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Date: Fri, 13 May 2011 10:06:09 +0800
From: Yongqiang Yang <xiaoqiangnk@...il.com>
To: Mingming Cao <cmm@...ibm.com>, achender@...ux.vnet.ibm.com
Cc: linux-ext4@...r.kernel.org, tytso@....edu
Subject: Re: [PATCH v2 3/3] ext4:Reimplement convert and split_unwritten.
On Fri, May 13, 2011 at 5:26 AM, Mingming Cao <cmm@...ibm.com> wrote:
> On Mon, 2011-05-02 at 19:05 -0700, Yongqiang Yang wrote:
>> v0->v1:
>> -- ext4_ext_convert_initialized() zeroout whole extent when the extent's
>> length is less than 14.
>>
>> convert and split unwritten are reimplemented based on ext4_split_extent()
>> added in last patch.
>>
>> Signed-off-by: Yongqiang Yang <xiaoqiangnk@...il.com>
>> Tested-by: Allison Henderson <achender@...ux.vnet.ibm.com>
>> ---
>> fs/ext4/extents.c | 480 ++++++++---------------------------------------------
>> 1 files changed, 72 insertions(+), 408 deletions(-)
>>
>> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
>> index db1d67c..9e7c7b3 100644
>> --- a/fs/ext4/extents.c
>> +++ b/fs/ext4/extents.c
>> @@ -2757,17 +2757,13 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
>> struct ext4_map_blocks *map,
>> struct ext4_ext_path *path)
>> {
>> - struct ext4_extent *ex, newex, orig_ex;
>> - struct ext4_extent *ex1 = NULL;
>> - struct ext4_extent *ex2 = NULL;
>> - struct ext4_extent *ex3 = NULL;
>> - struct ext4_extent_header *eh;
>> + struct ext4_map_blocks split_map;
>> + struct ext4_extent zero_ex;
>> + struct ext4_extent *ex;
>> ext4_lblk_t ee_block, eof_block;
>> unsigned int allocated, ee_len, depth;
>> - ext4_fsblk_t newblock;
>> int err = 0;
>> - int ret = 0;
>> - int may_zeroout;
>> + int split_flag = 0;
>>
>> ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
>> "block %llu, max_blocks %u\n", inode->i_ino,
>> @@ -2779,280 +2775,87 @@ static int ext4_ext_convert_to_initialized(handle_t *handle,
>> eof_block = map->m_lblk + map->m_len;
>>
>> depth = ext_depth(inode);
>> - eh = path[depth].p_hdr;
>> ex = path[depth].p_ext;
>> ee_block = le32_to_cpu(ex->ee_block);
>> ee_len = ext4_ext_get_actual_len(ex);
>> allocated = ee_len - (map->m_lblk - ee_block);
>> - newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex);
>> -
>> - ex2 = ex;
>> - orig_ex.ee_block = ex->ee_block;
>> - orig_ex.ee_len = cpu_to_le16(ee_len);
>> - ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex));
>>
>> + WARN_ON(map->m_lblk < ee_block);
>> /*
>> * It is safe to convert extent to initialized via explicit
>> * zeroout only if extent is fully insde i_size or new_size.
>> */
>> - may_zeroout = ee_block + ee_len <= eof_block;
>> + split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
>>
>> - err = ext4_ext_get_access(handle, inode, path + depth);
>> - if (err)
>> - goto out;
>> /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
>> - if (ee_len <= 2*EXT4_EXT_ZERO_LEN && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> + if (ee_len <= 2*EXT4_EXT_ZERO_LEN &&
>> + (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
>> + err = ext4_ext_zeroout(inode, ex);
>> if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zeroed the full extent */
>> - return allocated;
>> - }
>> -
>> - /* ex1: ee_block to map->m_lblk - 1 : uninitialized */
>> - if (map->m_lblk > ee_block) {
>> - ex1 = ex;
>> - ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
>> - ext4_ext_mark_uninitialized(ex1);
>> - ex2 = &newex;
>> - }
>> - /*
>> - * for sanity, update the length of the ex2 extent before
>> - * we insert ex3, if ex1 is NULL. This is to avoid temporary
>> - * overlap of blocks.
