| /* |
| * linux/fs/ext4/inode.c |
| * |
| * Copyright (C) 1992, 1993, 1994, 1995 |
| * Remy Card (card@masi.ibp.fr) |
| * Laboratoire MASI - Institut Blaise Pascal |
| * Universite Pierre et Marie Curie (Paris VI) |
| * |
| * from |
| * |
| * linux/fs/minix/inode.c |
| * |
| * Copyright (C) 1991, 1992 Linus Torvalds |
| * |
| * 64-bit file support on 64-bit platforms by Jakub Jelinek |
| * (jj@sunsite.ms.mff.cuni.cz) |
| * |
| * Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000 |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/time.h> |
| #include <linux/highuid.h> |
| #include <linux/pagemap.h> |
| #include <linux/quotaops.h> |
| #include <linux/string.h> |
| #include <linux/buffer_head.h> |
| #include <linux/writeback.h> |
| #include <linux/pagevec.h> |
| #include <linux/mpage.h> |
| #include <linux/namei.h> |
| #include <linux/uio.h> |
| #include <linux/bio.h> |
| #include <linux/workqueue.h> |
| #include <linux/kernel.h> |
| #include <linux/printk.h> |
| #include <linux/slab.h> |
| #include <linux/bitops.h> |
| |
| #include "ext4_jbd2.h" |
| #include "xattr.h" |
| #include "acl.h" |
| #include "truncate.h" |
| |
| #include <trace/events/ext4.h> |
| |
| #define MPAGE_DA_EXTENT_TAIL 0x01 |
| |
| static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw, |
| struct ext4_inode_info *ei) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| __u16 csum_lo; |
| __u16 csum_hi = 0; |
| __u32 csum; |
| |
| csum_lo = le16_to_cpu(raw->i_checksum_lo); |
| raw->i_checksum_lo = 0; |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && |
| EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) { |
| csum_hi = le16_to_cpu(raw->i_checksum_hi); |
| raw->i_checksum_hi = 0; |
| } |
| |
| csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, |
| EXT4_INODE_SIZE(inode->i_sb)); |
| |
| raw->i_checksum_lo = cpu_to_le16(csum_lo); |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && |
| EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) |
| raw->i_checksum_hi = cpu_to_le16(csum_hi); |
| |
| return csum; |
| } |
| |
| static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw, |
| struct ext4_inode_info *ei) |
| { |
| __u32 provided, calculated; |
| |
| if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
| cpu_to_le32(EXT4_OS_LINUX) || |
| !ext4_has_metadata_csum(inode->i_sb)) |
| return 1; |
| |
| provided = le16_to_cpu(raw->i_checksum_lo); |
| calculated = ext4_inode_csum(inode, raw, ei); |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && |
| EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) |
| provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16; |
| else |
| calculated &= 0xFFFF; |
| |
| return provided == calculated; |
| } |
| |
| static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw, |
| struct ext4_inode_info *ei) |
| { |
| __u32 csum; |
| |
| if (EXT4_SB(inode->i_sb)->s_es->s_creator_os != |
| cpu_to_le32(EXT4_OS_LINUX) || |
| !ext4_has_metadata_csum(inode->i_sb)) |
| return; |
| |
| csum = ext4_inode_csum(inode, raw, ei); |
| raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF); |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE && |
| EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) |
| raw->i_checksum_hi = cpu_to_le16(csum >> 16); |
| } |
| |
| static inline int ext4_begin_ordered_truncate(struct inode *inode, |
| loff_t new_size) |
| { |
| trace_ext4_begin_ordered_truncate(inode, new_size); |
| /* |
| * If jinode is zero, then we never opened the file for |
| * writing, so there's no need to call |
| * jbd2_journal_begin_ordered_truncate() since there's no |
| * outstanding writes we need to flush. |
| */ |
| if (!EXT4_I(inode)->jinode) |
| return 0; |
| return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode), |
| EXT4_I(inode)->jinode, |
| new_size); |
| } |
| |
| static void ext4_invalidatepage(struct page *page, unsigned int offset, |
| unsigned int length); |
| static int __ext4_journalled_writepage(struct page *page, unsigned int len); |
| static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh); |
| static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, |
| int pextents); |
| |
| /* |
| * Test whether an inode is a fast symlink. |
| */ |
| int ext4_inode_is_fast_symlink(struct inode *inode) |
| { |
| int ea_blocks = EXT4_I(inode)->i_file_acl ? |
| EXT4_CLUSTER_SIZE(inode->i_sb) >> 9 : 0; |
| |
| if (ext4_has_inline_data(inode)) |
| return 0; |
| |
| return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); |
| } |
| |
| /* |
| * Restart the transaction associated with *handle. This does a commit, |
| * so before we call here everything must be consistently dirtied against |
| * this transaction. |
| */ |
| int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode, |
| int nblocks) |
| { |
| int ret; |
| |
| /* |
| * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this |
| * moment, get_block can be called only for blocks inside i_size since |
| * page cache has been already dropped and writes are blocked by |
| * i_mutex. So we can safely drop the i_data_sem here. |
| */ |
| BUG_ON(EXT4_JOURNAL(inode) == NULL); |
| jbd_debug(2, "restarting handle %p\n", handle); |
| up_write(&EXT4_I(inode)->i_data_sem); |
| ret = ext4_journal_restart(handle, nblocks); |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_discard_preallocations(inode); |
| |
| return ret; |
| } |
| |
| /* |
| * Called at the last iput() if i_nlink is zero. |
| */ |
| void ext4_evict_inode(struct inode *inode) |
| { |
| handle_t *handle; |
| int err; |
| |
| trace_ext4_evict_inode(inode); |
| |
| if (inode->i_nlink) { |
| /* |
| * When journalling data dirty buffers are tracked only in the |
| * journal. So although mm thinks everything is clean and |
| * ready for reaping the inode might still have some pages to |
| * write in the running transaction or waiting to be |
| * checkpointed. Thus calling jbd2_journal_invalidatepage() |
| * (via truncate_inode_pages()) to discard these buffers can |
| * cause data loss. Also even if we did not discard these |
| * buffers, we would have no way to find them after the inode |
| * is reaped and thus user could see stale data if he tries to |
| * read them before the transaction is checkpointed. So be |
| * careful and force everything to disk here... We use |
| * ei->i_datasync_tid to store the newest transaction |
| * containing inode's data. |
| * |
| * Note that directories do not have this problem because they |
| * don't use page cache. |
| */ |
| if (ext4_should_journal_data(inode) && |
| (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) && |
| inode->i_ino != EXT4_JOURNAL_INO) { |
| journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; |
| tid_t commit_tid = EXT4_I(inode)->i_datasync_tid; |
| |
| jbd2_complete_transaction(journal, commit_tid); |
| filemap_write_and_wait(&inode->i_data); |
| } |
| truncate_inode_pages_final(&inode->i_data); |
| |
| WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); |
| goto no_delete; |
| } |
| |
| if (is_bad_inode(inode)) |
| goto no_delete; |
| dquot_initialize(inode); |
| |
| if (ext4_should_order_data(inode)) |
| ext4_begin_ordered_truncate(inode, 0); |
| truncate_inode_pages_final(&inode->i_data); |
| |
| WARN_ON(atomic_read(&EXT4_I(inode)->i_ioend_count)); |
| |
| /* |
| * Protect us against freezing - iput() caller didn't have to have any |
| * protection against it |
| */ |
| sb_start_intwrite(inode->i_sb); |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, |
| ext4_blocks_for_truncate(inode)+3); |
| if (IS_ERR(handle)) { |
| ext4_std_error(inode->i_sb, PTR_ERR(handle)); |
| /* |
| * If we're going to skip the normal cleanup, we still need to |
| * make sure that the in-core orphan linked list is properly |
| * cleaned up. |
| */ |
| ext4_orphan_del(NULL, inode); |
| sb_end_intwrite(inode->i_sb); |
| goto no_delete; |
| } |
| |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| inode->i_size = 0; |
| err = ext4_mark_inode_dirty(handle, inode); |
| if (err) { |
| ext4_warning(inode->i_sb, |
| "couldn't mark inode dirty (err %d)", err); |
| goto stop_handle; |
| } |
| if (inode->i_blocks) |
| ext4_truncate(inode); |
| |
| /* |
| * ext4_ext_truncate() doesn't reserve any slop when it |
| * restarts journal transactions; therefore there may not be |
| * enough credits left in the handle to remove the inode from |
| * the orphan list and set the dtime field. |
| */ |
| if (!ext4_handle_has_enough_credits(handle, 3)) { |
| err = ext4_journal_extend(handle, 3); |
| if (err > 0) |
| err = ext4_journal_restart(handle, 3); |
| if (err != 0) { |
| ext4_warning(inode->i_sb, |
| "couldn't extend journal (err %d)", err); |
| stop_handle: |
| ext4_journal_stop(handle); |
| ext4_orphan_del(NULL, inode); |
| sb_end_intwrite(inode->i_sb); |
| goto no_delete; |
| } |
| } |
| |
| /* |
| * Kill off the orphan record which ext4_truncate created. |
| * AKPM: I think this can be inside the above `if'. |
| * Note that ext4_orphan_del() has to be able to cope with the |
| * deletion of a non-existent orphan - this is because we don't |
| * know if ext4_truncate() actually created an orphan record. |
| * (Well, we could do this if we need to, but heck - it works) |
| */ |
| ext4_orphan_del(handle, inode); |
| EXT4_I(inode)->i_dtime = get_seconds(); |
| |
| /* |
| * One subtle ordering requirement: if anything has gone wrong |
| * (transaction abort, IO errors, whatever), then we can still |
| * do these next steps (the fs will already have been marked as |
| * having errors), but we can't free the inode if the mark_dirty |
| * fails. |
| */ |
| if (ext4_mark_inode_dirty(handle, inode)) |
| /* If that failed, just do the required in-core inode clear. */ |
| ext4_clear_inode(inode); |
| else |
| ext4_free_inode(handle, inode); |
| ext4_journal_stop(handle); |
| sb_end_intwrite(inode->i_sb); |
| return; |
| no_delete: |
| ext4_clear_inode(inode); /* We must guarantee clearing of inode... */ |
| } |
| |
| #ifdef CONFIG_QUOTA |
| qsize_t *ext4_get_reserved_space(struct inode *inode) |
| { |
| return &EXT4_I(inode)->i_reserved_quota; |
| } |
| #endif |
| |
| /* |
| * Called with i_data_sem down, which is important since we can call |
| * ext4_discard_preallocations() from here. |
| */ |
| void ext4_da_update_reserve_space(struct inode *inode, |
| int used, int quota_claim) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| |
| spin_lock(&ei->i_block_reservation_lock); |
| trace_ext4_da_update_reserve_space(inode, used, quota_claim); |
| if (unlikely(used > ei->i_reserved_data_blocks)) { |
| ext4_warning(inode->i_sb, "%s: ino %lu, used %d " |
| "with only %d reserved data blocks", |
| __func__, inode->i_ino, used, |
| ei->i_reserved_data_blocks); |
| WARN_ON(1); |
| used = ei->i_reserved_data_blocks; |
| } |
| |
| /* Update per-inode reservations */ |
| ei->i_reserved_data_blocks -= used; |
| percpu_counter_sub(&sbi->s_dirtyclusters_counter, used); |
| |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| |
| /* Update quota subsystem for data blocks */ |
| if (quota_claim) |
| 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, EXT4_C2B(sbi, used)); |
| } |
| |
| /* |
| * If we have done all the pending block allocations and if |
| * there aren't any writers on the inode, we can discard the |
| * inode's preallocations. |
| */ |
| if ((ei->i_reserved_data_blocks == 0) && |
| (atomic_read(&inode->i_writecount) == 0)) |
| ext4_discard_preallocations(inode); |
| } |
| |
| static int __check_block_validity(struct inode *inode, const char *func, |
| unsigned int line, |
| struct ext4_map_blocks *map) |
| { |
| if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk, |
| map->m_len)) { |
| ext4_error_inode(inode, func, line, map->m_pblk, |
| "lblock %lu mapped to illegal pblock " |
| "(length %d)", (unsigned long) map->m_lblk, |
| map->m_len); |
| return -EIO; |
| } |
| return 0; |
| } |
| |
| #define check_block_validity(inode, map) \ |
| __check_block_validity((inode), __func__, __LINE__, (map)) |
| |
| #ifdef ES_AGGRESSIVE_TEST |
| static void ext4_map_blocks_es_recheck(handle_t *handle, |
| struct inode *inode, |
| struct ext4_map_blocks *es_map, |
| struct ext4_map_blocks *map, |
| int flags) |
| { |
| int retval; |
| |
| map->m_flags = 0; |
| /* |
| * There is a race window that the result is not the same. |
| * e.g. xfstests #223 when dioread_nolock enables. The reason |
| * is that we lookup a block mapping in extent status tree with |
| * out taking i_data_sem. So at the time the unwritten extent |
| * could be converted. |
| */ |
| if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) |
| 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, flags & |
| EXT4_GET_BLOCKS_KEEP_SIZE); |
| } else { |
| retval = ext4_ind_map_blocks(handle, inode, map, flags & |
| EXT4_GET_BLOCKS_KEEP_SIZE); |
| } |
| if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) |
| up_read((&EXT4_I(inode)->i_data_sem)); |
| |
| /* |
| * We don't check m_len because extent will be collpased in status |
| * tree. So the m_len might not equal. |
| */ |
| if (es_map->m_lblk != map->m_lblk || |
| es_map->m_flags != map->m_flags || |
| es_map->m_pblk != map->m_pblk) { |
| printk("ES cache assertion failed for inode: %lu " |
| "es_cached ex [%d/%d/%llu/%x] != " |
| "found ex [%d/%d/%llu/%x] retval %d flags %x\n", |
| inode->i_ino, es_map->m_lblk, es_map->m_len, |
| es_map->m_pblk, es_map->m_flags, map->m_lblk, |
| map->m_len, map->m_pblk, map->m_flags, |
| retval, flags); |
| } |
| } |
| #endif /* ES_AGGRESSIVE_TEST */ |
| |
| /* |
| * The ext4_map_blocks() function tries to look up the requested blocks, |
| * and returns if the blocks are already mapped. |
| * |
| * Otherwise it takes the write lock of the i_data_sem and allocate blocks |
| * and store the allocated blocks in the result buffer head and mark it |
| * mapped. |
| * |
| * If file type is extents based, it will call ext4_ext_map_blocks(), |
| * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping |
| * based files |
| * |
| * On success, it returns the number of blocks being mapped or allocated. |
| * if create==0 and the blocks are pre-allocated and unwritten block, |
| * the result buffer head is unmapped. If the create ==1, it will make sure |
| * the buffer head is mapped. |
| * |
| * It returns 0 if plain look up failed (blocks have not been allocated), in |
| * that case, buffer head is unmapped |
| * |
| * It returns the error in case of allocation failure. |
| */ |
| int ext4_map_blocks(handle_t *handle, struct inode *inode, |
| struct ext4_map_blocks *map, int flags) |
| { |
| struct extent_status es; |
| int retval; |
| int ret = 0; |
| #ifdef ES_AGGRESSIVE_TEST |
| struct ext4_map_blocks orig_map; |
| |
| memcpy(&orig_map, map, sizeof(*map)); |
| #endif |
| |
| map->m_flags = 0; |
| ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u," |
| "logical block %lu\n", inode->i_ino, flags, map->m_len, |
| (unsigned long) map->m_lblk); |
| |
| /* |
| * ext4_map_blocks returns an int, and m_len is an unsigned int |
| */ |
| if (unlikely(map->m_len > INT_MAX)) |
| map->m_len = INT_MAX; |
| |
| /* We can handle the block number less than EXT_MAX_BLOCKS */ |
| if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS)) |
| return -EIO; |
| |
| /* Lookup extent status tree firstly */ |
| if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) { |
| if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) { |
| map->m_pblk = ext4_es_pblock(&es) + |
| map->m_lblk - es.es_lblk; |
| map->m_flags |= ext4_es_is_written(&es) ? |
| EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN; |
| retval = es.es_len - (map->m_lblk - es.es_lblk); |
| if (retval > map->m_len) |
| retval = map->m_len; |
| map->m_len = retval; |
| } else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) { |
| retval = 0; |
| } else { |
| BUG_ON(1); |
| } |
| #ifdef ES_AGGRESSIVE_TEST |
| ext4_map_blocks_es_recheck(handle, inode, map, |
| &orig_map, flags); |
| #endif |
| goto found; |
| } |
| |
| /* |
| * Try to see if we can get the block without requesting a new |
| * file system block. |
| */ |
| if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) |
| 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, flags & |
| EXT4_GET_BLOCKS_KEEP_SIZE); |
| } else { |
| retval = ext4_ind_map_blocks(handle, inode, map, flags & |
| EXT4_GET_BLOCKS_KEEP_SIZE); |
| } |
| if (retval > 0) { |
| unsigned int status; |
| |
| if (unlikely(retval != map->m_len)) { |
| ext4_warning(inode->i_sb, |
| "ES len assertion failed for inode " |
| "%lu: retval %d != map->m_len %d", |
| inode->i_ino, retval, map->m_len); |
| WARN_ON(1); |
| } |
| |
| status = map->m_flags & EXT4_MAP_UNWRITTEN ? |
| EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; |
| if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && |
| !(status & EXTENT_STATUS_WRITTEN) && |
| ext4_find_delalloc_range(inode, map->m_lblk, |
| map->m_lblk + map->m_len - 1)) |
| status |= EXTENT_STATUS_DELAYED; |
| ret = ext4_es_insert_extent(inode, map->m_lblk, |
| map->m_len, map->m_pblk, status); |
| if (ret < 0) |
| retval = ret; |
| } |
| if (!(flags & EXT4_GET_BLOCKS_NO_LOCK)) |
| up_read((&EXT4_I(inode)->i_data_sem)); |
| |
| found: |
| if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { |
| ret = check_block_validity(inode, map); |
| if (ret != 0) |
| return ret; |
| } |
| |
| /* If it is only a block(s) look up */ |
| if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) |
| return retval; |
| |
| /* |
| * Returns if the blocks have already allocated |
| * |
| * Note that if blocks have been preallocated |
| * ext4_ext_get_block() returns the create = 0 |
| * with buffer head unmapped. |
| */ |
| if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) |
| /* |
| * If we need to convert extent to unwritten |
| * we continue and do the actual work in |
| * ext4_ext_map_blocks() |
| */ |
| if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) |
| return retval; |
| |
| /* |
| * Here we clear m_flags because after allocating an new extent, |
| * it will be set again. |
| */ |
| map->m_flags &= ~EXT4_MAP_FLAGS; |
| |
| /* |
| * New blocks allocate and/or writing to unwritten extent |
| * will possibly result in updating i_data, so we take |
| * the write lock of i_data_sem, and call get_block() |
| * with create == 1 flag. |
| */ |
| down_write(&EXT4_I(inode)->i_data_sem); |
| |
| /* |
| * We need to check for EXT4 here because migrate |
| * could have changed the inode type in between |
| */ |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| retval = ext4_ext_map_blocks(handle, inode, map, flags); |
| } else { |
| retval = ext4_ind_map_blocks(handle, inode, map, flags); |
| |
| if (retval > 0 && map->m_flags & EXT4_MAP_NEW) { |
| /* |
| * We allocated new blocks which will result in |
| * i_data's format changing. Force the migrate |
| * to fail by clearing migrate flags |
| */ |
| ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE); |
| } |
| |
| /* |
| * Update reserved blocks/metadata blocks after successful |
| * block allocation which had been deferred till now. We don't |
| * support fallocate for non extent files. So we can update |
| * reserve space here. |
| */ |
| if ((retval > 0) && |
| (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)) |
| ext4_da_update_reserve_space(inode, retval, 1); |
| } |
| |
| if (retval > 0) { |
| unsigned int status; |
| |
| if (unlikely(retval != map->m_len)) { |
| ext4_warning(inode->i_sb, |
| "ES len assertion failed for inode " |
| "%lu: retval %d != map->m_len %d", |
| inode->i_ino, retval, map->m_len); |
| WARN_ON(1); |
| } |
| |
| /* |
| * If the extent has been zeroed out, we don't need to update |
| * extent status tree. |
| */ |
| if ((flags & EXT4_GET_BLOCKS_PRE_IO) && |
| ext4_es_lookup_extent(inode, map->m_lblk, &es)) { |
| if (ext4_es_is_written(&es)) |
| goto has_zeroout; |
| } |
| status = map->m_flags & EXT4_MAP_UNWRITTEN ? |
| EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; |
| if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) && |
| !(status & EXTENT_STATUS_WRITTEN) && |
| ext4_find_delalloc_range(inode, map->m_lblk, |
| map->m_lblk + map->m_len - 1)) |
| status |= EXTENT_STATUS_DELAYED; |
| ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, |
| map->m_pblk, status); |
| if (ret < 0) |
| retval = ret; |
| } |
| |
| has_zeroout: |
| up_write((&EXT4_I(inode)->i_data_sem)); |
