diff options
Diffstat (limited to 'fs/ext4/inode.c')
-rw-r--r-- | fs/ext4/inode.c | 516 |
1 files changed, 445 insertions, 71 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 0defe0b..240f6e2 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -42,7 +42,6 @@ #include "ext4_jbd2.h" #include "xattr.h" #include "acl.h" -#include "ext4_extents.h" #include "truncate.h" #include <trace/events/ext4.h> @@ -268,7 +267,7 @@ void ext4_da_update_reserve_space(struct inode *inode, struct ext4_inode_info *ei = EXT4_I(inode); spin_lock(&ei->i_block_reservation_lock); - trace_ext4_da_update_reserve_space(inode, used); + trace_ext4_da_update_reserve_space(inode, used, quota_claim); if (unlikely(used > ei->i_reserved_data_blocks)) { ext4_msg(inode->i_sb, KERN_NOTICE, "%s: ino %lu, used %d " "with only %d reserved data blocks\n", @@ -281,7 +280,7 @@ void ext4_da_update_reserve_space(struct inode *inode, /* Update per-inode reservations */ ei->i_reserved_data_blocks -= used; ei->i_reserved_meta_blocks -= ei->i_allocated_meta_blocks; - percpu_counter_sub(&sbi->s_dirtyblocks_counter, + percpu_counter_sub(&sbi->s_dirtyclusters_counter, used + ei->i_allocated_meta_blocks); ei->i_allocated_meta_blocks = 0; @@ -291,7 +290,7 @@ void ext4_da_update_reserve_space(struct inode *inode, * only when we have written all of the delayed * allocation blocks. */ - percpu_counter_sub(&sbi->s_dirtyblocks_counter, + percpu_counter_sub(&sbi->s_dirtyclusters_counter, ei->i_reserved_meta_blocks); ei->i_reserved_meta_blocks = 0; ei->i_da_metadata_calc_len = 0; @@ -300,14 +299,14 @@ void ext4_da_update_reserve_space(struct inode *inode, /* Update quota subsystem for data blocks */ if (quota_claim) - dquot_claim_block(inode, used); + dquot_claim_block(inode, EXT4_C2B(sbi, used)); else { /* * We did fallocate with an offset that is already delayed * allocated. So on delayed allocated writeback we should * not re-claim the quota for fallocated blocks. */ - dquot_release_reservation_block(inode, used); + dquot_release_reservation_block(inode, EXT4_C2B(sbi, used)); } /* @@ -399,6 +398,49 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx, } /* + * Sets the BH_Da_Mapped bit on the buffer heads corresponding to the given map. + */ +static void set_buffers_da_mapped(struct inode *inode, + struct ext4_map_blocks *map) +{ + struct address_space *mapping = inode->i_mapping; + struct pagevec pvec; + int i, nr_pages; + pgoff_t index, end; + + index = map->m_lblk >> (PAGE_CACHE_SHIFT - inode->i_blkbits); + end = (map->m_lblk + map->m_len - 1) >> + (PAGE_CACHE_SHIFT - inode->i_blkbits); + + pagevec_init(&pvec, 0); + while (index <= end) { + nr_pages = pagevec_lookup(&pvec, mapping, index, + min(end - index + 1, + (pgoff_t)PAGEVEC_SIZE)); + if (nr_pages == 0) + break; + for (i = 0; i < nr_pages; i++) { + struct page *page = pvec.pages[i]; + struct buffer_head *bh, *head; + + if (unlikely(page->mapping != mapping) || + !PageDirty(page)) + break; + + if (page_has_buffers(page)) { + bh = head = page_buffers(page); + do { + set_buffer_da_mapped(bh); + bh = bh->b_this_page; + } while (bh != head); + } + index++; + } + pagevec_release(&pvec); + } +} + +/* * The ext4_map_blocks() function tries to look up the requested blocks, * and returns if the blocks are already mapped. * @@ -416,7 +458,7 @@ static pgoff_t ext4_num_dirty_pages(struct inode *inode, pgoff_t idx, * the buffer head is mapped. * * It returns 0 if plain look up failed (blocks have not been allocated), in - * that casem, buffer head is unmapped + * that case, buffer head is unmapped * * It returns the error in case of allocation failure. */ @@ -435,9 +477,11 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, */ down_read((&EXT4_I(inode)->i_data_sem)); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { - retval = ext4_ext_map_blocks(handle, inode, map, 