This allows us to test various error handling code paths Previous-Version-Link: https://lore.kernel.org/r/20191204032335.7683-2-tytso@xxxxxxx Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> --- Andreas, thanks for the sugestion! I've made this change in the v3 patch. Notes: v2: change ext4_simulate_fail() to return a bool instead of an int v3: use integer codes instead of bitflags to indicate which failure to simulate fs/ext4/balloc.c | 4 +++- fs/ext4/ext4.h | 38 ++++++++++++++++++++++++++++++++++++++ fs/ext4/ialloc.c | 4 +++- fs/ext4/inode.c | 6 +++++- fs/ext4/namei.c | 11 ++++++++--- fs/ext4/sysfs.c | 23 +++++++++++++++++++++++ 6 files changed, 80 insertions(+), 6 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 102c38527a10..5f993a411251 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -371,7 +371,8 @@ static int ext4_validate_block_bitmap(struct super_block *sb, if (buffer_verified(bh)) goto verified; if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group, - desc, bh))) { + desc, bh) || + ext4_simulate_fail(sb, EXT4_SIM_BBITMAP_CRC))) { ext4_unlock_group(sb, block_group); ext4_error(sb, "bg %u: bad block bitmap checksum", block_group); ext4_mark_group_bitmap_corrupted(sb, block_group, @@ -505,6 +506,7 @@ int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group, if (!desc) return -EFSCORRUPTED; wait_on_buffer(bh); + ext4_simulate_fail_bh(sb, bh, EXT4_SIM_BBITMAP_EIO); if (!buffer_uptodate(bh)) { ext4_set_errno(sb, EIO); ext4_error(sb, "Cannot read block bitmap - " diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 1c9ac0fc8715..689c8efc7dd1 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1557,6 +1557,9 @@ struct ext4_sb_info { /* Barrier between changing inodes' journal flags and writepages ops. */ struct percpu_rw_semaphore s_journal_flag_rwsem; struct dax_device *s_daxdev; +#ifdef CONFIG_EXT4_DEBUG + unsigned long s_simulate_fail; +#endif }; static inline struct ext4_sb_info *EXT4_SB(struct super_block *sb) @@ -1575,6 +1578,41 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino) ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count)); } +/* + * Simulate_fail codes + */ +#define EXT4_SIM_BBITMAP_EIO 1 +#define EXT4_SIM_BBITMAP_CRC 2 +#define EXT4_SIM_IBITMAP_EIO 3 +#define EXT4_SIM_IBITMAP_CRC 4 +#define EXT4_SIM_INODE_EIO 5 +#define EXT4_SIM_INODE_CRC 6 +#define EXT4_SIM_DIRBLOCK_EIO 7 +#define EXT4_SIM_DIRBLOCK_CRC 8 + +static inline bool ext4_simulate_fail(struct super_block *sb, + unsigned long code) +{ +#ifdef CONFIG_EXT4_DEBUG + struct ext4_sb_info *sbi = EXT4_SB(sb); + + if (sbi->s_simulate_fail != code) + return false; + sbi->s_simulate_fail = 0; + return true; +#else + return false; +#endif +} + +static inline void ext4_simulate_fail_bh(struct super_block *sb, + struct buffer_head *bh, + unsigned long code) +{ + if (!IS_ERR(bh) && ext4_simulate_fail(sb, code)) + clear_buffer_uptodate(bh); +} + /* * Error number codes for s_{first,last}_error_errno * diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 9979e1a55be5..8e5bb8a3f151 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -94,7 +94,8 @@ static int ext4_validate_inode_bitmap(struct super_block *sb, goto verified; blk = ext4_inode_bitmap(sb, desc); if (!ext4_inode_bitmap_csum_verify(sb, block_group, desc, bh, - EXT4_INODES_PER_GROUP(sb) / 8)) { + EXT4_INODES_PER_GROUP(sb) / 8) || + ext4_simulate_fail(sb, EXT4_SIM_IBITMAP_CRC)) { ext4_unlock_group(sb, block_group); ext4_error(sb, "Corrupt inode bitmap - block_group = %u, " "inode_bitmap = %llu", block_group, blk); @@ -192,6 +193,7 @@ ext4_read_inode_bitmap(struct super_block *sb, ext4_group_t block_group) get_bh(bh); submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh); wait_on_buffer(bh); + ext4_simulate_fail_bh(sb, bh, EXT4_SIM_IBITMAP_EIO); if (!buffer_uptodate(bh)) { put_bh(bh); ext4_set_errno(sb, EIO); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1aed7c653b42..128e51c37b93 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4243,6 +4243,8 @@ static int __ext4_get_inode_loc(struct inode *inode, bh = sb_getblk(sb, block); if (unlikely(!bh)) return -ENOMEM; + if (ext4_simulate_fail(sb, EXT4_SIM_INODE_EIO)) + goto simulate_eio; if (!buffer_uptodate(bh)) { lock_buffer(bh); @@ -4341,6 +4343,7 @@ static int __ext4_get_inode_loc(struct inode *inode, blk_finish_plug(&plug); wait_on_buffer(bh); if (!buffer_uptodate(bh)) { + simulate_eio: ext4_set_errno(inode->i_sb, EIO); EXT4_ERROR_INODE_BLOCK(inode, block, "unable to read itable block"); @@ -4555,7 +4558,8 @@ struct inode *__ext4_iget(struct super_block *sb, unsigned long ino, sizeof(gen)); } - if (!ext4_inode_csum_verify(inode, raw_inode, ei)) { + if (!ext4_inode_csum_verify(inode, raw_inode, ei) || + ext4_simulate_fail(sb, EXT4_SIM_INODE_CRC)) { ext4_set_errno(inode->i_sb, EFSBADCRC); ext4_error_inode(inode, function, line, 0, "iget: checksum invalid"); diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index c74ed04d6781..3a0f65e21e8f 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -109,7 +109,10 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode, struct ext4_dir_entry *dirent; int is_dx_block = 0; - bh = ext4_bread(NULL, inode, block, 0); + if (ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_EIO)) + bh = ERR_PTR(-EIO); + else + bh = ext4_bread(NULL, inode, block, 0); if (IS_ERR(bh)) { __ext4_warning(inode->i_sb, func, line, "inode #%lu: lblock %lu: comm %s: " @@ -153,7 +156,8 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode, * caller is sure it should be an index block. */ if (is_dx_block && type == INDEX) { - if (ext4_dx_csum_verify(inode, dirent)) + if (ext4_dx_csum_verify(inode, dirent) && + !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) set_buffer_verified(bh); else { ext4_set_errno(inode->i_sb, EFSBADCRC); @@ -164,7 +168,8 @@ static struct buffer_head *__ext4_read_dirblock(struct inode *inode, } } if (!is_dx_block) { - if (ext4_dirblock_csum_verify(inode, bh)) + if (ext4_dirblock_csum_verify(inode, bh) && + !ext4_simulate_fail(inode->i_sb, EXT4_SIM_DIRBLOCK_CRC)) set_buffer_verified(bh); else { ext4_set_errno(inode->i_sb, EFSBADCRC); diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c index eb1efad0e20a..a990d28d191b 100644 --- a/fs/ext4/sysfs.c +++ b/fs/ext4/sysfs.c @@ -29,6 +29,7 @@ typedef enum { attr_last_error_time, attr_feature, attr_pointer_ui, + attr_pointer_ul, attr_pointer_atomic, attr_journal_task, } attr_id_t; @@ -160,6 +161,9 @@ static struct ext4_attr ext4_attr_##_name = { \ #define EXT4_RW_ATTR_SBI_UI(_name,_elname) \ EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname) +#define EXT4_RW_ATTR_SBI_UL(_name,_elname) \ + EXT4_ATTR_OFFSET(_name, 0644, pointer_ul, ext4_sb_info, _elname) + #define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \ static struct ext4_attr ext4_attr_##_name = { \ .attr = {.name = __stringify(_name), .mode = _mode }, \ @@ -194,6 +198,9 @@ EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.int EXT4_RW_ATTR_SBI_UI(warning_ratelimit_burst, s_warning_ratelimit_state.burst); EXT4_RW_ATTR_SBI_UI(msg_ratelimit_interval_ms, s_msg_ratelimit_state.interval); EXT4_RW_ATTR_SBI_UI(msg_ratelimit_burst, s_msg_ratelimit_state.burst); +#ifdef CONFIG_EXT4_DEBUG +EXT4_RW_ATTR_SBI_UL(simulate_fail, s_simulate_fail); +#endif EXT4_RO_ATTR_ES_UI(errors_count, s_error_count); EXT4_ATTR(first_error_time, 0444, first_error_time); EXT4_ATTR(last_error_time, 0444, last_error_time); @@ -228,6 +235,9 @@ static struct attribute *ext4_attrs[] = { ATTR_LIST(first_error_time), ATTR_LIST(last_error_time), ATTR_LIST(journal_task), +#ifdef CONFIG_EXT4_DEBUG + ATTR_LIST(simulate_fail), +#endif NULL, }; ATTRIBUTE_GROUPS(ext4); @@ -318,6 +328,11 @@ static ssize_t ext4_attr_show(struct kobject *kobj, else return snprintf(buf, PAGE_SIZE, "%u\n", *((unsigned int *) ptr)); + case attr_pointer_ul: + if (!ptr) + return 0; + return snprintf(buf, PAGE_SIZE, "%lu\n", + *((unsigned long *) ptr)); case attr_pointer_atomic: if (!ptr) return 0; @@ -361,6 +376,14 @@ static ssize_t ext4_attr_store(struct kobject *kobj, else *((unsigned int *) ptr) = t; return len; + case attr_pointer_ul: + if (!ptr) + return 0; + ret = kstrtoul(skip_spaces(buf), 0, &t); + if (ret) + return ret; + *((unsigned long *) ptr) = t; + return len; case attr_inode_readahead: return inode_readahead_blks_store(sbi, buf, len); case attr_trigger_test_error: -- 2.23.0