| if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) { |
| ret = check_block_validity(inode, map); |
| if (ret != 0) |
| return ret; |
| } |
| return retval; |
| } |
| |
| static void ext4_end_io_unwritten(struct buffer_head *bh, int uptodate) |
| { |
| struct inode *inode = bh->b_assoc_map->host; |
| /* XXX: breaks on 32-bit > 16GB. Is that even supported? */ |
| loff_t offset = (loff_t)(uintptr_t)bh->b_private << inode->i_blkbits; |
| int err; |
| if (!uptodate) |
| return; |
| WARN_ON(!buffer_unwritten(bh)); |
| err = ext4_convert_unwritten_extents(NULL, inode, offset, bh->b_size); |
| } |
| |
| /* Maximum number of blocks we map for direct IO at once. */ |
| #define DIO_MAX_BLOCKS 4096 |
| |
| static int _ext4_get_block(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh, int flags) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct ext4_map_blocks map; |
| int ret = 0, started = 0; |
| int dio_credits; |
| |
| if (ext4_has_inline_data(inode)) |
| return -ERANGE; |
| |
| map.m_lblk = iblock; |
| map.m_len = bh->b_size >> inode->i_blkbits; |
| |
| if (flags && !(flags & EXT4_GET_BLOCKS_NO_LOCK) && !handle) { |
| /* Direct IO write... */ |
| if (map.m_len > DIO_MAX_BLOCKS) |
| map.m_len = DIO_MAX_BLOCKS; |
| dio_credits = ext4_chunk_trans_blocks(inode, map.m_len); |
| handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, |
| dio_credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| return ret; |
| } |
| started = 1; |
| } |
| |
| ret = ext4_map_blocks(handle, inode, &map, flags); |
| if (ret > 0) { |
| ext4_io_end_t *io_end = ext4_inode_aio(inode); |
| |
| map_bh(bh, inode->i_sb, map.m_pblk); |
| bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; |
| if (IS_DAX(inode) && buffer_unwritten(bh) && !io_end) { |
| bh->b_assoc_map = inode->i_mapping; |
| bh->b_private = (void *)(unsigned long)iblock; |
| bh->b_end_io = ext4_end_io_unwritten; |
| } |
| if (io_end && io_end->flag & EXT4_IO_END_UNWRITTEN) |
| set_buffer_defer_completion(bh); |
| bh->b_size = inode->i_sb->s_blocksize * map.m_len; |
| ret = 0; |
| } |
| if (started) |
| ext4_journal_stop(handle); |
| return ret; |
| } |
| |
| int ext4_get_block(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh, int create) |
| { |
| return _ext4_get_block(inode, iblock, bh, |
| create ? EXT4_GET_BLOCKS_CREATE : 0); |
| } |
| |
| /* |
| * `handle' can be NULL if create is zero |
| */ |
| struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode, |
| ext4_lblk_t block, int create) |
| { |
| struct ext4_map_blocks map; |
| struct buffer_head *bh; |
| int err; |
| |
| J_ASSERT(handle != NULL || create == 0); |
| |
| map.m_lblk = block; |
| map.m_len = 1; |
| err = ext4_map_blocks(handle, inode, &map, |
| create ? EXT4_GET_BLOCKS_CREATE : 0); |
| |
| if (err == 0) |
| return create ? ERR_PTR(-ENOSPC) : NULL; |
| if (err < 0) |
| return ERR_PTR(err); |
| |
| bh = sb_getblk(inode->i_sb, map.m_pblk); |
| if (unlikely(!bh)) |
| return ERR_PTR(-ENOMEM); |
| if (map.m_flags & EXT4_MAP_NEW) { |
| J_ASSERT(create != 0); |
| J_ASSERT(handle != NULL); |
| |
| /* |
| * Now that we do not always journal data, we should |
| * keep in mind whether this should always journal the |
| * new buffer as metadata. For now, regular file |
| * writes use ext4_get_block instead, so it's not a |
| * problem. |
| */ |
| lock_buffer(bh); |
| BUFFER_TRACE(bh, "call get_create_access"); |
| err = ext4_journal_get_create_access(handle, bh); |
| if (unlikely(err)) { |
| unlock_buffer(bh); |
| goto errout; |
| } |
| if (!buffer_uptodate(bh)) { |
| memset(bh->b_data, 0, inode->i_sb->s_blocksize); |
| set_buffer_uptodate(bh); |
| } |
| unlock_buffer(bh); |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| if (unlikely(err)) |
| goto errout; |
| } else |
| BUFFER_TRACE(bh, "not a new buffer"); |
| return bh; |
| errout: |
| brelse(bh); |
| return ERR_PTR(err); |
| } |
| |
| struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode, |
| ext4_lblk_t block, int create) |
| { |
| struct buffer_head *bh; |
| |
| bh = ext4_getblk(handle, inode, block, create); |
| if (IS_ERR(bh)) |
| return bh; |
| if (!bh || buffer_uptodate(bh)) |
| return bh; |
| ll_rw_block(READ | REQ_META | REQ_PRIO, 1, &bh); |
| wait_on_buffer(bh); |
| if (buffer_uptodate(bh)) |
| return bh; |
| put_bh(bh); |
| return ERR_PTR(-EIO); |
| } |
| |
| int ext4_walk_page_buffers(handle_t *handle, |
| struct buffer_head *head, |
| unsigned from, |
| unsigned to, |
| int *partial, |
| int (*fn)(handle_t *handle, |
| struct buffer_head *bh)) |
| { |
| struct buffer_head *bh; |
| unsigned block_start, block_end; |
| unsigned blocksize = head->b_size; |
| int err, ret = 0; |
| struct buffer_head *next; |
| |
| for (bh = head, block_start = 0; |
| ret == 0 && (bh != head || !block_start); |
| block_start = block_end, bh = next) { |
| next = bh->b_this_page; |
| block_end = block_start + blocksize; |
| if (block_end <= from || block_start >= to) { |
| if (partial && !buffer_uptodate(bh)) |
| *partial = 1; |
| continue; |
| } |
| err = (*fn)(handle, bh); |
| if (!ret) |
| ret = err; |
| } |
| return ret; |
| } |
| |
| /* |
| * To preserve ordering, it is essential that the hole instantiation and |
| * the data write be encapsulated in a single transaction. We cannot |
| * close off a transaction and start a new one between the ext4_get_block() |
| * and the commit_write(). So doing the jbd2_journal_start at the start of |
| * prepare_write() is the right place. |
| * |
| * Also, this function can nest inside ext4_writepage(). In that case, we |
| * *know* that ext4_writepage() has generated enough buffer credits to do the |
| * whole page. So we won't block on the journal in that case, which is good, |
| * because the caller may be PF_MEMALLOC. |
| * |
| * By accident, ext4 can be reentered when a transaction is open via |
| * quota file writes. If we were to commit the transaction while thus |
| * reentered, there can be a deadlock - we would be holding a quota |
| * lock, and the commit would never complete if another thread had a |
| * transaction open and was blocking on the quota lock - a ranking |
| * violation. |
| * |
| * So what we do is to rely on the fact that jbd2_journal_stop/journal_start |
| * will _not_ run commit under these circumstances because handle->h_ref |
| * is elevated. We'll still have enough credits for the tiny quotafile |
| * write. |
| */ |
| int do_journal_get_write_access(handle_t *handle, |
| struct buffer_head *bh) |
| { |
| int dirty = buffer_dirty(bh); |
| int ret; |
| |
| if (!buffer_mapped(bh) || buffer_freed(bh)) |
| return 0; |
| /* |
| * __block_write_begin() could have dirtied some buffers. Clean |
| * the dirty bit as jbd2_journal_get_write_access() could complain |
| * otherwise about fs integrity issues. Setting of the dirty bit |
| * by __block_write_begin() isn't a real problem here as we clear |
| * the bit before releasing a page lock and thus writeback cannot |
| * ever write the buffer. |
| */ |
| if (dirty) |
| clear_buffer_dirty(bh); |
| BUFFER_TRACE(bh, "get write access"); |
| ret = ext4_journal_get_write_access(handle, bh); |
| if (!ret && dirty) |
| ret = ext4_handle_dirty_metadata(handle, NULL, bh); |
| return ret; |
| } |
| |
| static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create); |
| |
| #ifdef CONFIG_EXT4_FS_ENCRYPTION |
| static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len, |
| get_block_t *get_block) |
| { |
| unsigned from = pos & (PAGE_CACHE_SIZE - 1); |
| unsigned to = from + len; |
| struct inode *inode = page->mapping->host; |
| unsigned block_start, block_end; |
| sector_t block; |
| int err = 0; |
| unsigned blocksize = inode->i_sb->s_blocksize; |
| unsigned bbits; |
| struct buffer_head *bh, *head, *wait[2], **wait_bh = wait; |
| bool decrypt = false; |
| |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(from > PAGE_CACHE_SIZE); |
| BUG_ON(to > PAGE_CACHE_SIZE); |
| BUG_ON(from > to); |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, blocksize, 0); |
| head = page_buffers(page); |
| bbits = ilog2(blocksize); |
| block = (sector_t)page->index << (PAGE_CACHE_SHIFT - bbits); |
| |
| for (bh = head, block_start = 0; bh != head || !block_start; |
| block++, block_start = block_end, bh = bh->b_this_page) { |
| block_end = block_start + blocksize; |
| if (block_end <= from || block_start >= to) { |
| if (PageUptodate(page)) { |
| if (!buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| } |
| continue; |
| } |
| if (buffer_new(bh)) |
| clear_buffer_new(bh); |
| if (!buffer_mapped(bh)) { |
| WARN_ON(bh->b_size != blocksize); |
| err = get_block(inode, block, bh, 1); |
| if (err) |
| break; |
| if (buffer_new(bh)) { |
| unmap_underlying_metadata(bh->b_bdev, |
| bh->b_blocknr); |
| if (PageUptodate(page)) { |
| clear_buffer_new(bh); |
| set_buffer_uptodate(bh); |
| mark_buffer_dirty(bh); |
| continue; |
| } |
| if (block_end > to || block_start < from) |
| zero_user_segments(page, to, block_end, |
| block_start, from); |
| continue; |
| } |
| } |
| if (PageUptodate(page)) { |
| if (!buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| continue; |
| } |
| if (!buffer_uptodate(bh) && !buffer_delay(bh) && |
| !buffer_unwritten(bh) && |
| (block_start < from || block_end > to)) { |
| ll_rw_block(READ, 1, &bh); |
| *wait_bh++ = bh; |
| decrypt = ext4_encrypted_inode(inode) && |
| S_ISREG(inode->i_mode); |
| } |
| } |
| /* |
| * If we issued read requests, let them complete. |
| */ |
| while (wait_bh > wait) { |
| wait_on_buffer(*--wait_bh); |
| if (!buffer_uptodate(*wait_bh)) |
| err = -EIO; |
| } |
| if (unlikely(err)) |
| page_zero_new_buffers(page, from, to); |
| else if (decrypt) |
| err = ext4_decrypt_one(inode, page); |
| return err; |
| } |
| #endif |
| |
| static int ext4_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| struct inode *inode = mapping->host; |
| int ret, needed_blocks; |
| handle_t *handle; |
| int retries = 0; |
| struct page *page; |
| pgoff_t index; |
| unsigned from, to; |
| |
| trace_ext4_write_begin(inode, pos, len, flags); |
| /* |
| * Reserve one block more for addition to orphan list in case |
| * we allocate blocks but write fails for some reason |
| */ |
| needed_blocks = ext4_writepage_trans_blocks(inode) + 1; |
| index = pos >> PAGE_CACHE_SHIFT; |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = from + len; |
| |
| if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { |
| ret = ext4_try_to_write_inline_data(mapping, inode, pos, len, |
| flags, pagep); |
| if (ret < 0) |
| return ret; |
| if (ret == 1) |
| return 0; |
| } |
| |
| /* |
| * grab_cache_page_write_begin() can take a long time if the |
| * system is thrashing due to memory pressure, or if the page |
| * is being written back. So grab it first before we start |
| * the transaction handle. This also allows us to allocate |
| * the page (if needed) without using GFP_NOFS. |
| */ |
| retry_grab: |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) |
| return -ENOMEM; |
| unlock_page(page); |
| |
| retry_journal: |
| handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks); |
| if (IS_ERR(handle)) { |
| page_cache_release(page); |
| return PTR_ERR(handle); |
| } |
| |
| lock_page(page); |
| if (page->mapping != mapping) { |
| /* The page got truncated from under us */ |
| unlock_page(page); |
| page_cache_release(page); |
| ext4_journal_stop(handle); |
| goto retry_grab; |
| } |
| /* In case writeback began while the page was unlocked */ |
| wait_for_stable_page(page); |
| |
| #ifdef CONFIG_EXT4_FS_ENCRYPTION |
| if (ext4_should_dioread_nolock(inode)) |
| ret = ext4_block_write_begin(page, pos, len, |
| ext4_get_block_write); |
| else |
| ret = ext4_block_write_begin(page, pos, len, |
| ext4_get_block); |
| #else |
| if (ext4_should_dioread_nolock(inode)) |
| ret = __block_write_begin(page, pos, len, ext4_get_block_write); |
| else |
| ret = __block_write_begin(page, pos, len, ext4_get_block); |
| #endif |
| if (!ret && ext4_should_journal_data(inode)) { |
| ret = ext4_walk_page_buffers(handle, page_buffers(page), |
| from, to, NULL, |
| do_journal_get_write_access); |
| } |
| |
| if (ret) { |
| unlock_page(page); |
| /* |
| * __block_write_begin may have instantiated a few blocks |
| * outside i_size. Trim these off again. Don't need |
| * i_size_read because we hold i_mutex. |
| * |
| * Add inode to orphan list in case we crash before |
| * truncate finishes |
| */ |
| if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| ext4_orphan_add(handle, inode); |
| |
| ext4_journal_stop(handle); |
| if (pos + len > inode->i_size) { |
| ext4_truncate_failed_write(inode); |
| /* |
| * If truncate failed early the inode might |
| * still be on the orphan list; we need to |
| * make sure the inode is removed from the |
| * orphan list in that case. |
| */ |
| if (inode->i_nlink) |
| ext4_orphan_del(NULL, inode); |
| } |
| |
| if (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)) |
| goto retry_journal; |
| page_cache_release(page); |
| return ret; |
| } |
| *pagep = page; |
| return ret; |
| } |
| |
| /* For write_end() in data=journal mode */ |
| static int write_end_fn(handle_t *handle, struct buffer_head *bh) |
| { |
| int ret; |
| if (!buffer_mapped(bh) || buffer_freed(bh)) |
| return 0; |
| set_buffer_uptodate(bh); |
| ret = ext4_handle_dirty_metadata(handle, NULL, bh); |
| clear_buffer_meta(bh); |
| clear_buffer_prio(bh); |
| return ret; |
| } |
| |
| /* |
| * We need to pick up the new inode size which generic_commit_write gave us |
| * `file' can be NULL - eg, when called from page_symlink(). |
| * |
| * ext4 never places buffers on inode->i_mapping->private_list. metadata |
| * buffers are managed internally. |
| */ |
| static int ext4_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct inode *inode = mapping->host; |
| loff_t old_size = inode->i_size; |
| int ret = 0, ret2; |
| int i_size_changed = 0; |
| |
| trace_ext4_write_end(inode, pos, len, copied); |
| if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) { |
| ret = ext4_jbd2_file_inode(handle, inode); |
| if (ret) { |
| unlock_page(page); |
| page_cache_release(page); |
| goto errout; |
| } |
| } |
| |
| if (ext4_has_inline_data(inode)) { |
| ret = ext4_write_inline_data_end(inode, pos, len, |
| copied, page); |
| if (ret < 0) |
| goto errout; |
| copied = ret; |
| } else |
| copied = block_write_end(file, mapping, pos, |
| len, copied, page, fsdata); |
| /* |
| * it's important to update i_size while still holding page lock: |
| * page writeout could otherwise come in and zero beyond i_size. |
| */ |
| i_size_changed = ext4_update_inode_size(inode, pos + copied); |
| unlock_page(page); |
| page_cache_release(page); |
| |
| if (old_size < pos) |
| pagecache_isize_extended(inode, old_size, pos); |
| /* |
| * Don't mark the inode dirty under page lock. First, it unnecessarily |
| * makes the holding time of page lock longer. Second, it forces lock |
| * ordering of page lock and transaction start for journaling |
| * filesystems. |
| */ |
| if (i_size_changed) |
| ext4_mark_inode_dirty(handle, inode); |
| |
| if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| /* if we have allocated more blocks and copied |
| * less. We will have blocks allocated outside |
| * inode->i_size. So truncate them |
| */ |
| ext4_orphan_add(handle, inode); |
| errout: |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| |
| if (pos + len > inode->i_size) { |
| ext4_truncate_failed_write(inode); |
| /* |
| * If truncate failed early the inode might still be |
| * on the orphan list; we need to make sure the inode |
| * is removed from the orphan list in that case. |
| */ |
| if (inode->i_nlink) |
| ext4_orphan_del(NULL, inode); |
| } |
| |
| return ret ? ret : copied; |
| } |
| |
| static int ext4_journalled_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| handle_t *handle = ext4_journal_current_handle(); |
| struct inode *inode = mapping->host; |
| loff_t old_size = inode->i_size; |
| int ret = 0, ret2; |
| int partial = 0; |
| unsigned from, to; |
| int size_changed = 0; |
| |
| trace_ext4_journalled_write_end(inode, pos, len, copied); |
| from = pos & (PAGE_CACHE_SIZE - 1); |
| to = from + len; |
| |
| BUG_ON(!ext4_handle_valid(handle)); |
| |
| if (ext4_has_inline_data(inode)) |
| copied = ext4_write_inline_data_end(inode, pos, len, |
| copied, page); |
| else { |
| if (copied < len) { |
| if (!PageUptodate(page)) |
| copied = 0; |
| page_zero_new_buffers(page, from+copied, to); |
| } |
| |
| ret = ext4_walk_page_buffers(handle, page_buffers(page), from, |
| to, &partial, write_end_fn); |
| if (!partial) |
| SetPageUptodate(page); |
| } |
| size_changed = ext4_update_inode_size(inode, pos + copied); |
| ext4_set_inode_state(inode, EXT4_STATE_JDATA); |
| EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; |
| unlock_page(page); |
| page_cache_release(page); |
| |
| if (old_size < pos) |
| pagecache_isize_extended(inode, old_size, pos); |
| |
| if (size_changed) { |
| ret2 = ext4_mark_inode_dirty(handle, inode); |
| if (!ret) |
| ret = ret2; |
| } |
| |
| if (pos + len > inode->i_size && ext4_can_truncate(inode)) |
| /* if we have allocated more blocks and copied |
| * less. We will have blocks allocated outside |
| * inode->i_size. So truncate them |
| */ |
| ext4_orphan_add(handle, inode); |
| |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| if (pos + len > inode->i_size) { |
| ext4_truncate_failed_write(inode); |
| /* |
| * If truncate failed early the inode might still be |
| * on the orphan list; we need to make sure the inode |
| * is removed from the orphan list in that case. |
| */ |
| if (inode->i_nlink) |
| ext4_orphan_del(NULL, inode); |
| } |
| |
| return ret ? ret : copied; |
| } |
| |
| /* |
| * Reserve a single cluster located at lblock |
| */ |
| static int ext4_da_reserve_space(struct inode *inode, ext4_lblk_t lblock) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| unsigned int md_needed; |
| int ret; |
| |
| /* |
| * We will charge metadata quota at writeout time; this saves |
| * 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, EXT4_C2B(sbi, 1)); |
| if (ret) |
| return ret; |
| |
| /* |
| * recalculate the amount of metadata blocks to reserve |
| * in order to allocate nrblocks |
| * worse case is one extent per block |
| */ |
| spin_lock(&ei->i_block_reservation_lock); |
| /* |
| * ext4_calc_metadata_amount() has side effects, which we have |
| * to be prepared undo if we fail to claim space. |
| */ |
| md_needed = 0; |
| trace_ext4_da_reserve_space(inode, 0); |
| |
| if (ext4_claim_free_clusters(sbi, 1, 0)) { |
| spin_unlock(&ei->i_block_reservation_lock); |
| dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1)); |
| return -ENOSPC; |
| } |
| ei->i_reserved_data_blocks++; |
| spin_unlock(&ei->i_block_reservation_lock); |
| |
| return 0; /* success */ |
| } |
| |
| static void ext4_da_release_space(struct inode *inode, int to_free) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| |
| if (!to_free) |
| return; /* Nothing to release, exit */ |
| |
| spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
| |
| trace_ext4_da_release_space(inode, to_free); |
| if (unlikely(to_free > ei->i_reserved_data_blocks)) { |
| /* |
| * if there aren't enough reserved blocks, then the |
| * counter is messed up somewhere. Since this |
| * function is called from invalidate page, it's |
| * harmless to return without any action. |
| */ |
| ext4_warning(inode->i_sb, "ext4_da_release_space: " |
| "ino %lu, to_free %d with only %d reserved " |
| "data blocks", inode->i_ino, to_free, |
| ei->i_reserved_data_blocks); |
| WARN_ON(1); |
| to_free = ei->i_reserved_data_blocks; |
| } |
| ei->i_reserved_data_blocks -= to_free; |
| |
| /* update fs dirty data blocks counter */ |
| percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free); |
| |
| spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
| |
| dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free)); |
| } |
| |
| static void ext4_da_page_release_reservation(struct page *page, |
| unsigned int offset, |
| unsigned int length) |
| { |
| 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); |
| unsigned int stop = offset + length; |
| int num_clusters; |
| ext4_fsblk_t lblk; |
| |
| BUG_ON(stop > PAGE_CACHE_SIZE || stop < length); |
| |
| head = page_buffers(page); |
| bh = head; |
| do { |
| unsigned int next_off = curr_off + bh->b_size; |
| |
| if (next_off > stop) |
