/*
* support function for mpage_readpages. The fs supplied get_block might
* return an up to date buffer. This is used to map that buffer into
* the page, which allows readpage to avoid triggering a duplicate call
* to get_block.
*
* The idea is to avoid adding buffers to pages that don't already have
* them. So when the buffer is up to date and the page size == block size,
* this marks the page up to date instead of adding new buffers.
*/
static void
map_buffer_to_page(struct page *page, struct buffer_head *bh, int page_block)
{
struct inode *inode = page->mapping->host;
struct buffer_head *page_bh, *head;
int block = 0;
if (!page_has_buffers(page)) {
/*
* don't make any buffers if there is only one buffer on
* the page and the page just needs to be set up to date
*/
if (inode->i_blkbits == PAGE_CACHE_SHIFT &&
buffer_uptodate(bh)) {
SetPageUptodate(page);
return;
}
create_empty_buffers(page, 1 << inode->i_blkbits, 0);
}
head = page_buffers(page);
page_bh = head;
do {
if (block == page_block) {
page_bh->b_state = bh->b_state;
page_bh->b_bdev = bh->b_bdev;
page_bh->b_blocknr = bh->b_blocknr;
break;
}
page_bh = page_bh->b_this_page;
block++;
} while (page_bh != head);
}
/*
* If a ramdisk page has buffers, some may be uptodate and some may be not.
* To bring the page uptodate we zero out the non-uptodate buffers. The
* page must be locked.
*/
static void make_page_uptodate(struct page *page)
{
if (page_has_buffers(page)) {
struct buffer_head *bh = page_buffers(page);
struct buffer_head *head = bh;
do {
if (!buffer_uptodate(bh)) {
memset(bh->b_data, 0, bh->b_size);
/*
* akpm: I'm totally undecided about this. The
* buffer has just been magically brought "up to
* date", but nobody should want to be reading
* it anyway, because it hasn't been used for
* anything yet. It is still in a "not read
* from disk yet" state.
*
* But non-uptodate buffers against an uptodate
* page are against the rules. So do it anyway.
*/
set_buffer_uptodate(bh);
}
} while ((bh = bh->b_this_page) != head);
} else {
memset(page_address(page), 0, PAGE_CACHE_SIZE);
}
flush_dcache_page(page);
SetPageUptodate(page);
}
void nilfs_page_bug(struct page *page)
{
struct address_space *m;
unsigned long ino;
if (unlikely(!page)) {
printk(KERN_CRIT "NILFS_PAGE_BUG(NULL)\n");
return;
}
m = page->mapping;
ino = m ? m->host->i_ino : 0;
printk(KERN_CRIT "NILFS_PAGE_BUG(%p): cnt=%d index#=%llu flags=0x%lx "
"mapping=%p ino=%lu\n",
page, page_ref_count(page),
(unsigned long long)page->index, page->flags, m, ino);
if (page_has_buffers(page)) {
struct buffer_head *bh, *head;
int i = 0;
bh = head = page_buffers(page);
do {
printk(KERN_CRIT
" BH[%d] %p: cnt=%d block#=%llu state=0x%lx\n",
i++, bh, atomic_read(&bh->b_count),
(unsigned long long)bh->b_blocknr, bh->b_state);
bh = bh->b_this_page;
} while (bh != head);
}
}
void jbd2_journal_invalidatepage(journal_t *journal,
struct page *page,
unsigned long offset)
{
struct buffer_head *head, *bh, *next;
unsigned int curr_off = 0;
int may_free = 1;
if (!PageLocked(page))
BUG();
if (!page_has_buffers(page))
return;
head = bh = page_buffers(page);
do {
unsigned int next_off = curr_off + bh->b_size;
next = bh->b_this_page;
if (offset <= curr_off) {
lock_buffer(bh);
may_free &= journal_unmap_buffer(journal, bh);
