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Date: Fri, 13 May 2011 09:38:31 -0700
From: Allison Henderson <achender@...ux.vnet.ibm.com>
To: Yongqiang Yang <xiaoqiangnk@...il.com>
CC: Mingming Cao <cmm@...ibm.com>, linux-ext4@...r.kernel.org,
tytso@....edu
Subject: Re: [PATCH v2 3/3] ext4:Reimplement convert and split_unwritten.
On 5/12/2011 7:06 PM, Yongqiang Yang wrote:
> 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.
Hi all,
Well, I tried the above fix this morning, but it looks like it was only
able to run about a half hour. Some good news though, last night I
tried just changing "zero_ex.ee_len = cpu_to_le16(allocated -
map->m_len);" to "zero_ex.ee_len = cpu_to_le16(allocated);" in case 3
and it ran all night with no problems. Maybe we need both changes then.
I'll start another test run today.
Allison Henderson
>>
>>> }
>>
>>
>>> }
>>> - /* 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,
>>
>>
>>
>
>
>
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