0); + retval = ext4_ext_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); } else { - retval = ext4_ind_map_blocks(handle, inode, map, 0); + retval = ext4_ind_map_blocks(handle, inode, map, flags & + EXT4_GET_BLOCKS_KEEP_SIZE); } up_read((&EXT4_I(inode)->i_data_sem)); @@ -455,7 +499,7 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, * Returns if the blocks have already allocated * * Note that if blocks have been preallocated - * ext4_ext_get_block() returns th create = 0 + * ext4_ext_get_block() returns the create = 0 * with buffer head unmapped. */ if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) @@ -517,9 +561,17 @@ int ext4_map_blocks(handle_t *handle, struct inode *inode, (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) ext4_da_update_reserve_space(inode, retval, 1); } - if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) + if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) { ext4_clear_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED); + /* If we have successfully mapped the delayed allocated blocks, + * set the BH_Da_Mapped bit on them. Its important to do this + * under the protection of i_data_sem. + */ + if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) + set_buffers_da_mapped(inode, map); + } + up_write((&EXT4_I(inode)->i_data_sem)); if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { int ret = check_block_validity(inode, map); @@ -909,7 +961,11 @@ static int ext4_ordered_write_end(struct file *file, ext4_orphan_add(handle, inode); if (ret2 < 0) ret = ret2; + } else { + unlock_page(page); + page_cache_release(page); } + ret2 = ext4_journal_stop(handle); if (!ret) ret = ret2; @@ -1037,14 +1093,14 @@ static int ext4_journalled_write_end(struct file *file, } /* - * Reserve a single block located at lblock + * Reserve a single cluster located at lblock */ static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock) { int retries = 0; struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); struct ext4_inode_info *ei = EXT4_I(inode); - unsigned long md_needed; + unsigned int md_needed; int ret; /* @@ -1054,7 +1110,8 @@ static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock) */ repeat: spin_lock(&ei->i_block_reservation_lock); - md_needed = ext4_calc_metadata_amount(inode, lblock); + md_needed = EXT4_NUM_B2C(sbi, + ext4_calc_metadata_amount(inode, lblock)); trace_ext4_da_reserve_space(inode, md_needed); spin_unlock(&ei->i_block_reservation_lock); @@ -1063,15 +1120,15 @@ repeat: * us from metadata over-estimation, though we may go over by * a small amount in the end. Here we just reserve for data. */ - ret = dquot_reserve_block(inode, 1); + ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1)); if (ret) return ret; /* * We do still charge estimated metadata to the sb though; * we cannot afford to run out of free blocks. */ - if (ext4_claim_free_blocks(sbi, md_needed + 1, 0)) { - dquot_release_reservation_block(inode, 1); + if (ext4_claim_free_clusters(sbi, md_needed + 1, 0)) { + dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1)); if (ext4_should_retry_alloc(inode->i_sb, &retries)) { yield(); goto repeat; @@ -1118,19 +1175,21 @@ static void ext4_da_release_space(struct inode *inode, int to_free) * We can release all of the reserved metadata blocks * only when we have written all of the delayed * allocation blocks. + * Note that in case of bigalloc, i_reserved_meta_blocks, + * i_reserved_data_blocks, etc. refer to number of clusters. */ - percpu_counter_sub(&sbi->s_dirtyblocks_counter, + percpu_counter_sub(&sbi->s_dirtyclusters_counter, ei->i_reserved_meta_blocks); ei->i_reserved_meta_blocks = 0; ei->i_da_metadata_calc_len = 0; } /* update fs dirty data blocks counter */ - percpu_counter_sub(&sbi->s_dirtyblocks_counter, to_free); + percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free); spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); - dquot_release_reservation_block(inode, to_free); + dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free)); } static void ext4_da_page_release_reservation(struct page *page, @@ -1139,6 +1198,9 @@ static void ext4_da_page_release_reservation(struct page *page, int to_release = 0; struct buffer_head *head, *bh; unsigned int curr_off = 0; + struct inode *inode = page->mapping->host; + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + int num_clusters; head = page_buffers(page); bh = head; @@ -1148,10 +1210,24 @@ static void ext4_da_page_release_reservation(struct page *page, if ((offset <= curr_off) && (buffer_delay(bh))) { to_release++; clear_buffer_delay(bh); + clear_buffer_da_mapped(bh); } curr_off = next_off; } while ((bh = bh->b_this_page) != head); - ext4_da_release_space(page->mapping->host, to_release); + + /* If we have released all the blocks belonging to a cluster, then we + * need to release the reserved space for that cluster. */ + num_clusters = EXT4_NUM_B2C(sbi, to_release); + while (num_clusters > 0) { + ext4_fsblk_t lblk; + lblk = (page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits)) + + ((num_clusters - 1) << sbi->s_cluster_bits); + if (sbi->s_cluster_ratio == 1 || + !ext4_find_delalloc_cluster(inode, lblk, 1)) + ext4_da_release_space(inode, 1); + + num_clusters--; + } } /* @@ -1253,6 +1329,8 @@ static int mpage_da_submit_io(struct mpage_da_data *mpd, clear_buffer_delay(bh); bh->b_blocknr = pblock; } + if (buffer_da_mapped(bh)) + clear_buffer_da_mapped(bh); if (buffer_unwritten(bh) || buffer_mapped(bh)) BUG_ON(bh->b_blocknr != pblock); @@ -1346,12 +1424,15 @@ static void ext4_print_free_blocks(struct inode *inode) { struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); printk(KERN_CRIT "Total free blocks count %lld\n", - ext4_count_free_blocks(inode->i_sb)); + EXT4_C2B(EXT4_SB(inode->i_sb), + ext4_count_free_clusters(inode->i_sb))); printk(KERN_CRIT "Free/Dirty block details\n"); printk(KERN_CRIT "free_blocks=%lld\n", - (long long) percpu_counter_sum(&sbi->s_freeblocks_counter)); + (long long) EXT4_C2B(EXT4_SB(inode->i_sb), + percpu_counter_sum(&sbi->s_freeclusters_counter))); printk(KERN_CRIT "dirty_blocks=%lld\n", - (long long) percpu_counter_sum(&sbi->s_dirtyblocks_counter)); + (long long) EXT4_C2B(EXT4_SB(inode->i_sb), + percpu_counter_sum(&sbi->s_dirtyclusters_counter))); printk(KERN_CRIT "Block reservation details\n"); printk(KERN_CRIT "i_reserved_data_blocks=%u\n", EXT4_I(inode)->i_reserved_data_blocks); @@ -1430,8 +1511,7 @@ static void mpage_da_map_and_submit(struct mpage_da_data *mpd) if (err == -EAGAIN) goto submit_io; - if (err == -ENOSPC && - ext4_count_free_blocks(sb)) { + if (err == -ENOSPC && ext4_count_free_clusters(sb)) { mpd->retval = err; goto submit_io; } @@ -1471,13 +1551,15 @@ static void mpage_da_map_and_submit(struct mpage_da_data *mpd) for (i = 0; i < map.m_len; i++) unmap_underlying_metadata(bdev, map.m_pblk + i); - } - if (ext4_should_order_data(mpd->inode)) { - err = ext4_jbd2_file_inode(handle, mpd->inode); - if (err) - /* This only happens if the journal is aborted */ - return; + if (ext4_should_order_data(mpd->inode)) { + err = ext4_jbd2_file_inode(handle, mpd->inode); + if (err) { + /* Only if the journal is aborted */ + mpd->retval = err; + goto submit_io; + } + } } /* @@ -1584,6 +1666,66 @@ static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh) } /* + * This function is grabs code from the very beginning of + * ext4_map_blocks, but assumes that the caller is from delayed write + * time. This function looks up the requested blocks and sets the + * buffer delay bit under the protection of i_data_sem. + */ +static int ext4_da_map_blocks(struct inode *inode, sector_t