1 files changed, 123 insertions, 48 deletions

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 1a86282b9024..a5763e3505ba 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -639,8 +639,8 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
 	while (target > 0) {
 		count = target;
 		/* allocating blocks for indirect blocks and direct blocks */
-		current_block = ext4_new_meta_blocks(handle, inode,
-							goal, &count, err);
+		current_block = ext4_new_meta_blocks(handle, inode, goal,
+						     0, &count, err);
 		if (*err)
 			goto failed_out;
 
@@ -1930,7 +1930,7 @@ repeat:
 	 * We do still charge estimated metadata to the sb though;
 	 * we cannot afford to run out of free blocks.
 	 */
-	if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
+	if (ext4_claim_free_blocks(sbi, md_needed + 1, 0)) {
 		dquot_release_reservation_block(inode, 1);
 		if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
 			yield();
@@ -2502,6 +2502,7 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
 		 * for partial write.
 		 */
 		set_buffer_new(bh);
+		set_buffer_mapped(bh);
 	}
 	return 0;
 }
@@ -2588,7 +2589,7 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate);
  * because we should have holes filled from ext4_page_mkwrite(). We even don't
  * need to file the inode to the transaction's list in ordered mode because if
  * we are writing back data added by write(), the inode is already there and if
- * we are writing back data modified via mmap(), noone guarantees in which
+ * we are writing back data modified via mmap(), no one guarantees in which
  * transaction the data will hit the disk. In case we are journaling data, we
  * cannot start transaction directly because transaction start ranks above page
  * lock so we have to do some magic.
@@ -2690,7 +2691,7 @@ static int ext4_writepage(struct page *page,
 
 /*
  * This is called via ext4_da_writepages() to
- * calulate the total number of credits to reserve to fit
+ * calculate the total number of credits to reserve to fit
  * a single extent allocation into a single transaction,
  * ext4_da_writpeages() will loop calling this before
  * the block allocation.
@@ -2795,9 +2796,7 @@ static int write_cache_pages_da(struct address_space *mapping,
 				continue;
 			}
 
-			if (PageWriteback(page))
-				wait_on_page_writeback(page);
-
+			wait_on_page_writeback(page);
 			BUG_ON(PageWriteback(page));
 
 			if (mpd->next_page != page->index)
@@ -3304,7 +3303,7 @@ int ext4_alloc_da_blocks(struct inode *inode)
 	 * the pages by calling redirty_page_for_writepage() but that
 	 * would be ugly in the extreme.  So instead we would need to
 	 * replicate parts of the code in the above functions,
-	 * simplifying them becuase we wouldn't actually intend to
+	 * simplifying them because we wouldn't actually intend to
 	 * write out the pages, but rather only collect contiguous
 	 * logical block extents, call the multi-block allocator, and
 	 * then update the buffer heads with the block allocations.
@@ -3512,7 +3511,7 @@ retry:
 			loff_t end = offset + iov_length(iov, nr_segs);
 
 			if (end > isize)
-				vmtruncate(inode, isize);
+				ext4_truncate_failed_write(inode);
 		}
 	}
 	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
@@ -3694,7 +3693,7 @@ retry:
  *
  * The unwrritten extents will be converted to written when DIO is completed.
  * For async direct IO, since the IO may still pending when return, we
- * set up an end_io call back function, which will do the convertion
+ * set up an end_io call back function, which will do the conversion
  * when async direct IO completed.
  *
  * If the O_DIRECT write will extend the file then add this inode to the
@@ -3717,7 +3716,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
  		 * We could direct write to holes and fallocate.
 		 *
  		 * Allocated blocks to fill the hole are marked as uninitialized
- 		 * to prevent paralel buffered read to expose the stale data
+ 		 * to prevent parallel buffered read to expose the stale data
  		 * before DIO complete the data IO.
 		 *
  		 * As to previously fallocated extents, ext4 get_block
@@ -3778,7 +3777,7 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb,
 			int err;
 			/*
 			 * for non AIO case, since the IO is already
-			 * completed, we could do the convertion right here
+			 * completed, we could do the conversion right here
 			 */
 			err = ext4_convert_unwritten_extents(inode,
 							     offset, ret);
@@ -3915,9 +3914,30 @@ void ext4_set_aops(struct inode *inode)
 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, length, pos;
+	unsigned blocksize, max, pos;
 	ext4_lblk_t iblock;
 	struct inode *inode = mapping->host;
 	struct buffer_head *bh;
@@ -3930,7 +3950,15 @@ int ext4_block_truncate_page(handle_t *handle,
 		return -EINVAL;
 