unlock_buffer(bh);
}
curr_off = next_off;
bh = next;
} while (bh != head);
if (!offset) {
if (may_free && try_to_free_buffers(page))
J_ASSERT(!page_has_buffers(page));
}
}
static void gfs2_invalidatepage(struct page *page, unsigned int offset,
unsigned int length)
{
struct gfs2_sbd *sdp = GFS2_SB(page->mapping->host);
unsigned int stop = offset + length;
int partial_page = (offset || length < PAGE_CACHE_SIZE);
struct buffer_head *bh, *head;
unsigned long pos = 0;
BUG_ON(!PageLocked(page));
if (!partial_page)
ClearPageChecked(page);
if (!page_has_buffers(page))
goto out;
bh = head = page_buffers(page);
do {
if (pos + bh->b_size > stop)
return;
if (offset <= pos)
gfs2_discard(sdp, bh);
pos += bh->b_size;
bh = bh->b_this_page;
} while (bh != head);
out:
if (!partial_page)
try_to_release_page(page, 0);
}
static void
unmap_buffers(struct page *page, loff_t pos) {
struct buffer_head *bh ;
struct buffer_head *head ;
struct buffer_head *next ;
unsigned long tail_index ;
unsigned long cur_index ;
if (page) {
if (page_has_buffers(page)) {
tail_index = pos & (PAGE_CACHE_SIZE - 1) ;
cur_index = 0 ;
head = page_buffers(page) ;
bh = head ;
do {
next = bh->b_this_page ;
/* we want to unmap the buffers that contain the tail, and
** all the buffers after it (since the tail must be at the
** end of the file). We don't want to unmap file data
** before the tail, since it might be dirty and waiting to
** reach disk
*/
cur_index += bh->b_size ;
if (cur_index > tail_index) {
reiserfs_unmap_buffer(bh) ;
}
bh = next ;
} while (bh != head) ;
if ( PAGE_SIZE == bh->b_size ) {
clear_page_dirty(page);
}
}
}
}
/**
* int jbd2_journal_try_to_free_buffers() - try to free page buffers.
* @journal: journal for operation
* @page: to try and free
* @gfp_mask: we use the mask to detect how hard should we try to release
* buffers. If __GFP_WAIT and __GFP_FS is set, we wait for commit code to
* release the buffers.
*
*
* For all the buffers on this page,
* if they are fully written out ordered data, move them onto BUF_CLEAN
* so try_to_free_buffers() can reap them.
*
* This function returns non-zero if we wish try_to_free_buffers()
* to be called. We do this if the page is releasable by try_to_free_buffers().
* We also do it if the page has locked or dirty buffers and the caller wants
* us to perform sync or async writeout.
*
* This complicates JBD locking somewhat. We aren't protected by the
* BKL here. We wish to remove the buffer from its committing or
* running transaction's ->t_datalist via __jbd2_journal_unfile_buffer.
*
* This may *change* the value of transaction_t->t_datalist, so anyone
* who looks at t_datalist needs to lock against this function.
*
* Even worse, someone may be doing a jbd2_journal_dirty_data on this
* buffer. So we need to lock against that. jbd2_journal_dirty_data()
* will come out of the lock with the buffer dirty, which makes it
* ineligible for release here.
*
* Who else is affected by this? hmm... Really the only contender
* is do_get_write_access() - it could be looking at the buffer while
* journal_try_to_free_buffer() is changing its state. But that
* cannot happen because we never reallocate freed data as metadata
* while the data is part of a transaction. Yes?
