diff options
Diffstat (limited to 'fs/ext4/extents.c')
| -rw-r--r-- | fs/ext4/extents.c | 423 |
1 files changed, 386 insertions, 37 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 7a3832577923..a38e651c004e 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -723,7 +723,7 @@ err: * insert new index [@logical;@ptr] into the block at @curp; * check where to insert: before @curp or after @curp */ -static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, +int ext4_ext_insert_index(handle_t *handle, struct inode *inode, struct ext4_ext_path *curp, int logical, ext4_fsblk_t ptr) { @@ -1586,7 +1586,7 @@ out: */ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, struct ext4_ext_path *path, - struct ext4_extent *newext) + struct ext4_extent *newext, int flag) { struct ext4_extent_header *eh; struct ext4_extent *ex, *fex; @@ -1602,7 +1602,8 @@ int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, BUG_ON(path[depth].p_hdr == NULL); /* try to insert block into found extent and return */ - if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { + if (ex && (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT) + && ext4_can_extents_be_merged(inode, ex, newext)) { ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n", ext4_ext_is_uninitialized(newext), ext4_ext_get_actual_len(newext), @@ -1722,7 +1723,8 @@ has_space: merge: /* try to merge extents to the right */ - ext4_ext_try_to_merge(inode, path, nearex); + if (flag != EXT4_GET_BLOCKS_DIO_CREATE_EXT) + ext4_ext_try_to_merge(inode, path, nearex); /* try to merge extents to the left */ @@ -2490,7 +2492,6 @@ static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex) } #define EXT4_EXT_ZERO_LEN 7 - /* * This function is called by ext4_ext_get_blocks() if someone tries to write * to an uninitialized extent. It may result in splitting the uninitialized @@ -2583,7 +2584,8 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, ex3->ee_block = cpu_to_le32(iblock); ext4_ext_store_pblock(ex3, newblock); ex3->ee_len = cpu_to_le16(allocated); - err = ext4_ext_insert_extent(handle, inode, path, ex3); + err = ext4_ext_insert_extent(handle, inode, path, + ex3, 0); if (err == -ENOSPC) { err = ext4_ext_zeroout(inode, &orig_ex); if (err) @@ -2639,7 +2641,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, ext4_ext_store_pblock(ex3, newblock + max_blocks); ex3->ee_len = cpu_to_le16(allocated - max_blocks); ext4_ext_mark_uninitialized(ex3); - err = ext4_ext_insert_extent(handle, inode, path, ex3); + err = ext4_ext_insert_extent(handle, inode, path, ex3, 0); if (err == -ENOSPC) { err = ext4_ext_zeroout(inode, &orig_ex); if (err) @@ -2757,7 +2759,7 @@ static int ext4_ext_convert_to_initialized(handle_t *handle, err = ext4_ext_dirty(handle, inode, path + depth); goto out; insert: - err = ext4_ext_insert_extent(handle, inode, path, &newex); + err = ext4_ext_insert_extent(handle, inode, path, &newex, 0); if (err == -ENOSPC) { err = ext4_ext_zeroout(inode, &orig_ex); if (err) @@ -2785,6 +2787,320 @@ fix_extent_len: } /* + * This function is called by ext4_ext_get_blocks() from + * ext4_get_blocks_dio_write() when DIO to write + * to an uninitialized extent. + * + * Writing to an uninitized extent may result in splitting the uninitialized + * extent into multiple /intialized unintialized extents (up to three) + * There are three possibilities: + * a> There is no split required: Entire extent should be uninitialized + * b> Splits in two extents: Write is happening at either end of the extent + * c> Splits in three extents: Somone is writing in middle of the extent + * + * One of more index blocks maybe needed if the extent tree grow after + * the unintialized extent split. To prevent ENOSPC occur at the IO + * complete, we need to split the uninitialized extent before DIO submit + * the IO. The uninitilized extent called at this time will be split + * into three uninitialized extent(at most). After IO complete, the part + * being filled will be convert to initialized by the end_io callback function + * via ext4_convert_unwritten_extents(). + */ +static int ext4_split_unwritten_extents(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path, + ext4_lblk_t iblock, + unsigned int max_blocks, + int flags) +{ + 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; + ext4_lblk_t ee_block; + unsigned int allocated, ee_len, depth; + ext4_fsblk_t newblock; + int err = 0; + int ret = 0; + + ext_debug("ext4_split_unwritten_extents: inode %lu," + "iblock %llu, max_blocks %u\n", inode->i_ino, + (unsigned