[PATCH v3 RESEND] f2fs: support FIEMAP_FLAG_XATTR

[Chao Yu]

This patch enables ->fiemap to handle FIEMAP_FLAG_XATTR flag for xattr
mapping info lookup purpose.

It makes f2fs passing generic/425 test in fstest.

Signed-off-by: Chao Yu <yuch...@huawei.com>
---
 fs/f2fs/data.c | 69 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 68 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index 12155ee90468..3c1a0f1a3e53 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1136,6 +1136,68 @@ static inline loff_t blk_to_logical(struct inode *inode, 
sector_t blk)
        return (blk << inode->i_blkbits);
 }
 
+static int f2fs_xattr_fiemap(struct inode *inode,
+                               struct fiemap_extent_info *fieinfo)
+{
+       struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
+       struct page *page;
+       struct node_info ni;
+       __u64 phys = 0, len;
+       __u32 flags;
+       nid_t xnid = F2FS_I(inode)->i_xattr_nid;
+       int err = 0;
+
+       if (f2fs_has_inline_xattr(inode)) {
+               int offset;
+
+               page = f2fs_grab_cache_page(NODE_MAPPING(sbi),
+                                               inode->i_ino, false);
+               if (!page)
+                       return -ENOMEM;
+
+               get_node_info(sbi, inode->i_ino, &ni);
+
+               phys = (__u64)blk_to_logical(inode, ni.blk_addr);
+               offset = offsetof(struct f2fs_inode, i_addr) +
+                                       sizeof(__le32) * (DEF_ADDRS_PER_INODE -
+                                       F2FS_INLINE_XATTR_ADDRS(inode));
+
+               phys += offset;
+               len = inline_xattr_size(inode);
+
+               f2fs_put_page(page, 1);
+
+               flags = FIEMAP_EXTENT_DATA_INLINE | FIEMAP_EXTENT_NOT_ALIGNED;
+
+               if (!xnid)
+                       flags |= FIEMAP_EXTENT_LAST;
+
+               err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
+               if (err || err == 1)
+                       return err;
+       }
+
+       if (xnid) {
+               page = f2fs_grab_cache_page(NODE_MAPPING(sbi), xnid, false);
+               if (!page)
+                       return -ENOMEM;
+
+               get_node_info(sbi, xnid, &ni);
+
+               phys = (__u64)blk_to_logical(inode, ni.blk_addr);
+               len = inode->i_sb->s_blocksize;
+
+               f2fs_put_page(page, 1);
+
+               flags = FIEMAP_EXTENT_LAST;
+       }
+
+       if (phys)
+               err = fiemap_fill_next_extent(fieinfo, 0, phys, len, flags);
+
+       return (err < 0 ? err : 0);
+}
+
 int f2fs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                u64 start, u64 len)
 {
@@ -1146,12 +1208,17 @@ int f2fs_fiemap(struct inode *inode, struct 
fiemap_extent_info *fieinfo,
        u32 flags = 0;
        int ret = 0;
 
-       ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC);
+       ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR);
        if (ret)
                return ret;
 
        inode_lock(inode);
 
+       if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
+               ret = f2fs_xattr_fiemap(inode, fieinfo);
+               goto out;
+       }
+
        if (f2fs_has_inline_data(inode)) {
                ret = f2fs_inline_data_fiemap(inode, fieinfo, start, len);
                if (ret != -EAGAIN)
-- 
2.15.0.55.gc2ece9dc4de6