From: Allison Henderson Subject: Re: [Ext4 punch hole 5/6 v5] Ext4 Punch Hole Support: Map blocks punch hole flag Date: Tue, 19 Apr 2011 10:48:36 -0700 Message-ID: <4DADCAF4.8000402@linux.vnet.ibm.com> References: <4DAD3D05.8000103@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: linux-ext4@vger.kernel.org To: Yongqiang Yang Return-path: Received: from e4.ny.us.ibm.com ([32.97.182.144]:43830 "EHLO e4.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752608Ab1DSSQi (ORCPT ); Tue, 19 Apr 2011 14:16:38 -0400 Received: from d01relay06.pok.ibm.com (d01relay06.pok.ibm.com [9.56.227.116]) by e4.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p3JHuPVl012796 for ; Tue, 19 Apr 2011 13:56:25 -0400 Received: from d01av03.pok.ibm.com (d01av03.pok.ibm.com [9.56.224.217]) by d01relay06.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p3JIGP3x2523140 for ; Tue, 19 Apr 2011 14:16:25 -0400 Received: from d01av03.pok.ibm.com (loopback [127.0.0.1]) by d01av03.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p3JIDDBN007469 for ; Tue, 19 Apr 2011 15:16:24 -0300 In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On 4/19/2011 1:35 AM, Yongqiang Yang wrote: > On Tue, Apr 19, 2011 at 3:43 PM, Allison Henderson > wrote: >> This patch adds a new flag to map blocks that specifies >> the given range of blocks should be punched out. Extents >> are first converted to uninitialized extents before they are >> punched out. Because punching a hole may require that the >> extent be split, it is possible that the splitting may need >> more blocks than are available. To deal with this, reserved >> blocks are temporarily borrowed to allow the split to proceed. >> The borrowed blocks are then returned after the hole punch has >> released more blocks. >> >> The routine then returns the number of blocks successfully >> punched out. >> >> Signed-off-by: Allison Henderson >> --- >> :100644 100644 e3a721a... d97bc87... M fs/ext4/extents.c >> fs/ext4/extents.c | 99 +++++++++++++++++++++++++++++++++++++++++++++++------ >> 1 files changed, 88 insertions(+), 11 deletions(-) >> >> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c >> index e3a721a..d97bc87 100644 >> --- a/fs/ext4/extents.c >> +++ b/fs/ext4/extents.c >> @@ -3456,15 +3456,19 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, >> ext4_fsblk_t newblock = 0; >> int err = 0, depth, ret; >> unsigned int allocated = 0; >> + unsigned int punched_out = 0; >> + unsigned int result = 0; >> struct ext4_allocation_request ar; >> ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio; >> + struct ext4_map_blocks punch_map; >> >> ext_debug("blocks %u/%u requested for inode %lu\n", >> map->m_lblk, map->m_len, inode->i_ino); >> trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags); >> >> /* check in cache */ >> - if (ext4_ext_in_cache(inode, map->m_lblk,&newex)) { >> + if (ext4_ext_in_cache(inode, map->m_lblk,&newex)&& >> + ((flags& EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0)) { >> if (!newex.ee_start_lo&& !newex.ee_start_hi) { >> if ((flags& EXT4_GET_BLOCKS_CREATE) == 0) { >> /* >> @@ -3529,16 +3533,85 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode, >> ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk, >> ee_block, ee_len, newblock); >> >> - /* Do not put uninitialized extent in the cache */ >> - if (!ext4_ext_is_uninitialized(ex)) { >> - ext4_ext_put_in_cache(inode, ee_block, >> - ee_len, ee_start); >> - goto out; >> + if ((flags& EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0) { >> + /* >> + * Do not put uninitialized extent >> + * in the cache >> + */ >> + if (!ext4_ext_is_uninitialized(ex)) { >> + ext4_ext_put_in_cache(inode, ee_block, >> + ee_len, ee_start); >> + goto out; >> + } >> + ret = ext4_ext_handle_uninitialized_extents( >> + handle, inode, map, path, flags, >> + allocated, newblock); >> + return ret; >> } >> - ret = ext4_ext_handle_uninitialized_extents(handle, >> - inode, map, path, flags, allocated, >> - newblock); >> - return ret; >> + >> + /* >> + * Punch out the map length, but only to the >> + * end of the extent >> + */ >> + punched_out = allocated< map->m_len ? >> + allocated : map->m_len; >> + >> + /* >> + * Sense extents need to be converted to >> + * uninitialized, they must fit in an >> + * uninitialized extent >> + */ >> + if (punched_out> EXT_UNINIT_MAX_LEN) >> + punched_out = EXT_UNINIT_MAX_LEN; >> + >> + punch_map.m_lblk = map->m_lblk; >> + punch_map.m_pblk = newblock; >> + punch_map.m_len = punched_out; >> + punch_map.m_flags = 0; >> + >> + /* Check to see if the extent needs to be split */ >> + if (punch_map.m_len != ee_len || >> + punch_map.m_lblk != ee_block) { >> + >> + ret = ext4_ext_split_extents(handle, inode, >> +&punch_map, path, >> + EXT4_GET_BLOCKS_PRE_IO | >> + EXT4_HAS_FREE_BLKS_USE_ROOTBLKS, >> + 0); >> + >> + if (ret< 0) { >> + err = ret; >> + goto out2; >> + } >> + /* >> + * find extent for the block at >> + * the start of the hole >> + */ >> + ext4_ext_drop_refs(path); >> + kfree(path); >> + >> + path = ext4_ext_find_extent(inode, >> + map->m_lblk, NULL); >> + if (IS_ERR(path)) { >> + err = PTR_ERR(path); >> + path = NULL; >> + goto out2; >> + } >> + >> + depth = ext_depth(inode); >> + ex = path[depth].p_ext; >> + ee_len = ext4_ext_get_actual_len(ex); >> + ee_block = le32_to_cpu(ex->ee_block); >> + ee_start = ext4_ext_pblock(ex); >> + >> + } >> + >> + ext4_ext_mark_uninitialized(ex); > Is this change journaled? Hi there, Yes, the ext4_ext_map_blocks routine requires a journal handle as a parameter, so the calling function is required to set up the journal. > >> + >> + err = ext4_ext_remove_space(inode, map->m_lblk, >> + map->m_lblk + punched_out); >> + >> + goto out2; >> } >> } >> >> @@ -3683,7 +3756,11 @@ out2: >> } >> trace_ext4_ext_map_blocks_exit(inode, map->m_lblk, >> newblock, map->m_len, err ? err : allocated); >> - return err ? err : allocated; >> + >> + result = (flags& EXT4_GET_BLOCKS_PUNCH_OUT_EXT) ? >> + punched_out : allocated; >> + >> + return err ? err : result; >> } >> >> void ext4_ext_truncate(struct inode *inode) >> -- >> 1.7.1 >> >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > > >