(inode, &c, offset, newblocknum, laarr, &endnum);
#ifdef UDF_PREALLOCATE
/* We preallocate blocks only for regular files. It also makes sense
* for directories but there's a problem when to drop the
* preallocation. We might use some delayed work for that but I feel
* it's overengineering for a filesystem like UDF. */
if (S_ISREG(inode->i_mode))
udf_prealloc_extents(inode, c, lastblock, laarr, &endnum);
#endif
/* merge any continuous blocks in laarr */
udf_merge_extents(inode, laarr, &endnum);
/* write back the new extents, inserting new extents if the new number
* of extents is greater than the old number, and deleting extents if
* the new number of extents is less than the old number */
udf_update_extents(inode, laarr, startnum, endnum, &prev_epos);
brelse(prev_epos.bh);
brelse(cur_epos.bh);
brelse(next_epos.bh);
newblock = udf_get_pblock(inode->i_sb, newblocknum,
iinfo->i_location.partitionReferenceNum, 0);
if (!newblock) {
*err = -EIO;
return 0;
}
*new = 1;
iinfo->i_next_alloc_block = block;
iinfo->i_next_alloc_goal = newblocknum;
inode->i_ctime = current_time(inode);
if (IS_SYNC(inode))
udf_sync_inode(inode);
else
mark_inode_dirty(inode);
return newblock;
}
static void udf_split_extents(struct inode *inode, int *c, int offset,
int newblocknum,
struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
int *endnum)
{
unsigned long blocksize = inode->i_sb->s_blocksize;
unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
if ((laarr[*c].extLength >> 30) == (EXT_NOT_RECORDED_ALLOCATED >> 30) ||
(laarr[*c].extLength >> 30) ==
(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
int curr = *c;
int blen = ((laarr[curr].extLength & UDF_EXTENT_LENGTH_MASK) +
blocksize - 1) >> blocksize_bits;
int8_t etype = (laarr[curr].extLength >> 30);
if (blen == 1)
;
else if (!offset || blen == offset + 1) {
laarr[curr + 2] = laarr[curr + 1];
laarr[curr + 1] = laarr[curr];
} else {
laarr[curr + 3] = laarr[curr + 1];
laarr[curr + 2] = laarr[curr + 1] = laarr[curr];
}
if (offset) {
if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30)) {
udf_free_blocks(inode->i_sb, inode,
&laarr[curr].extLocation,
0, offset);
laarr[curr].extLength =
EXT_NOT_RECORDED_NOT_ALLOCATED |
(offset << blocksize_bits);
laarr[curr].extLocation.logicalBlockNum = 0;
laarr[curr].extLocation.
partitionReferenceNum = 0;
} else
laarr[curr].extLength = (etype << 30) |
(offset << blocksize_bits);
curr++;
(*c)++;
(*endnum)++;
}
laarr[curr].extLocation.logicalBlockNum = newblocknum;
if (etype == (EXT_NOT_RECORDED_NOT_ALLOCATED >> 30))
laarr[curr].extLocation.partitionReferenceNum =
UDF_I(inode)->i_location.partitionReferenceNum;
laarr[curr].extLength = EXT_RECORDED_ALLOCATED |
blocksize;
curr++;
if (blen != offset + 1) {
if (etype == (EXT_NOT_RECORDED_ALLOCATED >> 30))
laarr[curr].extLocation.logicalBlockNum +=
offset + 1;
laarr[curr].extLength = (etype << 30) |
((blen - (offset + 1)) << blocksize_bits);
curr++;
(*endnum)++;
}
}
}
static void udf_prealloc_extents(struct inode *inode, int c, int lastblock,
struct kernel_long_ad laarr[EXTENT_MERGE_SIZE],
int *endnum)
{
int start, length = 0, currlength = 0, i;
if (*endnum >= (c + 1)) {
if (!lastblock)
return;
else
start = c;
} else {
if ((laarr[c + 1].extLength >> 30) ==
(EXT_NOT_RECORDED_ALLOCATED >> 30)) {
start = c + 1;
length = currlength =
(((laarr[c + 1].extLength &
UDF_EXTENT_LENGTH_MASK) +
inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits);
} else
start = c;
}
for (i = start + 1; i <= *endnum; i++) {
if (i == *endnum) {
if (lastblock)
length += UDF_DEFAULT_PREALLOC_BLOCKS;
} else if ((laarr[i].extLength >> 30) ==
(EXT_NOT_RECORDED_NOT_ALLOCATED >> 30)) {
length += (((laarr[i].extLength &
UDF_EXTENT_LENGTH_MASK) +
inode->i_sb->s_blocksize - 1) >>
inode->i_sb->s_blocksize_bits);
} else
break;