 	blocksize = inode->i_sb->s_blocksize;
-	length = blocksize - (offset & (blocksize - 1));
+	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))
@@ -4025,7 +4053,7 @@ static inline int all_zeroes(__le32 *p, __le32 *q)
  *
  *	When we do truncate() we may have to clean the ends of several
  *	indirect blocks but leave the blocks themselves alive. Block is
- *	partially truncated if some data below the new i_size is refered
+ *	partially truncated if some data below the new i_size is referred
  *	from it (and it is on the path to the first completely truncated
  *	data block, indeed).  We have to free the top of that path along
  *	with everything to the right of the path. Since no allocation
@@ -4169,7 +4197,7 @@ out_err:
  * @first:	array of block numbers
  * @last:	points immediately past the end of array
  *
- * We are freeing all blocks refered from that array (numbers are stored as
+ * We are freeing all blocks referred from that array (numbers are stored as
  * little-endian 32-bit) and updating @inode->i_blocks appropriately.
  *
  * We accumulate contiguous runs of blocks to free.  Conveniently, if these
@@ -4261,7 +4289,7 @@ static void ext4_free_data(handle_t *handle, struct inode *inode,
  *	@last:	pointer immediately past the end of array
  *	@depth:	depth of the branches to free
  *
- *	We are freeing all blocks refered from these branches (numbers are
+ *	We are freeing all blocks referred from these branches (numbers are
  *	stored as little-endian 32-bit) and updating @inode->i_blocks
  *	appropriately.
  */
@@ -4379,8 +4407,6 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 
 int ext4_can_truncate(struct inode *inode)
 {
-	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
-		return 0;
 	if (S_ISREG(inode->i_mode))
 		return 1;
 	if (S_ISDIR(inode->i_mode))
@@ -4391,6 +4417,31 @@ int ext4_can_truncate(struct inode *inode)
 }
 
 /*
+ * ext4_punch_hole: punches a hole in a file by releaseing the blocks
+ * associated with the given offset and length
+ *
+ * @inode:  File inode
+ * @offset: The offset where the hole will begin
+ * @len:    The length of the hole
+ *
+ * Returns: 0 on sucess or negative on failure
+ */
+
+int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	if (!S_ISREG(inode->i_mode))
+		return -ENOTSUPP;
+
+	if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
+		/* TODO: Add support for non extent hole punching */
+		return -ENOTSUPP;
+	}
+
+	return ext4_ext_punch_hole(file, offset, length);
+}
+
+/*
  * ext4_truncate()
  *
  * We block out ext4_get_block() block instantiations across the entire
@@ -4429,8 +4480,8 @@ void ext4_truncate(struct inode *inode)
 	Indirect chain[4];
 	Indirect *partial;
 	__le32 nr = 0;
-	int n;
-	ext4_lblk_t last_block;
+	int n = 0;
+	ext4_lblk_t last_block, max_block;
 	unsigned blocksize = inode->i_sb->s_blocksize;
 
 	trace_ext4_truncate_enter(inode);
@@ -4455,14 +4506,18 @@ void ext4_truncate(struct inode *inode)
 
 	last_block = (inode->i_size + blocksize-1)
 					>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+	max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+					>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
 
 	if (inode->i_size & (blocksize - 1))
 		if (ext4_block_truncate_page(handle, mapping, inode->i_size))
 			goto out_stop;
 
-	n = ext4_block_to_path(inode, last_block, offsets, NULL);
-	if (n == 0)
-		goto out_stop;	/* error */
+	if (last_block != max_block) {
+		n = ext4_block_to_path(inode, last_block, offsets, NULL);
+		if (n == 0)
+			goto out_stop;	/* error */
+	}
 
 	/*
 	 * OK.  This truncate is going to happen.  We add the inode to the
@@ -4493,7 +4548,13 @@ void ext4_truncate(struct inode *inode)
 	 */
 	ei->i_disksize = inode->i_size;
 
-	if (n == 1) {		/* direct blocks */
+	if (last_block == max_block) {
+		/*
+		 * It is unnecessary to free any data blocks if last_block is
+		 * equal to the indirect block limit.
+		 */
+		goto out_unlock;
+	} else if (n == 1) {		/* direct blocks */
 		ext4_free_data(handle, inode, NULL, i_data+offsets[0],
 			       i_data + EXT4_NDIR_BLOCKS);
 		goto do_indirects;
@@ -4553,6 +4614,7 @@ do_indirects:
 		;
 	}
 