*
* Return 0 on failure, 1 on success
*/
int jbd2_journal_try_to_free_buffers(journal_t *journal,
struct page *page, gfp_t gfp_mask)
{
struct buffer_head *head;
struct buffer_head *bh;
int ret = 0;
J_ASSERT(PageLocked(page));
head = page_buffers(page);
bh = head;
do {
struct journal_head *jh;
jh = jbd2_journal_grab_journal_head(bh);
if (!jh)
continue;
jbd_lock_bh_state(bh);
__journal_try_to_free_buffer(journal, bh);
jbd2_journal_put_journal_head(jh);
jbd_unlock_bh_state(bh);
if (buffer_jbd(bh))
goto busy;
} while ((bh = bh->b_this_page) != head);
ret = try_to_free_buffers(page);
busy:
return ret;
}
static int nilfs_set_page_dirty(struct page *page)
{
int ret = __set_page_dirty_nobuffers(page);
if (page_has_buffers(page)) {
struct inode *inode = page->mapping->host;
unsigned nr_dirty = 0;
struct buffer_head *bh, *head;
/*
* This page is locked by callers, and no other thread
* concurrently marks its buffers dirty since they are
* only dirtied through routines in fs/buffer.c in
* which call sites of mark_buffer_dirty are protected
* by page lock.
*/
bh = head = page_buffers(page);
do {
/* Do not mark hole blocks dirty */
if (buffer_dirty(bh) || !buffer_mapped(bh))
continue;
set_buffer_dirty(bh);
nr_dirty++;
} while (bh = bh->b_this_page, bh != head);
if (nr_dirty)
nilfs_set_file_dirty(inode, nr_dirty);
}
return ret;
}
/*
* We're now finished for good with this page. Update the page state via the
* associated buffer_heads, paying attention to the start and end offsets that
* we need to process on the page.
*
* Landmine Warning: bh->b_end_io() will call end_page_writeback() on the last
* buffer in the IO. Once it does this, it is unsafe to access the bufferhead or
* the page at all, as we may be racing with memory reclaim and it can free both
* the bufferhead chain and the page as it will see the page as clean and
* unused.
*/
static void
xfs_finish_page_writeback(
struct inode *inode,
struct bio_vec *bvec,
int error)
{
unsigned int end = bvec->bv_offset + bvec->bv_len - 1;
struct buffer_head *head, *bh, *next;
unsigned int off = 0;
unsigned int bsize;
ASSERT(bvec->bv_offset < PAGE_SIZE);
ASSERT((bvec->bv_offset & ((1 << inode->i_blkbits) - 1)) == 0);
ASSERT(end < PAGE_SIZE);
ASSERT((bvec->bv_len & ((1 << inode->i_blkbits) - 1)) == 0);
bh = head = page_buffers(bvec->bv_page);
bsize = bh->b_size;
do {
next = bh->b_this_page;
if (off < bvec->bv_offset)
goto next_bh;
if (off > end)
break;
bh->b_end_io(bh, !error);
next_bh:
off += bsize;
} while ((bh = next) != head);
}
static void ext4_finish_bio(struct bio *bio)
{
int i;
struct bio_vec *bvec;
bio_for_each_segment_all(bvec, bio, i) {
struct page *page = bvec->bv_page;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
struct page *data_page = NULL;
#endif
struct buffer_head *bh, *head;
unsigned bio_start = bvec->bv_offset;
unsigned bio_end = bio_start + bvec->bv_len;
unsigned under_io = 0;
unsigned long flags;
if (!page)
continue;
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (!page->mapping) {
/* The bounce data pages are unmapped. */
data_page = page;
fscrypt_pullback_bio_page(&page, false);
}
#endif
if (bio->bi_status) {
SetPageError(page);
mapping_set_error(page->mapping, -EIO);
}
bh = head = page_buffers(page);
/*
* We check all buffers in the page under BH_Uptodate_Lock
* to avoid races with other end io clearing async_write flags
*/
local_irq_save(flags);
bit_spin_lock(BH_Uptodate_Lock, &head->b_state);
do {
if (bh_offset(bh) < bio_start ||
bh_offset(bh) + bh->b_size > bio_end) {
if (buffer_async_write(bh))
under_io++;
continue;
}
clear_buffer_async_write(bh);
