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Message-ID: <1305253114.9708.89.camel@mingming-laptop>
Date: Thu, 12 May 2011 19:18:34 -0700
From: Mingming Cao <cmm@...ibm.com>
To: Yongqiang Yang <xiaoqiangnk@...il.com>
Cc: achender@...ux.vnet.ibm.com, linux-ext4@...r.kernel.org,
tytso@....edu
Subject: Re: [PATCH v2 3/3] ext4:Reimplement convert and split_unwritten.
On Fri, 2011-05-13 at 10:06 +0800, 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.
The requested part is going to be written with data, but since the
entire [map->m_lblk, allocated] is a relatively small range(<7 blocks),
the cost of zero out this small range is pretty much the same as zero
out a portion of it. The saving is, we dont have to the split and
convert the request part from uninitialized to initialized when the
overwritten data reach to disk.
Mingming
> >
> >
> >> + 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,
> >
> >
> >
>
>
>
--
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