| break; |
| |
| if ((offset <= curr_off) && (buffer_delay(bh))) { |
| to_release++; |
| clear_buffer_delay(bh); |
| } |
| curr_off = next_off; |
| } while ((bh = bh->b_this_page) != head); |
| |
| if (to_release) { |
| lblk = page->index << (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| ext4_es_remove_extent(inode, lblk, 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) { |
| 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)) |
| ext4_da_release_space(inode, 1); |
| |
| num_clusters--; |
| } |
| } |
| |
| /* |
| * Delayed allocation stuff |
| */ |
| |
| struct mpage_da_data { |
| struct inode *inode; |
| struct writeback_control *wbc; |
| |
| pgoff_t first_page; /* The first page to write */ |
| pgoff_t next_page; /* Current page to examine */ |
| pgoff_t last_page; /* Last page to examine */ |
| /* |
| * Extent to map - this can be after first_page because that can be |
| * fully mapped. We somewhat abuse m_flags to store whether the extent |
| * is delalloc or unwritten. |
| */ |
| struct ext4_map_blocks map; |
| struct ext4_io_submit io_submit; /* IO submission data */ |
| }; |
| |
| static void mpage_release_unused_pages(struct mpage_da_data *mpd, |
| bool invalidate) |
| { |
| int nr_pages, i; |
| pgoff_t index, end; |
| struct pagevec pvec; |
| struct inode *inode = mpd->inode; |
| struct address_space *mapping = inode->i_mapping; |
| |
| /* This is necessary when next_page == 0. */ |
| if (mpd->first_page >= mpd->next_page) |
| return; |
| |
| index = mpd->first_page; |
| end = mpd->next_page - 1; |
| if (invalidate) { |
| ext4_lblk_t start, last; |
| start = index << (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| last = end << (PAGE_CACHE_SHIFT - inode->i_blkbits); |
| ext4_es_remove_extent(inode, start, last - start + 1); |
| } |
| |
| pagevec_init(&pvec, 0); |
| while (index <= end) { |
| nr_pages = pagevec_lookup(&pvec, mapping, index, PAGEVEC_SIZE); |
| if (nr_pages == 0) |
| break; |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| if (page->index > end) |
| break; |
| BUG_ON(!PageLocked(page)); |
| BUG_ON(PageWriteback(page)); |
| if (invalidate) { |
| block_invalidatepage(page, 0, PAGE_CACHE_SIZE); |
| ClearPageUptodate(page); |
| } |
| unlock_page(page); |
| } |
| index = pvec.pages[nr_pages - 1]->index + 1; |
| pagevec_release(&pvec); |
| } |
| } |
| |
| static void ext4_print_free_blocks(struct inode *inode) |
| { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| struct super_block *sb = inode->i_sb; |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| |
| ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld", |
| EXT4_C2B(EXT4_SB(inode->i_sb), |
| ext4_count_free_clusters(sb))); |
| ext4_msg(sb, KERN_CRIT, "Free/Dirty block details"); |
| ext4_msg(sb, KERN_CRIT, "free_blocks=%lld", |
| (long long) EXT4_C2B(EXT4_SB(sb), |
| percpu_counter_sum(&sbi->s_freeclusters_counter))); |
| ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld", |
| (long long) EXT4_C2B(EXT4_SB(sb), |
| percpu_counter_sum(&sbi->s_dirtyclusters_counter))); |
| ext4_msg(sb, KERN_CRIT, "Block reservation details"); |
| ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u", |
| ei->i_reserved_data_blocks); |
| return; |
| } |
| |
| static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh) |
| { |
| return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(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) |
| { |
| struct extent_status es; |
| int retval; |
| sector_t invalid_block = ~((sector_t) 0xffff); |
| #ifdef ES_AGGRESSIVE_TEST |
| struct ext4_map_blocks orig_map; |
| |
| memcpy(&orig_map, map, sizeof(*map)); |
| #endif |
| |
| 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); |
| |
| /* Lookup extent status tree firstly */ |
| if (ext4_es_lookup_extent(inode, iblock, &es)) { |
| if (ext4_es_is_hole(&es)) { |
| retval = 0; |
| down_read(&EXT4_I(inode)->i_data_sem); |
| goto add_delayed; |
| } |
| |
| /* |
| * Delayed extent could be allocated by fallocate. |
| * So we need to check it. |
| */ |
| if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) { |
| map_bh(bh, inode->i_sb, invalid_block); |
| set_buffer_new(bh); |
| set_buffer_delay(bh); |
| return 0; |
| } |
| |
| map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk; |
| retval = es.es_len - (iblock - es.es_lblk); |
| if (retval > map->m_len) |
| retval = map->m_len; |
| map->m_len = retval; |
| if (ext4_es_is_written(&es)) |
| map->m_flags |= EXT4_MAP_MAPPED; |
| else if (ext4_es_is_unwritten(&es)) |
| map->m_flags |= EXT4_MAP_UNWRITTEN; |
| else |
| BUG_ON(1); |
| |
| #ifdef ES_AGGRESSIVE_TEST |
| ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0); |
| #endif |
| return retval; |
| } |
| |
| /* |
| * 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_has_inline_data(inode)) |
| retval = 0; |
| else 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); |
| |
| add_delayed: |
| if (retval == 0) { |
| int ret; |
| /* |
| * XXX: __block_prepare_write() unmaps passed block, |
| * is it OK? |
| */ |
| /* |
| * If the block was allocated from previously allocated cluster, |
| * then we don't need to reserve it again. However we still need |
| * to reserve metadata for every block we're going to write. |
| */ |
| if (EXT4_SB(inode->i_sb)->s_cluster_ratio <= 1 || |
| !ext4_find_delalloc_cluster(inode, map->m_lblk)) { |
| ret = ext4_da_reserve_space(inode, iblock); |
| if (ret) { |
| /* not enough space to reserve */ |
| retval = ret; |
| goto out_unlock; |
| } |
| } |
| |
| ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, |
| ~0, EXTENT_STATUS_DELAYED); |
| if (ret) { |
| retval = ret; |
| goto out_unlock; |
| } |
| |
| map_bh(bh, inode->i_sb, invalid_block); |
| set_buffer_new(bh); |
| set_buffer_delay(bh); |
| } else if (retval > 0) { |
| int ret; |
| unsigned int status; |
| |
| if (unlikely(retval != map->m_len)) { |
| ext4_warning(inode->i_sb, |
| "ES len assertion failed for inode " |
| "%lu: retval %d != map->m_len %d", |
| inode->i_ino, retval, map->m_len); |
| WARN_ON(1); |
| } |
| |
| status = map->m_flags & EXT4_MAP_UNWRITTEN ? |
| EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN; |
| ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len, |
| map->m_pblk, status); |
| if (ret != 0) |
| retval = ret; |
| } |
| |
| out_unlock: |
| up_read((&EXT4_I(inode)->i_data_sem)); |
| |
| return retval; |
| } |
| |
| /* |
| * This is a special get_block_t callback which is used by |
| * ext4_da_write_begin(). It will either return mapped block or |
| * reserve space for a single block. |
| * |
| * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set. |
| * We also have b_blocknr = -1 and b_bdev initialized properly |
| * |
| * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set. |
| * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev |
| * initialized properly. |
| */ |
| int ext4_da_get_block_prep(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh, int create) |
| { |
| struct ext4_map_blocks map; |
| int ret = 0; |
| |
| BUG_ON(create == 0); |
| BUG_ON(bh->b_size != inode->i_sb->s_blocksize); |
| |
| map.m_lblk = iblock; |
| map.m_len = 1; |
| |
| /* |
| * first, we need to know whether the block is allocated already |
| * preallocated blocks are unmapped but should treated |
| * the same as allocated blocks. |
| */ |
| ret = ext4_da_map_blocks(inode, iblock, &map, bh); |
| if (ret <= 0) |
| return ret; |
| |
| map_bh(bh, inode->i_sb, map.m_pblk); |
| bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | map.m_flags; |
| |
| if (buffer_unwritten(bh)) { |
| /* A delayed write to unwritten bh should be marked |
| * new and mapped. Mapped ensures that we don't do |
| * get_block multiple times when we write to the same |
| * offset and new ensures that we do proper zero out |
| * for partial write. |
| */ |
| set_buffer_new(bh); |
| set_buffer_mapped(bh); |
| } |
| return 0; |
| } |
| |
| static int bget_one(handle_t *handle, struct buffer_head *bh) |
| { |
| get_bh(bh); |
| return 0; |
| } |
| |
| static int bput_one(handle_t *handle, struct buffer_head *bh) |
| { |
| put_bh(bh); |
| return 0; |
| } |
| |
| static int __ext4_journalled_writepage(struct page *page, |
| unsigned int len) |
| { |
| struct address_space *mapping = page->mapping; |
| struct inode *inode = mapping->host; |
| struct buffer_head *page_bufs = NULL; |
| handle_t *handle = NULL; |
| int ret = 0, err = 0; |
| int inline_data = ext4_has_inline_data(inode); |
| struct buffer_head *inode_bh = NULL; |
| |
| ClearPageChecked(page); |
| |
| if (inline_data) { |
| BUG_ON(page->index != 0); |
| BUG_ON(len > ext4_get_max_inline_size(inode)); |
| inode_bh = ext4_journalled_write_inline_data(inode, len, page); |
| if (inode_bh == NULL) |
| goto out; |
| } else { |
| page_bufs = page_buffers(page); |
| if (!page_bufs) { |
| BUG(); |
| goto out; |
| } |
| ext4_walk_page_buffers(handle, page_bufs, 0, len, |
| NULL, bget_one); |
| } |
| /* As soon as we unlock the page, it can go away, but we have |
| * references to buffers so we are safe */ |
| unlock_page(page); |
| |
| handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, |
| ext4_writepage_trans_blocks(inode)); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out; |
| } |
| |
| BUG_ON(!ext4_handle_valid(handle)); |
| |
| if (inline_data) { |
| BUFFER_TRACE(inode_bh, "get write access"); |
| ret = ext4_journal_get_write_access(handle, inode_bh); |
| |
| err = ext4_handle_dirty_metadata(handle, inode, inode_bh); |
| |
| } else { |
| ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, |
| do_journal_get_write_access); |
| |
| err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL, |
| write_end_fn); |
| } |
| if (ret == 0) |
| ret = err; |
| EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid; |
| err = ext4_journal_stop(handle); |
| if (!ret) |
| ret = err; |
| |
| if (!ext4_has_inline_data(inode)) |
| ext4_walk_page_buffers(NULL, page_bufs, 0, len, |
| NULL, bput_one); |
| ext4_set_inode_state(inode, EXT4_STATE_JDATA); |
| out: |
| brelse(inode_bh); |
| return ret; |
| } |
| |
| /* |
| * Note that we don't need to start a transaction unless we're journaling data |
| * because we should have holes filled from ext4_page_mkwrite(). We even don't |
| * need to file the inode to the transaction's list in ordered mode because if |
| * we are writing back data added by write(), the inode is already there and if |
| * we are writing back data modified via mmap(), no one guarantees in which |
| * transaction the data will hit the disk. In case we are journaling data, we |
| * cannot start transaction directly because transaction start ranks above page |
| * lock so we have to do some magic. |
| * |
| * This function can get called via... |
| * - ext4_writepages after taking page lock (have journal handle) |
| * - journal_submit_inode_data_buffers (no journal handle) |
| * - shrink_page_list via the kswapd/direct reclaim (no journal handle) |
| * - grab_page_cache when doing write_begin (have journal handle) |
| * |
| * We don't do any block allocation in this function. If we have page with |
| * multiple blocks we need to write those buffer_heads that are mapped. This |
| * is important for mmaped based write. So if we do with blocksize 1K |
| * truncate(f, 1024); |
| * a = mmap(f, 0, 4096); |
| * a[0] = 'a'; |
| * truncate(f, 4096); |
| * we have in the page first buffer_head mapped via page_mkwrite call back |
| * but other buffer_heads would be unmapped but dirty (dirty done via the |
| * do_wp_page). So writepage should write the first block. If we modify |
| * the mmap area beyond 1024 we will again get a page_fault and the |
| * page_mkwrite callback will do the block allocation and mark the |
| * buffer_heads mapped. |
| * |
| * We redirty the page if we have any buffer_heads that is either delay or |
| * unwritten in the page. |
| * |
| * We can get recursively called as show below. |
| * |
| * ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> |
| * ext4_writepage() |
| * |
| * But since we don't do any block allocation we should not deadlock. |
| * Page also have the dirty flag cleared so we don't get recurive page_lock. |
| */ |
| static int ext4_writepage(struct page *page, |
| struct writeback_control *wbc) |
| { |
| int ret = 0; |
| loff_t size; |
| unsigned int len; |
| struct buffer_head *page_bufs = NULL; |
| struct inode *inode = page->mapping->host; |
| struct ext4_io_submit io_submit; |
| bool keep_towrite = false; |
| |
| trace_ext4_writepage(page); |
| size = i_size_read(inode); |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| |
| page_bufs = page_buffers(page); |
| /* |
| * We cannot do block allocation or other extent handling in this |
| * function. If there are buffers needing that, we have to redirty |
| * the page. But we may reach here when we do a journal commit via |
| * journal_submit_inode_data_buffers() and in that case we must write |
| * allocated buffers to achieve data=ordered mode guarantees. |
| */ |
| if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL, |
| ext4_bh_delay_or_unwritten)) { |
| redirty_page_for_writepage(wbc, page); |
| if (current->flags & PF_MEMALLOC) { |
| /* |
| * For memory cleaning there's no point in writing only |
| * some buffers. So just bail out. Warn if we came here |
| * from direct reclaim. |
| */ |
| WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD)) |
| == PF_MEMALLOC); |
| unlock_page(page); |
| return 0; |
| } |
| keep_towrite = true; |
| } |
| |
| if (PageChecked(page) && ext4_should_journal_data(inode)) |
| /* |
| * It's mmapped pagecache. Add buffers and journal it. There |
| * doesn't seem much point in redirtying the page here. |
| */ |
| return __ext4_journalled_writepage(page, len); |
| |
| ext4_io_submit_init(&io_submit, wbc); |
| io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS); |
| if (!io_submit.io_end) { |
| redirty_page_for_writepage(wbc, page); |
| unlock_page(page); |
| return -ENOMEM; |
| } |
| ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite); |
| ext4_io_submit(&io_submit); |
| /* Drop io_end reference we got from init */ |
| ext4_put_io_end_defer(io_submit.io_end); |
| return ret; |
| } |
| |
| static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page) |
| { |
| int len; |
| loff_t size = i_size_read(mpd->inode); |
| int err; |
| |
| BUG_ON(page->index != mpd->first_page); |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| clear_page_dirty_for_io(page); |
| err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false); |
| if (!err) |
| mpd->wbc->nr_to_write--; |
| mpd->first_page++; |
| |
| return err; |
| } |
| |
| #define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay)) |
| |
| /* |
| * mballoc gives us at most this number of blocks... |
| * XXX: That seems to be only a limitation of ext4_mb_normalize_request(). |
| * The rest of mballoc seems to handle chunks up to full group size. |
| */ |
| #define MAX_WRITEPAGES_EXTENT_LEN 2048 |
| |
| /* |
| * mpage_add_bh_to_extent - try to add bh to extent of blocks to map |
| * |
| * @mpd - extent of blocks |
| * @lblk - logical number of the block in the file |
| * @bh - buffer head we want to add to the extent |
| * |
| * The function is used to collect contig. blocks in the same state. If the |
| * buffer doesn't require mapping for writeback and we haven't started the |
| * extent of buffers to map yet, the function returns 'true' immediately - the |
| * caller can write the buffer right away. Otherwise the function returns true |
| * if the block has been added to the extent, false if the block couldn't be |
| * added. |
| */ |
| static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk, |
| struct buffer_head *bh) |
| { |
| struct ext4_map_blocks *map = &mpd->map; |
| |
| /* Buffer that doesn't need mapping for writeback? */ |
| if (!buffer_dirty(bh) || !buffer_mapped(bh) || |
| (!buffer_delay(bh) && !buffer_unwritten(bh))) { |
| /* So far no extent to map => we write the buffer right away */ |
| if (map->m_len == 0) |
| return true; |
| return false; |
| } |
| |
| /* First block in the extent? */ |
| if (map->m_len == 0) { |
| map->m_lblk = lblk; |
| map->m_len = 1; |
| map->m_flags = bh->b_state & BH_FLAGS; |
| return true; |
| } |
| |
| /* Don't go larger than mballoc is willing to allocate */ |
| if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN) |
| return false; |
| |
| /* Can we merge the block to our big extent? */ |
| if (lblk == map->m_lblk + map->m_len && |
| (bh->b_state & BH_FLAGS) == map->m_flags) { |
| map->m_len++; |
| return true; |
| } |
| return false; |
| } |
| |
| /* |
| * mpage_process_page_bufs - submit page buffers for IO or add them to extent |
| * |
| * @mpd - extent of blocks for mapping |
| * @head - the first buffer in the page |
| * @bh - buffer we should start processing from |
| * @lblk - logical number of the block in the file corresponding to @bh |
| * |
| * Walk through page buffers from @bh upto @head (exclusive) and either submit |
| * the page for IO if all buffers in this page were mapped and there's no |
| * accumulated extent of buffers to map or add buffers in the page to the |
| * extent of buffers to map. The function returns 1 if the caller can continue |
| * by processing the next page, 0 if it should stop adding buffers to the |
| * extent to map because we cannot extend it anymore. It can also return value |
| * < 0 in case of error during IO submission. |
| */ |
| static int mpage_process_page_bufs(struct mpage_da_data *mpd, |
| struct buffer_head *head, |
| struct buffer_head *bh, |
| ext4_lblk_t lblk) |
| { |
| struct inode *inode = mpd->inode; |
| int err; |
| ext4_lblk_t blocks = (i_size_read(inode) + (1 << inode->i_blkbits) - 1) |
| >> inode->i_blkbits; |
| |
| do { |
| BUG_ON(buffer_locked(bh)); |
| |
| if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) { |
| /* Found extent to map? */ |
| if (mpd->map.m_len) |
| return 0; |
| /* Everything mapped so far and we hit EOF */ |
| break; |
| } |
| } while (lblk++, (bh = bh->b_this_page) != head); |
| /* So far everything mapped? Submit the page for IO. */ |
| if (mpd->map.m_len == 0) { |
| err = mpage_submit_page(mpd, head->b_page); |
| if (err < 0) |
| return err; |
| } |
| return lblk < blocks; |
| } |
| |
| /* |
| * mpage_map_buffers - update buffers corresponding to changed extent and |
| * submit fully mapped pages for IO |
| * |
| * @mpd - description of extent to map, on return next extent to map |
| * |
| * Scan buffers corresponding to changed extent (we expect corresponding pages |
| * to be already locked) and update buffer state according to new extent state. |
| * We map delalloc buffers to their physical location, clear unwritten bits, |
| * and mark buffers as uninit when we perform writes to unwritten extents |
| * and do extent conversion after IO is finished. If the last page is not fully |
| * mapped, we update @map to the next extent in the last page that needs |
| * mapping. Otherwise we submit the page for IO. |
| */ |
| static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd) |
| { |
| struct pagevec pvec; |
| int nr_pages, i; |
| struct inode *inode = mpd->inode; |
| struct buffer_head *head, *bh; |
| int bpp_bits = PAGE_CACHE_SHIFT - inode->i_blkbits; |
| pgoff_t start, end; |
| ext4_lblk_t lblk; |
| sector_t pblock; |
| int err; |
| |
| start = mpd->map.m_lblk >> bpp_bits; |
| end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits; |
| lblk = start << bpp_bits; |
| pblock = mpd->map.m_pblk; |
| |
| pagevec_init(&pvec, 0); |
| while (start <= end) { |
| nr_pages = pagevec_lookup(&pvec, inode->i_mapping, start, |
| PAGEVEC_SIZE); |
| if (nr_pages == 0) |
| break; |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| |
| if (page->index > end) |
| break; |
| /* Up to 'end' pages must be contiguous */ |
| BUG_ON(page->index != start); |
| bh = head = page_buffers(page); |
| do { |
| if (lblk < mpd->map.m_lblk) |
| continue; |
| if (lblk >= mpd->map.m_lblk + mpd->map.m_len) { |
| /* |
| * Buffer after end of mapped extent. |
| * Find next buffer in the page to map. |
| */ |
| mpd->map.m_len = 0; |
| mpd->map.m_flags = 0; |
| /* |
| * FIXME: If dioread_nolock supports |
| * blocksize < pagesize, we need to make |
| * sure we add size mapped so far to |
| * io_end->size as the following call |
| * can submit the page for IO. |
| */ |
| err = mpage_process_page_bufs(mpd, head, |
