NTFS: Fix fs/ntfs/aops.c::ntfs_{read,write}_block() to handle the case (8273d5d4) · Commits · git / linux-net

fs/ntfs/ChangeLog

+2 −0

Original line number	Diff line number	Diff line
		@@ -84,6 +84,8 @@ ToDo/Notes:
		- Optimize fs/ntfs/aops.c::ntfs_write_block() by extending the page
		lock protection over the buffer submission for i/o which allows the
		removal of the get_bh()/put_bh() pairs for each buffer.
		- Fix fs/ntfs/aops.c::ntfs_{read,write}_block() to handle the case
		where a concurrent truncate has truncated the runlist under our feet.

		2.1.23 - Implement extension of resident files and make writing safe as well as
		many bug fixes, cleanups, and enhancements...

fs/ntfs/aops.c

+40 −11

Original line number	Diff line number	Diff line
		@@ -204,6 +204,7 @@ static int ntfs_read_block(struct page *page)
		nr = i = 0;
		do {
		u8 *kaddr;
		int err;

		if (unlikely(buffer_uptodate(bh)))
		continue;
		@@ -211,6 +212,7 @@ static int ntfs_read_block(struct page *page)
		arr[nr++] = bh;
		continue;
		}
		err = 0;
		bh->b_bdev = vol->sb->s_bdev;
		/* Is the block within the allowed limits? */
		if (iblock < lblock) {
		@@ -252,7 +254,6 @@ static int ntfs_read_block(struct page *page)
		goto handle_hole;
		/* If first try and runlist unmapped, map and retry. */
		if (!is_retry && lcn == LCN_RL_NOT_MAPPED) {
		int err;
		is_retry = TRUE;
		/*
		* Attempt to map runlist, dropping lock for
		@@ -263,20 +264,30 @@ static int ntfs_read_block(struct page *page)
		if (likely(!err))
		goto lock_retry_remap;
		rl = NULL;
		lcn = err;
		} else if (!rl)
		up_read(&ni->runlist.lock);
		/*
		* If buffer is outside the runlist, treat it as a
		* hole. This can happen due to concurrent truncate
		* for example.
		*/
		if (err == -ENOENT \|\| lcn == LCN_ENOENT) {
		err = 0;
		goto handle_hole;
		}
		/* Hard error, zero out region. */
		if (!err)
		err = -EIO;
		bh->b_blocknr = -1;
		SetPageError(page);
		ntfs_error(vol->sb, "Failed to read from inode 0x%lx, "
		"attribute type 0x%x, vcn 0x%llx, "
		"offset 0x%x because its location on "
		"disk could not be determined%s "
		"(error code %lli).", ni->mft_no,
		"(error code %i).", ni->mft_no,
		ni->type, (unsigned long long)vcn,
		vcn_ofs, is_retry ? " even after "
		"retrying" : "", (long long)lcn);
		"retrying" : "", err);
		}
		/*
		* Either iblock was outside lblock limits or
		@@ -289,8 +300,9 @@ static int ntfs_read_block(struct page *page)
		handle_zblock:
		kaddr = kmap_atomic(page, KM_USER0);
		memset(kaddr + i * blocksize, 0, blocksize);
		flush_dcache_page(page);
		kunmap_atomic(kaddr, KM_USER0);
		flush_dcache_page(page);
		if (likely(!err))
		set_buffer_uptodate(bh);
		} while (i++, iblock++, (bh = bh->b_this_page) != head);

		@@ -711,20 +723,37 @@ static int ntfs_write_block(struct page page, struct writeback_control wbc)
		if (likely(!err))
		goto lock_retry_remap;
		rl = NULL;
		lcn = err;
		} else if (!rl)
		up_read(&ni->runlist.lock);
		/*
		* If buffer is outside the runlist, truncate has cut it out
		* of the runlist. Just clean and clear the buffer and set it
		* uptodate so it can get discarded by the VM.
		*/
		if (err == -ENOENT \|\| lcn == LCN_ENOENT) {
		u8 *kaddr;

		bh->b_blocknr = -1;
		clear_buffer_dirty(bh);
		kaddr = kmap_atomic(page, KM_USER0);
		memset(kaddr + bh_offset(bh), 0, blocksize);
		kunmap_atomic(kaddr, KM_USER0);
		flush_dcache_page(page);
		set_buffer_uptodate(bh);
		err = 0;
		continue;
		}
		/* Failed to map the buffer, even after retrying. */
		if (!err)
		err = -EIO;
		bh->b_blocknr = -1;
		ntfs_error(vol->sb, "Failed to write to inode 0x%lx, "
		"attribute type 0x%x, vcn 0x%llx, offset 0x%x "
		"because its location on disk could not be "
		"determined%s (error code %lli).", ni->mft_no,
		"determined%s (error code %i).", ni->mft_no,
		ni->type, (unsigned long long)vcn,
		vcn_ofs, is_retry ? " even after "
		"retrying" : "", (long long)lcn);
		if (!err)
		err = -EIO;
		"retrying" : "", err);
		break;
		} while (block++, (bh = bh->b_this_page) != head);