iblock, + struct ext4_map_blocks *map, + struct buffer_head *bh) +{ + int retval; + sector_t invalid_block = ~((sector_t) 0xffff); + + if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es)) + invalid_block = ~0; + + map->m_flags = 0; + ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u," + "logical block %lu\n", inode->i_ino, map->m_len, + (unsigned long) map->m_lblk); + /* + * Try to see if we can get the block without requesting a new + * file system block. + */ + down_read((&EXT4_I(inode)->i_data_sem)); + if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) + retval = ext4_ext_map_blocks(NULL, inode, map, 0); + else + retval = ext4_ind_map_blocks(NULL, inode, map, 0); + + if (retval == 0) { + /* + * XXX: __block_prepare_write() unmaps passed block, + * is it OK? + */ + /* If the block was allocated from previously allocated cluster, + * then we dont need to reserve it again. */ + if (!(map->m_flags & EXT4_MAP_FROM_CLUSTER)) { + retval = ext4_da_reserve_space(inode, iblock); + if (retval) + /* not enough space to reserve */ + goto out_unlock; + } + + /* Clear EXT4_MAP_FROM_CLUSTER flag since its purpose is served + * and it should not appear on the bh->b_state. + */ + map->m_flags &= ~EXT4_MAP_FROM_CLUSTER; + + map_bh(bh, inode->i_sb, invalid_block); + set_buffer_new(bh); + set_buffer_delay(bh); + } + +out_unlock: + up_read((&EXT4_I(inode)->i_data_sem)); + + return retval; +} + +/* * This is a special get_blocks_t callback which is used by * ext4_da_write_begin(). It will either return mapped block or * reserve space for a single block. @@ -1600,10 +1742,6 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, { struct ext4_map_blocks map; int ret = 0; - sector_t invalid_block = ~((sector_t) 0xffff); - - if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es)) - invalid_block = ~0; BUG_ON(create == 0); BUG_ON(bh->b_size != inode->i_sb->s_blocksize); @@ -1616,25 +1754,9 @@ static int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, * preallocated blocks are unmapped but should treated * the same as allocated blocks. */ - ret = ext4_map_blocks(NULL, inode, &map, 0); - if (ret < 0) + ret = ext4_da_map_blocks(inode, iblock, &map, bh); + if (ret <= 0) return ret; - if (ret == 0) { - if (buffer_delay(bh)) - return 0; /* Not sure this could or should happen */ - /* - * XXX: __block_write_begin() unmaps passed block, is it OK? - */ - ret = ext4_da_reserve_space(inode, iblock); - if (ret) - /* not enough space to reserve */ - return ret; - - map_bh(bh, inode->i_sb, invalid_block); - set_buffer_new(bh); - set_buffer_delay(bh); - return 0; - } map_bh(bh, inode->i_sb, map.m_pblk); bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; @@ -2050,6 +2172,7 @@ static int ext4_da_writepages(struct address_space *mapping, struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); pgoff_t done_index = 0; pgoff_t end; + struct blk_plug plug; trace_ext4_da_writepages(inode, wbc); @@ -2128,6 +2251,7 @@ retry: if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) tag_pages_for_writeback(mapping, index, end); + blk_start_plug(&plug); while (!ret && wbc->nr_to_write > 0) { /* @@ -2178,11 +2302,12 @@ retry: ret = 0; } else if (ret == MPAGE_DA_EXTENT_TAIL) { /* - * got one extent now try with - * rest of the pages + * Got one extent now try with rest of the pages. + * If mpd.retval is set -EIO, journal is aborted. + * So we don't need to write any more. */ pages_written += mpd.pages_written; - ret = 0; + ret = mpd.retval; io_done = 1; } else if (wbc->nr_to_write) /* @@ -2192,6 +2317,7 @@ retry: */ break; } + blk_finish_plug(&plug); if (!io_done && !cycled) { cycled = 1; index = 0; @@ -2230,10 +2356,11 @@ static int ext4_nonda_switch(struct super_block *sb) * Delalloc need an accurate free block accounting. So switch * to non delalloc when we are