>> - */
>> - if (!ex1 && allocated > map->m_len)
>> - ex2->ee_len = cpu_to_le16(map->m_len);
>> - /* ex3: to ee_block + ee_len : uninitialised */
>> - if (allocated > map->m_len) {
>> - unsigned int newdepth;
>> - /* If extent has less than EXT4_EXT_ZERO_LEN zerout directly */
>> - if (allocated <= EXT4_EXT_ZERO_LEN && may_zeroout) {
>> - /*
>> - * map->m_lblk == ee_block is handled by the zerouout
>> - * at the beginning.
>> - * Mark first half uninitialized.
>> - * Mark second half initialized and zero out the
>> - * initialized extent
>> - */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = cpu_to_le16(ee_len - allocated);
>> - ext4_ext_mark_uninitialized(ex);
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> -
>> - ex3 = &newex;
>> - ex3->ee_block = cpu_to_le32(map->m_lblk);
>> - ext4_ext_store_pblock(ex3, newblock);
>> - ex3->ee_len = cpu_to_le16(allocated);
>> - err = ext4_ext_insert_extent(handle, inode, path,
>> - ex3, 0);
>> - if (err == -ENOSPC) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex,
>> - ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* blocks available from map->m_lblk */
>> - return allocated;
>> -
>> - } else if (err)
>> - goto fix_extent_len;
>> -
>> - /*
>> - * We need to zero out the second half because
>> - * an fallocate request can update file size and
>> - * converting the second half to initialized extent
>> - * implies that we can leak some junk data to user
>> - * space.
>> - */
>> - err = ext4_ext_zeroout(inode, ex3);
>> - if (err) {
>> - /*
>> - * We should actually mark the
>> - * second half as uninit and return error
>> - * Insert would have changed the extent
>> - */
>> - depth = ext_depth(inode);
>> - ext4_ext_drop_refs(path);
>> - path = ext4_ext_find_extent(inode, map->m_lblk,
>> - path);
>> - if (IS_ERR(path)) {
>> - err = PTR_ERR(path);
>> - return err;
>> - }
>> - /* get the second half extent details */
>> - ex = path[depth].p_ext;
>> - err = ext4_ext_get_access(handle, inode,
>> - path + depth);
>> - if (err)
>> - return err;
>> - ext4_ext_mark_uninitialized(ex);
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - return err;
>> - }
>> -
>> - /* zeroed the second half */
>> - return allocated;
>> - }
>> - ex3 = &newex;
>> - ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
>> - ext4_ext_store_pblock(ex3, newblock + map->m_len);
>> - ex3->ee_len = cpu_to_le16(allocated - map->m_len);
>> - ext4_ext_mark_uninitialized(ex3);
>> - err = ext4_ext_insert_extent(handle, inode, path, ex3, 0);
>> - if (err == -ENOSPC && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zeroed the full extent */
>> - /* blocks available from map->m_lblk */
>> - return allocated;
>> -
>> - } else if (err)
>> - goto fix_extent_len;
>> - /*
>> - * The depth, and hence eh & ex might change
>> - * as part of the insert above.
>> - */
>> - newdepth = ext_depth(inode);
>> - /*
>> - * update the extent length after successful insert of the
>> - * split extent
>> - */
>> - ee_len -= ext4_ext_get_actual_len(ex3);
>> - orig_ex.ee_len = cpu_to_le16(ee_len);
>> - may_zeroout = ee_block + ee_len <= eof_block;
>> -
>> - depth = newdepth;
>> - ext4_ext_drop_refs(path);
>> - path = ext4_ext_find_extent(inode, map->m_lblk, path);
>> - if (IS_ERR(path)) {
>> - err = PTR_ERR(path);
>> goto out;
>> - }
>> - eh = path[depth].p_hdr;
>> - ex = path[depth].p_ext;
>> - if (ex2 != &newex)
>> - ex2 = ex;
>>
>> err = ext4_ext_get_access(handle, inode, path + depth);
>> if (err)
>> goto out;
>> -
>> - allocated = map->m_len;
>> -
>> - /* If extent has less than EXT4_EXT_ZERO_LEN and we are trying
>> - * to insert a extent in the middle zerout directly
>> - * otherwise give the extent a chance to merge to left
>> - */
>> - if (le16_to_cpu(orig_ex.ee_len) <= EXT4_EXT_ZERO_LEN &&
>> - map->m_lblk != ee_block && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zero out the first half */
>> - /* blocks available from map->m_lblk */
>> - return allocated;
>> - }
>> - }
>> - /*
>> - * If there was a change of depth as part of the
>> - * insertion of ex3 above, we need to update the length
>> - * of the ex1 extent again here
>> - */
>> - if (ex1 && ex1 != ex) {
>> - ex1 = ex;
>> - ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
>> - ext4_ext_mark_uninitialized(ex1);
>> - ex2 = &newex;
>> - }
>> - /* ex2: map->m_lblk to map->m_lblk + maxblocks-1 : initialised */
>> - ex2->ee_block = cpu_to_le32(map->m_lblk);
>> - ext4_ext_store_pblock(ex2, newblock);
>> - ex2->ee_len = cpu_to_le16(allocated);
>> - if (ex2 != ex)
>> - goto insert;
>> - /*
>> - * New (initialized) extent starts from the first block
>> - * in the current extent. i.e., ex2 == ex
>> - * We have to see if it can be merged with the extent
>> - * on the left.
