f2fs: factor a f2fs_map_blocks_cached helper

[ Upstream commit 0094e98bd1477a6b7d97c25b47b19a7317c35279 ]

Add a helper to deal with everything needed to return a f2fs_map_blocks
structure based on a lookup in the extent cache.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: 9d5c4f5c7a2c ("f2fs: fix wrong block mapping for multi-devices")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 75c1af00c6892e7402d8b50c0309f6ad916b26b5..dc1ffdcbae8893aaefa260cbd3a9812fc545068e 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1459,6 +1459,41 @@ int f2fs_get_block_locked(struct dnode_of_data *dn, pgoff_t index)
        return err;
 }
 
+static bool f2fs_map_blocks_cached(struct inode *inode,
+               struct f2fs_map_blocks *map, int flag)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+       unsigned int maxblocks = map->m_len;
+       pgoff_t pgoff = (pgoff_t)map->m_lblk;
+       struct extent_info ei = {};
+
+       if (!f2fs_lookup_read_extent_cache(inode, pgoff, &ei))
+               return false;
+
+       map->m_pblk = ei.blk + pgoff - ei.fofs;
+       map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgoff);
+       map->m_flags = F2FS_MAP_MAPPED;
+       if (map->m_next_extent)
+               *map->m_next_extent = pgoff + map->m_len;
+
+       /* for hardware encryption, but to avoid potential issue in future */
+       if (flag == F2FS_GET_BLOCK_DIO)
+               f2fs_wait_on_block_writeback_range(inode,
+                                       map->m_pblk, map->m_len);
+
+       if (f2fs_allow_multi_device_dio(sbi, flag)) {
+               int bidx = f2fs_target_device_index(sbi, map->m_pblk);
+               struct f2fs_dev_info *dev = &sbi->devs[bidx];
+
+               map->m_bdev = dev->bdev;
+               map->m_pblk -= dev->start_blk;
+               map->m_len = min(map->m_len, dev->end_blk + 1 - map->m_pblk);
+       } else {
+               map->m_bdev = inode->i_sb->s_bdev;
+       }
+       return true;
+}
+
 /*
  * f2fs_map_blocks() tries to find or build mapping relationship which
  * maps continuous logical blocks to physical blocks, and return such
@@ -1474,7 +1509,6 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag)
        int err = 0, ofs = 1;
        unsigned int ofs_in_node, last_ofs_in_node;
        blkcnt_t prealloc;
-       struct extent_info ei = {0, };
        block_t blkaddr;
        unsigned int start_pgofs;
        int bidx = 0;
@@ -1482,6 +1516,9 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag)
        if (!maxblocks)
                return 0;
 
+       if (!map->m_may_create && f2fs_map_blocks_cached(inode, map, flag))
+               goto out;
+
        map->m_bdev = inode->i_sb->s_bdev;
        map->m_multidev_dio =
                f2fs_allow_multi_device_dio(F2FS_I_SB(inode), flag);
@@ -1493,32 +1530,6 @@ int f2fs_map_blocks(struct inode *inode, struct f2fs_map_blocks *map, int flag)
        pgofs = (pgoff_t)map->m_lblk;
        end = pgofs + maxblocks;
 
-       if (map->m_may_create ||
-           !f2fs_lookup_read_extent_cache(inode, pgofs, &ei))
-               goto next_dnode;
-
-       /* Found the map in read extent cache */
-       map->m_pblk = ei.blk + pgofs - ei.fofs;
-       map->m_len = min((pgoff_t)maxblocks, ei.fofs + ei.len - pgofs);
-       map->m_flags = F2FS_MAP_MAPPED;
-       if (map->m_next_extent)
-               *map->m_next_extent = pgofs + map->m_len;
-
-       /* for hardware encryption, but to avoid potential issue in future */
-       if (flag == F2FS_GET_BLOCK_DIO)
-               f2fs_wait_on_block_writeback_range(inode,
-                                               map->m_pblk, map->m_len);
-
-       if (map->m_multidev_dio) {
-               bidx = f2fs_target_device_index(sbi, map->m_pblk);
-
-               map->m_bdev = FDEV(bidx).bdev;
-               map->m_pblk -= FDEV(bidx).start_blk;
-               map->m_len = min(map->m_len,
-                               FDEV(bidx).end_blk + 1 - map->m_pblk);
-       }
-       goto out;
-
 next_dnode:
        if (map->m_may_create)
                f2fs_do_map_lock(sbi, flag, true);