[PATCH OLK-5.10 0/4] fix race between setxattr and write back
Ye Bin (4): ext2: remove ext2_new_block() ext2: introduce flag argument for ext2_new_blocks() ext2: fix race between setxattr and write back ext2: dump current reservation window info fs/ext2/balloc.c | 32 +++++++++++++++++--------------- fs/ext2/ext2.h | 8 ++++++-- fs/ext2/inode.c | 2 +- fs/ext2/xattr.c | 4 +++- 4 files changed, 27 insertions(+), 19 deletions(-) -- 2.31.1
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7TN3J -------------------------------- Now, only xattr allocate block use ext2_new_block(), so just opencode it in the xattr code. Signed-off-by: Ye Bin <yebin10@huawei.com> --- fs/ext2/balloc.c | 7 ------- fs/ext2/ext2.h | 1 - fs/ext2/xattr.c | 4 +++- 3 files changed, 3 insertions(+), 9 deletions(-) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index 5dc0a31f4a08..d764ae094c6f 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1431,13 +1431,6 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, return 0; } -ext2_fsblk_t ext2_new_block(struct inode *inode, unsigned long goal, int *errp) -{ - unsigned long count = 1; - - return ext2_new_blocks(inode, goal, &count, errp); -} - #ifdef EXT2FS_DEBUG unsigned long ext2_count_free(struct buffer_head *map, unsigned int numchars) diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 5136b7289e8d..950e3a496d01 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -718,7 +718,6 @@ static inline struct ext2_inode_info *EXT2_I(struct inode *inode) /* balloc.c */ extern int ext2_bg_has_super(struct super_block *sb, int group); extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group); -extern ext2_fsblk_t ext2_new_block(struct inode *, unsigned long, int *); extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long, unsigned long *, int *); extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index 841fa6d9d744..8fbc6891ab5d 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -694,7 +694,9 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, /* We need to allocate a new block */ ext2_fsblk_t goal = ext2_group_first_block_no(sb, EXT2_I(inode)->i_block_group); - int block = ext2_new_block(inode, goal, &error); + unsigned long count = 1; + int block = ext2_new_blocks(inode, goal, &count, + &error); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block); -- 2.31.1
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7TN3J -------------------------------- This patch introduce introduce flag argument for ext2_new_blocks(), and also introduce EXT2_ALLOC_NORESERVE flags. Signed-off-by: Ye Bin <yebin10@huawei.com> --- fs/ext2/balloc.c | 3 ++- fs/ext2/ext2.h | 7 ++++++- fs/ext2/inode.c | 2 +- fs/ext2/xattr.c | 2 +- 4 files changed, 10 insertions(+), 4 deletions(-) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index d764ae094c6f..d115fade4735 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1195,6 +1195,7 @@ int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, * @goal: given target block(filesystem wide) * @count: target number of blocks to allocate * @errp: error code + * @flag allocate flags * * ext2_new_blocks uses a goal block to assist allocation. If the goal is * free, or there is a free block within 32 blocks of the goal, that block @@ -1204,7 +1205,7 @@ int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, * This function also updates quota and i_blocks field. */ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, - unsigned long *count, int *errp) + unsigned long *count, int *errp, unsigned int flag) { struct buffer_head *bitmap_bh = NULL; struct buffer_head *gdp_bh; diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h index 950e3a496d01..c61b4c949c37 100644 --- a/fs/ext2/ext2.h +++ b/fs/ext2/ext2.h @@ -410,6 +410,11 @@ struct ext2_inode { #define EXT2_ERRORS_PANIC 3 /* Panic */ #define EXT2_ERRORS_DEFAULT EXT2_ERRORS_CONTINUE +/* + * Behaviour if use reservation window in ext2_new_blocks() + */ +#define EXT2_ALLOC_NORESERVE 0x1 + /* * Structure of the super block */ @@ -719,7 +724,7 @@ static inline struct ext2_inode_info *EXT2_I(struct inode *inode) extern int ext2_bg_has_super(struct super_block *sb, int group); extern unsigned long ext2_bg_num_gdb(struct super_block *sb, int group); extern ext2_fsblk_t ext2_new_blocks(struct inode *, unsigned long, - unsigned long *, int *); + unsigned long *, int *, unsigned int); extern int ext2_data_block_valid(struct