* Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
*/
-#include <linux/module.h>
#include <linux/fs.h>
#include <linux/time.h>
#include <linux/jbd2.h>
static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
static int __ext4_journalled_writepage(struct page *page, unsigned int len);
static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
+static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
+ struct inode *inode, struct page *page, loff_t from,
+ loff_t length, int flags);
/*
* Test whether an inode is a fast symlink.
clear_buffer_unwritten(bh);
}
- /* skip page if block allocation undone */
- if (buffer_delay(bh) || buffer_unwritten(bh))
+ /*
+ * skip page if block allocation undone and
+ * block is dirty
+ */
+ if (ext4_bh_delay_or_unwritten(NULL, bh))
skip_page = 1;
bh = bh->b_this_page;
block_start += bh->b_size;
* a[0] = 'a';
* truncate(f, 4096);
* we have in the page first buffer_head mapped via page_mkwrite call back
- * but other bufer_heads would be unmapped but dirty(dirty done via the
+ * but other buffer_heads would be unmapped but dirty (dirty done via the
* do_wp_page). So writepage should write the first block. If we modify
* the mmap area beyond 1024 we will again get a page_fault and the
* page_mkwrite callback will do the block allocation and mark the
pgoff_t index;
struct inode *inode = mapping->host;
handle_t *handle;
- loff_t page_len;
index = pos >> PAGE_CACHE_SHIFT;
*/
if (pos + len > inode->i_size)
ext4_truncate_failed_write(inode);
- } else {
- page_len = pos & (PAGE_CACHE_SIZE - 1);
- if (page_len > 0) {
- ret = ext4_discard_partial_page_buffers_no_lock(handle,
- inode, page, pos - page_len, page_len,
- EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED);
- }
}
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
loff_t new_i_size;
unsigned long start, end;
int write_mode = (int)(unsigned long)fsdata;
- loff_t page_len;
if (write_mode == FALL_BACK_TO_NONDELALLOC) {
if (ext4_should_order_data(inode)) {
*/
new_i_size = pos + copied;
- if (new_i_size > EXT4_I(inode)->i_disksize) {
+ if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
if (ext4_da_should_update_i_disksize(page, end)) {
down_write(&EXT4_I(inode)->i_data_sem);
if (new_i_size > EXT4_I(inode)->i_disksize) {
}
ret2 = generic_write_end(file, mapping, pos, len, copied,
page, fsdata);
-
- page_len = PAGE_CACHE_SIZE -
- ((pos + copied - 1) & (PAGE_CACHE_SIZE - 1));
-
- if (page_len > 0) {
- ret = ext4_discard_partial_page_buffers_no_lock(handle,
- inode, page, pos + copied - 1, page_len,
- EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED);
- }
-
copied = ret2;
if (ret2 < 0)
ret = ret2;
if (!io_end || !size)
goto out;
- ext_debug("ext4_end_io_dio(): io_end 0x%p"
+ ext_debug("ext4_end_io_dio(): io_end 0x%p "
"for inode %lu, iocb 0x%p, offset %llu, size %llu\n",
iocb->private, io_end->inode->i_ino, iocb, offset,
size);
+ iocb->private = NULL;
+
/* if not aio dio with unwritten extents, just free io and return */
if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) {
ext4_free_io_end(io_end);
- iocb->private = NULL;
out:
if (is_async)
aio_complete(iocb, ret, 0);
spin_unlock_irqrestore(&ei->i_completed_io_lock, flags);
/* queue the work to convert unwritten extents to written */
- iocb->private = NULL;
queue_work(wq, &io_end->work);
/* XXX: probably should move into the real I/O completion handler */
*
* Returns zero on sucess or negative on failure.
*/
-int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
+static int ext4_discard_partial_page_buffers_no_lock(handle_t *handle,
struct inode *inode, struct page *page, loff_t from,
loff_t length, int flags)
{
iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
- if (!page_has_buffers(page)) {
- /*
- * If the range to be discarded covers a partial block
- * we need to get the page buffers. This is because
- * partial blocks cannot be released and the page needs
- * to be updated with the contents of the block before
- * we write the zeros on top of it.
- */
- if ((from & (blocksize - 1)) ||
- ((from + length) & (blocksize - 1))) {
- create_empty_buffers(page, blocksize, 0);
- } else {
- /*
- * If there are no partial blocks,
- * there is nothing to update,
- * so we can return now
- */
- return 0;
- }
- }
+ if (!page_has_buffers(page))
+ create_empty_buffers(page, blocksize, 0);
/* Find the buffer that contains "offset" */
bh = page_buffers(page);
return err;
}
-/*
- * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
- * up to the end of the block which corresponds to `from'.
- * This required during truncate. We need to physically zero the tail end
- * of that block so it doesn't yield old data if the file is later grown.