| bh, lblk); |
| pagevec_release(&pvec); |
| if (err > 0) |
| err = 0; |
| return err; |
| } |
| if (buffer_delay(bh)) { |
| clear_buffer_delay(bh); |
| bh->b_blocknr = pblock++; |
| } |
| clear_buffer_unwritten(bh); |
| } while (lblk++, (bh = bh->b_this_page) != head); |
| |
| /* |
| * FIXME: This is going to break if dioread_nolock |
| * supports blocksize < pagesize as we will try to |
| * convert potentially unmapped parts of inode. |
| */ |
| mpd->io_submit.io_end->size += PAGE_CACHE_SIZE; |
| /* Page fully mapped - let IO run! */ |
| err = mpage_submit_page(mpd, page); |
| if (err < 0) { |
| pagevec_release(&pvec); |
| return err; |
| } |
| start++; |
| } |
| pagevec_release(&pvec); |
| } |
| /* Extent fully mapped and matches with page boundary. We are done. */ |
| mpd->map.m_len = 0; |
| mpd->map.m_flags = 0; |
| return 0; |
| } |
| |
| static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd) |
| { |
| struct inode *inode = mpd->inode; |
| struct ext4_map_blocks *map = &mpd->map; |
| int get_blocks_flags; |
| int err, dioread_nolock; |
| |
| trace_ext4_da_write_pages_extent(inode, map); |
| /* |
| * Call ext4_map_blocks() to allocate any delayed allocation blocks, or |
| * to convert an unwritten extent to be initialized (in the case |
| * where we have written into one or more preallocated blocks). It is |
| * possible that we're going to need more metadata blocks than |
| * previously reserved. However we must not fail because we're in |
| * writeback and there is nothing we can do about it so it might result |
| * in data loss. So use reserved blocks to allocate metadata if |
| * possible. |
| * |
| * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if |
| * the blocks in question are delalloc blocks. This indicates |
| * that the blocks and quotas has already been checked when |
| * the data was copied into the page cache. |
| */ |
| get_blocks_flags = EXT4_GET_BLOCKS_CREATE | |
| EXT4_GET_BLOCKS_METADATA_NOFAIL; |
| dioread_nolock = ext4_should_dioread_nolock(inode); |
| if (dioread_nolock) |
| get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT; |
| if (map->m_flags & (1 << BH_Delay)) |
| get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE; |
| |
| err = ext4_map_blocks(handle, inode, map, get_blocks_flags); |
| if (err < 0) |
| return err; |
| if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) { |
| if (!mpd->io_submit.io_end->handle && |
| ext4_handle_valid(handle)) { |
| mpd->io_submit.io_end->handle = handle->h_rsv_handle; |
| handle->h_rsv_handle = NULL; |
| } |
| ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end); |
| } |
| |
| BUG_ON(map->m_len == 0); |
| if (map->m_flags & EXT4_MAP_NEW) { |
| struct block_device *bdev = inode->i_sb->s_bdev; |
| int i; |
| |
| for (i = 0; i < map->m_len; i++) |
| unmap_underlying_metadata(bdev, map->m_pblk + i); |
| } |
| return 0; |
| } |
| |
| /* |
| * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length |
| * mpd->len and submit pages underlying it for IO |
| * |
| * @handle - handle for journal operations |
| * @mpd - extent to map |
| * @give_up_on_write - we set this to true iff there is a fatal error and there |
| * is no hope of writing the data. The caller should discard |
| * dirty pages to avoid infinite loops. |
| * |
| * The function maps extent starting at mpd->lblk of length mpd->len. If it is |
| * delayed, blocks are allocated, if it is unwritten, we may need to convert |
| * them to initialized or split the described range from larger unwritten |
| * extent. Note that we need not map all the described range since allocation |
| * can return less blocks or the range is covered by more unwritten extents. We |
| * cannot map more because we are limited by reserved transaction credits. On |
| * the other hand we always make sure that the last touched page is fully |
| * mapped so that it can be written out (and thus forward progress is |
| * guaranteed). After mapping we submit all mapped pages for IO. |
| */ |
| static int mpage_map_and_submit_extent(handle_t *handle, |
| struct mpage_da_data *mpd, |
| bool *give_up_on_write) |
| { |
| struct inode *inode = mpd->inode; |
| struct ext4_map_blocks *map = &mpd->map; |
| int err; |
| loff_t disksize; |
| int progress = 0; |
| |
| mpd->io_submit.io_end->offset = |
| ((loff_t)map->m_lblk) << inode->i_blkbits; |
| do { |
| err = mpage_map_one_extent(handle, mpd); |
| if (err < 0) { |
| struct super_block *sb = inode->i_sb; |
| |
| if (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED) |
| goto invalidate_dirty_pages; |
| /* |
| * Let the uper layers retry transient errors. |
| * In the case of ENOSPC, if ext4_count_free_blocks() |
| * is non-zero, a commit should free up blocks. |
| */ |
| if ((err == -ENOMEM) || |
| (err == -ENOSPC && ext4_count_free_clusters(sb))) { |
| if (progress) |
| goto update_disksize; |
| return err; |
| } |
| ext4_msg(sb, KERN_CRIT, |
| "Delayed block allocation failed for " |
| "inode %lu at logical offset %llu with" |
| " max blocks %u with error %d", |
| inode->i_ino, |
| (unsigned long long)map->m_lblk, |
| (unsigned)map->m_len, -err); |
| ext4_msg(sb, KERN_CRIT, |
| "This should not happen!! Data will " |
| "be lost\n"); |
| if (err == -ENOSPC) |
| ext4_print_free_blocks(inode); |
| invalidate_dirty_pages: |
| *give_up_on_write = true; |
| return err; |
| } |
| progress = 1; |
| /* |
| * Update buffer state, submit mapped pages, and get us new |
| * extent to map |
| */ |
| err = mpage_map_and_submit_buffers(mpd); |
| if (err < 0) |
| goto update_disksize; |
| } while (map->m_len); |
| |
| update_disksize: |
| /* |
| * Update on-disk size after IO is submitted. Races with |
| * truncate are avoided by checking i_size under i_data_sem. |
| */ |
| disksize = ((loff_t)mpd->first_page) << PAGE_CACHE_SHIFT; |
| if (disksize > EXT4_I(inode)->i_disksize) { |
| int err2; |
| loff_t i_size; |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| i_size = i_size_read(inode); |
| if (disksize > i_size) |
| disksize = i_size; |
| if (disksize > EXT4_I(inode)->i_disksize) |
| EXT4_I(inode)->i_disksize = disksize; |
| err2 = ext4_mark_inode_dirty(handle, inode); |
| up_write(&EXT4_I(inode)->i_data_sem); |
| if (err2) |
| ext4_error(inode->i_sb, |
| "Failed to mark inode %lu dirty", |
| inode->i_ino); |
| if (!err) |
| err = err2; |
| } |
| return err; |
| } |
| |
| /* |
| * Calculate the total number of credits to reserve for one writepages |
| * iteration. This is called from ext4_writepages(). We map an extent of |
| * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping |
| * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN + |
| * bpp - 1 blocks in bpp different extents. |
| */ |
| static int ext4_da_writepages_trans_blocks(struct inode *inode) |
| { |
| int bpp = ext4_journal_blocks_per_page(inode); |
| |
| return ext4_meta_trans_blocks(inode, |
| MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp); |
| } |
| |
| /* |
| * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages |
| * and underlying extent to map |
| * |
| * @mpd - where to look for pages |
| * |
| * Walk dirty pages in the mapping. If they are fully mapped, submit them for |
| * IO immediately. When we find a page which isn't mapped we start accumulating |
| * extent of buffers underlying these pages that needs mapping (formed by |
| * either delayed or unwritten buffers). We also lock the pages containing |
| * these buffers. The extent found is returned in @mpd structure (starting at |
| * mpd->lblk with length mpd->len blocks). |
| * |
| * Note that this function can attach bios to one io_end structure which are |
| * neither logically nor physically contiguous. Although it may seem as an |
| * unnecessary complication, it is actually inevitable in blocksize < pagesize |
| * case as we need to track IO to all buffers underlying a page in one io_end. |
| */ |
| static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd) |
| { |
| struct address_space *mapping = mpd->inode->i_mapping; |
| struct pagevec pvec; |
| unsigned int nr_pages; |
| long left = mpd->wbc->nr_to_write; |
| pgoff_t index = mpd->first_page; |
| pgoff_t end = mpd->last_page; |
| int tag; |
| int i, err = 0; |
| int blkbits = mpd->inode->i_blkbits; |
| ext4_lblk_t lblk; |
| struct buffer_head *head; |
| |
| if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages) |
| tag = PAGECACHE_TAG_TOWRITE; |
| else |
| tag = PAGECACHE_TAG_DIRTY; |
| |
| pagevec_init(&pvec, 0); |
| mpd->map.m_len = 0; |
| mpd->next_page = index; |
| while (index <= end) { |
| nr_pages = pagevec_lookup_tag(&pvec, mapping, &index, tag, |
| min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1); |
| if (nr_pages == 0) |
| goto out; |
| |
| for (i = 0; i < nr_pages; i++) { |
| struct page *page = pvec.pages[i]; |
| |
| /* |
| * At this point, the page may be truncated or |
| * invalidated (changing page->mapping to NULL), or |
| * even swizzled back from swapper_space to tmpfs file |
| * mapping. However, page->index will not change |
| * because we have a reference on the page. |
| */ |
| if (page->index > end) |
| goto out; |
| |
| /* |
| * Accumulated enough dirty pages? This doesn't apply |
| * to WB_SYNC_ALL mode. For integrity sync we have to |
| * keep going because someone may be concurrently |
| * dirtying pages, and we might have synced a lot of |
| * newly appeared dirty pages, but have not synced all |
| * of the old dirty pages. |
| */ |
| if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0) |
| goto out; |
| |
| /* If we can't merge this page, we are done. */ |
| if (mpd->map.m_len > 0 && mpd->next_page != page->index) |
| goto out; |
| |
| lock_page(page); |
| /* |
| * If the page is no longer dirty, or its mapping no |
| * longer corresponds to inode we are writing (which |
| * means it has been truncated or invalidated), or the |
| * page is already under writeback and we are not doing |
| * a data integrity writeback, skip the page |
| */ |
| if (!PageDirty(page) || |
| (PageWriteback(page) && |
| (mpd->wbc->sync_mode == WB_SYNC_NONE)) || |
| unlikely(page->mapping != mapping)) { |
| unlock_page(page); |
| continue; |
| } |
| |
| wait_on_page_writeback(page); |
| BUG_ON(PageWriteback(page)); |
| |
| if (mpd->map.m_len == 0) |
| mpd->first_page = page->index; |
| mpd->next_page = page->index + 1; |
| /* Add all dirty buffers to mpd */ |
| lblk = ((ext4_lblk_t)page->index) << |
| (PAGE_CACHE_SHIFT - blkbits); |
| head = page_buffers(page); |
| err = mpage_process_page_bufs(mpd, head, head, lblk); |
| if (err <= 0) |
| goto out; |
| err = 0; |
| left--; |
| } |
| pagevec_release(&pvec); |
| cond_resched(); |
| } |
| return 0; |
| out: |
| pagevec_release(&pvec); |
| return err; |
| } |
| |
| static int __writepage(struct page *page, struct writeback_control *wbc, |
| void *data) |
| { |
| struct address_space *mapping = data; |
| int ret = ext4_writepage(page, wbc); |
| mapping_set_error(mapping, ret); |
| return ret; |
| } |
| |
| static int ext4_writepages(struct address_space *mapping, |
| struct writeback_control *wbc) |
| { |
| pgoff_t writeback_index = 0; |
| long nr_to_write = wbc->nr_to_write; |
| int range_whole = 0; |
| int cycled = 1; |
| handle_t *handle = NULL; |
| struct mpage_da_data mpd; |
| struct inode *inode = mapping->host; |
| int needed_blocks, rsv_blocks = 0, ret = 0; |
| struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb); |
| bool done; |
| struct blk_plug plug; |
| bool give_up_on_write = false; |
| |
| trace_ext4_writepages(inode, wbc); |
| |
| /* |
| * No pages to write? This is mainly a kludge to avoid starting |
| * a transaction for special inodes like journal inode on last iput() |
| * because that could violate lock ordering on umount |
| */ |
| if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) |
| goto out_writepages; |
| |
| if (ext4_should_journal_data(inode)) { |
| struct blk_plug plug; |
| |
| blk_start_plug(&plug); |
| ret = write_cache_pages(mapping, wbc, __writepage, mapping); |
| blk_finish_plug(&plug); |
| goto out_writepages; |
| } |
| |
| /* |
| * If the filesystem has aborted, it is read-only, so return |
| * right away instead of dumping stack traces later on that |
| * will obscure the real source of the problem. We test |
| * EXT4_MF_FS_ABORTED instead of sb->s_flag's MS_RDONLY because |
| * the latter could be true if the filesystem is mounted |
| * read-only, and in that case, ext4_writepages should |
| * *never* be called, so if that ever happens, we would want |
| * the stack trace. |
| */ |
| if (unlikely(sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) { |
| ret = -EROFS; |
| goto out_writepages; |
| } |
| |
| if (ext4_should_dioread_nolock(inode)) { |
| /* |
| * We may need to convert up to one extent per block in |
| * the page and we may dirty the inode. |
| */ |
| rsv_blocks = 1 + (PAGE_CACHE_SIZE >> inode->i_blkbits); |
| } |
| |
| /* |
| * If we have inline data and arrive here, it means that |
| * we will soon create the block for the 1st page, so |
| * we'd better clear the inline data here. |
| */ |
| if (ext4_has_inline_data(inode)) { |
| /* Just inode will be modified... */ |
| handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto out_writepages; |
| } |
| BUG_ON(ext4_test_inode_state(inode, |
| EXT4_STATE_MAY_INLINE_DATA)); |
| ext4_destroy_inline_data(handle, inode); |
| ext4_journal_stop(handle); |
| } |
| |
| if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) |
| range_whole = 1; |
| |
| if (wbc->range_cyclic) { |
| writeback_index = mapping->writeback_index; |
| if (writeback_index) |
| cycled = 0; |
| mpd.first_page = writeback_index; |
| mpd.last_page = -1; |
| } else { |
| mpd.first_page = wbc->range_start >> PAGE_CACHE_SHIFT; |
| mpd.last_page = wbc->range_end >> PAGE_CACHE_SHIFT; |
| } |
| |
| mpd.inode = inode; |
| mpd.wbc = wbc; |
| ext4_io_submit_init(&mpd.io_submit, wbc); |
| retry: |
| if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages) |
| tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page); |
| done = false; |
| blk_start_plug(&plug); |
| while (!done && mpd.first_page <= mpd.last_page) { |
| /* For each extent of pages we use new io_end */ |
| mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL); |
| if (!mpd.io_submit.io_end) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| /* |
| * We have two constraints: We find one extent to map and we |
| * must always write out whole page (makes a difference when |
| * blocksize < pagesize) so that we don't block on IO when we |
| * try to write out the rest of the page. Journalled mode is |
| * not supported by delalloc. |
| */ |
| BUG_ON(ext4_should_journal_data(inode)); |
| needed_blocks = ext4_da_writepages_trans_blocks(inode); |
| |
| /* start a new transaction */ |
| handle = ext4_journal_start_with_reserve(inode, |
| EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: " |
| "%ld pages, ino %lu; err %d", __func__, |
| wbc->nr_to_write, inode->i_ino, ret); |
| /* Release allocated io_end */ |
| ext4_put_io_end(mpd.io_submit.io_end); |
| break; |
| } |
| |
| trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc); |
| ret = mpage_prepare_extent_to_map(&mpd); |
| if (!ret) { |
| if (mpd.map.m_len) |
| ret = mpage_map_and_submit_extent(handle, &mpd, |
| &give_up_on_write); |
| else { |
| /* |
| * We scanned the whole range (or exhausted |
| * nr_to_write), submitted what was mapped and |
| * didn't find anything needing mapping. We are |
| * done. |
| */ |
| done = true; |
| } |
| } |
| ext4_journal_stop(handle); |
| /* Submit prepared bio */ |
| ext4_io_submit(&mpd.io_submit); |
| /* Unlock pages we didn't use */ |
| mpage_release_unused_pages(&mpd, give_up_on_write); |
| /* Drop our io_end reference we got from init */ |
| ext4_put_io_end(mpd.io_submit.io_end); |
| |
| if (ret == -ENOSPC && sbi->s_journal) { |
| /* |
| * Commit the transaction which would |
| * free blocks released in the transaction |
| * and try again |
| */ |
| jbd2_journal_force_commit_nested(sbi->s_journal); |
| ret = 0; |
| continue; |
| } |
| /* Fatal error - ENOMEM, EIO... */ |
| if (ret) |
| break; |
| } |
| blk_finish_plug(&plug); |
| if (!ret && !cycled && wbc->nr_to_write > 0) { |
| cycled = 1; |
| mpd.last_page = writeback_index - 1; |
| mpd.first_page = 0; |
| goto retry; |
| } |
| |
| /* Update index */ |
| if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0)) |
| /* |
| * Set the writeback_index so that range_cyclic |
| * mode will write it back later |
| */ |
| mapping->writeback_index = mpd.first_page; |
| |
| out_writepages: |
| trace_ext4_writepages_result(inode, wbc, ret, |
| nr_to_write - wbc->nr_to_write); |
| return ret; |
| } |
| |
| static int ext4_nonda_switch(struct super_block *sb) |
| { |
| s64 free_clusters, dirty_clusters; |
| struct ext4_sb_info *sbi = EXT4_SB(sb); |
| |
| /* |
| * switch to non delalloc mode if we are running low |
| * on free block. The free block accounting via percpu |
| * counters can get slightly wrong with percpu_counter_batch getting |
| * accumulated on each CPU without updating global counters |
| * Delalloc need an accurate free block accounting. So switch |
| * to non delalloc when we are near to error range. |
| */ |
| free_clusters = |
| percpu_counter_read_positive(&sbi->s_freeclusters_counter); |
| dirty_clusters = |
| percpu_counter_read_positive(&sbi->s_dirtyclusters_counter); |
| /* |
| * Start pushing delalloc when 1/2 of free blocks are dirty. |
| */ |
| if (dirty_clusters && (free_clusters < 2 * dirty_clusters)) |
| try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE); |
| |
| if (2 * free_clusters < 3 * dirty_clusters || |
| free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) { |
| /* |
| * free block count is less than 150% of dirty blocks |
| * or free blocks is less than watermark |
| */ |
| return 1; |
| } |
| return 0; |
| } |
| |
| /* We always reserve for an inode update; the superblock could be there too */ |
| static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len) |
| { |
| if (likely(EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb, |
| EXT4_FEATURE_RO_COMPAT_LARGE_FILE))) |
| return 1; |
| |
| if (pos + len <= 0x7fffffffULL) |
| return 1; |
| |
| /* We might need to update the superblock to set LARGE_FILE */ |
| return 2; |
| } |
| |
| static int ext4_da_write_begin(struct file *file, struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned flags, |
| struct page **pagep, void **fsdata) |
| { |
| int ret, retries = 0; |
| struct page *page; |
| pgoff_t index; |
| struct inode *inode = mapping->host; |
| handle_t *handle; |
| |
| index = pos >> PAGE_CACHE_SHIFT; |
| |
| if (ext4_nonda_switch(inode->i_sb)) { |
| *fsdata = (void *)FALL_BACK_TO_NONDELALLOC; |
| return ext4_write_begin(file, mapping, pos, |
| len, flags, pagep, fsdata); |
| } |
| *fsdata = (void *)0; |
| trace_ext4_da_write_begin(inode, pos, len, flags); |
| |
| if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) { |
| ret = ext4_da_write_inline_data_begin(mapping, inode, |
| pos, len, flags, |
| pagep, fsdata); |
| if (ret < 0) |
| return ret; |
| if (ret == 1) |
| return 0; |
| } |
| |
| /* |
| * grab_cache_page_write_begin() can take a long time if the |
| * system is thrashing due to memory pressure, or if the page |
| * is being written back. So grab it first before we start |
| * the transaction handle. This also allows us to allocate |
| * the page (if needed) without using GFP_NOFS. |
| */ |
| retry_grab: |
| page = grab_cache_page_write_begin(mapping, index, flags); |
| if (!page) |
| return -ENOMEM; |
| unlock_page(page); |
| |
| /* |
| * With delayed allocation, we don't log the i_disksize update |
| * if there is delayed block allocation. But we still need |
| * to journalling the i_disksize update if writes to the end |
| * of file which has an already mapped buffer. |
| */ |
| retry_journal: |
| handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, |
| ext4_da_write_credits(inode, pos, len)); |
| if (IS_ERR(handle)) { |
| page_cache_release(page); |
| return PTR_ERR(handle); |
| } |
| |
| lock_page(page); |
| if (page->mapping != mapping) { |
| /* The page got truncated from under us */ |
| unlock_page(page); |
| page_cache_release(page); |
| ext4_journal_stop(handle); |
| goto retry_grab; |
| } |
| /* In case writeback began while the page was unlocked */ |
| wait_for_stable_page(page); |
| |
| #ifdef CONFIG_EXT4_FS_ENCRYPTION |