if (bio->bi_status)
buffer_io_error(bh);
} while ((bh = bh->b_this_page) != head);
bit_spin_unlock(BH_Uptodate_Lock, &head->b_state);
local_irq_restore(flags);
if (!under_io) {
#ifdef CONFIG_EXT4_FS_ENCRYPTION
if (data_page)
fscrypt_restore_control_page(data_page);
#endif
end_page_writeback(page);
}
}
}
void nilfs_clear_dirty_pages(struct address_space *mapping)
{
struct pagevec pvec;
unsigned int i;
pgoff_t index = 0;
pagevec_init(&pvec, 0);
while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
PAGEVEC_SIZE)) {
for (i = 0; i < pagevec_count(&pvec); i++) {
struct page *page = pvec.pages[i];
struct buffer_head *bh, *head;
lock_page(page);
ClearPageUptodate(page);
ClearPageMappedToDisk(page);
bh = head = page_buffers(page);
do {
lock_buffer(bh);
clear_buffer_dirty(bh);
clear_buffer_nilfs_volatile(bh);
clear_buffer_uptodate(bh);
clear_buffer_mapped(bh);
unlock_buffer(bh);
bh = bh->b_this_page;
} while (bh != head);
__nilfs_clear_page_dirty(page);
unlock_page(page);
}
pagevec_release(&pvec);
cond_resched();
}
}
///////////////////////////////////////////////////////////
// TracePageBuffers
//
//
///////////////////////////////////////////////////////////
void
TracePageBuffers(
IN struct page* page,
IN int hdr
)
{
if ( hdr ) {
DebugTrace(+1, UFSD_LEVEL_PAGE_BH, ("p=%p f=%lx:\n", page, page->flags ));
} else if ( UFSD_TraceLevel & UFSD_LEVEL_PAGE_BH ) {
UFSD_TraceInc( +1 );
}
if ( page_has_buffers( page ) ) {
struct buffer_head* head = page_buffers(page);
struct buffer_head* bh = head;
do {
if ( (sector_t)-1 == bh->b_blocknr ) {
DebugTrace( 0, UFSD_LEVEL_PAGE_BH, ("bh=%p,%lx\n", bh, bh->b_state) );
} else {
DebugTrace( 0, UFSD_LEVEL_PAGE_BH, ("bh=%p,%lx,%"PSCT"x\n", bh, bh->b_state, bh->b_blocknr ) );
}
bh = bh->b_this_page;
} while( bh != head );
} else {
DebugTrace(0, UFSD_LEVEL_PAGE_BH, ("no buffers\n" ));
}
if ( UFSD_TraceLevel & UFSD_LEVEL_PAGE_BH )
UFSD_TraceInc( -1 );
}
handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
struct page *page,
unsigned from,
unsigned to)
{
struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
handle_t *handle;
int ret = 0;
handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
if (IS_ERR(handle)) {
ret = -ENOMEM;
mlog_errno(ret);
goto out;
}
if (ocfs2_should_order_data(inode)) {
ret = walk_page_buffers(handle,
page_buffers(page),
from, to, NULL,
ocfs2_journal_dirty_data);
if (ret < 0)
mlog_errno(ret);
}
out:
if (ret) {
if (!IS_ERR(handle))
ocfs2_commit_trans(osb, handle);
handle = ERR_PTR(ret);
}
return handle;
}
/*
* write out a page to a file
*/
static void write_page(struct bitmap *bitmap, struct page *page, int wait)
{
struct buffer_head *bh;
if (bitmap->file == NULL) {
switch (write_sb_page(bitmap, page, wait)) {
case -EINVAL:
bitmap->flags |= BITMAP_WRITE_ERROR;
}
} else {
bh = page_buffers(page);
while (bh && bh->b_blocknr) {
atomic_inc(&bitmap->pending_writes);
set_buffer_locked(bh);
set_buffer_mapped(bh);
submit_bh(WRITE, bh);
bh = bh->b_this_page;
}
if (wait) {
wait_event(bitmap->write_wait,
atomic_read(&bitmap->pending_writes)==0);
}
}
if (bitmap->flags & BITMAP_WRITE_ERROR)
bitmap_file_kick(bitmap);
}
int ext4_bio_write_page(struct ext4_io_submit *io,
struct page *page,
int len,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
unsigned block_start, block_end, blocksize;
struct ext4_io_page *io_page;
struct buffer_head *bh, *head;
int ret = 0;
blocksize = 1 << inode->i_blkbits;
BUG_ON(PageWriteback(page));
set_page_writeback(page);
ClearPageError(page);
io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
if (!io_page) {
set_page_dirty(page);
unlock_page(page);
