Linux-libre 4.2-gnu

1 files changed, 287 insertions, 53 deletions

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 87ba10d1d..2553aa8b6 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -39,6 +39,7 @@
 #include <linux/slab.h>
 #include <asm/uaccess.h>
 #include <linux/fiemap.h>
+#include <linux/backing-dev.h>
 #include "ext4_jbd2.h"
 #include "ext4_extents.h"
 #include "xattr.h"
@@ -4456,6 +4457,8 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 		ar.flags |= EXT4_MB_HINT_NOPREALLOC;
 	if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
 		ar.flags |= EXT4_MB_DELALLOC_RESERVED;
+	if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
+		ar.flags |= EXT4_MB_USE_RESERVED;
 	newblock = ext4_mb_new_blocks(handle, &ar, &err);
 	if (!newblock)
 		goto out2;
@@ -4663,6 +4666,7 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 	int ret = 0;
 	int ret2 = 0;
 	int retries = 0;
+	int depth = 0;
 	struct ext4_map_blocks map;
 	unsigned int credits;
 	loff_t epos;
@@ -4677,13 +4681,32 @@ static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
 	if (len <= EXT_UNWRITTEN_MAX_LEN)
 		flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
 
+	/* Wait all existing dio workers, newcomers will block on i_mutex */
+	ext4_inode_block_unlocked_dio(inode);
+	inode_dio_wait(inode);
+
 	/*
 	 * credits to insert 1 extent into extent tree
 	 */
 	credits = ext4_chunk_trans_blocks(inode, len);
+	/*
+	 * We can only call ext_depth() on extent based inodes
+	 */
+	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		depth = ext_depth(inode);
+	else
+		depth = -1;
 
 retry:
 	while (ret >= 0 && len) {
+		/*
+		 * Recalculate credits when extent tree depth changes.
+		 */
+		if (depth >= 0 && depth != ext_depth(inode)) {
+			credits = ext4_chunk_trans_blocks(inode, len);
+			depth = ext_depth(inode);
+		}
+
 		handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
 					    credits);
 		if (IS_ERR(handle)) {
@@ -4725,6 +4748,8 @@ retry:
 		goto retry;
 	}
 
+	ext4_inode_resume_unlocked_dio(inode);
+
 	return ret > 0 ? ret2 : ret;
 }
 
@@ -4912,12 +4937,14 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	 * bug we should fix....
 	 */
 	if (ext4_encrypted_inode(inode) &&
-	    (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE)))
+	    (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
+		     FALLOC_FL_ZERO_RANGE)))
 		return -EOPNOTSUPP;
 
 	/* Return error if mode is not supported */
 	if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
-		     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+		     FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
+		     FALLOC_FL_INSERT_RANGE))
 		return -EOPNOTSUPP;
 
 	if (mode & FALLOC_FL_PUNCH_HOLE)
@@ -4930,6 +4957,9 @@ long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	if (mode & FALLOC_FL_COLLAPSE_RANGE)
 		return ext4_collapse_range(inode, offset, len);
 
+	if (mode & FALLOC_FL_INSERT_RANGE)
+		return ext4_insert_range(inode, offset, len);
+
 	if (mode & FALLOC_FL_ZERO_RANGE)
 		return ext4_zero_range(file, offset, len, mode);
 
@@ -5224,13 +5254,13 @@ ext4_access_path(handle_t *handle, struct inode *inode,
 /*
  * ext4_ext_shift_path_extents:
  * Shift the extents of a path structure lying between path[depth].p_ext
- * and EXT_LAST_EXTENT(path[depth].p_hdr) downwards, by subtracting shift
- * from starting block for each extent.
+ * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
+ * if it is right shift or left shift operation.
  */
 static int
 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
 			    struct inode *inode, handle_t *handle,
-			    ext4_lblk_t *start)
+			    enum SHIFT_DIRECTION SHIFT)
 {
 	int depth, err = 0;
 	struct ext4_extent *ex_start, *ex_last;
@@ -5252,19 +5282,25 @@ ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
 			if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
 				update = 1;
 
