Merge branch 'chandan/prep-subpage-blocksize' into for-chris-4.6

# Conflicts:
#	fs/btrfs/file.c

1 files changed, 62 insertions, 37 deletions

diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 098bb8f690c9..5a58e292bdad 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -498,7 +498,7 @@ int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
 	loff_t isize = i_size_read(inode);
 
 	start_pos = pos & ~((u64)root->sectorsize - 1);
-	num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
+	num_bytes = round_up(write_bytes + pos - start_pos, root->sectorsize);
 
 	end_of_last_block = start_pos + num_bytes - 1;
 	err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
@@ -1379,16 +1379,19 @@ fail:
 static noinline int
 lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
 				size_t num_pages, loff_t pos,
+				size_t write_bytes,
 				u64 *lockstart, u64 *lockend,
 				struct extent_state **cached_state)
 {
+	struct btrfs_root *root = BTRFS_I(inode)->root;
 	u64 start_pos;
 	u64 last_pos;
 	int i;
 	int ret = 0;
 
-	start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
-	last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1;
+	start_pos = round_down(pos, root->sectorsize);
+	last_pos = start_pos
+		+ round_up(pos + write_bytes - start_pos, root->sectorsize) - 1;
 
 	if (start_pos < inode->i_size) {
 		struct btrfs_ordered_extent *ordered;
@@ -1503,6 +1506,7 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 
 	while (iov_iter_count(i) > 0) {
 		size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+		size_t sector_offset;
 		size_t write_bytes = min(iov_iter_count(i),
 					 nrptrs * (size_t)PAGE_CACHE_SIZE -
 					 offset);
@@ -1511,6 +1515,8 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 		size_t reserve_bytes;
 		size_t dirty_pages;
 		size_t copied;
+		size_t dirty_sectors;
+		size_t num_sectors;
 
 		WARN_ON(num_pages > nrptrs);
 
@@ -1523,7 +1529,9 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 			break;
 		}
 
-		reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
+		sector_offset = pos & (root->sectorsize - 1);
+		reserve_bytes = round_up(write_bytes + sector_offset,
+				root->sectorsize);
 
 		if (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
 					     BTRFS_INODE_PREALLOC)) {
@@ -1542,7 +1550,9 @@ static noinline ssize_t __btrfs_buffered_write(struct file *file,
 				 */
 				num_pages = DIV_ROUND_UP(write_bytes + offset,
 							 PAGE_CACHE_SIZE);
-				reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
+				reserve_bytes = round_up(write_bytes
+							+ sector_offset,
+							root->sectorsize);
 				goto reserve_metadata;
 			}
 		}
@@ -1576,8 +1586,8 @@ again:
 			break;
 
 		ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
-						      pos, &lockstart, &lockend,
-						      &cached_state);
+						pos, write_bytes, &lockstart,
+						&lockend, &cached_state);
 		if (ret < 0) {
 			if (ret == -EAGAIN)
 				goto again;
@@ -1612,9 +1622,16 @@ again:
 		 * we still have an outstanding extent for the chunk we actually
 		 * managed to copy.
 		 */
-		if (num_pages > dirty_pages) {
-			release_bytes = (num_pages - dirty_pages) <<
-				PAGE_CACHE_SHIFT;
+		num_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
+						reserve_bytes);
+		dirty_sectors = round_up(copied + sector_offset,
+					root->sectorsize);
+		dirty_sectors = BTRFS_BYTES_TO_BLKS(root->fs_info,
+						dirty_sectors);
+
+		if (num_sectors > dirty_sectors) {
+			release_bytes = (write_bytes - copied)
+				& ~((u64)root->sectorsize - 1);
 			if (copied > 0) {
 				spin_lock(&BTRFS_I(inode)->lock);
 				BTRFS_I(inode)->outstanding_extents++;
@@ -1633,7 +1650,8 @@ again:
 			}
 		}
 
-		release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
+		release_bytes = round_up(copied + sector_offset,
+					root->sectorsize);
 
 		if (copied > 0)
 			ret = btrfs_dirty_pages(root, inode, pages,
@@ -1654,8 +1672,7 @@ again:
 
 		if (only_release_metadata && copied > 0) {
 			lockstart = round_down(pos, root->sectorsize);
-			lockend = lockstart +
-				(dirty_pages << PAGE_CACHE_SHIFT) - 1;
+			lockend = round_up(pos + copied, root->sectorsize) - 1;
 
 			set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
 				       lockend, EXTENT_NORESERVE, NULL,
@@ -1761,6 +1778,8 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	ssize_t err;
 	loff_t pos;
 	size_t count;
+	loff_t oldsize;
+	int clean_page = 0;
 