return -ENOMEM;
}
io_page->p_page = page;
atomic_set(&io_page->p_count, 1);
get_page(page);
for (bh = head = page_buffers(page), block_start = 0;
bh != head || !block_start;
block_start = block_end, bh = bh->b_this_page) {
block_end = block_start + blocksize;
if (block_start >= len) {
clear_buffer_dirty(bh);
set_buffer_uptodate(bh);
continue;
}
ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
if (ret) {
/*
* We only get here on ENOMEM. Not much else
* we can do but mark the page as dirty, and
* better luck next time.
*/
set_page_dirty(page);
break;
}
}
unlock_page(page);
/*
* If the page was truncated before we could do the writeback,
* or we had a memory allocation error while trying to write
* the first buffer head, we won't have submitted any pages for
* I/O. In that case we need to make sure we've cleared the
* PageWriteback bit from the page to prevent the system from
* wedging later on.
*/
put_io_page(io_page);
return ret;
}
static int gfs2_aspace_writepage(struct page *page, struct writeback_control *wbc)
{
struct buffer_head *bh, *head;
int nr_underway = 0;
int write_op = REQ_META |
(wbc->sync_mode == WB_SYNC_ALL ? WRITE_SYNC_PLUG : WRITE);
BUG_ON(!PageLocked(page));
BUG_ON(!page_has_buffers(page));
head = page_buffers(page);
bh = head;
do {
if (!buffer_mapped(bh))
continue;
/*
* If it's a fully non-blocking write attempt and we cannot
* lock the buffer then redirty the page. Note that this can
* potentially cause a busy-wait loop from pdflush and kswapd
* activity, but those code paths have their own higher-level
* throttling.
*/
if (wbc->sync_mode != WB_SYNC_NONE) {
lock_buffer(bh);
} else if (!trylock_buffer(bh)) {
redirty_page_for_writepage(wbc, page);
continue;
}
if (test_clear_buffer_dirty(bh)) {
mark_buffer_async_write(bh);
} else {
unlock_buffer(bh);
}
} while ((bh = bh->b_this_page) != head);
/*
* The page and its buffers are protected by PageWriteback(), so we can
* drop the bh refcounts early.
*/
BUG_ON(PageWriteback(page));
set_page_writeback(page);
do {
struct buffer_head *next = bh->b_this_page;
if (buffer_async_write(bh)) {
submit_bh(write_op, bh);
nr_underway++;
}
bh = next;
} while (bh != head);
unlock_page(page);
if (nr_underway == 0)
end_page_writeback(page);
return 0;
}
static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
struct page *page = vmf->page;
struct inode *inode = vma->vm_file->f_dentry->d_inode;
struct nilfs_transaction_info ti;
int ret;
if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info)))
return VM_FAULT_SIGBUS;
lock_page(page);
if (page->mapping != inode->i_mapping ||
page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
unlock_page(page);
return VM_FAULT_NOPAGE;
}
if (PageMappedToDisk(page))
goto mapped;
if (page_has_buffers(page)) {
struct buffer_head *bh, *head;
int fully_mapped = 1;
bh = head = page_buffers(page);
do {
if (!buffer_mapped(bh)) {
fully_mapped = 0;
break;
}
} while (bh = bh->b_this_page, bh != head);
if (fully_mapped) {
SetPageMappedToDisk(page);
goto mapped;
}
}
unlock_page(page);
ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
if (unlikely(ret))
return VM_FAULT_SIGBUS;
ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
if (ret != VM_FAULT_LOCKED) {
nilfs_transaction_abort(inode->i_sb);
return ret;
}
nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits));
nilfs_transaction_commit(inode->i_sb);
mapped:
wait_on_page_writeback(page);
return VM_FAULT_LOCKED;
}
/**
* nilfs_copy_page -- copy the page with buffers
* @dst: destination page
* @src: source page
* @copy_dirty: flag whether to copy dirty states on the page's buffer heads.