ext2_sb_info *sbi, ext2_fsblk_t start_blk, unsigned int count); extern void ext2_free_blocks (struct inode *, unsigned long, diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 11c5c6fe75bb..c8c274b60d1c 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -415,7 +415,7 @@ static int ext2_alloc_blocks(struct inode *inode, while (1) { count = target; /* allocating blocks for indirect blocks and direct blocks */ - current_block = ext2_new_blocks(inode,goal,&count,err); + current_block = ext2_new_blocks(inode, goal, &count, err, 0); if (*err) goto failed_out; diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index 8fbc6891ab5d..681168caaa31 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -696,7 +696,7 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, EXT2_I(inode)->i_block_group); unsigned long count = 1; int block = ext2_new_blocks(inode, goal, &count, - &error); + &error, 0); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block); -- 2.31.1
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7TN3J -------------------------------- There's a issue as follows: Block Allocation Reservation Windows Map (ext2_try_to_allocate_with_rsv): reservation window 0x000000006f105382 start: 0, end: 0 reservation window 0x000000008fd1a555 start: 1044, end: 1059 Window map complete. kernel BUG at fs/ext2/balloc.c:1158! invalid opcode: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:ext2_try_to_allocate_with_rsv.isra.0+0x15c4/0x1800 Call Trace: <TASK> ext2_new_blocks+0x935/0x1690 ext2_new_block+0x73/0xa0 ext2_xattr_set2+0x74f/0x1730 ext2_xattr_set+0x12b6/0x2260 ext2_xattr_user_set+0x9c/0x110 __vfs_setxattr+0x139/0x1d0 __vfs_setxattr_noperm+0xfc/0x370 __vfs_setxattr_locked+0x205/0x2c0 vfs_setxattr+0x19d/0x3b0 do_setxattr+0xff/0x220 setxattr+0x123/0x150 path_setxattr+0x193/0x1e0 __x64_sys_setxattr+0xc8/0x170 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue may happens as follows: setxattr write back ext2_xattr_set ext2_xattr_set2 ext2_new_block ext2_new_blocks ext2_try_to_allocate_with_rsv alloc_new_reservation --> group=0 [0, 1023] rsv [1016, 1023] do_writepages mpage_writepages write_cache_pages __mpage_writepage ext2_get_block ext2_get_blocks ext2_alloc_branch ext2_new_blocks ext2_try_to_allocate_with_rsv alloc_new_reservation -->group=1 [1024, 2047] rsv [1044, 1059] if ((my_rsv->rsv_start > group_last_block) || (my_rsv->rsv_end < group_first_block) rsv_window_dump BUG(); Now ext2 mkwrite delay allocate new blocks. So there maybe allocate blocks when do write back. However, there is no concurrent protection between ext2_xattr_set() and do_writepages(). To solve about issue don't use reservation window when allocate block for xattr. Signed-off-by: Ye Bin <yebin10@huawei.com> --- fs/ext2/balloc.c | 15 +++++++++------ fs/ext2/xattr.c | 4 ++-- 2 files changed, 11 insertions(+), 8 deletions(-) diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index d115fade4735..633b613c1bf6 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -1249,13 +1249,16 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal, * it's a regular file, and * the desired window size is greater than 0 (One could use ioctl * command EXT2_IOC_SETRSVSZ to set the window size to 0 to turn off - * reservation on that particular file) + * reservation on that particular file), and unspecified Do not use + * reservation window. */ - block_i = EXT2_I(inode)->i_block_alloc_info; - if (block_i) { - windowsz = block_i->rsv_window_node.rsv_goal_size; - if (windowsz > 0) - my_rsv = &block_i->rsv_window_node; + if (!(flag & EXT2_ALLOC_NORESERVE)) { + block_i = EXT2_I(inode)->i_block_alloc_info; + if (block_i) { + windowsz = block_i->rsv_window_node.rsv_goal_size; + if (windowsz > 0) + my_rsv = &block_i->rsv_window_node; + } } if (!ext2_has_free_blocks(sbi)) { diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c index 681168caaa31..9aa75ed78b89 100644 --- a/fs/ext2/xattr.c +++ b/fs/ext2/xattr.c @@ -695,8 +695,8 @@ ext2_xattr_set2(struct inode *inode, struct buffer_head *old_bh, ext2_fsblk_t goal = ext2_group_first_block_no(sb, EXT2_I(inode)->i_block_group); unsigned long count = 1; - int block = ext2_new_blocks(inode, goal, &count, - &error, 0); + int block = ext2_new_blocks(inode, goal, &count, &error, + EXT2_ALLOC_NORESERVE); if (error) goto cleanup; ea_idebug(inode, "creating block %d", block); -- 2.31.1
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