| ret = ext4_block_write_begin(page, pos, len, |
| ext4_da_get_block_prep); |
| #else |
| ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep); |
| #endif |
| if (ret < 0) { |
| unlock_page(page); |
| ext4_journal_stop(handle); |
| /* |
| * block_write_begin may have instantiated a few blocks |
| * outside i_size. Trim these off again. Don't need |
| * i_size_read because we hold i_mutex. |
| */ |
| if (pos + len > inode->i_size) |
| ext4_truncate_failed_write(inode); |
| |
| if (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)) |
| goto retry_journal; |
| |
| page_cache_release(page); |
| return ret; |
| } |
| |
| *pagep = page; |
| return ret; |
| } |
| |
| /* |
| * Check if we should update i_disksize |
| * when write to the end of file but not require block allocation |
| */ |
| static int ext4_da_should_update_i_disksize(struct page *page, |
| unsigned long offset) |
| { |
| struct buffer_head *bh; |
| struct inode *inode = page->mapping->host; |
| unsigned int idx; |
| int i; |
| |
| bh = page_buffers(page); |
| idx = offset >> inode->i_blkbits; |
| |
| for (i = 0; i < idx; i++) |
| bh = bh->b_this_page; |
| |
| if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh)) |
| return 0; |
| return 1; |
| } |
| |
| static int ext4_da_write_end(struct file *file, |
| struct address_space *mapping, |
| loff_t pos, unsigned len, unsigned copied, |
| struct page *page, void *fsdata) |
| { |
| struct inode *inode = mapping->host; |
| int ret = 0, ret2; |
| handle_t *handle = ext4_journal_current_handle(); |
| loff_t new_i_size; |
| unsigned long start, end; |
| int write_mode = (int)(unsigned long)fsdata; |
| |
| if (write_mode == FALL_BACK_TO_NONDELALLOC) |
| return ext4_write_end(file, mapping, pos, |
| len, copied, page, fsdata); |
| |
| trace_ext4_da_write_end(inode, pos, len, copied); |
| start = pos & (PAGE_CACHE_SIZE - 1); |
| end = start + copied - 1; |
| |
| /* |
| * generic_write_end() will run mark_inode_dirty() if i_size |
| * changes. So let's piggyback the i_disksize mark_inode_dirty |
| * into that. |
| */ |
| new_i_size = pos + copied; |
| if (copied && new_i_size > EXT4_I(inode)->i_disksize) { |
| if (ext4_has_inline_data(inode) || |
| ext4_da_should_update_i_disksize(page, end)) { |
| ext4_update_i_disksize(inode, new_i_size); |
| /* We need to mark inode dirty even if |
| * new_i_size is less that inode->i_size |
| * bu greater than i_disksize.(hint delalloc) |
| */ |
| ext4_mark_inode_dirty(handle, inode); |
| } |
| } |
| |
| if (write_mode != CONVERT_INLINE_DATA && |
| ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) && |
| ext4_has_inline_data(inode)) |
| ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied, |
| page); |
| else |
| ret2 = generic_write_end(file, mapping, pos, len, copied, |
| page, fsdata); |
| |
| copied = ret2; |
| if (ret2 < 0) |
| ret = ret2; |
| ret2 = ext4_journal_stop(handle); |
| if (!ret) |
| ret = ret2; |
| |
| return ret ? ret : copied; |
| } |
| |
| static void ext4_da_invalidatepage(struct page *page, unsigned int offset, |
| unsigned int length) |
| { |
| /* |
| * Drop reserved blocks |
| */ |
| BUG_ON(!PageLocked(page)); |
| if (!page_has_buffers(page)) |
| goto out; |
| |
| ext4_da_page_release_reservation(page, offset, length); |
| |
| out: |
| ext4_invalidatepage(page, offset, length); |
| |
| return; |
| } |
| |
| /* |
| * Force all delayed allocation blocks to be allocated for a given inode. |
| */ |
| int ext4_alloc_da_blocks(struct inode *inode) |
| { |
| trace_ext4_alloc_da_blocks(inode); |
| |
| if (!EXT4_I(inode)->i_reserved_data_blocks) |
| return 0; |
| |
| /* |
| * We do something simple for now. The filemap_flush() will |
| * also start triggering a write of the data blocks, which is |
| * not strictly speaking necessary (and for users of |
| * laptop_mode, not even desirable). However, to do otherwise |
| * would require replicating code paths in: |
| * |
| * ext4_writepages() -> |
| * write_cache_pages() ---> (via passed in callback function) |
| * __mpage_da_writepage() --> |
| * mpage_add_bh_to_extent() |
| * mpage_da_map_blocks() |
| * |
| * The problem is that write_cache_pages(), located in |
| * mm/page-writeback.c, marks pages clean in preparation for |
| * doing I/O, which is not desirable if we're not planning on |
| * doing I/O at all. |
| * |
| * We could call write_cache_pages(), and then redirty all of |
| * the pages by calling redirty_page_for_writepage() but that |
| * would be ugly in the extreme. So instead we would need to |
| * replicate parts of the code in the above functions, |
| * simplifying them because we wouldn't actually intend to |
| * write out the pages, but rather only collect contiguous |
| * logical block extents, call the multi-block allocator, and |
| * then update the buffer heads with the block allocations. |
| * |
| * For now, though, we'll cheat by calling filemap_flush(), |
| * which will map the blocks, and start the I/O, but not |
| * actually wait for the I/O to complete. |
| */ |
| return filemap_flush(inode->i_mapping); |
| } |
| |
| /* |
| * bmap() is special. It gets used by applications such as lilo and by |
| * the swapper to find the on-disk block of a specific piece of data. |
| * |
| * Naturally, this is dangerous if the block concerned is still in the |
| * journal. If somebody makes a swapfile on an ext4 data-journaling |
| * filesystem and enables swap, then they may get a nasty shock when the |
| * data getting swapped to that swapfile suddenly gets overwritten by |
| * the original zero's written out previously to the journal and |
| * awaiting writeback in the kernel's buffer cache. |
| * |
| * So, if we see any bmap calls here on a modified, data-journaled file, |
| * take extra steps to flush any blocks which might be in the cache. |
| */ |
| static sector_t ext4_bmap(struct address_space *mapping, sector_t block) |
| { |
| struct inode *inode = mapping->host; |
| journal_t *journal; |
| int err; |
| |
| /* |
| * We can get here for an inline file via the FIBMAP ioctl |
| */ |
| if (ext4_has_inline_data(inode)) |
| return 0; |
| |
| if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) && |
| test_opt(inode->i_sb, DELALLOC)) { |
| /* |
| * With delalloc we want to sync the file |
| * so that we can make sure we allocate |
| * blocks for file |
| */ |
| filemap_write_and_wait(mapping); |
| } |
| |
| if (EXT4_JOURNAL(inode) && |
| ext4_test_inode_state(inode, EXT4_STATE_JDATA)) { |
| /* |
| * This is a REALLY heavyweight approach, but the use of |
| * bmap on dirty files is expected to be extremely rare: |
| * only if we run lilo or swapon on a freshly made file |
| * do we expect this to happen. |
| * |
| * (bmap requires CAP_SYS_RAWIO so this does not |
| * represent an unprivileged user DOS attack --- we'd be |
| * in trouble if mortal users could trigger this path at |
| * will.) |
| * |
| * NB. EXT4_STATE_JDATA is not set on files other than |
| * regular files. If somebody wants to bmap a directory |
| * or symlink and gets confused because the buffer |
| * hasn't yet been flushed to disk, they deserve |
| * everything they get. |
| */ |
| |
| ext4_clear_inode_state(inode, EXT4_STATE_JDATA); |
| journal = EXT4_JOURNAL(inode); |
| jbd2_journal_lock_updates(journal); |
| err = jbd2_journal_flush(journal); |
| jbd2_journal_unlock_updates(journal); |
| |
| if (err) |
| return 0; |
| } |
| |
| return generic_block_bmap(mapping, block, ext4_get_block); |
| } |
| |
| static int ext4_readpage(struct file *file, struct page *page) |
| { |
| int ret = -EAGAIN; |
| struct inode *inode = page->mapping->host; |
| |
| trace_ext4_readpage(page); |
| |
| if (ext4_has_inline_data(inode)) |
| ret = ext4_readpage_inline(inode, page); |
| |
| if (ret == -EAGAIN) |
| return ext4_mpage_readpages(page->mapping, NULL, page, 1); |
| |
| return ret; |
| } |
| |
| static int |
| ext4_readpages(struct file *file, struct address_space *mapping, |
| struct list_head *pages, unsigned nr_pages) |
| { |
| struct inode *inode = mapping->host; |
| |
| /* If the file has inline data, no need to do readpages. */ |
| if (ext4_has_inline_data(inode)) |
| return 0; |
| |
| return ext4_mpage_readpages(mapping, pages, NULL, nr_pages); |
| } |
| |
| static void ext4_invalidatepage(struct page *page, unsigned int offset, |
| unsigned int length) |
| { |
| trace_ext4_invalidatepage(page, offset, length); |
| |
| /* No journalling happens on data buffers when this function is used */ |
| WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page))); |
| |
| block_invalidatepage(page, offset, length); |
| } |
| |
| static int __ext4_journalled_invalidatepage(struct page *page, |
| unsigned int offset, |
| unsigned int length) |
| { |
| journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| |
| trace_ext4_journalled_invalidatepage(page, offset, length); |
| |
| /* |
| * If it's a full truncate we just forget about the pending dirtying |
| */ |
| if (offset == 0 && length == PAGE_CACHE_SIZE) |
| ClearPageChecked(page); |
| |
| return jbd2_journal_invalidatepage(journal, page, offset, length); |
| } |
| |
| /* Wrapper for aops... */ |
| static void ext4_journalled_invalidatepage(struct page *page, |
| unsigned int offset, |
| unsigned int length) |
| { |
| WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0); |
| } |
| |
| static int ext4_releasepage(struct page *page, gfp_t wait) |
| { |
| journal_t *journal = EXT4_JOURNAL(page->mapping->host); |
| |
| trace_ext4_releasepage(page); |
| |
| /* Page has dirty journalled data -> cannot release */ |
| if (PageChecked(page)) |
| return 0; |
| if (journal) |
| return jbd2_journal_try_to_free_buffers(journal, page, wait); |
| else |
| return try_to_free_buffers(page); |
| } |
| |
| /* |
| * ext4_get_block used when preparing for a DIO write or buffer write. |
| * We allocate an uinitialized extent if blocks haven't been allocated. |
| * The extent will be converted to initialized after the IO is complete. |
| */ |
| int ext4_get_block_write(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| ext4_debug("ext4_get_block_write: inode %lu, create flag %d\n", |
| inode->i_ino, create); |
| return _ext4_get_block(inode, iblock, bh_result, |
| EXT4_GET_BLOCKS_IO_CREATE_EXT); |
| } |
| |
| static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, |
| struct buffer_head *bh_result, int create) |
| { |
| ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n", |
| inode->i_ino, create); |
| return _ext4_get_block(inode, iblock, bh_result, |
| EXT4_GET_BLOCKS_NO_LOCK); |
| } |
| |
| static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, |
| ssize_t size, void *private) |
| { |
| ext4_io_end_t *io_end = iocb->private; |
| |
| /* if not async direct IO just return */ |
| if (!io_end) |
| return; |
| |
| ext_debug("ext4_end_io_dio(): io_end 0x%p " |
| "for inode %lu, iocb 0x%p, offset %llu, size %zd\n", |
| iocb->private, io_end->inode->i_ino, iocb, offset, |
| size); |
| |
| iocb->private = NULL; |
| io_end->offset = offset; |
| io_end->size = size; |
| ext4_put_io_end(io_end); |
| } |
| |
| /* |
| * For ext4 extent files, ext4 will do direct-io write to holes, |
| * preallocated extents, and those write extend the file, no need to |
| * fall back to buffered IO. |
| * |
| * For holes, we fallocate those blocks, mark them as unwritten |
| * If those blocks were preallocated, we mark sure they are split, but |
| * still keep the range to write as unwritten. |
| * |
| * The unwritten extents will be converted to written when DIO is completed. |
| * For async direct IO, since the IO may still pending when return, we |
| * set up an end_io call back function, which will do the conversion |
| * when async direct IO completed. |
| * |
| * If the O_DIRECT write will extend the file then add this inode to the |
| * orphan list. So recovery will truncate it back to the original size |
| * if the machine crashes during the write. |
| * |
| */ |
| static ssize_t ext4_ext_direct_IO(struct kiocb *iocb, struct iov_iter *iter, |
| loff_t offset) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| ssize_t ret; |
| size_t count = iov_iter_count(iter); |
| int overwrite = 0; |
| get_block_t *get_block_func = NULL; |
| int dio_flags = 0; |
| loff_t final_size = offset + count; |
| ext4_io_end_t *io_end = NULL; |
| |
| /* Use the old path for reads and writes beyond i_size. */ |
| if (iov_iter_rw(iter) != WRITE || final_size > inode->i_size) |
| return ext4_ind_direct_IO(iocb, iter, offset); |
| |
| BUG_ON(iocb->private == NULL); |
| |
| /* |
| * Make all waiters for direct IO properly wait also for extent |
| * conversion. This also disallows race between truncate() and |
| * overwrite DIO as i_dio_count needs to be incremented under i_mutex. |
| */ |
| if (iov_iter_rw(iter) == WRITE) |
| inode_dio_begin(inode); |
| |
| /* If we do a overwrite dio, i_mutex locking can be released */ |
| overwrite = *((int *)iocb->private); |
| |
| if (overwrite) { |
| down_read(&EXT4_I(inode)->i_data_sem); |
| mutex_unlock(&inode->i_mutex); |
| } |
| |
| /* |
| * We could direct write to holes and fallocate. |
| * |
| * Allocated blocks to fill the hole are marked as |
| * unwritten to prevent parallel buffered read to expose |
| * the stale data before DIO complete the data IO. |
| * |
| * As to previously fallocated extents, ext4 get_block will |
| * just simply mark the buffer mapped but still keep the |
| * extents unwritten. |
| * |
| * For non AIO case, we will convert those unwritten extents |
| * to written after return back from blockdev_direct_IO. |
| * |
| * For async DIO, the conversion needs to be deferred when the |
| * IO is completed. The ext4 end_io callback function will be |
| * called to take care of the conversion work. Here for async |
| * case, we allocate an io_end structure to hook to the iocb. |
| */ |
| iocb->private = NULL; |
| ext4_inode_aio_set(inode, NULL); |
| if (!is_sync_kiocb(iocb)) { |
| io_end = ext4_init_io_end(inode, GFP_NOFS); |
| if (!io_end) { |
| ret = -ENOMEM; |
| goto retake_lock; |
| } |
| /* |
| * Grab reference for DIO. Will be dropped in ext4_end_io_dio() |
| */ |
| iocb->private = ext4_get_io_end(io_end); |
| /* |
| * we save the io structure for current async direct |
| * IO, so that later ext4_map_blocks() could flag the |
| * io structure whether there is a unwritten extents |
| * needs to be converted when IO is completed. |
| */ |
| ext4_inode_aio_set(inode, io_end); |
| } |
| |
| if (overwrite) { |
| get_block_func = ext4_get_block_write_nolock; |
| } else { |
| get_block_func = ext4_get_block_write; |
| dio_flags = DIO_LOCKING; |
| } |
| #ifdef CONFIG_EXT4_FS_ENCRYPTION |
| BUG_ON(ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)); |
| #endif |
| if (IS_DAX(inode)) |
| ret = dax_do_io(iocb, inode, iter, offset, get_block_func, |
| ext4_end_io_dio, dio_flags); |
| else |
| ret = __blockdev_direct_IO(iocb, inode, |
| inode->i_sb->s_bdev, iter, offset, |
| get_block_func, |
| ext4_end_io_dio, NULL, dio_flags); |
| |
| /* |
| * Put our reference to io_end. This can free the io_end structure e.g. |
| * in sync IO case or in case of error. It can even perform extent |
| * conversion if all bios we submitted finished before we got here. |
| * Note that in that case iocb->private can be already set to NULL |
| * here. |
| */ |
| if (io_end) { |
| ext4_inode_aio_set(inode, NULL); |
| ext4_put_io_end(io_end); |
| /* |
| * When no IO was submitted ext4_end_io_dio() was not |
| * called so we have to put iocb's reference. |
| */ |
| if (ret <= 0 && ret != -EIOCBQUEUED && iocb->private) { |
| WARN_ON(iocb->private != io_end); |
| WARN_ON(io_end->flag & EXT4_IO_END_UNWRITTEN); |
| ext4_put_io_end(io_end); |
| iocb->private = NULL; |
| } |
| } |
| if (ret > 0 && !overwrite && ext4_test_inode_state(inode, |
| EXT4_STATE_DIO_UNWRITTEN)) { |
| int err; |
| /* |
| * for non AIO case, since the IO is already |
| * completed, we could do the conversion right here |
| */ |
| err = ext4_convert_unwritten_extents(NULL, inode, |
| offset, ret); |
| if (err < 0) |
| ret = err; |
| ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN); |
| } |
| |
| retake_lock: |
| if (iov_iter_rw(iter) == WRITE) |
| inode_dio_end(inode); |
| /* take i_mutex locking again if we do a ovewrite dio */ |
| if (overwrite) { |
| up_read(&EXT4_I(inode)->i_data_sem); |
| mutex_lock(&inode->i_mutex); |
| } |
| |
| return ret; |
| } |
| |
| static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter, |
| loff_t offset) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file->f_mapping->host; |
| size_t count = iov_iter_count(iter); |
| ssize_t ret; |
| |
| #ifdef CONFIG_EXT4_FS_ENCRYPTION |
| if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode)) |
| return 0; |
| #endif |
| |
| /* |
| * If we are doing data journalling we don't support O_DIRECT |
| */ |
| if (ext4_should_journal_data(inode)) |
| return 0; |
| |
| /* Let buffer I/O handle the inline data case. */ |
| if (ext4_has_inline_data(inode)) |
| return 0; |
| |
| trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter)); |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| ret = ext4_ext_direct_IO(iocb, iter, offset); |
| else |
| ret = ext4_ind_direct_IO(iocb, iter, offset); |
| trace_ext4_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret); |
| return ret; |
| } |
| |
| /* |
| * Pages can be marked dirty completely asynchronously from ext4's journalling |
| * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do |
| * much here because ->set_page_dirty is called under VFS locks. The page is |
| * not necessarily locked. |
| * |
| * We cannot just dirty the page and leave attached buffers clean, because the |
| * buffers' dirty state is "definitive". We cannot just set the buffers dirty |
| * or jbddirty because all the journalling code will explode. |
| * |
| * So what we do is to mark the page "pending dirty" and next time writepage |
| * is called, propagate that into the buffers appropriately. |
| */ |
| static int ext4_journalled_set_page_dirty(struct page *page) |
| { |
| SetPageChecked(page); |
| return __set_page_dirty_nobuffers(page); |
| } |
| |
| static const struct address_space_operations ext4_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_writepage, |
| .writepages = ext4_writepages, |
| .write_begin = ext4_write_begin, |
| .write_end = ext4_write_end, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .migratepage = buffer_migrate_page, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| .error_remove_page = generic_error_remove_page, |
| }; |
| |
| static const struct address_space_operations ext4_journalled_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_writepage, |
| .writepages = ext4_writepages, |
| .write_begin = ext4_write_begin, |
| .write_end = ext4_journalled_write_end, |
| .set_page_dirty = ext4_journalled_set_page_dirty, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_journalled_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| .error_remove_page = generic_error_remove_page, |
| }; |
| |
| static const struct address_space_operations ext4_da_aops = { |
| .readpage = ext4_readpage, |
| .readpages = ext4_readpages, |
| .writepage = ext4_writepage, |
| .writepages = ext4_writepages, |
| .write_begin = ext4_da_write_begin, |
| .write_end = ext4_da_write_end, |
| .bmap = ext4_bmap, |
| .invalidatepage = ext4_da_invalidatepage, |
| .releasepage = ext4_releasepage, |
| .direct_IO = ext4_direct_IO, |
| .migratepage = buffer_migrate_page, |
| .is_partially_uptodate = block_is_partially_uptodate, |
| .error_remove_page = generic_error_remove_page, |
| }; |
| |
| void ext4_set_aops(struct inode *inode) |
| { |
| switch (ext4_inode_journal_mode(inode)) { |
| case EXT4_INODE_ORDERED_DATA_MODE: |
| ext4_set_inode_state(inode, EXT4_STATE_ORDERED_MODE); |
| break; |
| case EXT4_INODE_WRITEBACK_DATA_MODE: |
| ext4_clear_inode_state(inode, EXT4_STATE_ORDERED_MODE); |
| break; |
| case EXT4_INODE_JOURNAL_DATA_MODE: |
| inode->i_mapping->a_ops = &ext4_journalled_aops; |
| return; |
| default: |
| BUG(); |
| } |
| if (test_opt(inode->i_sb, DELALLOC)) |
| inode->i_mapping->a_ops = &ext4_da_aops; |
| else |
| inode->i_mapping->a_ops = &ext4_aops; |
| } |
| |
| static int __ext4_block_zero_page_range(handle_t *handle, |
| struct address_space *mapping, loff_t from, loff_t length) |
| { |
| ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; |
| unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| unsigned blocksize, pos; |
| ext4_lblk_t iblock; |
| struct inode *inode = mapping->host; |
| struct buffer_head *bh; |
| 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; |
| |
| blocksize = inode->i_sb->s_blocksize; |
| |
| iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
| |
| if (!page_has_buffers(page)) |
| create_empty_buffers(page, blocksize, 0); |
| |
| /* Find the buffer that contains "offset" */ |
| bh = page_buffers(page); |
| pos = blocksize; |
| while (offset >= pos) { |
| bh = bh->b_this_page; |
| iblock++; |
| pos += blocksize; |
| } |
| if (buffer_freed(bh)) { |
| BUFFER_TRACE(bh, "freed: skip"); |
| goto unlock; |
| } |
| if (!buffer_mapped(bh)) { |
| 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 unlock; |
| } |
| } |
| |
| /* 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 unlock; |
| if (S_ISREG(inode->i_mode) && |
| ext4_encrypted_inode(inode)) { |
| /* We expect the key to be set. */ |
| BUG_ON(!ext4_has_encryption_key(inode)); |
| BUG_ON(blocksize != PAGE_CACHE_SIZE); |
| WARN_ON_ONCE(ext4_decrypt_one(inode, page)); |
| } |
| } |
| if (ext4_should_journal_data(inode)) { |
| BUFFER_TRACE(bh, "get write access"); |
| err = ext4_journal_get_write_access(handle, bh); |
| if (err) |
| goto unlock; |
| } |
| zero_user(page, offset, length); |
| BUFFER_TRACE(bh, "zeroed end of block"); |
| |
| if (ext4_should_journal_data(inode)) { |
| err = ext4_handle_dirty_metadata(handle, inode, bh); |
| } else { |
| err = 0; |
| mark_buffer_dirty(bh); |
| if (ext4_test_inode_state(inode, EXT4_STATE_ORDERED_MODE)) |
| err = ext4_jbd2_file_inode(handle, inode); |
| } |
| |
| unlock: |
| unlock_page(page); |
| page_cache_release(page); |
| return err; |
| } |
| |
| /* |
| * ext4_block_zero_page_range() zeros out a mapping of length 'length' |
| * starting from file offset 'from'. The range to be zero'd must |
| * be contained with in one block. If the specified range exceeds |
| * the end of the block it will be shortened to end of the block |
| * that cooresponds to 'from' |
| */ |
| static int ext4_block_zero_page_range(handle_t *handle, |
| struct address_space *mapping, loff_t from, loff_t length) |
| { |
| struct inode *inode = mapping->host; |
| unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| unsigned blocksize = inode->i_sb->s_blocksize; |
| unsigned max = blocksize - (offset & (blocksize - 1)); |
| |
| /* |
| * correct length if it does not fall between |
| * 'from' and the end of the block |
| */ |
| if (length > max || length < 0) |
| length = max; |
| |
| if (IS_DAX(inode)) |
| return dax_zero_page_range(inode, from, length, ext4_get_block); |
| return __ext4_block_zero_page_range(handle, mapping, from, length); |
| } |
| |
| /* |
| * ext4_block_truncate_page() zeroes out a mapping from file offset `from' |
| * up to the end of the block which corresponds to `from'. |
| * This required during truncate. We need to physically zero the tail end |
| * of that block so it doesn't yield old data if the file is later grown. |
| */ |
| static int ext4_block_truncate_page(handle_t *handle, |
| struct address_space *mapping, loff_t from) |
| { |
| unsigned offset = from & (PAGE_CACHE_SIZE-1); |
| unsigned length; |
| unsigned blocksize; |
| struct inode *inode = mapping->host; |
| |
| blocksize = inode->i_sb->s_blocksize; |
| length = blocksize - (offset & (blocksize - 1)); |
| |
| return ext4_block_zero_page_range(handle, mapping, from, length); |
| } |
| |
| int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode, |
| loff_t lstart, loff_t length) |
| { |
| struct super_block *sb = inode->i_sb; |
| struct address_space *mapping = inode->i_mapping; |
| unsigned partial_start, partial_end; |
| ext4_fsblk_t start, end; |
| loff_t byte_end = (lstart + length - 1); |
| int err = 0; |
| |
| partial_start = lstart & (sb->s_blocksize - 1); |
| partial_end = byte_end & (sb->s_blocksize - 1); |
| |
| start = lstart >> sb->s_blocksize_bits; |
| end = byte_end >> sb->s_blocksize_bits; |
| |
| /* Handle partial zero within the single block */ |
| if (start == end && |
| (partial_start || (partial_end != sb->s_blocksize - 1))) { |
| err = ext4_block_zero_page_range(handle, mapping, |
| lstart, length); |
| return err; |
| } |
| /* Handle partial zero out on the start of the range */ |
| if (partial_start) { |
| err = ext4_block_zero_page_range(handle, mapping, |
| lstart, sb->s_blocksize); |
| if (err) |
| return err; |
| } |
| /* Handle partial zero out on the end of the range */ |
| if (partial_end != sb->s_blocksize - 1) |
| err = ext4_block_zero_page_range(handle, mapping, |
| byte_end - partial_end, |
| partial_end + 1); |
| return err; |
| } |
| |
| int ext4_can_truncate(struct inode *inode) |
| { |
| if (S_ISREG(inode->i_mode)) |
| return 1; |
| if (S_ISDIR(inode->i_mode)) |
| return 1; |
| if (S_ISLNK(inode->i_mode)) |
| return !ext4_inode_is_fast_symlink(inode); |
| return 0; |
| } |
| |
| /* |
| * ext4_punch_hole: punches a hole in a file by releaseing the blocks |
| * associated with the given offset and length |
| * |
| * @inode: File inode |
| * @offset: The offset where the hole will begin |
| * @len: The length of the hole |
| * |
| * Returns: 0 on success or negative on failure |
| */ |
| |
| int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) |
| { |
| struct super_block *sb = inode->i_sb; |
| ext4_lblk_t first_block, stop_block; |
| struct address_space *mapping = inode->i_mapping; |
| loff_t first_block_offset, last_block_offset; |
| handle_t *handle; |
| unsigned int credits; |
| int ret = 0; |
| |
| if (!S_ISREG(inode->i_mode)) |
| return -EOPNOTSUPP; |
| |
| trace_ext4_punch_hole(inode, offset, length, 0); |
| |
| /* |
| * Write out all dirty pages to avoid race conditions |
| * Then release them. |
| */ |
| if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { |
| ret = filemap_write_and_wait_range(mapping, offset, |
| offset + length - 1); |
| if (ret) |
| return ret; |
| } |
| |
| mutex_lock(&inode->i_mutex); |
| |
| /* No need to punch hole beyond i_size */ |
| if (offset >= inode->i_size) |
| goto out_mutex; |
| |
| /* |
| * If the hole extends beyond i_size, set the hole |
| * to end after the page that contains i_size |
| */ |
| if (offset + length > inode->i_size) { |
| length = inode->i_size + |
| PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) - |
| offset; |
| } |
| |
| if (offset & (sb->s_blocksize - 1) || |
| (offset + length) & (sb->s_blocksize - 1)) { |
| /* |
| * Attach jinode to inode for jbd2 if we do any zeroing of |
| * partial block |
| */ |
| ret = ext4_inode_attach_jinode(inode); |
| if (ret < 0) |
| goto out_mutex; |
| |
| } |
| |
| first_block_offset = round_up(offset, sb->s_blocksize); |
| last_block_offset = round_down((offset + length), sb->s_blocksize) - 1; |
| |
| /* Now release the pages and zero block aligned part of pages*/ |
| if (last_block_offset > first_block_offset) |
| truncate_pagecache_range(inode, first_block_offset, |
| last_block_offset); |
| |
| /* Wait all existing dio workers, newcomers will block on i_mutex */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| credits = ext4_writepage_trans_blocks(inode); |
| else |
| credits = ext4_blocks_for_truncate(inode); |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| ext4_std_error(sb, ret); |
| goto out_dio; |
| } |
| |
| ret = ext4_zero_partial_blocks(handle, inode, offset, |
| length); |
| if (ret) |
| goto out_stop; |
| |
| first_block = (offset + sb->s_blocksize - 1) >> |
| EXT4_BLOCK_SIZE_BITS(sb); |
| stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb); |
| |
| /* If there are no blocks to remove, return now */ |
| if (first_block >= stop_block) |
| goto out_stop; |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| ext4_discard_preallocations(inode); |
| |
| ret = ext4_es_remove_extent(inode, first_block, |
| stop_block - first_block); |
| if (ret) { |
| up_write(&EXT4_I(inode)->i_data_sem); |
| goto out_stop; |
| } |
| |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| ret = ext4_ext_remove_space(inode, first_block, |
| stop_block - 1); |
| else |
| ret = ext4_ind_remove_space(handle, inode, first_block, |
| stop_block); |
| |
| up_write(&EXT4_I(inode)->i_data_sem); |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| |
| /* Now release the pages again to reduce race window */ |
| if (last_block_offset > first_block_offset) |
| truncate_pagecache_range(inode, first_block_offset, |
| last_block_offset); |
| |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| out_stop: |
| ext4_journal_stop(handle); |
| out_dio: |
| ext4_inode_resume_unlocked_dio(inode); |
| out_mutex: |
| mutex_unlock(&inode->i_mutex); |
| return ret; |
| } |
| |
| int ext4_inode_attach_jinode(struct inode *inode) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct jbd2_inode *jinode; |
| |
| if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal) |
| return 0; |
| |
| jinode = jbd2_alloc_inode(GFP_KERNEL); |
| spin_lock(&inode->i_lock); |
| if (!ei->jinode) { |
| if (!jinode) { |
| spin_unlock(&inode->i_lock); |
| return -ENOMEM; |
| } |
| ei->jinode = jinode; |
| jbd2_journal_init_jbd_inode(ei->jinode, inode); |
| jinode = NULL; |
| } |
| spin_unlock(&inode->i_lock); |
| if (unlikely(jinode != NULL)) |
| jbd2_free_inode(jinode); |
| return 0; |
| } |
| |
| /* |
| * ext4_truncate() |
| * |
| * We block out ext4_get_block() block instantiations across the entire |
| * transaction, and VFS/VM ensures that ext4_truncate() cannot run |
| * simultaneously on behalf of the same inode. |
| * |
| * As we work through the truncate and commit bits of it to the journal there |
| * is one core, guiding principle: the file's tree must always be consistent on |
| * disk. We must be able to restart the truncate after a crash. |
| * |
| * The file's tree may be transiently inconsistent in memory (although it |
| * probably isn't), but whenever we close off and commit a journal transaction, |
| * the contents of (the filesystem + the journal) must be consistent and |
| * restartable. It's pretty simple, really: bottom up, right to left (although |
| * left-to-right works OK too). |
| * |
| * Note that at recovery time, journal replay occurs *before* the restart of |
| * truncate against the orphan inode list. |
| * |
| * The committed inode has the new, desired i_size (which is the same as |
| * i_disksize in this case). After a crash, ext4_orphan_cleanup() will see |
| * that this inode's truncate did not complete and it will again call |
| * ext4_truncate() to have another go. So there will be instantiated blocks |
| * to the right of the truncation point in a crashed ext4 filesystem. But |
| * that's fine - as long as they are linked from the inode, the post-crash |
| * ext4_truncate() run will find them and release them. |
| */ |
| void ext4_truncate(struct inode *inode) |
| { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| unsigned int credits; |
| handle_t *handle; |
| struct address_space *mapping = inode->i_mapping; |
| |
| /* |
| * There is a possibility that we're either freeing the inode |
| * or it's a completely new inode. In those cases we might not |
| * have i_mutex locked because it's not necessary. |
| */ |
| if (!(inode->i_state & (I_NEW|I_FREEING))) |
| WARN_ON(!mutex_is_locked(&inode->i_mutex)); |
| trace_ext4_truncate_enter(inode); |
| |
| if (!ext4_can_truncate(inode)) |
| return; |
| |
| ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS); |
| |
| if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC)) |
| ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE); |
| |
| if (ext4_has_inline_data(inode)) { |
| int has_inline = 1; |
| |
| ext4_inline_data_truncate(inode, &has_inline); |
| if (has_inline) |
| return; |
| } |
| |
| /* If we zero-out tail of the page, we have to create jinode for jbd2 */ |
| if (inode->i_size & (inode->i_sb->s_blocksize - 1)) { |
| if (ext4_inode_attach_jinode(inode) < 0) |
| return; |
| } |
| |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| credits = ext4_writepage_trans_blocks(inode); |
| else |
| credits = ext4_blocks_for_truncate(inode); |
| |
| handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits); |
| if (IS_ERR(handle)) { |
| ext4_std_error(inode->i_sb, PTR_ERR(handle)); |
| return; |
| } |
| |
| if (inode->i_size & (inode->i_sb->s_blocksize - 1)) |
| ext4_block_truncate_page(handle, mapping, inode->i_size); |
| |
| /* |
| * We add the inode to the orphan list, so that if this |
| * truncate spans multiple transactions, and we crash, we will |
| * resume the truncate when the filesystem recovers. It also |
| * marks the inode dirty, to catch the new size. |
| * |
| * Implication: the file must always be in a sane, consistent |
| * truncatable state while each transaction commits. |
| */ |
| if (ext4_orphan_add(handle, inode)) |
| goto out_stop; |
| |
| down_write(&EXT4_I(inode)->i_data_sem); |
| |
| ext4_discard_preallocations(inode); |
| |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) |
| ext4_ext_truncate(handle, inode); |
| else |
| ext4_ind_truncate(handle, inode); |
| |
| up_write(&ei->i_data_sem); |
| |
| if (IS_SYNC(inode)) |
| ext4_handle_sync(handle); |
| |
| out_stop: |
| /* |
| * If this was a simple ftruncate() and the file will remain alive, |
| * then we need to clear up the orphan record which we created above. |
| * However, if this was a real unlink then we were called by |
| * ext4_evict_inode(), and we allow that function to clean up the |
| * orphan info for us. |
| */ |
| if (inode->i_nlink) |
| ext4_orphan_del(handle, inode); |
| |
| inode->i_mtime = inode->i_ctime = ext4_current_time(inode); |
| ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_stop(handle); |
| |
| trace_ext4_truncate_exit(inode); |
| } |
| |
| /* |
| * ext4_get_inode_loc returns with an extra refcount against the inode's |
| * underlying buffer_head on success. If 'in_mem' is true, we have all |
| * data in memory that is needed to recreate the on-disk version of this |
| * inode. |
| */ |
| static int __ext4_get_inode_loc(struct inode *inode, |
| struct ext4_iloc *iloc, int in_mem) |
| { |
| struct ext4_group_desc *gdp; |
| struct buffer_head *bh; |
| struct super_block *sb = inode->i_sb; |
| ext4_fsblk_t block; |
| int inodes_per_block, inode_offset; |
| |
| iloc->bh = NULL; |
| if (!ext4_valid_inum(sb, inode->i_ino)) |
| return -EIO; |
| |
| iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb); |
| gdp = ext4_get_group_desc(sb, iloc->block_group, NULL); |
| if (!gdp) |
| return -EIO; |
| |
| /* |
| * Figure out the offset within the block group inode table |
| */ |
| inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; |
| inode_offset = ((inode->i_ino - 1) % |
| EXT4_INODES_PER_GROUP(sb)); |
| block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block); |
| iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb); |
| |
| bh = sb_getblk(sb, block); |
| if (unlikely(!bh)) |
| return -ENOMEM; |
| if (!buffer_uptodate(bh)) { |
| lock_buffer(bh); |
| |
| /* |
| * If the buffer has the write error flag, we have failed |
| * to write out another inode in the same block. In this |
| * case, we don't have to read the block because we may |
| * read the old inode data successfully. |
| */ |
| if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) |
| set_buffer_uptodate(bh); |
| |
| if (buffer_uptodate(bh)) { |
| /* someone brought it uptodate while we waited */ |
| unlock_buffer(bh); |
| goto has_buffer; |
| } |
| |
| /* |
| * If we have all information of the inode in memory and this |
| * is the only valid inode in the block, we need not read the |
| * block. |
| */ |
| if (in_mem) { |
| struct buffer_head *bitmap_bh; |
| int i, start; |
| |
| start = inode_offset & ~(inodes_per_block - 1); |
| |
| /* Is the inode bitmap in cache? */ |
| bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp)); |
| if (unlikely(!bitmap_bh)) |
| goto make_io; |
| |
| /* |
| * If the inode bitmap isn't in cache then the |
| * optimisation may end up performing two reads instead |
| * of one, so skip it. |
| */ |
| if (!buffer_uptodate(bitmap_bh)) { |
| brelse(bitmap_bh); |
| goto make_io; |
| } |
| for (i = start; i < start + inodes_per_block; i++) { |
| if (i == inode_offset) |
| continue; |
| if (ext4_test_bit(i, bitmap_bh->b_data)) |
| break; |
| } |
| brelse(bitmap_bh); |
| if (i == start + inodes_per_block) { |
| /* all other inodes are free, so skip I/O */ |
| memset(bh->b_data, 0, bh->b_size); |
| set_buffer_uptodate(bh); |
| unlock_buffer(bh); |
| goto has_buffer; |
| } |
| } |
| |
| make_io: |
| /* |
| * If we need to do any I/O, try to pre-readahead extra |
| * blocks from the inode table. |
| */ |
| if (EXT4_SB(sb)->s_inode_readahead_blks) { |
| ext4_fsblk_t b, end, table; |
| unsigned num; |
| __u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks; |
| |
| table = ext4_inode_table(sb, gdp); |
| /* s_inode_readahead_blks is always a power of 2 */ |
| b = block & ~((ext4_fsblk_t) ra_blks - 1); |
| if (table > b) |
| b = table; |
| end = b + ra_blks; |
| num = EXT4_INODES_PER_GROUP(sb); |
| if (ext4_has_group_desc_csum(sb)) |
| num -= ext4_itable_unused_count(sb, gdp); |
| table += num / inodes_per_block; |
| if (end > table) |
| end = table; |
| while (b <= end) |
| sb_breadahead(sb, b++); |
| } |
| |
| /* |
| * There are other valid inodes in the buffer, this inode |
| * has in-inode xattrs, or we don't have this inode in memory. |
| * Read the block from disk. |
| */ |
| trace_ext4_load_inode(inode); |
| get_bh(bh); |
| bh->b_end_io = end_buffer_read_sync; |
| submit_bh(READ | REQ_META | REQ_PRIO, bh); |
| wait_on_buffer(bh); |
| if (!buffer_uptodate(bh)) { |
| EXT4_ERROR_INODE_BLOCK(inode, block, |
| "unable to read itable block"); |
| brelse(bh); |
| return -EIO; |
| } |
| } |
| has_buffer: |
| iloc->bh = bh; |
| return 0; |
| } |
| |
| int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc) |
| { |
| /* We have all inode data except xattrs in memory here. */ |
| return __ext4_get_inode_loc(inode, iloc, |
| !ext4_test_inode_state(inode, EXT4_STATE_XATTR)); |
| } |
| |
| void ext4_set_inode_flags(struct inode *inode) |
| { |
| unsigned int flags = EXT4_I(inode)->i_flags; |
| unsigned int new_fl = 0; |
| |
| if (flags & EXT4_SYNC_FL) |
| new_fl |= S_SYNC; |
| if (flags & EXT4_APPEND_FL) |
| new_fl |= S_APPEND; |
| if (flags & EXT4_IMMUTABLE_FL) |
| new_fl |= S_IMMUTABLE; |
| if (flags & EXT4_NOATIME_FL) |
| new_fl |= S_NOATIME; |
| if (flags & EXT4_DIRSYNC_FL) |
| new_fl |= S_DIRSYNC; |
| if (test_opt(inode->i_sb, DAX)) |
| new_fl |= S_DAX; |
| inode_set_flags(inode, new_fl, |
| S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX); |
| } |
| |
| /* Propagate flags from i_flags to EXT4_I(inode)->i_flags */ |
| void ext4_get_inode_flags(struct ext4_inode_info *ei) |
| { |
| unsigned int vfs_fl; |
| unsigned long old_fl, new_fl; |
| |
| do { |
| vfs_fl = ei->vfs_inode.i_flags; |
| old_fl = ei->i_flags; |
| new_fl = old_fl & ~(EXT4_SYNC_FL|EXT4_APPEND_FL| |
| EXT4_IMMUTABLE_FL|EXT4_NOATIME_FL| |
| EXT4_DIRSYNC_FL); |
| if (vfs_fl & S_SYNC) |
| new_fl |= EXT4_SYNC_FL; |
| if (vfs_fl & S_APPEND) |
| new_fl |= EXT4_APPEND_FL; |
| if (vfs_fl & S_IMMUTABLE) |
| new_fl |= EXT4_IMMUTABLE_FL; |
| if (vfs_fl & S_NOATIME) |
| new_fl |= EXT4_NOATIME_FL; |
| if (vfs_fl & S_DIRSYNC) |
| new_fl |= EXT4_DIRSYNC_FL; |
| } while (cmpxchg(&ei->i_flags, old_fl, new_fl) != old_fl); |
| } |
| |
| static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode, |
| struct ext4_inode_info *ei) |
| { |
| blkcnt_t i_blocks ; |
| struct inode *inode = &(ei->vfs_inode); |
| struct super_block *sb = inode->i_sb; |
| |
| if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { |
| /* we are using combined 48 bit field */ |
| i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 | |
| le32_to_cpu(raw_inode->i_blocks_lo); |
| if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) { |
| /* i_blocks represent file system block size */ |
| return i_blocks << (inode->i_blkbits - 9); |
| } else { |
| return i_blocks; |
| } |
| } else { |
| return le32_to_cpu(raw_inode->i_blocks_lo); |
| } |
| } |
| |
| static inline void ext4_iget_extra_inode(struct inode *inode, |
| struct ext4_inode *raw_inode, |
| struct ext4_inode_info *ei) |
| { |
| __le32 *magic = (void *)raw_inode + |
| EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize; |
