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Commit 750c9c47 authored by Dmitry Monakhov's avatar Dmitry Monakhov Committed by Theodore Ts'o
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ext4: remove messy logic from ext4_ext_rm_leaf 

- Both callers(truncate and punch_hole) already aligned left end point
  so we no longer need split logic here.
- Remove dead duplicated code.
- Call ext4_ext_dirty only after we have updated eh_entries, otherwise
  we'll loose entries update. Regression caused by d583fb87
  266'th testcase in xfstests (http://patchwork.ozlabs.org/patch/120872

)

Signed-off-by: default avatarDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
parent 1939dd84

fs/ext4/extents.c

+12 −91
Original line number Diff line number Diff line
@@ -2311,13 +2311,12 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 
	int err = 0, correct_index = 0;

	int depth = ext_depth(inode), credits;

	struct ext4_extent_header *eh;

	ext4_lblk_t a, b, block;

	ext4_lblk_t a, b;

	unsigned num;

	ext4_lblk_t ex_ee_block;

	unsigned short ex_ee_len;

	unsigned uninitialized = 0;

	struct ext4_extent *ex;

	struct ext4_map_blocks map;



	/* the header must be checked already in ext4_ext_remove_space() */

	ext_debug("truncate since %u in leaf\n", start);
@@ -2360,86 +2359,18 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 
			ex_ee_block = le32_to_cpu(ex->ee_block);

			ex_ee_len = ext4_ext_get_actual_len(ex);

			continue;

		} else if (a != ex_ee_block &&

			b != ex_ee_block + ex_ee_len - 1) {

			/*

			 * If this is a truncate, then this condition should

			 * never happen because at least one of the end points

			 * needs to be on the edge of the extent.

			 */

			if (end == EXT_MAX_BLOCKS - 1) {

				ext_debug("  bad truncate %u:%u\n",

		} else if (b != ex_ee_block + ex_ee_len - 1) {

			EXT4_ERROR_INODE(inode,"  bad truncate %u:%u\n",

					 start, end);

				block = 0;

				num = 0;

			err = -EIO;

			goto out;

			}

			/*

			 * else this is a hole punch, so the extent needs to

			 * be split since neither edge of the hole is on the

			 * extent edge

			 */

			else{

				map.m_pblk = ext4_ext_pblock(ex);

				map.m_lblk = ex_ee_block;

				map.m_len = b - ex_ee_block;



				err = ext4_split_extent(handle,

					inode, path, &map, 0,

					EXT4_GET_BLOCKS_PUNCH_OUT_EXT |

					EXT4_GET_BLOCKS_PRE_IO);



				if (err < 0)

					goto out;



				ex_ee_len = ext4_ext_get_actual_len(ex);



				b = ex_ee_block+ex_ee_len - 1 < end ?

					ex_ee_block+ex_ee_len - 1 : end;



				/* Then remove tail of this extent */

				block = ex_ee_block;

				num = a - block;

			}

		} else if (a != ex_ee_block) {

			/* remove tail of the extent */

			block = ex_ee_block;

			num = a - block;

		} else if (b != ex_ee_block + ex_ee_len - 1) {

			/* remove head of the extent */

			block = b;

			num =  ex_ee_block + ex_ee_len - b;



			/*

			 * If this is a truncate, this condition

			 * should never happen

			 */

			if (end == EXT_MAX_BLOCKS - 1) {

				ext_debug("  bad truncate %u:%u\n",

					start, end);

				err = -EIO;

				goto out;

			}

			num = a - ex_ee_block;

		} else {

			/* remove whole extent: excellent! */

			block = ex_ee_block;

			num = 0;

			if (a != ex_ee_block) {

				ext_debug("  bad truncate %u:%u\n",

					start, end);

				err = -EIO;

				goto out;

		}



			if (b != ex_ee_block + ex_ee_len - 1) {

				ext_debug("  bad truncate %u:%u\n",

					start, end);

				err = -EIO;

				goto out;

			}

		}



		/*

		 * 3 for leaf, sb, and inode plus 2 (bmap and group

		 * descriptor) for each block group; assume two block
@@ -2466,19 +2397,10 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 
		if (err)

			goto out;



		if (num == 0) {

		if (num == 0)

			/* this extent is removed; mark slot entirely unused */

			ext4_ext_store_pblock(ex, 0);

		} else if (block != ex_ee_block) {

			/*

			 * If this was a head removal, then we need to update

			 * the physical block since it is now at a different

			 * location

			 */

			ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a));

		}



		ex->ee_block = cpu_to_le32(block);

		ex->ee_len = cpu_to_le16(num);

		/*

		 * Do not mark uninitialized if all the blocks in the
@@ -2486,11 +2408,6 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 
		 */

		if (uninitialized && num)

			ext4_ext_mark_uninitialized(ex);



		err = ext4_ext_dirty(handle, inode, path + depth);

		if (err)

			goto out;



		/*

		 * If the extent was completely released,

		 * we need to remove it from the leaf
@@ -2513,6 +2430,10 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, 
		} else

			*partial_cluster = 0;



		err = ext4_ext_dirty(handle, inode, path + depth);

		if (err)

			goto out;



		ext_debug("new extent: %u:%u:%llu\n", block, num,

				ext4_ext_pblock(ex));

		ex--;