>> - */
>> - if (ex2 > EXT_FIRST_EXTENT(eh)) {
>> - /*
>> - * To merge left, pass "ex2 - 1" to try_to_merge(),
>> - * since it merges towards right _only_.
>> - */
>> - ret = ext4_ext_try_to_merge(inode, path, ex2 - 1);
>> - if (ret) {
>> - err = ext4_ext_correct_indexes(handle, inode, path);
>> - if (err)
>> - goto out;
>> - depth = ext_depth(inode);
>> - ex2--;
>> - }
>> + ext4_ext_mark_initialized(ex);
>> + ext4_ext_try_to_merge(inode, path, ex);
>> + err = ext4_ext_dirty(handle, inode, path + depth);
>> + goto out;
>> }
>> +
>> /*
>> - * Try to Merge towards right. This might be required
>> - * only when the whole extent is being written to.
>> - * i.e. ex2 == ex and ex3 == NULL.
>> + * four cases:
>> + * 1. split the extent into three extents.
>> + * 2. split the extent into two extents, zeroout the first half.
>> + * 3. split the extent into two extents, zeroout the second half.
>> + * 4. split the extent into two extents with out zeroout.
>> */
>> - if (!ex3) {
>> - ret = ext4_ext_try_to_merge(inode, path, ex2);
>> - if (ret) {
>> - err = ext4_ext_correct_indexes(handle, inode, path);
>> + split_map.m_lblk = map->m_lblk;
>> + split_map.m_len = map->m_len;
>> +
>> + if (allocated > map->m_len) {
>> + if (allocated <= EXT4_EXT_ZERO_LEN &&
>> + (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
>> + /* case 3 */
>> + zero_ex.ee_block =
>> + cpu_to_le32(map->m_lblk + map->m_len);
>> + zero_ex.ee_len = cpu_to_le16(allocated - map->m_len);
> Hmm, the original code zero out the entire [map->m_lblk, allocated],
> where here we only zero out a portion of it. it doesnt match the split
> len below also.
Yeah, I just zero out a portion of it which is not the requested. I
think the requested part will have non-zero data.
>
>
>> + ext4_ext_store_pblock(&zero_ex,
>> + ext4_ext_pblock(ex) + map->m_lblk - ee_block);
>> + err = ext4_ext_zeroout(inode, &zero_ex);
>> if (err)
>> goto out;
>> + split_map.m_lblk = map->m_lblk;
>> + split_map.m_len = allocated;
>> + } else if ((map->m_lblk - ee_block + map->m_len <
>> + EXT4_EXT_ZERO_LEN) &&
>> + (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
>> + /* case 2 */
>> + if (map->m_lblk != ee_block) {
>> + zero_ex.ee_block = ex->ee_block;
>> + zero_ex.ee_len = cpu_to_le16(map->m_lblk -
>> + ee_block);
> similar to above, the original code zero out the entire [ex->ee_block,
> map->m_lblk - ee_block + map->m_len], where here we only zero out a
> portion of it. same to the mismatch of the split len also.
Similar to above. Just a optimization.
>
>
>> + ext4_ext_store_pblock(&zero_ex,
>> + ext4_ext_pblock(ex));
>> + err = ext4_ext_zeroout(inode, &zero_ex);
>> + if (err)
>> + goto out;
>> + }
>> +
>> - allocated = map->m_lblk - ee_block + map->m_len;
>> +
>> + split_map.m_lblk = ee_block;
>> + split_map.m_len = map->m_lblk - ee_block + map->m_len;
+ allocated = map->m_len;
>
> I am also puzzled whether the zeroed-out extent get marked as
> initialized, as done in original patch. The whole point of zero out is
> to avoid frequent split of the unitizlized extent if the extent is
> short. I will take a closer look at the previous patch.