- */
-int ext4_block_truncate_page(handle_t *handle,
- struct address_space *mapping, loff_t from)
-{
- unsigned offset = from & (PAGE_CACHE_SIZE-1);
- unsigned length;
- unsigned blocksize;
- struct inode *inode = mapping->host;
-
- blocksize = inode->i_sb->s_blocksize;
- length = blocksize - (offset & (blocksize - 1));
-
- return ext4_block_zero_page_range(handle, mapping, from, length);
-}
-
-/*
- * ext4_block_zero_page_range() zeros out a mapping of length 'length'
- * starting from file offset 'from'. The range to be zero'd must
- * be contained with in one block. If the specified range exceeds
- * the end of the block it will be shortened to end of the block
- * that cooresponds to 'from'
- */
-int ext4_block_zero_page_range(handle_t *handle,
- struct address_space *mapping, loff_t from, loff_t length)
-{
- ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT;
- unsigned offset = from & (PAGE_CACHE_SIZE-1);
- unsigned blocksize, max, pos;
- ext4_lblk_t iblock;
- struct inode *inode = mapping->host;
- struct buffer_head *bh;
- struct page *page;
- int err = 0;
-
- page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT,
- mapping_gfp_mask(mapping) & ~__GFP_FS);
- if (!page)
- return -ENOMEM;
-
- blocksize = inode->i_sb->s_blocksize;
- max = blocksize - (offset & (blocksize - 1));
-
- /*
- * correct length if it does not fall between
- * 'from' and the end of the block
- */
- if (length > max || length < 0)
- length = max;
-
- iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
-
- if (!page_has_buffers(page))
- create_empty_buffers(page, blocksize, 0);
-
- /* Find the buffer that contains "offset" */
- bh = page_buffers(page);
- pos = blocksize;
- while (offset >= pos) {
- bh = bh->b_this_page;
- iblock++;
- pos += blocksize;
- }
-
- err = 0;
- if (buffer_freed(bh)) {
- BUFFER_TRACE(bh, "freed: skip");
- goto unlock;
- }
-
- if (!buffer_mapped(bh)) {
- BUFFER_TRACE(bh, "unmapped");
- ext4_get_block(inode, iblock, bh, 0);
- /* unmapped? It's a hole - nothing to do */
- if (!buffer_mapped(bh)) {
- BUFFER_TRACE(bh, "still unmapped");
- goto unlock;
- }
- }
-
- /* Ok, it's mapped. Make sure it's up-to-date */
- if (PageUptodate(page))
- set_buffer_uptodate(bh);
-
- if (!buffer_uptodate(bh)) {
- err = -EIO;
- ll_rw_block(READ, 1, &bh);
- wait_on_buffer(bh);
- /* Uhhuh. Read error. Complain and punt. */
- if (!buffer_uptodate(bh))
- goto unlock;
- }
-
- if (ext4_should_journal_data(inode)) {
- BUFFER_TRACE(bh, "get write access");
- err = ext4_journal_get_write_access(handle, bh);
- if (err)
- goto unlock;
- }
-
- zero_user(page, offset, length);
-
- BUFFER_TRACE(bh, "zeroed end of block");
-
- err = 0;
- if (ext4_should_journal_data(inode)) {
- err = ext4_handle_dirty_metadata(handle, inode, bh);
- } else
- mark_buffer_dirty(bh);
-
-unlock:
- unlock_page(page);
- page_cache_release(page);
- return err;
-}
-
int ext4_can_truncate(struct inode *inode)
{
if (S_ISREG(inode->i_mode))
* transaction, and VFS/VM ensures that ext4_truncate() cannot run
* simultaneously on behalf of the same inode.
*
- * As we work through the truncate and commmit bits of it to the journal there
+ * As we work through the truncate and commit bits of it to the journal there
* is one core, guiding principle: the file's tree must always be consistent on
* disk. We must be able to restart the truncate after a crash.
*
return 0;
if (is_journal_aborted(journal))
return -EROFS;
+ /* We have to allocate physical blocks for delalloc blocks
+ * before flushing journal. otherwise delalloc blocks can not
+ * be allocated any more. even more truncate on delalloc blocks
+ * could trigger BUG by flushing delalloc blocks in journal.
+ * There is no delalloc block in non-journal data mode.
+ */
+ if (val && test_opt(inode->i_sb, DELALLOC)) {
+ err = ext4_alloc_da_blocks(inode);
+ if (err < 0)
+ return err;
+ }
jbd2_journal_lock_updates(journal);
- jbd2_journal_flush(journal);
/*
* OK, there are no updates running now, and all cached data is
if (val)
ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
- else
+ else {
+ jbd2_journal_flush(journal);
ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
+ }
ext4_set_aops(inode);
jbd2_journal_unlock_updates(journal);
projects / mirror_ubuntu-zesty-kernel.git / blobdiff