*
* This function is for both data pages and btnode pages. The dirty flag
* should be treated by caller. The page must not be under i/o.
* Both src and dst page must be locked
*/
static void nilfs_copy_page(struct page *dst, struct page *src, int copy_dirty)
{
struct buffer_head *dbh, *dbufs, *sbh, *sbufs;
unsigned long mask = NILFS_BUFFER_INHERENT_BITS;
BUG_ON(PageWriteback(dst));
sbh = sbufs = page_buffers(src);
if (!page_has_buffers(dst))
create_empty_buffers(dst, sbh->b_size, 0);
if (copy_dirty)
mask |= BIT(BH_Dirty);
dbh = dbufs = page_buffers(dst);
do {
lock_buffer(sbh);
lock_buffer(dbh);
dbh->b_state = sbh->b_state & mask;
dbh->b_blocknr = sbh->b_blocknr;
dbh->b_bdev = sbh->b_bdev;
sbh = sbh->b_this_page;
dbh = dbh->b_this_page;
} while (dbh != dbufs);
copy_highpage(dst, src);
if (PageUptodate(src) && !PageUptodate(dst))
SetPageUptodate(dst);
else if (!PageUptodate(src) && PageUptodate(dst))
ClearPageUptodate(dst);
if (PageMappedToDisk(src) && !PageMappedToDisk(dst))
SetPageMappedToDisk(dst);
else if (!PageMappedToDisk(src) && PageMappedToDisk(dst))
ClearPageMappedToDisk(dst);
do {
unlock_buffer(sbh);
unlock_buffer(dbh);
sbh = sbh->b_this_page;
dbh = dbh->b_this_page;
} while (dbh != dbufs);
}
void nilfs_invalidatepage(struct page *page, unsigned long offset)
{
struct buffer_head *bh = NULL;
if (PagePrivate(page)) {
bh = page_buffers(page);
BUG_ON(buffer_nilfs_allocated(bh));
}
block_invalidatepage(page, offset);
}
/**
* nilfs_page_buffers_clean - check if a page has dirty buffers or not.
* @page: page to be checked
*
* nilfs_page_buffers_clean() returns zero if the page has dirty buffers.
* Otherwise, it returns non-zero value.