>
> Another issue, upon success, "allocated" will return from this function.
> But here allocated is the zero out length that start from ee_block, not
> the length from map->m_lblk. this is wrong, the caller
> ext4_ext_map_blocks expecting the length of mapped blocks from
> map->m_lblk. We now return more mapped blocks than what really done. I
> suspect the fsx error come from this bug.
Yeah. it is a bug.
Hi Allison,
Could you test with modification above? Here is a bug. I will also test it.
Thank you.
>
>> }
>
>
>> }
>> - /* Mark modified extent as dirty */
>> - err = ext4_ext_dirty(handle, inode, path + depth);
>> - goto out;
>> -insert:
>> - err = ext4_ext_insert_extent(handle, inode, path, &newex, 0);
>> - if (err == -ENOSPC && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zero out the first half */
>> - return allocated;
>> - } else if (err)
>> - goto fix_extent_len;
>> +
>> + allocated = ext4_split_extent(handle, inode, path,
>> + &split_map, split_flag, 0);
>> + if (allocated < 0)
>> + err = allocated;
>> +
>> out:
>> - ext4_ext_show_leaf(inode, path);
>> return err ? err : allocated;
>> -
>> -fix_extent_len:
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_mark_uninitialized(ex);
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - return err;
>> }
>>
>> /*
>> @@ -3083,15 +2886,11 @@ static int ext4_split_unwritten_extents(handle_t *handle,
>> struct ext4_ext_path *path,
>> int flags)
>> {
>> - struct ext4_extent *ex, newex, orig_ex;
>> - struct ext4_extent *ex1 = NULL;
>> - struct ext4_extent *ex2 = NULL;
>> - struct ext4_extent *ex3 = NULL;
>> - ext4_lblk_t ee_block, eof_block;
>> - unsigned int allocated, ee_len, depth;
>> - ext4_fsblk_t newblock;
>> - int err = 0;
>> - int may_zeroout;
>> + ext4_lblk_t eof_block;
>> + ext4_lblk_t ee_block;
>> + struct ext4_extent *ex;
>> + unsigned int ee_len;
>> + int split_flag = 0, depth;
>>
>> ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
>> "block %llu, max_blocks %u\n", inode->i_ino,
>> @@ -3101,155 +2900,20 @@ static int ext4_split_unwritten_extents(handle_t *handle,
>> inode->i_sb->s_blocksize_bits;
>> if (eof_block < map->m_lblk + map->m_len)
>> eof_block = map->m_lblk + map->m_len;
>> -
>> - depth = ext_depth(inode);
>> - ex = path[depth].p_ext;
>> - ee_block = le32_to_cpu(ex->ee_block);
>> - ee_len = ext4_ext_get_actual_len(ex);
>> - allocated = ee_len - (map->m_lblk - ee_block);
>> - newblock = map->m_lblk - ee_block + ext4_ext_pblock(ex);
>> -
>> - ex2 = ex;
>> - orig_ex.ee_block = ex->ee_block;
>> - orig_ex.ee_len = cpu_to_le16(ee_len);
>> - ext4_ext_store_pblock(&orig_ex, ext4_ext_pblock(ex));
>> -
>> /*
>> * It is safe to convert extent to initialized via explicit
>> * zeroout only if extent is fully insde i_size or new_size.
>> */
>> - may_zeroout = ee_block + ee_len <= eof_block;
>> -
>> - /*
>> - * If the uninitialized extent begins at the same logical
>> - * block where the write begins, and the write completely
>> - * covers the extent, then we don't need to split it.
>> - */
>> - if ((map->m_lblk == ee_block) && (allocated <= map->m_len))
>> - return allocated;
>> -
>> - err = ext4_ext_get_access(handle, inode, path + depth);
>> - if (err)
>> - goto out;
>> - /* ex1: ee_block to map->m_lblk - 1 : uninitialized */
>> - if (map->m_lblk > ee_block) {
>> - ex1 = ex;
>> - ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
>> - ext4_ext_mark_uninitialized(ex1);
>> - ex2 = &newex;
>> - }
>> - /*
>> - * for sanity, update the length of the ex2 extent before
>> - * we insert ex3, if ex1 is NULL. This is to avoid temporary
>> - * overlap of blocks.