long long)iblock, max_blocks); + 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 - (iblock - ee_block); + newblock = iblock - ee_block + 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, ext_pblock(ex)); + + /* + * if the entire unintialized extent length less than + * the size of extent to write, there is no need to split + * uninitialized extent + */ + if (allocated <= max_blocks) + return ret; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + /* ex1: ee_block to iblock - 1 : uninitialized */ + if (iblock > ee_block) { + ex1 = ex; + ex1->ee_len = cpu_to_le16(iblock - 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 > max_blocks) + ex2->ee_len = cpu_to_le16(max_blocks); + /* ex3: to ee_block + ee_len : uninitialised */ + if (allocated > max_blocks) { + unsigned int newdepth; + ex3 = &newex; + ex3->ee_block = cpu_to_le32(iblock + max_blocks); + ext4_ext_store_pblock(ex3, newblock + max_blocks); + ex3->ee_len = cpu_to_le16(allocated - max_blocks); + ext4_ext_mark_uninitialized(ex3); + err = ext4_ext_insert_extent(handle, inode, path, ex3, flags); + if (err == -ENOSPC) { + 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, ext_pblock(&orig_ex)); + ext4_ext_dirty(handle, inode, path + depth); + /* zeroed the full extent */ + /* blocks available from iblock */ + 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 + */ + orig_ex.ee_len = cpu_to_le16(ee_len - + ext4_ext_get_actual_len(ex3)); + depth = newdepth; + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, iblock, 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 = max_blocks; + } + /* + * 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(iblock - ee_block); + ext4_ext_mark_uninitialized(ex1); + ex2 = &newex; + } + /* + * ex2: iblock to iblock + maxblocks-1 : to be direct IO written, + * uninitialised still. + */ + ex2->ee_block = cpu_to_le32(iblock); + 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) { + 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, 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, ext_pblock(&orig_ex)); + ext4_ext_mark_uninitialized(ex); + ext4_ext_dirty(handle, inode, path + depth); + return err; +} +static int ext4_convert_unwritten_extents_dio(handle_t *handle, + struct inode *inode, + struct ext4_ext_path *path) +{ + struct ext4_extent *ex; + struct ext4_extent_header *eh; + int depth; + int err = 0; + int ret = 0; + + depth = ext_depth(inode); + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + /* first mark the extent as initialized */ + ext4_ext_mark_initialized(ex); + + /* + * We have to see if it can be merged with the extent + * on the left. + */ + if (ex > EXT_FIRST_EXTENT(eh)) { + /* + * To merge left, pass "ex - 1" to try_to_merge(), + * since it merges towards right _only_. + */ + ret = ext4_ext_try_to_merge(inode, path, ex - 1); + if (ret) { + err = ext4_ext_correct_indexes(handle, inode, path); + if (err) + goto out; + depth = ext_depth(inode); + ex--; + } + } + /* + * Try to Merge towards right. + */ + ret = ext4_ext_try_to_merge(inode, path, ex); + if (ret) { + err = ext4_ext_correct_indexes(handle, inode, path); + if (err) + goto out; + depth = ext_depth(inode); + } + /* Mark modified extent as dirty */ + err = ext4_ext_dirty(handle, inode, path + depth); +out: + ext4_ext_show_leaf(inode, path); + return err; +} + +static int +ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode, + ext4_lblk_t iblock, unsigned int max_blocks, + struct ext4_ext_path *path, int flags, + unsigned int allocated, struct buffer_head *bh_result, + ext4_fsblk_t newblock) +{ + int ret = 0; + int err = 0; + + ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical" + "block %llu, max_blocks %u, flags %d, allocated %u", + inode->i_ino, (unsigned long long)iblock, max_blocks, + flags, allocated); + ext4_ext_show_leaf(inode, path); + + /* DIO get_block() before submit the IO, split the extent */ + if (flags == EXT4_GET_BLOCKS_DIO_CREATE_EXT) { + ret = ext4_split_unwritten_extents(handle, + inode, path, iblock, + max_blocks, flags); + goto out; + } + /* DIO end_io complete, convert the filled extent to written */ + if (flags == EXT4_GET_BLOCKS_DIO_CONVERT_EXT) { + ret = ext4_convert_unwritten_extents_dio(handle, inode, + path); + goto out2; + } + /* buffered IO case */ + /* + * repeat fallocate creation request + * we already have an unwritten extent + */ + if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) + goto map_out; + + /* buffered READ or buffered write_begin() lookup */ + if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { + /* + * We have blocks reserved already. We + * return allocated blocks so that delalloc + * won't do block reservation for us. But + * the buffer head will be unmapped so that + * a read from the block returns 0s. + */ + set_buffer_unwritten(bh_result); + goto out1; + } + + /* buffered write, writepage time, convert*/ + ret = ext4_ext_convert_to_initialized(handle, inode, + path, iblock, + max_blocks); +out: + if (ret <= 0) { + err = ret; + goto out2; + } else + allocated = ret; + set_buffer_new(bh_result); +map_out: + set_buffer_mapped(bh_result); +out1: + if (allocated > max_blocks) + allocated = max_blocks; + ext4_ext_show_leaf(inode, path); + bh_result->b_bdev = inode->i_sb->s_bdev; + bh_result->b_blocknr = newblock; +out2: + if (path) { + ext4_ext_drop_refs(path); + kfree(path); + } + return err ? err : allocated; +} +/* * Block allocation/map/preallocation routine for extents based files * * @@ -2889,33 +3205,10 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, EXT4_EXT_CACHE_EXTENT); goto out; } - if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) - goto out; - if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) { - if (allocated > max_blocks) - allocated = max_blocks; - /* - * We have blocks reserved already. We - * return allocated blocks so that delalloc - * won't do block reservation for us. But - * the buffer head will be unmapped so that - * a read from the block returns 0s. - */ - set_buffer_unwritten(bh_result); - bh_result->b_bdev = inode->i_sb->s_bdev; - bh_result->b_blocknr = newblock; - goto out2; - } - - ret = ext4_ext_convert_to_initialized(handle, inode, - path, iblock, - max_blocks); - if (ret <= 0) { - err = ret; - goto out2; - } else - allocated = ret; - goto outnew; + ret = ext4_ext_handle_uninitialized_extents(handle, + inode, iblock, max_blocks, path, + flags, allocated, bh_result, newblock); + return ret; } } @@ -2988,7 +3281,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, newex.ee_len = cpu_to_le16(ar.len); if (flags & EXT4_GET_BLOCKS_UNINIT_EXT) /* Mark uninitialized */ ext4_ext_mark_uninitialized(&newex); - err = ext4_ext_insert_extent(handle, inode, path, &newex); + err = ext4_ext_insert_extent(handle, inode, path, &newex, flags); if (err) { /* free data blocks we just allocated */ /* not a good idea to call discard here directly, @@ -3002,7 +3295,6 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, /* previous routine could use block we allocated */ newblock = ext_pblock(&newex); allocated = ext4_ext_get_actual_len(&newex); -outnew: set_buffer_new(bh_result); /* Cache only when it is _not_ an uninitialized extent */ @@ -3201,6 +3493,63 @@ retry: } /* + * This function convert a range of blocks to written extents + * The caller of this function will pass the start offset and the size. + * all unwritten extents within this range will be converted to + * written extents. + * + * This function is called from the direct IO end io call back + * function, to convert the fallocated extents after IO is completed. + */ +int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset, + loff_t len) +{ + handle_t *handle; + ext4_lblk_t block; + unsigned int max_blocks; + int ret = 0; + int ret2 = 0; + struct buffer_head map_bh; + unsigned int credits, blkbits = inode->i_blkbits; + + block = offset >> blkbits; + /* + * We can't just convert len to max_blocks because + * If blocksize = 4096 offset = 3072 and len = 2048 + */ + max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) + - block; + /* + * credits to insert 1 extent into extent tree + */ + credits = ext4_chunk_trans_blocks(inode, max_blocks); + while (ret >= 0 && ret < max_blocks) { + block = block + ret; + max_blocks = max_blocks - ret; + handle = ext4_journal_start(inode, credits); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + break; + } + map_bh.b_state = 0; + ret = ext4_get_blocks(handle, inode, block, + max_blocks, &map_bh, + EXT4_GET_BLOCKS_DIO_CONVERT_EXT); + if (ret <= 0) { + WARN_ON(ret <= 0); + printk(KERN_ERR "%s: ext4_ext_get_blocks " + "returned error inode#%lu, block=%u, " + "max_blocks=%u", __func__, + inode->i_ino, block, max_blocks); + } + ext4_mark_inode_dirty(handle, inode); + ret2 = ext4_journal_stop(handle); + if (ret <= 0 || ret2 ) + break; + } + return ret > 0 ? ret2 : ret; +} +/* * Callback function called for each extent to gather FIEMAP information. */ static int ext4_ext_fiemap_cb(struct inode *inode, struct ext4_ext_path *path, |