 	inode_lock(inode);
 	err = generic_write_checks(iocb, from);
@@ -1799,14 +1818,17 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 	pos = iocb->ki_pos;
 	count = iov_iter_count(from);
 	start_pos = round_down(pos, root->sectorsize);
-	if (start_pos > i_size_read(inode)) {
+	oldsize = i_size_read(inode);
+	if (start_pos > oldsize) {
 		/* Expand hole size to cover write data, preventing empty gap */
 		end_pos = round_up(pos + count, root->sectorsize);
-		err = btrfs_cont_expand(inode, i_size_read(inode), end_pos);
+		err = btrfs_cont_expand(inode, oldsize, end_pos);
 		if (err) {
 			inode_unlock(inode);
 			goto out;
 		}
+		if (start_pos > round_up(oldsize, root->sectorsize))
+			clean_page = 1;
 	}
 
 	if (sync)
@@ -1818,6 +1840,9 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
 		num_written = __btrfs_buffered_write(file, from, pos);
 		if (num_written > 0)
 			iocb->ki_pos = pos + num_written;
+		if (clean_page)
+			pagecache_isize_extended(inode, oldsize,
+						i_size_read(inode));
 	}
 
 	inode_unlock(inode);
@@ -2293,10 +2318,10 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 	int ret = 0;
 	int err = 0;
 	unsigned int rsv_count;
-	bool same_page;
+	bool same_block;
 	bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
 	u64 ino_size;
-	bool truncated_page = false;
+	bool truncated_block = false;
 	bool updated_inode = false;
 
 	ret = btrfs_wait_ordered_range(inode, offset, len);
@@ -2304,7 +2329,7 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 		return ret;
 
 	inode_lock(inode);
-	ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
+	ino_size = round_up(inode->i_size, root->sectorsize);
 	ret = find_first_non_hole(inode, &offset, &len);
 	if (ret < 0)
 		goto out_only_mutex;
@@ -2317,31 +2342,30 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 	lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
 	lockend = round_down(offset + len,
 			     BTRFS_I(inode)->root->sectorsize) - 1;
-	same_page = ((offset >> PAGE_CACHE_SHIFT) ==
-		    ((offset + len - 1) >> PAGE_CACHE_SHIFT));
-
+	same_block = (BTRFS_BYTES_TO_BLKS(root->fs_info, offset))
+		== (BTRFS_BYTES_TO_BLKS(root->fs_info, offset + len - 1));
 	/*
-	 * We needn't truncate any page which is beyond the end of the file
+	 * We needn't truncate any block which is beyond the end of the file
 	 * because we are sure there is no data there.
 	 */
 	/*
-	 * Only do this if we are in the same page and we aren't doing the
-	 * entire page.
+	 * Only do this if we are in the same block and we aren't doing the
+	 * entire block.
 	 */
-	if (same_page && len < PAGE_CACHE_SIZE) {
+	if (same_block && len < root->sectorsize) {
 		if (offset < ino_size) {
-			truncated_page = true;
-			ret = btrfs_truncate_page(inode, offset, len, 0);
+			truncated_block = true;
+			ret = btrfs_truncate_block(inode, offset, len, 0);
 		} else {
 			ret = 0;
 		}
 		goto out_only_mutex;
 	}
 
-	/* zero back part of the first page */
+	/* zero back part of the first block */
 	if (offset < ino_size) {
-		truncated_page = true;
-		ret = btrfs_truncate_page(inode, offset, 0, 0);
+		truncated_block = true;
+		ret = btrfs_truncate_block(inode, offset, 0, 0);
 		if (ret) {
 			inode_unlock(inode);
 			return ret;
@@ -2376,9 +2400,10 @@ static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
 		if (!ret) {
 			/* zero the front end of the last page */
 			if (tail_start + tail_len < ino_size) {
-				truncated_page = true;
-				ret = btrfs_truncate_page(inode,
-						tail_start + tail_len, 0, 1);
+				truncated_block = true;
+				ret = btrfs_truncate_block(inode,
+							tail_start + tail_len,
+							0, 1);
 				if (ret)
 					goto out_only_mutex;
 			}
@@ -2558,7 +2583,7 @@ out:
 	unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
 			     &cached_state, GFP_NOFS);
 out_only_mutex:
-	if (!updated_inode && truncated_page && !ret && !err) {
+	if (!updated_inode && truncated_block && !ret && !err) {
 		/*
 		 * If we only end up zeroing part of a page, we still need to
 		 * update the inode item, so that all the time fields are
@@ -2678,10 +2703,10 @@ static long btrfs_fallocate(struct file *file, int mode,
 	} else if (offset + len > inode->i_size) {
 		/*
 		 * If we are fallocating from the end of the file onward we
-		 * need to zero out the end of the page if i_size lands in the
-		 * middle of a page.
+		 * need to zero out the end of the block if i_size lands in the
+		 * middle of a block.
 		 */
-		ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
+		ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
 		if (ret)
 			goto out;
 	}