near to error range. */ - free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); - dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyblocks_counter); + free_blocks = EXT4_C2B(sbi, + percpu_counter_read_positive(&sbi->s_freeclusters_counter)); + dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter); if (2 * free_blocks < 3 * dirty_blocks || - free_blocks < (dirty_blocks + EXT4_FREEBLOCKS_WATERMARK)) { + free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) { /* * free block count is less than 150% of dirty blocks * or free blocks is less than watermark @@ -2245,7 +2372,7 @@ static int ext4_nonda_switch(struct super_block *sb) * start pushing delalloc when 1/2 of free blocks are dirty. */ if (free_blocks < 2 * dirty_blocks) - writeback_inodes_sb_if_idle(sb); + writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE); return 0; } @@ -2259,6 +2386,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping, pgoff_t index; struct inode *inode = mapping->host; handle_t *handle; + loff_t page_len; index = pos >> PAGE_CACHE_SHIFT; @@ -2305,6 +2433,13 @@ retry: */ if (pos + len > inode->i_size) ext4_truncate_failed_write(inode); + } else { + page_len = pos & (PAGE_CACHE_SIZE - 1); + if (page_len > 0) { + ret = ext4_discard_partial_page_buffers_no_lock(handle, + inode, page, pos - page_len, page_len, + EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED); + } } if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) @@ -2347,6 +2482,7 @@ static int ext4_da_write_end(struct file *file, loff_t new_i_size; unsigned long start, end; int write_mode = (int)(unsigned long)fsdata; + loff_t page_len; if (write_mode == FALL_BACK_TO_NONDELALLOC) { if (ext4_should_order_data(inode)) { @@ -2395,6 +2531,16 @@ static int ext4_da_write_end(struct file *file, } ret2 = generic_write_end(file, mapping, pos, len, copied, page, fsdata); + + page_len = PAGE_CACHE_SIZE - + ((pos + copied - 1) & (PAGE_CACHE_SIZE - 1)); + + if (page_len > 0) { + ret = ext4_discard_partial_page_buffers_no_lock(handle, + inode, page, pos + copied - 1, page_len, + EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED); + } + copied = ret2; if (ret2 < 0) ret = ret2; @@ -2689,10 +2835,7 @@ static void ext4_end_io_buffer_write(struct buffer_head *bh, int uptodate) * but being more careful is always safe for the future change. */ inode = io_end->inode; - if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { - io_end->flag |= EXT4_IO_END_UNWRITTEN; - atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten); - } + ext4_set_io_unwritten_flag(inode, io_end); /* Add the io_end to per-inode completed io list*/ spin_lock_irqsave(&EXT4_I(inode)->i_completed_io_lock, flags); @@ -2858,6 +3001,12 @@ static ssize_t ext4_direct_IO(int rw, struct kiocb *iocb, struct inode *inode = file->f_mapping->host; ssize_t ret; + /* + * If we are doing data journalling we don't support O_DIRECT + */ + if (ext4_should_journal_data(inode)) + return 0; + trace_ext4_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw); if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) ret = ext4_ext_direct_IO(rw, iocb, iov, offset, nr_segs); @@ -2927,6 +3076,7 @@ static const struct address_space_operations ext4_journalled_aops = { .bmap = ext4_bmap, .invalidatepage = ext4_invalidatepage, .releasepage = ext4_releasepage, + .direct_IO = ext4_direct_IO, .is_partially_uptodate = block_is_partially_uptodate, .error_remove_page = generic_error_remove_page, }; @@ -2963,6 +3113,227 @@ void ext4_set_aops(struct inode *inode) inode->i_mapping->a_ops = &ext4_journalled_aops; } + +/* + * ext4_discard_partial_page_buffers() + * Wrapper function for ext4_discard_partial_page_buffers_no_lock. + * This function finds and locks the page containing the offset + * "from" and passes it to ext4_discard_partial_page_buffers_no_lock. + * Calling