*/
int nilfs_page_buffers_clean(struct page *page)
{
struct buffer_head *bh, *head;
bh = head = page_buffers(page);
do {
if (buffer_dirty(bh))
return 0;
bh = bh->b_this_page;
} while (bh != head);
return 1;
}
static void free_buffers(struct page *page)
{
struct buffer_head *bh = page_buffers(page);
while (bh) {
struct buffer_head *next = bh->b_this_page;
free_buffer_head(bh);
bh = next;
}
__clear_page_buffers(page);
put_page(page);
}
int gfs2_releasepage(struct page *page, gfp_t gfp_mask)
{
struct inode *aspace = page->mapping->host;
struct gfs2_sbd *sdp = aspace->i_sb->s_fs_info;
struct buffer_head *bh, *head;
struct gfs2_bufdata *bd;
unsigned long t = jiffies + gfs2_tune_get(sdp, gt_stall_secs) * HZ;
if (!page_has_buffers(page))
goto out;
head = bh = page_buffers(page);
do {
while (atomic_read(&bh->b_count)) {
if (!atomic_read(&aspace->i_writecount))
return 0;
if (!(gfp_mask & __GFP_WAIT))
return 0;
if (time_after_eq(jiffies, t)) {
stuck_releasepage(bh);
/* should we withdraw here? */
return 0;
}
yield();
}
gfs2_assert_warn(sdp, !buffer_pinned(bh));
gfs2_assert_warn(sdp, !buffer_dirty(bh));
gfs2_log_lock(sdp);
bd = bh->b_private;
if (bd) {
gfs2_assert_warn(sdp, bd->bd_bh == bh);
gfs2_assert_warn(sdp, list_empty(&bd->bd_list_tr));
gfs2_assert_warn(sdp, !bd->bd_ail);
bd->bd_bh = NULL;
if (!list_empty(&bd->bd_le.le_list))
bd = NULL;
bh->b_private = NULL;
}
gfs2_log_unlock(sdp);
if (bd)
kmem_cache_free(gfs2_bufdata_cachep, bd);
bh = bh->b_this_page;
} while (bh != head);
out:
return try_to_free_buffers(page);
}
static int ufs_alloc_lastblock(struct inode *inode)
{
int err = 0;
struct address_space *mapping = inode->i_mapping;
struct ufs_sb_private_info *uspi = UFS_SB(inode->i_sb)->s_uspi;
unsigned lastfrag, i, end;
struct page *lastpage;
struct buffer_head *bh;
lastfrag = (i_size_read(inode) + uspi->s_fsize - 1) >> uspi->s_fshift;
if (!lastfrag)
goto out;
lastfrag--;
lastpage = ufs_get_locked_page(mapping, lastfrag >>
(PAGE_CACHE_SHIFT - inode->i_blkbits));
if (IS_ERR(lastpage)) {
err = -EIO;
goto out;
}
end = lastfrag & ((1 << (PAGE_CACHE_SHIFT - inode->i_blkbits)) - 1);
bh = page_buffers(lastpage);
for (i = 0; i < end; ++i)
bh = bh->b_this_page;
err = ufs_getfrag_block(inode, lastfrag, bh, 1);
if (unlikely(err))
goto out_unlock;
if (buffer_new(bh)) {
clear_buffer_new(bh);
unmap_underlying_metadata(bh->b_bdev,
bh->b_blocknr);
/*
* we do not zeroize fragment, because of
* if it maped to hole, it already contains zeroes
*/
set_buffer_uptodate(bh);
mark_buffer_dirty(bh);
set_page_dirty(lastpage);
}
out_unlock:
ufs_put_locked_page(lastpage);
out:
return err;
}
/*
* Internal use only
*/
__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
const struct buffer_head *bh)
{
struct buffer_head *pbh;
__u64 key;
key = page_index(bh->b_page) << (PAGE_SHIFT -
bmap->b_inode->i_blkbits);
for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
key++;
return key;
}
static inline void print_buffers(struct page *page, sector_t block)
{
struct buffer_head *bh, *head;
if(!page_has_buffers(page)) {
printk("Warning: page doesn't have buffers, not sure how that happened, allocating buffer !!!\n");
create_empty_buffers(page, LFS_BSIZE, 0);
bh = head = page_buffers(page);
do {
map_bh(bh, page->mapping->host->i_sb, block++);
bh = bh->b_this_page;
} while(bh != head);
}
bh = head = page_buffers(page);
do {
if(!buffer_mapped(bh))
dprintk("The buffer seems to be not mapped ??");
//dprintk("mapped to blocknr = %Lu\n", bh->b_blocknr);