| if (*magic == cpu_to_le32(EXT4_XATTR_MAGIC)) { |
| ext4_set_inode_state(inode, EXT4_STATE_XATTR); |
| ext4_find_inline_data_nolock(inode); |
| } else |
| EXT4_I(inode)->i_inline_off = 0; |
| } |
| |
| struct inode *ext4_iget(struct super_block *sb, unsigned long ino) |
| { |
| struct ext4_iloc iloc; |
| struct ext4_inode *raw_inode; |
| struct ext4_inode_info *ei; |
| struct inode *inode; |
| journal_t *journal = EXT4_SB(sb)->s_journal; |
| long ret; |
| int block; |
| uid_t i_uid; |
| gid_t i_gid; |
| |
| inode = iget_locked(sb, ino); |
| if (!inode) |
| return ERR_PTR(-ENOMEM); |
| if (!(inode->i_state & I_NEW)) |
| return inode; |
| |
| ei = EXT4_I(inode); |
| iloc.bh = NULL; |
| |
| ret = __ext4_get_inode_loc(inode, &iloc, 0); |
| if (ret < 0) |
| goto bad_inode; |
| raw_inode = ext4_raw_inode(&iloc); |
| |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); |
| if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > |
| EXT4_INODE_SIZE(inode->i_sb)) { |
| EXT4_ERROR_INODE(inode, "bad extra_isize (%u != %u)", |
| EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize, |
| EXT4_INODE_SIZE(inode->i_sb)); |
| ret = -EIO; |
| goto bad_inode; |
| } |
| } else |
| ei->i_extra_isize = 0; |
| |
| /* Precompute checksum seed for inode metadata */ |
| if (ext4_has_metadata_csum(sb)) { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| __u32 csum; |
| __le32 inum = cpu_to_le32(inode->i_ino); |
| __le32 gen = raw_inode->i_generation; |
| csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum, |
| sizeof(inum)); |
| ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen, |
| sizeof(gen)); |
| } |
| |
| if (!ext4_inode_csum_verify(inode, raw_inode, ei)) { |
| EXT4_ERROR_INODE(inode, "checksum invalid"); |
| ret = -EIO; |
| goto bad_inode; |
| } |
| |
| inode->i_mode = le16_to_cpu(raw_inode->i_mode); |
| i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); |
| i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); |
| if (!(test_opt(inode->i_sb, NO_UID32))) { |
| i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; |
| i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; |
| } |
| i_uid_write(inode, i_uid); |
| i_gid_write(inode, i_gid); |
| set_nlink(inode, le16_to_cpu(raw_inode->i_links_count)); |
| |
| ext4_clear_state_flags(ei); /* Only relevant on 32-bit archs */ |
| ei->i_inline_off = 0; |
| ei->i_dir_start_lookup = 0; |
| ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); |
| /* We now have enough fields to check if the inode was active or not. |
| * This is needed because nfsd might try to access dead inodes |
| * the test is that same one that e2fsck uses |
| * NeilBrown 1999oct15 |
| */ |
| if (inode->i_nlink == 0) { |
| if ((inode->i_mode == 0 || |
| !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) && |
| ino != EXT4_BOOT_LOADER_INO) { |
| /* this inode is deleted */ |
| ret = -ESTALE; |
| goto bad_inode; |
| } |
| /* The only unlinked inodes we let through here have |
| * valid i_mode and are being read by the orphan |
| * recovery code: that's fine, we're about to complete |
| * the process of deleting those. |
| * OR it is the EXT4_BOOT_LOADER_INO which is |
| * not initialized on a new filesystem. */ |
| } |
| ei->i_flags = le32_to_cpu(raw_inode->i_flags); |
| inode->i_blocks = ext4_inode_blocks(raw_inode, ei); |
| ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo); |
| if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_64BIT)) |
| ei->i_file_acl |= |
| ((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32; |
| inode->i_size = ext4_isize(raw_inode); |
| ei->i_disksize = inode->i_size; |
| #ifdef CONFIG_QUOTA |
| ei->i_reserved_quota = 0; |
| #endif |
| inode->i_generation = le32_to_cpu(raw_inode->i_generation); |
| ei->i_block_group = iloc.block_group; |
| ei->i_last_alloc_group = ~0; |
| /* |
| * NOTE! The in-memory inode i_data array is in little-endian order |
| * even on big-endian machines: we do NOT byteswap the block numbers! |
| */ |
| for (block = 0; block < EXT4_N_BLOCKS; block++) |
| ei->i_data[block] = raw_inode->i_block[block]; |
| INIT_LIST_HEAD(&ei->i_orphan); |
| |
| /* |
| * Set transaction id's of transactions that have to be committed |
| * to finish f[data]sync. We set them to currently running transaction |
| * as we cannot be sure that the inode or some of its metadata isn't |
| * part of the transaction - the inode could have been reclaimed and |
| * now it is reread from disk. |
| */ |
| if (journal) { |
| transaction_t *transaction; |
| tid_t tid; |
| |
| read_lock(&journal->j_state_lock); |
| if (journal->j_running_transaction) |
| transaction = journal->j_running_transaction; |
| else |
| transaction = journal->j_committing_transaction; |
| if (transaction) |
| tid = transaction->t_tid; |
| else |
| tid = journal->j_commit_sequence; |
| read_unlock(&journal->j_state_lock); |
| ei->i_sync_tid = tid; |
| ei->i_datasync_tid = tid; |
| } |
| |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| if (ei->i_extra_isize == 0) { |
| /* The extra space is currently unused. Use it. */ |
| ei->i_extra_isize = sizeof(struct ext4_inode) - |
| EXT4_GOOD_OLD_INODE_SIZE; |
| } else { |
| ext4_iget_extra_inode(inode, raw_inode, ei); |
| } |
| } |
| |
| EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode); |
| EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode); |
| EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode); |
| EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode); |
| |
| if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) { |
| inode->i_version = le32_to_cpu(raw_inode->i_disk_version); |
| if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) { |
| if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| inode->i_version |= |
| (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32; |
| } |
| } |
| |
| ret = 0; |
| if (ei->i_file_acl && |
| !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) { |
| EXT4_ERROR_INODE(inode, "bad extended attribute block %llu", |
| ei->i_file_acl); |
| ret = -EIO; |
| goto bad_inode; |
| } else if (!ext4_has_inline_data(inode)) { |
| if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) { |
| if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
| (S_ISLNK(inode->i_mode) && |
| !ext4_inode_is_fast_symlink(inode)))) |
| /* Validate extent which is part of inode */ |
| ret = ext4_ext_check_inode(inode); |
| } else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || |
| (S_ISLNK(inode->i_mode) && |
| !ext4_inode_is_fast_symlink(inode))) { |
| /* Validate block references which are part of inode */ |
| ret = ext4_ind_check_inode(inode); |
| } |
| } |
| if (ret) |
| goto bad_inode; |
| |
| if (S_ISREG(inode->i_mode)) { |
| inode->i_op = &ext4_file_inode_operations; |
| inode->i_fop = &ext4_file_operations; |
| ext4_set_aops(inode); |
| } else if (S_ISDIR(inode->i_mode)) { |
| inode->i_op = &ext4_dir_inode_operations; |
| inode->i_fop = &ext4_dir_operations; |
| } else if (S_ISLNK(inode->i_mode)) { |
| if (ext4_encrypted_inode(inode)) { |
| inode->i_op = &ext4_encrypted_symlink_inode_operations; |
| ext4_set_aops(inode); |
| } else if (ext4_inode_is_fast_symlink(inode)) { |
| inode->i_link = (char *)ei->i_data; |
| inode->i_op = &ext4_fast_symlink_inode_operations; |
| nd_terminate_link(ei->i_data, inode->i_size, |
| sizeof(ei->i_data) - 1); |
| } else { |
| inode->i_op = &ext4_symlink_inode_operations; |
| ext4_set_aops(inode); |
| } |
| } else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) || |
| S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { |
| inode->i_op = &ext4_special_inode_operations; |
| if (raw_inode->i_block[0]) |
| init_special_inode(inode, inode->i_mode, |
| old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); |
| else |
| init_special_inode(inode, inode->i_mode, |
| new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); |
| } else if (ino == EXT4_BOOT_LOADER_INO) { |
| make_bad_inode(inode); |
| } else { |
| ret = -EIO; |
| EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode); |
| goto bad_inode; |
| } |
| brelse(iloc.bh); |
| ext4_set_inode_flags(inode); |
| unlock_new_inode(inode); |
| return inode; |
| |
| bad_inode: |
| brelse(iloc.bh); |
| iget_failed(inode); |
| return ERR_PTR(ret); |
| } |
| |
| struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino) |
| { |
| if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO) |
| return ERR_PTR(-EIO); |
| return ext4_iget(sb, ino); |
| } |
| |
| static int ext4_inode_blocks_set(handle_t *handle, |
| struct ext4_inode *raw_inode, |
| struct ext4_inode_info *ei) |
| { |
| struct inode *inode = &(ei->vfs_inode); |
| u64 i_blocks = inode->i_blocks; |
| struct super_block *sb = inode->i_sb; |
| |
| if (i_blocks <= ~0U) { |
| /* |
| * i_blocks can be represented in a 32 bit variable |
| * as multiple of 512 bytes |
| */ |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = 0; |
| ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| return 0; |
| } |
| if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) |
| return -EFBIG; |
| |
| if (i_blocks <= 0xffffffffffffULL) { |
| /* |
| * i_blocks can be represented in a 48 bit variable |
| * as multiple of 512 bytes |
| */ |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| } else { |
| ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE); |
| /* i_block is stored in file system block size */ |
| i_blocks = i_blocks >> (inode->i_blkbits - 9); |
| raw_inode->i_blocks_lo = cpu_to_le32(i_blocks); |
| raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32); |
| } |
| return 0; |
| } |
| |
| struct other_inode { |
| unsigned long orig_ino; |
| struct ext4_inode *raw_inode; |
| }; |
| |
| static int other_inode_match(struct inode * inode, unsigned long ino, |
| void *data) |
| { |
| struct other_inode *oi = (struct other_inode *) data; |
| |
| if ((inode->i_ino != ino) || |
| (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW | |
| I_DIRTY_SYNC | I_DIRTY_DATASYNC)) || |
| ((inode->i_state & I_DIRTY_TIME) == 0)) |
| return 0; |
| spin_lock(&inode->i_lock); |
| if (((inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW | |
| I_DIRTY_SYNC | I_DIRTY_DATASYNC)) == 0) && |
| (inode->i_state & I_DIRTY_TIME)) { |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| |
| inode->i_state &= ~(I_DIRTY_TIME | I_DIRTY_TIME_EXPIRED); |
| spin_unlock(&inode->i_lock); |
| |
| spin_lock(&ei->i_raw_lock); |
| EXT4_INODE_SET_XTIME(i_ctime, inode, oi->raw_inode); |
| EXT4_INODE_SET_XTIME(i_mtime, inode, oi->raw_inode); |
| EXT4_INODE_SET_XTIME(i_atime, inode, oi->raw_inode); |
| ext4_inode_csum_set(inode, oi->raw_inode, ei); |
| spin_unlock(&ei->i_raw_lock); |
| trace_ext4_other_inode_update_time(inode, oi->orig_ino); |
| return -1; |
| } |
| spin_unlock(&inode->i_lock); |
| return -1; |
| } |
| |
| /* |
| * Opportunistically update the other time fields for other inodes in |
| * the same inode table block. |
| */ |
| static void ext4_update_other_inodes_time(struct super_block *sb, |
| unsigned long orig_ino, char *buf) |
| { |
| struct other_inode oi; |
| unsigned long ino; |
| int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block; |
| int inode_size = EXT4_INODE_SIZE(sb); |
| |
| oi.orig_ino = orig_ino; |
| ino = (orig_ino & ~(inodes_per_block - 1)) + 1; |
| for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) { |
| if (ino == orig_ino) |
| continue; |
| oi.raw_inode = (struct ext4_inode *) buf; |
| (void) find_inode_nowait(sb, ino, other_inode_match, &oi); |
| } |
| } |
| |
| /* |
| * Post the struct inode info into an on-disk inode location in the |
| * buffer-cache. This gobbles the caller's reference to the |
| * buffer_head in the inode location struct. |
| * |
| * The caller must have write access to iloc->bh. |
| */ |
| static int ext4_do_update_inode(handle_t *handle, |
| struct inode *inode, |
| struct ext4_iloc *iloc) |
| { |
| struct ext4_inode *raw_inode = ext4_raw_inode(iloc); |
| struct ext4_inode_info *ei = EXT4_I(inode); |
| struct buffer_head *bh = iloc->bh; |
| struct super_block *sb = inode->i_sb; |
| int err = 0, rc, block; |
| int need_datasync = 0, set_large_file = 0; |
| uid_t i_uid; |
| gid_t i_gid; |
| |
| spin_lock(&ei->i_raw_lock); |
| |
| /* For fields not tracked in the in-memory inode, |
| * initialise them to zero for new inodes. */ |
| if (ext4_test_inode_state(inode, EXT4_STATE_NEW)) |
| memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size); |
| |
| ext4_get_inode_flags(ei); |
| raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
| i_uid = i_uid_read(inode); |
| i_gid = i_gid_read(inode); |
| if (!(test_opt(inode->i_sb, NO_UID32))) { |
| raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid)); |
| raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid)); |
| /* |
| * Fix up interoperability with old kernels. Otherwise, old inodes get |
| * re-used with the upper 16 bits of the uid/gid intact |
| */ |
| if (!ei->i_dtime) { |
| raw_inode->i_uid_high = |
| cpu_to_le16(high_16_bits(i_uid)); |
| raw_inode->i_gid_high = |
| cpu_to_le16(high_16_bits(i_gid)); |
| } else { |
| raw_inode->i_uid_high = 0; |
| raw_inode->i_gid_high = 0; |
| } |
| } else { |
| raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid)); |
| raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid)); |
| raw_inode->i_uid_high = 0; |
| raw_inode->i_gid_high = 0; |
| } |
| raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); |
| |
| EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode); |
| EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode); |
| EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode); |
| EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode); |
| |
| err = ext4_inode_blocks_set(handle, raw_inode, ei); |
| if (err) { |
| spin_unlock(&ei->i_raw_lock); |
| goto out_brelse; |
| } |
| raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); |
| raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF); |
| if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) |
| raw_inode->i_file_acl_high = |
| cpu_to_le16(ei->i_file_acl >> 32); |
| raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl); |
| if (ei->i_disksize != ext4_isize(raw_inode)) { |
| ext4_isize_set(raw_inode, ei->i_disksize); |
| need_datasync = 1; |
| } |
| if (ei->i_disksize > 0x7fffffffULL) { |
| if (!EXT4_HAS_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_LARGE_FILE) || |
| EXT4_SB(sb)->s_es->s_rev_level == |
| cpu_to_le32(EXT4_GOOD_OLD_REV)) |
| set_large_file = 1; |
| } |
| raw_inode->i_generation = cpu_to_le32(inode->i_generation); |
| if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { |
| if (old_valid_dev(inode->i_rdev)) { |
| raw_inode->i_block[0] = |
| cpu_to_le32(old_encode_dev(inode->i_rdev)); |
| raw_inode->i_block[1] = 0; |
| } else { |
| raw_inode->i_block[0] = 0; |
| raw_inode->i_block[1] = |
| cpu_to_le32(new_encode_dev(inode->i_rdev)); |
| raw_inode->i_block[2] = 0; |
| } |
| } else if (!ext4_has_inline_data(inode)) { |
| for (block = 0; block < EXT4_N_BLOCKS; block++) |
| raw_inode->i_block[block] = ei->i_data[block]; |
| } |
| |
| if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) { |
| raw_inode->i_disk_version = cpu_to_le32(inode->i_version); |
| if (ei->i_extra_isize) { |
| if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi)) |
| raw_inode->i_version_hi = |
| cpu_to_le32(inode->i_version >> 32); |
| raw_inode->i_extra_isize = |
| cpu_to_le16(ei->i_extra_isize); |
| } |
| } |
| ext4_inode_csum_set(inode, raw_inode, ei); |
| spin_unlock(&ei->i_raw_lock); |
| if (inode->i_sb->s_flags & MS_LAZYTIME) |
| ext4_update_other_inodes_time(inode->i_sb, inode->i_ino, |
| bh->b_data); |
| |
| BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata"); |
| rc = ext4_handle_dirty_metadata(handle, NULL, bh); |
| if (!err) |
| err = rc; |
| ext4_clear_inode_state(inode, EXT4_STATE_NEW); |
| if (set_large_file) { |
| BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access"); |
| err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh); |
| if (err) |
| goto out_brelse; |
| ext4_update_dynamic_rev(sb); |
| EXT4_SET_RO_COMPAT_FEATURE(sb, |
| EXT4_FEATURE_RO_COMPAT_LARGE_FILE); |
| ext4_handle_sync(handle); |
| err = ext4_handle_dirty_super(handle, sb); |
| } |
| ext4_update_inode_fsync_trans(handle, inode, need_datasync); |
| out_brelse: |
| brelse(bh); |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| |
| /* |
| * ext4_write_inode() |
| * |
| * We are called from a few places: |
| * |
| * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files. |
| * Here, there will be no transaction running. We wait for any running |
| * transaction to commit. |
| * |
| * - Within flush work (sys_sync(), kupdate and such). |
| * We wait on commit, if told to. |
| * |
| * - Within iput_final() -> write_inode_now() |
| * We wait on commit, if told to. |
| * |
| * In all cases it is actually safe for us to return without doing anything, |
| * because the inode has been copied into a raw inode buffer in |
| * ext4_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL |
| * writeback. |
| * |
| * Note that we are absolutely dependent upon all inode dirtiers doing the |
| * right thing: they *must* call mark_inode_dirty() after dirtying info in |
| * which we are interested. |
| * |
| * It would be a bug for them to not do this. The code: |
| * |
| * mark_inode_dirty(inode) |
| * stuff(); |
| * inode->i_size = expr; |
| * |
| * is in error because write_inode() could occur while `stuff()' is running, |
| * and the new i_size will be lost. Plus the inode will no longer be on the |
| * superblock's dirty inode list. |
| */ |
| int ext4_write_inode(struct inode *inode, struct writeback_control *wbc) |
| { |
| int err; |
| |
| if (WARN_ON_ONCE(current->flags & PF_MEMALLOC)) |
| return 0; |
| |
| if (EXT4_SB(inode->i_sb)->s_journal) { |
| if (ext4_journal_current_handle()) { |
| jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); |
| dump_stack(); |
| return -EIO; |
| } |
| |
| /* |
| * No need to force transaction in WB_SYNC_NONE mode. Also |
| * ext4_sync_fs() will force the commit after everything is |
| * written. |
| */ |
| if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync) |
| return 0; |
| |
| err = ext4_force_commit(inode->i_sb); |
| } else { |
| struct ext4_iloc iloc; |
| |
| err = __ext4_get_inode_loc(inode, &iloc, 0); |
| if (err) |
| return err; |
| /* |
| * sync(2) will flush the whole buffer cache. No need to do |
| * it here separately for each inode. |
| */ |
| if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync) |
| sync_dirty_buffer(iloc.bh); |
| if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) { |
| EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr, |
| "IO error syncing inode"); |
| err = -EIO; |
| } |
| brelse(iloc.bh); |
| } |
| return err; |
| } |
| |
| /* |
| * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate |
| * buffers that are attached to a page stradding i_size and are undergoing |
| * commit. In that case we have to wait for commit to finish and try again. |
| */ |
| static void ext4_wait_for_tail_page_commit(struct inode *inode) |
| { |
| struct page *page; |
| unsigned offset; |
| journal_t *journal = EXT4_SB(inode->i_sb)->s_journal; |
| tid_t commit_tid = 0; |
| int ret; |
| |
| offset = inode->i_size & (PAGE_CACHE_SIZE - 1); |
| /* |
| * All buffers in the last page remain valid? Then there's nothing to |
| * do. We do the check mainly to optimize the common PAGE_CACHE_SIZE == |
| * blocksize case |
| */ |
| if (offset > PAGE_CACHE_SIZE - (1 << inode->i_blkbits)) |
| return; |
| while (1) { |
| page = find_lock_page(inode->i_mapping, |
| inode->i_size >> PAGE_CACHE_SHIFT); |
| if (!page) |
| return; |
| ret = __ext4_journalled_invalidatepage(page, offset, |
| PAGE_CACHE_SIZE - offset); |
| unlock_page(page); |
| page_cache_release(page); |
| if (ret != -EBUSY) |
| return; |
| commit_tid = 0; |
| read_lock(&journal->j_state_lock); |
| if (journal->j_committing_transaction) |
| commit_tid = journal->j_committing_transaction->t_tid; |
| read_unlock(&journal->j_state_lock); |
| if (commit_tid) |
| jbd2_log_wait_commit(journal, commit_tid); |
| } |
| } |
| |
| /* |
| * ext4_setattr() |
| * |
| * Called from notify_change. |
| * |
| * We want to trap VFS attempts to truncate the file as soon as |
| * possible. In particular, we want to make sure that when the VFS |
| * shrinks i_size, we put the inode on the orphan list and modify |
