f2fs: fix out-place-update DIO write

In get_more_blocks(), we may override @create as below code:

	create = dio->op == REQ_OP_WRITE;
	if (dio->flags & DIO_SKIP_HOLES) {
		if (fs_startblk <= ((i_size_read(dio->inode) - 1) >>
						i_blkbits))
			create = 0;
	}

But in f2fs_map_blocks(), we only trigger f2fs_balance_fs() if @create
is 1, so in LFS mode, dio overwrite under LFS mode can easily run out
of free segments, result in below panic.

 Call Trace:
  allocate_segment_by_default+0xa8/0x270 [f2fs]
  f2fs_allocate_data_block+0x1ea/0x5c0 [f2fs]
  __allocate_data_block+0x306/0x480 [f2fs]
  f2fs_map_blocks+0x6f6/0x920 [f2fs]
  __get_data_block+0x4f/0xb0 [f2fs]
  get_data_block_dio_write+0x50/0x60 [f2fs]
  do_blockdev_direct_IO+0xcd5/0x21e0
  __blockdev_direct_IO+0x3a/0x3c
  f2fs_direct_IO+0x1ff/0x4a0 [f2fs]
  generic_file_direct_write+0xd9/0x160
  __generic_file_write_iter+0xbb/0x1e0
  f2fs_file_write_iter+0xaf/0x220 [f2fs]
  __vfs_write+0xd0/0x130
  vfs_write+0xb2/0x1b0
  SyS_pwrite64+0x69/0xa0
  ? vtime_user_exit+0x29/0x70
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25
 RIP: new_curseg+0x36f/0x380 [f2fs] RSP: ffffac570393f7a8

So this patch introduces a parameter map.m_may_create to indicate that
f2fs_map_blocks() is called from write or read path, which can give the
right hint to let f2fs_map_blocks() trigger OPU allocation and call
f2fs_balanc_fs() correctly.

BTW, it disables physical address preallocation for direct IO in
f2fs_preallocate_blocks, which is redundant to OPU allocation of
f2fs_map_blocks.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 1d15535..aa8843a 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -957,6 +957,9 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
                        return err;
        }
 
+       if (direct_io && allow_outplace_dio(inode, iocb, from))
+               return 0;
+
        if (is_inode_flag_set(inode, FI_NO_PREALLOC))
                return 0;
 
@@ -970,6 +973,7 @@ int f2fs_preallocate_blocks(struct kiocb *iocb, struct iov_iter *from)
        map.m_next_pgofs = NULL;
        map.m_next_extent = NULL;
        map.m_seg_type = NO_CHECK_TYPE;
+       map.m_may_create = true;
 
        if (direct_io) {
                map.m_seg_type = f2fs_rw_hint_to_seg_type(iocb->ki_hint);
@@ -1028,7 +1032,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
        unsigned int maxblocks = map->m_len;
        struct dnode_of_data dn;
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
-       int mode = create ? ALLOC_NODE : LOOKUP_NODE;
+       int mode = map->m_may_create ? ALLOC_NODE : LOOKUP_NODE;
        pgoff_t pgofs, end_offset, end;
        int err = 0, ofs = 1;
        unsigned int ofs_in_node, last_ofs_in_node;
@@ -1062,7 +1066,7 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map,
        }
 
 next_dnode:
-       if (create)
+       if (map->m_may_create)
                __do_map_lock(sbi, flag, true);
 
        /* When reading holes, we need its node page */
@@ -1099,8 +1103,8 @@ next_block:
 
        if (is_valid_data_blkaddr(sbi, blkaddr)) {
                /* use out-place-update for driect IO under LFS mode */
-               if (test_opt(sbi, LFS) && create &&
-                               flag == F2FS_GET_BLOCK_DIO) {
+               if (test_opt(sbi, LFS) && flag == F2FS_GET_BLOCK_DIO &&
+                                                       map->m_may_create) {
                        err = __allocate_data_block(&dn, map->m_seg_type);
                        if (!err)
                                set_inode_flag(inode, FI_APPEND_WRITE);
@@ -1209,7 +1213,7 @@ skip:
 
        f2fs_put_dnode(&dn);
 