bh = bh->b_this_page;
} while(bh != head);
}
static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh,
u64 block, struct page *page)
{
struct inode *inode = &ip->i_inode;
struct buffer_head *bh;
int release = 0;
if (!page || page->index) {
page = grab_cache_page(inode->i_mapping, 0);
if (!page)
return -ENOMEM;
release = 1;
}
if (!PageUptodate(page)) {
void *kaddr = kmap(page);
u64 dsize = i_size_read(inode);
if (dsize > (dibh->b_size - sizeof(struct gfs2_dinode)))
dsize = dibh->b_size - sizeof(struct gfs2_dinode);
memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), dsize);
memset(kaddr + dsize, 0, PAGE_CACHE_SIZE - dsize);
kunmap(page);
SetPageUptodate(page);
}
if (!page_has_buffers(page))
create_empty_buffers(page, 1 << inode->i_blkbits,
(1 << BH_Uptodate));
bh = page_buffers(page);
if (!buffer_mapped(bh))
map_bh(bh, inode->i_sb, block);
set_buffer_uptodate(bh);
if (!gfs2_is_jdata(ip))
mark_buffer_dirty(bh);
if (!gfs2_is_writeback(ip))
gfs2_trans_add_bh(ip->i_gl, bh, 0);
if (release) {
unlock_page(page);
page_cache_release(page);
}
return 0;
}
int ext4_bio_write_page(struct ext4_io_submit *io,
struct page *page,
int len,
struct writeback_control *wbc)
{
struct inode *inode = page->mapping->host;
unsigned block_start, block_end, blocksize;
struct ext4_io_page *io_page;
struct buffer_head *bh, *head;
int ret = 0;
blocksize = 1 << inode->i_blkbits;
BUG_ON(!PageLocked(page));
BUG_ON(PageWriteback(page));
io_page = kmem_cache_alloc(io_page_cachep, GFP_NOFS);
if (!io_page) {
set_page_dirty(page);
unlock_page(page);
return -ENOMEM;
}
io_page->p_page = page;
atomic_set(&io_page->p_count, 1);
get_page(page);
set_page_writeback(page);
ClearPageError(page);
for (bh = head = page_buffers(page), block_start = 0;
bh != head || !block_start;
block_start = block_end, bh = bh->b_this_page) {
block_end = block_start + blocksize;
if (block_start >= len) {
zero_user_segment(page, block_start, block_end);
clear_buffer_dirty(bh);
set_buffer_uptodate(bh);
continue;
}
clear_buffer_dirty(bh);
ret = io_submit_add_bh(io, io_page, inode, wbc, bh);
if (ret) {
set_page_dirty(page);
break;
}
}
unlock_page(page);
put_io_page(io_page);
return ret;
}
static void print_buffer(struct page* page)
{
struct address_space* mapping = page_mapping(page);
struct buffer_head *bh, *head;
spin_lock(&mapping->private_lock);
bh = head = page_buffers(page);
printk("buffers:");
do {
printk(" state:%lx count:%d", bh->b_state, atomic_read(&bh->b_count));
bh = bh->b_this_page;
} while (bh != head);
printk("\n");
spin_unlock(&mapping->private_lock);
}
static void gfs2_page_add_databufs(struct gfs2_inode *ip, struct page *page,
unsigned int from, unsigned int to)
{
struct buffer_head *head = page_buffers(page);
unsigned int bsize = head->b_size;
struct buffer_head *bh;
unsigned int start, end;
for (bh = head, start = 0; bh != head || !start;
bh = bh->b_this_page, start = end) {
end = start + bsize;
if (end <= from || start >= to)
continue;
gfs2_trans_add_bh(ip->i_gl, bh, 0);
}
}
unsigned int nilfs_page_count_clean_buffers(struct page *page,
unsigned int from, unsigned int to)
{
unsigned int block_start, block_end;
struct buffer_head *bh, *head;
unsigned int nc = 0;
for (bh = head = page_buffers(page), block_start = 0;
bh != head || !block_start;
block_start = block_end, bh = bh->b_this_page) {
block_end = block_start + bh->b_size;
if (block_end > from && block_start < to && !buffer_dirty(bh))
nc++;
}
return nc;
}