functions that already have the page locked should call + * ext4_discard_partial_page_buffers_no_lock directly. + */ +int ext4_discard_partial_page_buffers(handle_t *handle, + struct address_space *mapping, loff_t from, + loff_t length, int flags) +{ + struct inode *inode = mapping->host; + struct page *page; + int err = 0; + + page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT, + mapping_gfp_mask(mapping) & ~__GFP_FS); + if (!page) + return -ENOMEM; + + err = ext4_discard_partial_page_buffers_no_lock(handle, inode, page, + from, length, flags); + + unlock_page(page); + page_cache_release(page); + return err; +} + +/* + * ext4_discard_partial_page_buffers_no_lock() + * Zeros a page range of length 'length' starting from offset 'from'. + * Buffer heads that correspond to the block aligned regions of the + * zeroed range will be unmapped. Unblock aligned regions + * will have the corresponding buffer head mapped if needed so that + * that region of the page can be updated with the partial zero out. + * + * This function assumes that the page has already been locked. The + * The range to be discarded must be contained with in the given page. + * If the specified range exceeds the end of the page it will be shortened + * to the end of the page that corresponds to 'from'. This function is + * appropriate for updating a page and it buffer heads to be unmapped and + * zeroed for blocks that have been either released, or are going to be + * released. + * + * handle: The journal handle + * inode: The files inode + * page: A locked page that contains the offset "from" + * from: The starting byte offset (from the begining of the file) + * to begin discarding + * len: The length of bytes to discard + * flags: Optional flags that may be used: + * + * EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED + * Only zero the regions of the page whose buffer heads + * have already been unmapped. This flag is appropriate + * for updateing the contents of a page whose blocks may + * have already been released, and we only want to zero + * out the regions that correspond to those released blocks. + * + * Returns zero on sucess or negative on failure. + */ +int ext4_discard_partial_page_buffers_no_lock(handle_t *handle, + struct inode *inode, struct page *page, loff_t from, + loff_t length, int flags) +{ + ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; + unsigned int offset = from & (PAGE_CACHE_SIZE-1); + unsigned int blocksize, max, pos; + ext4_lblk_t iblock; + struct buffer_head *bh; + int err = 0; + + blocksize = inode->i_sb->s_blocksize; + max = PAGE_CACHE_SIZE - offset; + + if (index != page->index) + return -EINVAL; + + /* + * correct length if it does not fall between + * 'from' and the end of the page + */ + if (length > max || length < 0) + length = max; + + iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); + + if (!page_has_buffers(page)) { + /* + * If the range to be discarded covers a partial block + * we need to get the page buffers. This is because + * partial blocks cannot be released and the page needs + * to be updated with the contents of the block before + * we write the zeros on top of it. + */ + if ((from & (blocksize - 1)) || + ((from + length) & (blocksize - 1))) { + create_empty_buffers(page, blocksize, 0); + } else { + /* + * If there are no partial blocks, + * there is nothing to update, + * so we can return now + */ + return 0; + } + } + + /* Find the buffer that contains "offset" */ + bh = page_buffers(page); + pos = blocksize; + while (offset >= pos) { + bh = bh->b_this_page; + iblock++; + pos += blocksize; + } + + pos = offset; + while (pos < offset + length) { + unsigned int end_of_block, range_to_discard; + + err = 0; + + /* The length of space left to zero and unmap */ + range_to_discard = offset + length - pos; + + /* The length of space until the end of the block */ + end_of_block = blocksize - (pos & (blocksize-1)); + + /* + * Do not unmap or zero past end of block + * for this buffer head + */ + if (range_to_discard > end_of_block) + range_to_discard = end_of_block; + + + /* + * Skip this buffer head if we are only zeroing unampped + * regions of the page + */ + if (flags & EXT4_DISCARD_PARTIAL_PG_ZERO_UNMAPPED && + buffer_mapped(bh)) + goto next; + + /* If the range is block aligned, unmap */ + if (range_to_discard == blocksize) { + clear_buffer_dirty(bh); + bh->b_bdev = NULL; + clear_buffer_mapped(bh); + clear_buffer_req(bh); + clear_buffer_new(bh); + clear_buffer_delay(bh); + clear_buffer_unwritten(bh); + clear_buffer_uptodate(bh); + zero_user(page, pos, range_to_discard); + BUFFER_TRACE(bh, "Buffer discarded"); + goto next; + } + + /* + * If this block is not completely contained in the range + * to be discarded, then it is not going to be released. Because + * we need to keep this block, we need to make sure this part + * of the page is uptodate before we modify it by writeing + * partial zeros on it. + */ + if (!buffer_mapped(bh)) { + /* + * Buffer head must be mapped before we can read + * from the block + */ + BUFFER_TRACE(bh, "unmapped"); + ext4_get_block(inode, iblock, bh, 0); + /* unmapped? It's a hole - nothing to do */ + if (!buffer_mapped(bh)) { + BUFFER_TRACE(bh, "still unmapped"); + goto next; + } + } + + /* Ok, it's mapped. Make sure it's up-to-date */ + if (PageUptodate(page)) + set_buffer_uptodate(bh); + + if (!buffer_uptodate(bh)) { + err = -EIO; + ll_rw_block(READ, 1, &bh); + wait_on_buffer(bh); + /* Uhhuh. Read error. Complain and punt.*/ + if (!buffer_uptodate(bh)) + goto next; + } + + if (ext4_should_journal_data(inode)) { + BUFFER_TRACE(bh, "get write access"); + err = ext4_journal_get_write_access(handle, bh); + if (err) + goto next; + } + + zero_user(page, pos, range_to_discard); + + err = 0; + if (ext4_should_journal_data(inode)) { + err = ext4_handle_dirty_metadata(handle, inode, bh); + } else + mark_buffer_dirty(bh); + + BUFFER_TRACE(bh, "Partial buffer zeroed"); +next: + bh = bh->b_this_page; + iblock++; + pos += range_to_discard; + } + + return err; +} + /* * ext4_block_truncate_page() zeroes out a mapping from file offset `from' * up to the end of the block which corresponds to `from'. @@ -3005,7 +3376,7 @@ int ext4_block_zero_page_range(handle_t *handle, page = find_or_create_page(mapping, from >> PAGE_CACHE_SHIFT, mapping_gfp_mask(mapping) & ~__GFP_FS); if (!page) - return -EINVAL; + return -ENOMEM; blocksize = inode->i_sb->s_blocksize; max = blocksize - (offset & (blocksize - 1)); @@ -3074,11 +3445,8 @@ int ext4_block_zero_page_range(handle_t *handle, err = 0; if (ext4_should_journal_data(inode)) { err = ext4_handle_dirty_metadata(handle, inode, bh); - } else { - if (ext4_should_order_data(inode) && EXT4_I(inode)->jinode) - err = ext4_jbd2_file_inode(handle, inode); + } else mark_buffer_dirty(bh); - } unlock: unlock_page(page); @@ -3119,6 +3487,11 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length) return -ENOTSUPP; } + if (EXT4_SB(inode->i_sb)->s_cluster_ratio > 1) { + /* TODO: Add support for bigalloc file systems */ + return -ENOTSUPP; + } + return ext4_ext_punch_hole(file, offset, length); } @@ -3418,7 +3791,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino) inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; } - inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); + set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ ei->i_dir_start_lookup = 0; @@ -4420,6 +4793,7 @@ retry_alloc: PAGE_CACHE_SIZE, NULL, do_journal_get_write_access)) { unlock_page(page); ret = VM_FAULT_SIGBUS; + ext4_journal_stop(handle); goto out; } ext4_set_inode_state(inode, EXT4_STATE_JDATA); |