+out_unlock:
 	up_write(&ei->i_data_sem);
 	inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
 	ext4_mark_inode_dirty(handle, inode);
@@ -4605,7 +4667,7 @@ static int __ext4_get_inode_loc(struct inode *inode,
 	/*
 	 * Figure out the offset within the block group inode table
 	 */
-	inodes_per_block = (EXT4_BLOCK_SIZE(sb) / EXT4_INODE_SIZE(sb));
+	inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
 	inode_offset = ((inode->i_ino - 1) %
 			EXT4_INODES_PER_GROUP(sb));
 	block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
@@ -5299,8 +5361,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 
 	if (S_ISREG(inode->i_mode) &&
 	    attr->ia_valid & ATTR_SIZE &&
-	    (attr->ia_size < inode->i_size ||
-	     (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))) {
+	    (attr->ia_size < inode->i_size)) {
 		handle_t *handle;
 
 		handle = ext4_journal_start(inode, 3);
@@ -5334,14 +5395,15 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 				goto err_out;
 			}
 		}
-		/* ext4_truncate will clear the flag */
-		if ((ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS)))
-			ext4_truncate(inode);
 	}
 
-	if ((attr->ia_valid & ATTR_SIZE) &&
-	    attr->ia_size != i_size_read(inode))
-		rc = vmtruncate(inode, attr->ia_size);
+	if (attr->ia_valid & ATTR_SIZE) {
+		if (attr->ia_size != i_size_read(inode)) {
+			truncate_setsize(inode, attr->ia_size);
+			ext4_truncate(inode);
+		} else if (ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
+			ext4_truncate(inode);
+	}
 
 	if (!rc) {
 		setattr_copy(inode, attr);
@@ -5398,13 +5460,12 @@ static int ext4_indirect_trans_blocks(struct inode *inode, int nrblocks,
 	/* if nrblocks are contiguous */
 	if (chunk) {
 		/*
-		 * With N contiguous data blocks, it need at most
-		 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
-		 * 2 dindirect blocks
-		 * 1 tindirect block
+		 * With N contiguous data blocks, we need at most
+		 * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+		 * 2 dindirect blocks, and 1 tindirect block
 		 */
-		indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
-		return indirects + 3;
+		return DIV_ROUND_UP(nrblocks,
+				    EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
 	}
 	/*
 	 * if nrblocks are not contiguous, worse case, each block touch
@@ -5478,7 +5539,7 @@ static int ext4_meta_trans_blocks(struct inode *inode, int nrblocks, int chunk)
 }
 
 /*
- * Calulate the total number of credits to reserve to fit
+ * Calculate the total number of credits to reserve to fit
  * the modification of a single pages into a single transaction,
  * which may include multiple chunks of block allocations.
  *
@@ -5672,7 +5733,7 @@ int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
  * so would cause a commit on atime updates, which we don't bother doing.
  * We handle synchronous inodes at the highest possible level.
  */
-void ext4_dirty_inode(struct inode *inode)
+void ext4_dirty_inode(struct inode *inode, int flags)
 {
 	handle_t *handle;
 
@@ -5800,15 +5861,19 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 		goto out_unlock;
 	}
 	ret = 0;
-	if (PageMappedToDisk(page))
-		goto out_unlock;
+
+	lock_page(page);
+	wait_on_page_writeback(page);
+	if (PageMappedToDisk(page)) {
+		up_read(&inode->i_alloc_sem);
+		return VM_FAULT_LOCKED;
+	}
 
 	if (page->index == size >> PAGE_CACHE_SHIFT)
 		len = size & ~PAGE_CACHE_MASK;
 	else
 		len = PAGE_CACHE_SIZE;
 
-	lock_page(page);
 	/*
 	 * return if we have all the buffers mapped. This avoid
 	 * the need to call write_begin/write_end which does a
@@ -5818,8 +5883,8 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (page_has_buffers(page)) {
 		if (!walk_page_buffers(NULL, page_buffers(page), 0, len, NULL,
 					ext4_bh_unmapped)) {
-			unlock_page(page);
-			goto out_unlock;
+			up_read(&inode->i_alloc_sem);
+			return VM_FAULT_LOCKED;
 		}
 	}
 	unlock_page(page);
@@ -5839,6 +5904,16 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
 	if (ret < 0)
 		goto out_unlock;
 	ret = 0;
+
+	/*
+	 * write_begin/end might have created a dirty page and someone
+	 * could wander in and start the IO.  Make sure that hasn't
+	 * happened.
+	 */
+	lock_page(page);
+	wait_on_page_writeback(page);
+	up_read(&inode->i_alloc_sem);
+	return VM_FAULT_LOCKED;
 out_unlock:
 	if (ret)
 		ret = VM_FAULT_SIGBUS;