-       if (create) {
+       if (map->m_may_create) {
                __do_map_lock(sbi, flag, false);
                f2fs_balance_fs(sbi, dn.node_changed);
        }
@@ -1235,7 +1239,7 @@ sync_out:
        }
        f2fs_put_dnode(&dn);
 unlock_out:
-       if (create) {
+       if (map->m_may_create) {
                __do_map_lock(sbi, flag, false);
                f2fs_balance_fs(sbi, dn.node_changed);
        }
@@ -1271,7 +1275,7 @@ bool f2fs_overwrite_io(struct inode *inode, loff_t pos, size_t len)
 
 static int __get_data_block(struct inode *inode, sector_t iblock,
                        struct buffer_head *bh, int create, int flag,
-                       pgoff_t *next_pgofs, int seg_type)
+                       pgoff_t *next_pgofs, int seg_type, bool may_write)
 {
        struct f2fs_map_blocks map;
        int err;
@@ -1281,6 +1285,7 @@ static int __get_data_block(struct inode *inode, sector_t iblock,
        map.m_next_pgofs = next_pgofs;
        map.m_next_extent = NULL;
        map.m_seg_type = seg_type;
+       map.m_may_create = may_write;
 
        err = f2fs_map_blocks(inode, &map, create, flag);
        if (!err) {
@@ -1297,16 +1302,25 @@ static int get_data_block(struct inode *inode, sector_t iblock,
 {
        return __get_data_block(inode, iblock, bh_result, create,
                                                        flag, next_pgofs,
-                                                       NO_CHECK_TYPE);
+                                                       NO_CHECK_TYPE, create);
+}
+
+static int get_data_block_dio_write(struct inode *inode, sector_t iblock,
+                       struct buffer_head *bh_result, int create)
+{
+       return __get_data_block(inode, iblock, bh_result, create,
+                               F2FS_GET_BLOCK_DIO, NULL,
+                               f2fs_rw_hint_to_seg_type(inode->i_write_hint),
+                               true);
 }
 
 static int get_data_block_dio(struct inode *inode, sector_t iblock,
                        struct buffer_head *bh_result, int create)
 {
        return __get_data_block(inode, iblock, bh_result, create,
-                                               F2FS_GET_BLOCK_DIO, NULL,
-                                               f2fs_rw_hint_to_seg_type(
-                                                       inode->i_write_hint));
+                               F2FS_GET_BLOCK_DIO, NULL,
+                               f2fs_rw_hint_to_seg_type(inode->i_write_hint),
+                               false);
 }
 
 static int get_data_block_bmap(struct inode *inode, sector_t iblock,
@@ -1318,7 +1332,7 @@ static int get_data_block_bmap(struct inode *inode, sector_t iblock,
 
        return __get_data_block(inode, iblock, bh_result, create,
                                                F2FS_GET_BLOCK_BMAP, NULL,
-                                               NO_CHECK_TYPE);
+                                               NO_CHECK_TYPE, create);
 }
 
 static inline sector_t logical_to_blk(struct inode *inode, loff_t offset)
@@ -1525,6 +1539,7 @@ static int f2fs_mpage_readpages(struct address_space *mapping,
        map.m_next_pgofs = NULL;
        map.m_next_extent = NULL;
        map.m_seg_type = NO_CHECK_TYPE;
+       map.m_may_create = false;
 
        for (; nr_pages; nr_pages--) {
                if (pages) {
@@ -2642,7 +2657,8 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
        }
 
        err = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
-                       iter, get_data_block_dio, NULL, f2fs_dio_submit_bio,
+                       iter, rw == WRITE ? get_data_block_dio_write :
+                       get_data_block_dio, NULL, f2fs_dio_submit_bio,
                        DIO_LOCKING | DIO_SKIP_HOLES);
 
        if (do_opu)

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index df10394..26ad1de 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -602,6 +602,7 @@ struct f2fs_map_blocks {
        pgoff_t *m_next_pgofs;          /* point next possible non-hole pgofs */
        pgoff_t *m_next_extent;         /* point to next possible extent */
        int m_seg_type;
+       bool m_may_create;              /* indicate it is from write path */
 };
 
 /* for flag in get_data_block */

diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index 439d340..3271830 100644 (file)
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -1499,7 +1499,8 @@ static int expand_inode_data(struct inode *inode, loff_t offset,
 {
        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
        struct f2fs_map_blocks map = { .m_next_pgofs = NULL,
-                       .m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE };
+                       .m_next_extent = NULL, .m_seg_type = NO_CHECK_TYPE,
+                       .m_may_create = true };
        pgoff_t pg_end;
        loff_t new_size = i_size_read(inode);
        loff_t off_end;