-			*start = le32_to_cpu(ex_last->ee_block) +
-				ext4_ext_get_actual_len(ex_last);
-
 			while (ex_start <= ex_last) {
-				le32_add_cpu(&ex_start->ee_block, -shift);
-				/* Try to merge to the left. */
-				if ((ex_start >
-				     EXT_FIRST_EXTENT(path[depth].p_hdr)) &&
-				    ext4_ext_try_to_merge_right(inode,
-							path, ex_start - 1))
+				if (SHIFT == SHIFT_LEFT) {
+					le32_add_cpu(&ex_start->ee_block,
+						-shift);
+					/* Try to merge to the left. */
+					if ((ex_start >
+					    EXT_FIRST_EXTENT(path[depth].p_hdr))
+					    &&
+					    ext4_ext_try_to_merge_right(inode,
+					    path, ex_start - 1))
+						ex_last--;
+					else
+						ex_start++;
+				} else {
+					le32_add_cpu(&ex_last->ee_block, shift);
+					ext4_ext_try_to_merge_right(inode, path,
+						ex_last);
 					ex_last--;
-				else
-					ex_start++;
+				}
 			}
 			err = ext4_ext_dirty(handle, inode, path + depth);
 			if (err)
@@ -5279,7 +5315,10 @@ ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
 		if (err)
 			goto out;
 
-		le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
+		if (SHIFT == SHIFT_LEFT)
+			le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
+		else
+			le32_add_cpu(&path[depth].p_idx->ei_block, shift);
 		err = ext4_ext_dirty(handle, inode, path + depth);
 		if (err)
 			goto out;
@@ -5297,19 +5336,20 @@ out:
 
 /*
  * ext4_ext_shift_extents:
- * All the extents which lies in the range from start to the last allocated
- * block for the file are shifted downwards by shift blocks.
+ * All the extents which lies in the range from @start to the last allocated
+ * block for the @inode are shifted either towards left or right (depending
+ * upon @SHIFT) by @shift blocks.
  * On success, 0 is returned, error otherwise.
  */
 static int
 ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
-		       ext4_lblk_t start, ext4_lblk_t shift)
+		       ext4_lblk_t start, ext4_lblk_t shift,
+		       enum SHIFT_DIRECTION SHIFT)
 {
 	struct ext4_ext_path *path;
 	int ret = 0, depth;
 	struct ext4_extent *extent;
-	ext4_lblk_t stop_block;
-	ext4_lblk_t ex_start, ex_end;
+	ext4_lblk_t stop, *iterator, ex_start, ex_end;
 
 	/* Let path point to the last extent */
 	path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
@@ -5321,58 +5361,84 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
 	if (!extent)
 		goto out;
 
-	stop_block = le32_to_cpu(extent->ee_block) +
+	stop = le32_to_cpu(extent->ee_block) +
 			ext4_ext_get_actual_len(extent);
 
-	/* Nothing to shift, if hole is at the end of file */
-	if (start >= stop_block)
-		goto out;
+       /*
+	 * In case of left shift, Don't start shifting extents until we make
+	 * sure the hole is big enough to accommodate the shift.
+	*/
+	if (SHIFT == SHIFT_LEFT) {
+		path = ext4_find_extent(inode, start - 1, &path, 0);
+		if (IS_ERR(path))
+			return PTR_ERR(path);
+		depth = path->p_depth;
+		extent =  path[depth].p_ext;
+		if (extent) {
+			ex_start = le32_to_cpu(extent->ee_block);
+			ex_end = le32_to_cpu(extent->ee_block) +
+				ext4_ext_get_actual_len(extent);
+		} else {
+			ex_start = 0;
+			ex_end = 0;
+		}
 
-	/*
-	 * Don't start shifting extents until we make sure the hole is big
-	 * enough to accomodate the shift.
-	 */
-	path = ext4_find_extent(inode, start - 1, &path, 0);
-	if (IS_ERR(path))
-		return PTR_ERR(path);
-	depth = path->p_depth;
-	extent =  path[depth].p_ext;
-	if (extent) {
-		ex_start = le32_to_cpu(extent->ee_block);
-		ex_end = le32_to_cpu(extent->ee_block) +
-			ext4_ext_get_actual_len(extent);
-	} else {
-		ex_start = 0;
-		ex_end = 0;
+		if ((start == ex_start && shift > ex_start) ||
+		    (shift > start - ex_end)) {
+			ext4_ext_drop_refs(path);
+			kfree(path);
+			return -EINVAL;
+		}
 	}
 