>> - */
>> - if (!ex1 && allocated > map->m_len)
>> - ex2->ee_len = cpu_to_le16(map->m_len);
>> - /* ex3: to ee_block + ee_len : uninitialised */
>> - if (allocated > map->m_len) {
>> - unsigned int newdepth;
>> - ex3 = &newex;
>> - ex3->ee_block = cpu_to_le32(map->m_lblk + map->m_len);
>> - ext4_ext_store_pblock(ex3, newblock + map->m_len);
>> - ex3->ee_len = cpu_to_le16(allocated - map->m_len);
>> - ext4_ext_mark_uninitialized(ex3);
>> - err = ext4_ext_insert_extent(handle, inode, path, ex3, flags);
>> - if (err == -ENOSPC && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zeroed the full extent */
>> - /* blocks available from map->m_lblk */
>> - return allocated;
>> -
>> - } else if (err)
>> - goto fix_extent_len;
>> - /*
>> - * The depth, and hence eh & ex might change
>> - * as part of the insert above.
>> - */
>> - newdepth = ext_depth(inode);
>> - /*
>> - * update the extent length after successful insert of the
>> - * split extent
>> - */
>> - ee_len -= ext4_ext_get_actual_len(ex3);
>> - orig_ex.ee_len = cpu_to_le16(ee_len);
>> - may_zeroout = ee_block + ee_len <= eof_block;
>> -
>> - depth = newdepth;
>> - ext4_ext_drop_refs(path);
>> - path = ext4_ext_find_extent(inode, map->m_lblk, path);
>> - if (IS_ERR(path)) {
>> - err = PTR_ERR(path);
>> - goto out;
>> - }
>> - ex = path[depth].p_ext;
>> - if (ex2 != &newex)
>> - ex2 = ex;
>> + depth = ext_depth(inode);
>> + ex = path[depth].p_ext;
>> + ee_block = le32_to_cpu(ex->ee_block);
>> + ee_len = ext4_ext_get_actual_len(ex);
>>
>> - err = ext4_ext_get_access(handle, inode, path + depth);
>> - if (err)
>> - goto out;
>> + split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
>> + split_flag |= EXT4_EXT_MARK_UNINIT2;
>>
>> - allocated = map->m_len;
>> - }
>> - /*
>> - * If there was a change of depth as part of the
>> - * insertion of ex3 above, we need to update the length
>> - * of the ex1 extent again here
>> - */
>> - if (ex1 && ex1 != ex) {
>> - ex1 = ex;
>> - ex1->ee_len = cpu_to_le16(map->m_lblk - ee_block);
>> - ext4_ext_mark_uninitialized(ex1);
>> - ex2 = &newex;
>> - }
>> - /*
>> - * ex2: map->m_lblk to map->m_lblk + map->m_len-1 : to be written
>> - * using direct I/O, uninitialised still.
>> - */
>> - ex2->ee_block = cpu_to_le32(map->m_lblk);
>> - ext4_ext_store_pblock(ex2, newblock);
>> - ex2->ee_len = cpu_to_le16(allocated);
>> - ext4_ext_mark_uninitialized(ex2);
>> - if (ex2 != ex)
>> - goto insert;
>> - /* Mark modified extent as dirty */
>> - err = ext4_ext_dirty(handle, inode, path + depth);
>> - ext_debug("out here\n");
>> - goto out;
>> -insert:
>> - err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
>> - if (err == -ENOSPC && may_zeroout) {
>> - err = ext4_ext_zeroout(inode, &orig_ex);
>> - if (err)
>> - goto fix_extent_len;
>> - /* update the extent length and mark as initialized */
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - /* zero out the first half */
>> - return allocated;
>> - } else if (err)
>> - goto fix_extent_len;
>> -out:
>> - ext4_ext_show_leaf(inode, path);
>> - return err ? err : allocated;
>> -
>> -fix_extent_len:
>> - ex->ee_block = orig_ex.ee_block;
>> - ex->ee_len = orig_ex.ee_len;
>> - ext4_ext_store_pblock(ex, ext4_ext_pblock(&orig_ex));
>> - ext4_ext_mark_uninitialized(ex);
>> - ext4_ext_dirty(handle, inode, path + depth);
>> - return err;
>> + flags |= EXT4_GET_BLOCKS_PRE_IO;
>> + return ext4_split_extent(handle, inode, path, map, split_flag, flags);
>> }
>>
>> static int ext4_convert_unwritten_extents_endio(handle_t *handle,
>
>
>
--
Best Wishes
Yongqiang Yang
--
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