| * i_disksize immediately, so that during the subsequent flushing of |
| * dirty pages and freeing of disk blocks, we can guarantee that any |
| * commit will leave the blocks being flushed in an unused state on |
| * disk. (On recovery, the inode will get truncated and the blocks will |
| * be freed, so we have a strong guarantee that no future commit will |
| * leave these blocks visible to the user.) |
| * |
| * Another thing we have to assure is that if we are in ordered mode |
| * and inode is still attached to the committing transaction, we must |
| * we start writeout of all the dirty pages which are being truncated. |
| * This way we are sure that all the data written in the previous |
| * transaction are already on disk (truncate waits for pages under |
| * writeback). |
| * |
| * Called with inode->i_mutex down. |
| */ |
| int ext4_setattr(struct dentry *dentry, struct iattr *attr) |
| { |
| struct inode *inode = d_inode(dentry); |
| int error, rc = 0; |
| int orphan = 0; |
| const unsigned int ia_valid = attr->ia_valid; |
| |
| error = inode_change_ok(inode, attr); |
| if (error) |
| return error; |
| |
| if (is_quota_modification(inode, attr)) |
| dquot_initialize(inode); |
| if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) || |
| (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) { |
| handle_t *handle; |
| |
| /* (user+group)*(old+new) structure, inode write (sb, |
| * inode block, ? - but truncate inode update has it) */ |
| handle = ext4_journal_start(inode, EXT4_HT_QUOTA, |
| (EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) + |
| EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3); |
| if (IS_ERR(handle)) { |
| error = PTR_ERR(handle); |
| goto err_out; |
| } |
| error = dquot_transfer(inode, attr); |
| if (error) { |
| ext4_journal_stop(handle); |
| return error; |
| } |
| /* Update corresponding info in inode so that everything is in |
| * one transaction */ |
| if (attr->ia_valid & ATTR_UID) |
| inode->i_uid = attr->ia_uid; |
| if (attr->ia_valid & ATTR_GID) |
| inode->i_gid = attr->ia_gid; |
| error = ext4_mark_inode_dirty(handle, inode); |
| ext4_journal_stop(handle); |
| } |
| |
| if (attr->ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) { |
| handle_t *handle; |
| |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) { |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| |
| if (attr->ia_size > sbi->s_bitmap_maxbytes) |
| return -EFBIG; |
| } |
| |
| if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size) |
| inode_inc_iversion(inode); |
| |
| if (S_ISREG(inode->i_mode) && |
| (attr->ia_size < inode->i_size)) { |
| if (ext4_should_order_data(inode)) { |
| error = ext4_begin_ordered_truncate(inode, |
| attr->ia_size); |
| if (error) |
| goto err_out; |
| } |
| handle = ext4_journal_start(inode, EXT4_HT_INODE, 3); |
| if (IS_ERR(handle)) { |
| error = PTR_ERR(handle); |
| goto err_out; |
| } |
| if (ext4_handle_valid(handle)) { |
| error = ext4_orphan_add(handle, inode); |
| orphan = 1; |
| } |
| down_write(&EXT4_I(inode)->i_data_sem); |
| EXT4_I(inode)->i_disksize = attr->ia_size; |
| rc = ext4_mark_inode_dirty(handle, inode); |
| if (!error) |
| error = rc; |
| /* |
| * We have to update i_size under i_data_sem together |
| * with i_disksize to avoid races with writeback code |
| * running ext4_wb_update_i_disksize(). |
| */ |
| if (!error) |
| i_size_write(inode, attr->ia_size); |
| up_write(&EXT4_I(inode)->i_data_sem); |
| ext4_journal_stop(handle); |
| if (error) { |
| ext4_orphan_del(NULL, inode); |
| goto err_out; |
| } |
| } else { |
| loff_t oldsize = inode->i_size; |
| |
| i_size_write(inode, attr->ia_size); |
| pagecache_isize_extended(inode, oldsize, inode->i_size); |
| } |
| |
| /* |
| * Blocks are going to be removed from the inode. Wait |
| * for dio in flight. Temporarily disable |
| * dioread_nolock to prevent livelock. |
| */ |
| if (orphan) { |
| if (!ext4_should_journal_data(inode)) { |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| ext4_inode_resume_unlocked_dio(inode); |
| } else |
| ext4_wait_for_tail_page_commit(inode); |
| } |
| /* |
| * Truncate pagecache after we've waited for commit |
| * in data=journal mode to make pages freeable. |
| */ |
| truncate_pagecache(inode, inode->i_size); |
| } |
| /* |
| * We want to call ext4_truncate() even if attr->ia_size == |
| * inode->i_size for cases like truncation of fallocated space |
| */ |
| if (attr->ia_valid & ATTR_SIZE) |
| ext4_truncate(inode); |
| |
| if (!rc) { |
| setattr_copy(inode, attr); |
| mark_inode_dirty(inode); |
| } |
| |
| /* |
| * If the call to ext4_truncate failed to get a transaction handle at |
| * all, we need to clean up the in-core orphan list manually. |
| */ |
| if (orphan && inode->i_nlink) |
| ext4_orphan_del(NULL, inode); |
| |
| if (!rc && (ia_valid & ATTR_MODE)) |
| rc = posix_acl_chmod(inode, inode->i_mode); |
| |
| err_out: |
| ext4_std_error(inode->i_sb, error); |
| if (!error) |
| error = rc; |
| return error; |
| } |
| |
| int ext4_getattr(struct vfsmount *mnt, struct dentry *dentry, |
| struct kstat *stat) |
| { |
| struct inode *inode; |
| unsigned long long delalloc_blocks; |
| |
| inode = d_inode(dentry); |
| generic_fillattr(inode, stat); |
| |
| /* |
| * If there is inline data in the inode, the inode will normally not |
| * have data blocks allocated (it may have an external xattr block). |
| * Report at least one sector for such files, so tools like tar, rsync, |
| * others doen't incorrectly think the file is completely sparse. |
| */ |
| if (unlikely(ext4_has_inline_data(inode))) |
| stat->blocks += (stat->size + 511) >> 9; |
| |
| /* |
| * We can't update i_blocks if the block allocation is delayed |
| * otherwise in the case of system crash before the real block |
| * allocation is done, we will have i_blocks inconsistent with |
| * on-disk file blocks. |
| * We always keep i_blocks updated together with real |
| * allocation. But to not confuse with user, stat |
| * will return the blocks that include the delayed allocation |
| * blocks for this file. |
| */ |
| delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb), |
| EXT4_I(inode)->i_reserved_data_blocks); |
| stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9); |
| return 0; |
| } |
| |
| static int ext4_index_trans_blocks(struct inode *inode, int lblocks, |
| int pextents) |
| { |
| if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) |
| return ext4_ind_trans_blocks(inode, lblocks); |
| return ext4_ext_index_trans_blocks(inode, pextents); |
| } |
| |
| /* |
| * Account for index blocks, block groups bitmaps and block group |
| * descriptor blocks if modify datablocks and index blocks |
| * worse case, the indexs blocks spread over different block groups |
| * |
| * If datablocks are discontiguous, they are possible to spread over |
| * different block groups too. If they are contiguous, with flexbg, |
| * they could still across block group boundary. |
| * |
| * Also account for superblock, inode, quota and xattr blocks |
| */ |
| static int ext4_meta_trans_blocks(struct inode *inode, int lblocks, |
| int pextents) |
| { |
| ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb); |
| int gdpblocks; |
| int idxblocks; |
| int ret = 0; |
| |
| /* |
| * How many index blocks need to touch to map @lblocks logical blocks |
| * to @pextents physical extents? |
| */ |
| idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents); |
| |
| ret = idxblocks; |
| |
| /* |
| * Now let's see how many group bitmaps and group descriptors need |
| * to account |
| */ |
| groups = idxblocks + pextents; |
| gdpblocks = groups; |
| if (groups > ngroups) |
| groups = ngroups; |
| if (groups > EXT4_SB(inode->i_sb)->s_gdb_count) |
| gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count; |
| |
| /* bitmaps and block group descriptor blocks */ |
| ret += groups + gdpblocks; |
| |
| /* Blocks for super block, inode, quota and xattr blocks */ |
| ret += EXT4_META_TRANS_BLOCKS(inode->i_sb); |
| |
| return ret; |
| } |
| |
| /* |
| * Calculate the total number of credits to reserve to fit |
| * the modification of a single pages into a single transaction, |
| * which may include multiple chunks of block allocations. |
| * |
| * This could be called via ext4_write_begin() |
| * |
| * We need to consider the worse case, when |
| * one new block per extent. |
| */ |
| int ext4_writepage_trans_blocks(struct inode *inode) |
| { |
| int bpp = ext4_journal_blocks_per_page(inode); |
| int ret; |
| |
| ret = ext4_meta_trans_blocks(inode, bpp, bpp); |
| |
| /* Account for data blocks for journalled mode */ |
| if (ext4_should_journal_data(inode)) |
| ret += bpp; |
| return ret; |
| } |
| |
| /* |
| * Calculate the journal credits for a chunk of data modification. |
| * |
| * This is called from DIO, fallocate or whoever calling |
| * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks. |
| * |
| * journal buffers for data blocks are not included here, as DIO |
| * and fallocate do no need to journal data buffers. |
| */ |
| int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks) |
| { |
| return ext4_meta_trans_blocks(inode, nrblocks, 1); |
| } |
| |
| /* |
| * The caller must have previously called ext4_reserve_inode_write(). |
| * Give this, we know that the caller already has write access to iloc->bh. |
| */ |
| int ext4_mark_iloc_dirty(handle_t *handle, |
| struct inode *inode, struct ext4_iloc *iloc) |
| { |
| int err = 0; |
| |
| if (IS_I_VERSION(inode)) |
| inode_inc_iversion(inode); |
| |
| /* the do_update_inode consumes one bh->b_count */ |
| get_bh(iloc->bh); |
| |
| /* ext4_do_update_inode() does jbd2_journal_dirty_metadata */ |
| err = ext4_do_update_inode(handle, inode, iloc); |
| put_bh(iloc->bh); |
| return err; |
| } |
| |
| /* |
| * On success, We end up with an outstanding reference count against |
| * iloc->bh. This _must_ be cleaned up later. |
| */ |
| |
| int |
| ext4_reserve_inode_write(handle_t *handle, struct inode *inode, |
| struct ext4_iloc *iloc) |
| { |
| int err; |
| |
| err = ext4_get_inode_loc(inode, iloc); |
| if (!err) { |
| BUFFER_TRACE(iloc->bh, "get_write_access"); |
| err = ext4_journal_get_write_access(handle, iloc->bh); |
| if (err) { |
| brelse(iloc->bh); |
| iloc->bh = NULL; |
| } |
| } |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| |
| /* |
| * Expand an inode by new_extra_isize bytes. |
| * Returns 0 on success or negative error number on failure. |
| */ |
| static int ext4_expand_extra_isize(struct inode *inode, |
| unsigned int new_extra_isize, |
| struct ext4_iloc iloc, |
| handle_t *handle) |
| { |
| struct ext4_inode *raw_inode; |
| struct ext4_xattr_ibody_header *header; |
| |
| if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) |
| return 0; |
| |
| raw_inode = ext4_raw_inode(&iloc); |
| |
| header = IHDR(inode, raw_inode); |
| |
| /* No extended attributes present */ |
| if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) || |
| header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) { |
| memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0, |
| new_extra_isize); |
| EXT4_I(inode)->i_extra_isize = new_extra_isize; |
| return 0; |
| } |
| |
| /* try to expand with EAs present */ |
| return ext4_expand_extra_isize_ea(inode, new_extra_isize, |
| raw_inode, handle); |
| } |
| |
| /* |
| * What we do here is to mark the in-core inode as clean with respect to inode |
| * dirtiness (it may still be data-dirty). |
| * This means that the in-core inode may be reaped by prune_icache |
| * without having to perform any I/O. This is a very good thing, |
| * because *any* task may call prune_icache - even ones which |
| * have a transaction open against a different journal. |
| * |
| * Is this cheating? Not really. Sure, we haven't written the |
| * inode out, but prune_icache isn't a user-visible syncing function. |
| * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) |
| * we start and wait on commits. |
| */ |
| int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_iloc iloc; |
| struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); |
| static unsigned int mnt_count; |
| int err, ret; |
| |
| might_sleep(); |
| trace_ext4_mark_inode_dirty(inode, _RET_IP_); |
| err = ext4_reserve_inode_write(handle, inode, &iloc); |
| if (ext4_handle_valid(handle) && |
| EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize && |
| !ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) { |
| /* |
| * We need extra buffer credits since we may write into EA block |
| * with this same handle. If journal_extend fails, then it will |
| * only result in a minor loss of functionality for that inode. |
| * If this is felt to be critical, then e2fsck should be run to |
| * force a large enough s_min_extra_isize. |
| */ |
| if ((jbd2_journal_extend(handle, |
| EXT4_DATA_TRANS_BLOCKS(inode->i_sb))) == 0) { |
| ret = ext4_expand_extra_isize(inode, |
| sbi->s_want_extra_isize, |
| iloc, handle); |
| if (ret) { |
| ext4_set_inode_state(inode, |
| EXT4_STATE_NO_EXPAND); |
| if (mnt_count != |
| le16_to_cpu(sbi->s_es->s_mnt_count)) { |
| ext4_warning(inode->i_sb, |
| "Unable to expand inode %lu. Delete" |
| " some EAs or run e2fsck.", |
| inode->i_ino); |
| mnt_count = |
| le16_to_cpu(sbi->s_es->s_mnt_count); |
| } |
| } |
| } |
| } |
| if (!err) |
| err = ext4_mark_iloc_dirty(handle, inode, &iloc); |
| return err; |
| } |
| |
| /* |
| * ext4_dirty_inode() is called from __mark_inode_dirty() |
| * |
| * We're really interested in the case where a file is being extended. |
| * i_size has been changed by generic_commit_write() and we thus need |
| * to include the updated inode in the current transaction. |
| * |
| * Also, dquot_alloc_block() will always dirty the inode when blocks |
| * are allocated to the file. |
| * |
| * If the inode is marked synchronous, we don't honour that here - doing |
| * so would cause a commit on atime updates, which we don't bother doing. |
| * We handle synchronous inodes at the highest possible level. |
| * |
| * If only the I_DIRTY_TIME flag is set, we can skip everything. If |
| * I_DIRTY_TIME and I_DIRTY_SYNC is set, the only inode fields we need |
| * to copy into the on-disk inode structure are the timestamp files. |
| */ |
| void ext4_dirty_inode(struct inode *inode, int flags) |
| { |
| handle_t *handle; |
| |
| if (flags == I_DIRTY_TIME) |
| return; |
| handle = ext4_journal_start(inode, EXT4_HT_INODE, 2); |
| if (IS_ERR(handle)) |
| goto out; |
| |
| ext4_mark_inode_dirty(handle, inode); |
| |
| ext4_journal_stop(handle); |
| out: |
| return; |
| } |
| |
| #if 0 |
| /* |
| * Bind an inode's backing buffer_head into this transaction, to prevent |
| * it from being flushed to disk early. Unlike |
| * ext4_reserve_inode_write, this leaves behind no bh reference and |
| * returns no iloc structure, so the caller needs to repeat the iloc |
| * lookup to mark the inode dirty later. |
| */ |
| static int ext4_pin_inode(handle_t *handle, struct inode *inode) |
| { |
| struct ext4_iloc iloc; |
| |
| int err = 0; |
| if (handle) { |
| err = ext4_get_inode_loc(inode, &iloc); |
| if (!err) { |
| BUFFER_TRACE(iloc.bh, "get_write_access"); |
| err = jbd2_journal_get_write_access(handle, iloc.bh); |
| if (!err) |
| err = ext4_handle_dirty_metadata(handle, |
| NULL, |
| iloc.bh); |
| brelse(iloc.bh); |
| } |
| } |
| ext4_std_error(inode->i_sb, err); |
| return err; |
| } |
| #endif |
| |
| int ext4_change_inode_journal_flag(struct inode *inode, int val) |
| { |
| journal_t *journal; |
| handle_t *handle; |
| int err; |
| |
| /* |
| * We have to be very careful here: changing a data block's |
| * journaling status dynamically is dangerous. If we write a |
| * data block to the journal, change the status and then delete |
| * that block, we risk forgetting to revoke the old log record |
| * from the journal and so a subsequent replay can corrupt data. |
| * So, first we make sure that the journal is empty and that |
| * nobody is changing anything. |
| */ |
| |
| journal = EXT4_JOURNAL(inode); |
| if (!journal) |
| return 0; |
| if (is_journal_aborted(journal)) |
| return -EROFS; |
| /* We have to allocate physical blocks for delalloc blocks |
| * before flushing journal. otherwise delalloc blocks can not |
| * be allocated any more. even more truncate on delalloc blocks |
| * could trigger BUG by flushing delalloc blocks in journal. |
| * There is no delalloc block in non-journal data mode. |
| */ |
| if (val && test_opt(inode->i_sb, DELALLOC)) { |
| err = ext4_alloc_da_blocks(inode); |
| if (err < 0) |
| return err; |
| } |
| |
| /* Wait for all existing dio workers */ |
| ext4_inode_block_unlocked_dio(inode); |
| inode_dio_wait(inode); |
| |
| jbd2_journal_lock_updates(journal); |
| |
| /* |
| * OK, there are no updates running now, and all cached data is |
| * synced to disk. We are now in a completely consistent state |
| * which doesn't have anything in the journal, and we know that |
| * no filesystem updates are running, so it is safe to modify |
| * the inode's in-core data-journaling state flag now. |
| */ |
| |
| if (val) |
| ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); |
| else { |
| err = jbd2_journal_flush(journal); |
| if (err < 0) { |
| jbd2_journal_unlock_updates(journal); |
| ext4_inode_resume_unlocked_dio(inode); |
| return err; |
| } |
| ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA); |
| } |
| ext4_set_aops(inode); |
| |
| jbd2_journal_unlock_updates(journal); |
| ext4_inode_resume_unlocked_dio(inode); |
| |
| /* Finally we can mark the inode as dirty. */ |
| |
| handle = ext4_journal_start(inode, EXT4_HT_INODE, 1); |
| if (IS_ERR(handle)) |
| return PTR_ERR(handle); |
| |
| err = ext4_mark_inode_dirty(handle, inode); |
| ext4_handle_sync(handle); |
| ext4_journal_stop(handle); |
| ext4_std_error(inode->i_sb, err); |
| |
| return err; |
| } |
| |
| static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh) |
| { |
| return !buffer_mapped(bh); |
| } |
| |
| int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) |
| { |
| struct page *page = vmf->page; |
| loff_t size; |
| unsigned long len; |
| int ret; |
| struct file *file = vma->vm_file; |
| struct inode *inode = file_inode(file); |
| struct address_space *mapping = inode->i_mapping; |
| handle_t *handle; |
| get_block_t *get_block; |
| int retries = 0; |
| |
| sb_start_pagefault(inode->i_sb); |
| file_update_time(vma->vm_file); |
| /* Delalloc case is easy... */ |
| if (test_opt(inode->i_sb, DELALLOC) && |
| !ext4_should_journal_data(inode) && |
| !ext4_nonda_switch(inode->i_sb)) { |
| do { |
| ret = __block_page_mkwrite(vma, vmf, |
| ext4_da_get_block_prep); |
| } while (ret == -ENOSPC && |
| ext4_should_retry_alloc(inode->i_sb, &retries)); |
| goto out_ret; |
| } |
| |
| lock_page(page); |
| size = i_size_read(inode); |
| /* Page got truncated from under us? */ |
| if (page->mapping != mapping || page_offset(page) > size) { |
| unlock_page(page); |
| ret = VM_FAULT_NOPAGE; |
| goto out; |
| } |
| |
| if (page->index == size >> PAGE_CACHE_SHIFT) |
| len = size & ~PAGE_CACHE_MASK; |
| else |
| len = PAGE_CACHE_SIZE; |
| /* |
| * Return if we have all the buffers mapped. This avoids the need to do |
| * journal_start/journal_stop which can block and take a long time |
| */ |
| if (page_has_buffers(page)) { |
| if (!ext4_walk_page_buffers(NULL, page_buffers(page), |
| 0, len, NULL, |
| ext4_bh_unmapped)) { |
| /* Wait so that we don't change page under IO */ |
| wait_for_stable_page(page); |
| ret = VM_FAULT_LOCKED; |
| goto out; |
| } |
| } |
| unlock_page(page); |
| /* OK, we need to fill the hole... */ |
| if (ext4_should_dioread_nolock(inode)) |
| get_block = ext4_get_block_write; |
| else |
| get_block = ext4_get_block; |
| retry_alloc: |
| handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, |
| ext4_writepage_trans_blocks(inode)); |
| if (IS_ERR(handle)) { |
| ret = VM_FAULT_SIGBUS; |
| goto out; |
| } |
| ret = __block_page_mkwrite(vma, vmf, get_block); |
| if (!ret && ext4_should_journal_data(inode)) { |
| if (ext4_walk_page_buffers(handle, page_buffers(page), 0, |
| 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); |
| } |
| ext4_journal_stop(handle); |
| if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) |
| goto retry_alloc; |
| out_ret: |
| ret = block_page_mkwrite_return(ret); |
| out: |
| sb_end_pagefault(inode->i_sb); |
| return ret; |
| } |