-	if ((start == ex_start && shift > ex_start) ||
-	    (shift > start - ex_end))
-		return -EINVAL;
+	/*
+	 * In case of left shift, iterator points to start and it is increased
+	 * till we reach stop. In case of right shift, iterator points to stop
+	 * and it is decreased till we reach start.
+	 */
+	if (SHIFT == SHIFT_LEFT)
+		iterator = &start;
+	else
+		iterator = &stop;
 
 	/* Its safe to start updating extents */
-	while (start < stop_block) {
-		path = ext4_find_extent(inode, start, &path, 0);
+	while (start < stop) {
+		path = ext4_find_extent(inode, *iterator, &path, 0);
 		if (IS_ERR(path))
 			return PTR_ERR(path);
 		depth = path->p_depth;
 		extent = path[depth].p_ext;
 		if (!extent) {
 			EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
-					 (unsigned long) start);
+					 (unsigned long) *iterator);
 			return -EIO;
 		}
-		if (start > le32_to_cpu(extent->ee_block)) {
+		if (SHIFT == SHIFT_LEFT && *iterator >
+		    le32_to_cpu(extent->ee_block)) {
 			/* Hole, move to the next extent */
 			if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
 				path[depth].p_ext++;
 			} else {
-				start = ext4_ext_next_allocated_block(path);
+				*iterator = ext4_ext_next_allocated_block(path);
 				continue;
 			}
 		}
+
+		if (SHIFT == SHIFT_LEFT) {
+			extent = EXT_LAST_EXTENT(path[depth].p_hdr);
+			*iterator = le32_to_cpu(extent->ee_block) +
+					ext4_ext_get_actual_len(extent);
+		} else {
+			extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
+			*iterator =  le32_to_cpu(extent->ee_block) > 0 ?
+				le32_to_cpu(extent->ee_block) - 1 : 0;
+			/* Update path extent in case we need to stop */
+			while (le32_to_cpu(extent->ee_block) < start)
+				extent++;
+			path[depth].p_ext = extent;
+		}
 		ret = ext4_ext_shift_path_extents(path, shift, inode,
-				handle, &start);
+				handle, SHIFT);
 		if (ret)
 			break;
 	}
@@ -5485,7 +5551,7 @@ int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
 	ext4_discard_preallocations(inode);
 
 	ret = ext4_ext_shift_extents(inode, handle, punch_stop,
-				     punch_stop - punch_start);
+				     punch_stop - punch_start, SHIFT_LEFT);
 	if (ret) {
 		up_write(&EXT4_I(inode)->i_data_sem);
 		goto out_stop;
@@ -5510,6 +5576,174 @@ out_mutex:
 	return ret;
 }
 
+/*
+ * ext4_insert_range:
+ * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
+ * The data blocks starting from @offset to the EOF are shifted by @len
+ * towards right to create a hole in the @inode. Inode size is increased
+ * by len bytes.
+ * Returns 0 on success, error otherwise.
+ */
+int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
+{
+	struct super_block *sb = inode->i_sb;
+	handle_t *handle;
+	struct ext4_ext_path *path;
+	struct ext4_extent *extent;
+	ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
+	unsigned int credits, ee_len;
+	int ret = 0, depth, split_flag = 0;
+	loff_t ioffset;
+
+	/*
+	 * We need to test this early because xfstests assumes that an
+	 * insert range of (0, 1) will return EOPNOTSUPP if the file
+	 * system does not support insert range.
+	 */
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
+		return -EOPNOTSUPP;
+
+	/* Insert range works only on fs block size aligned offsets. */
+	if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
+			len & (EXT4_CLUSTER_SIZE(sb) - 1))
+		return -EINVAL;
+
+	if (!S_ISREG(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	trace_ext4_insert_range(inode, offset, len);
+
+	offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
+	len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
+
+	/* Call ext4_force_commit to flush all data in case of data=journal */
+	if (ext4_should_journal_data(inode)) {
+		ret = ext4_force_commit(inode->i_sb);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * Need to round down to align start offset to page size boundary
+	 * for page size > block size.
+	 */
+	ioffset = round_down(offset, PAGE_SIZE);
+
+	/* Write out all dirty pages */
+	ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
+			LLONG_MAX);
+	if (ret)
+		return ret;
+
+	/* Take mutex lock */
+	mutex_lock(&inode->i_mutex);
+
+	/* Currently just for extent based files */
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+		ret = -EOPNOTSUPP;
+		goto out_mutex;
+	}
+
+	/* Check for wrap through zero */
+	if (inode->i_size + len > inode->i_sb->s_maxbytes) {
+		ret = -EFBIG;
+		goto out_mutex;
+	}
+
+	/* Offset should be less than i_size */
+	if (offset >= i_size_read(inode)) {
+		ret = -EINVAL;
+		goto out_mutex;
+	}
+
+	truncate_pagecache(inode, ioffset);
+
+	/* Wait for existing dio to complete */
+	ext4_inode_block_unlocked_dio(inode);
+	inode_dio_wait(inode);
+
+	credits = ext4_writepage_trans_blocks(inode);
+	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
+	if (IS_ERR(handle)) {
+		ret = PTR_ERR(handle);
+		goto out_dio;
+	}
+
+	/* Expand file to avoid data loss if there is error while shifting */
+	inode->i_size += len;
+	EXT4_I(inode)->i_disksize += len;
+	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
+	ret = ext4_mark_inode_dirty(handle, inode);
+	if (ret)
+		goto out_stop;
+
+	down_write(&EXT4_I(inode)->i_data_sem);
+	ext4_discard_preallocations(inode);
+
+	path = ext4_find_extent(inode, offset_lblk, NULL, 0);
+	if (IS_ERR(path)) {
+		up_write(&EXT4_I(inode)->i_data_sem);
+		goto out_stop;
+	}
+
+	depth = ext_depth(inode);
+	extent = path[depth].p_ext;
+	if (extent) {
+		ee_start_lblk = le32_to_cpu(extent->ee_block);
+		ee_len = ext4_ext_get_actual_len(extent);
+
+		/*
+		 * If offset_lblk is not the starting block of extent, split
+		 * the extent @offset_lblk
+		 */
+		if ((offset_lblk > ee_start_lblk) &&
+				(offset_lblk < (ee_start_lblk + ee_len))) {
+			if (ext4_ext_is_unwritten(extent))
+				split_flag = EXT4_EXT_MARK_UNWRIT1 |
+					EXT4_EXT_MARK_UNWRIT2;
+			ret = ext4_split_extent_at(handle, inode, &path,
+					offset_lblk, split_flag,
+					EXT4_EX_NOCACHE |
+					EXT4_GET_BLOCKS_PRE_IO |
+					EXT4_GET_BLOCKS_METADATA_NOFAIL);
+		}
+
+		ext4_ext_drop_refs(path);
+		kfree(path);
+		if (ret < 0) {
+			up_write(&EXT4_I(inode)->i_data_sem);
+			goto out_stop;
+		}
+	}
+
+	ret = ext4_es_remove_extent(inode, offset_lblk,
+			EXT_MAX_BLOCKS - offset_lblk);
+	if (ret) {
+		up_write(&EXT4_I(inode)->i_data_sem);
+		goto out_stop;
+	}
+
+	/*
+	 * if offset_lblk lies in a hole which is at start of file, use
+	 * ee_start_lblk to shift extents
+	 */
+	ret = ext4_ext_shift_extents(inode, handle,
+		ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
+		len_lblk, SHIFT_RIGHT);
+
+	up_write(&EXT4_I(inode)->i_data_sem);
+	if (IS_SYNC(inode))
+		ext4_handle_sync(handle);
+
+out_stop:
+	ext4_journal_stop(handle);
+out_dio:
+	ext4_inode_resume_unlocked_dio(inode);
+out_mutex:
+	mutex_unlock(&inode->i_mutex);
+	return ret;
+}
+
 /**
  * ext4_swap_extents - Swap extents between two inodes
  *
@@ -5542,7 +5776,7 @@ ext4_swap_extents(handle_t *handle, struct inode *inode1,
 	BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
 	BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
 	BUG_ON(!mutex_is_locked(&inode1->i_mutex));
-	BUG_ON(!mutex_is_locked(&inode1->i_mutex));
+	BUG_ON(!mutex_is_locked(&inode2->i_mutex));
 
 	*erp = ext4_es_remove_extent(inode1, lblk1, count);
 	if (unlikely(*erp))