erofs: use inode_set_cached_link()

Symlink lengths are now cached in in-memory inodes directly so that
readlink can be sped up.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 2ecc28abd6cd0418fa6141d431b7d74b9a56aa91..294f6637682520902be86013849d9f698f8f0b23 100644 (file)
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -8,21 +8,29 @@
 #include <linux/compat.h>
 #include <trace/events/erofs.h>
 
-static int erofs_fill_symlink(struct inode *inode, void *kaddr,
-                             unsigned int m_pofs)
+static int erofs_fill_symlink(struct inode *inode, void *bptr, unsigned int ofs)
 {
        struct erofs_inode *vi = EROFS_I(inode);
-       loff_t off;
-
-       m_pofs += vi->xattr_isize;
-       /* check if it cannot be handled with fast symlink scheme */
-       if (vi->datalayout != EROFS_INODE_FLAT_INLINE ||
-           check_add_overflow(m_pofs, inode->i_size, &off) ||
-           off > i_blocksize(inode))
-               return 0;
-
-       inode->i_link = kmemdup_nul(kaddr + m_pofs, inode->i_size, GFP_KERNEL);
-       return inode->i_link ? 0 : -ENOMEM;
+       char *link;
+       loff_t end;
+
+       ofs += vi->xattr_isize;
+       /* check whether the symlink data is small enough to be inlined */
+       if (vi->datalayout == EROFS_INODE_FLAT_INLINE &&
+           !check_add_overflow(ofs, inode->i_size, &end) &&
+           end <= i_blocksize(inode)) {
+               link = kmemdup_nul(bptr + ofs, inode->i_size, GFP_KERNEL);
+               if (!link)
+                       return -ENOMEM;
+               if (unlikely(!inode->i_size || strlen(link) != inode->i_size)) {
+                       erofs_err(inode->i_sb, "invalid fast symlink size %llu @ nid %llu",
+                                 inode->i_size | 0ULL, vi->nid);
+                       kfree(link);
+                       return -EFSCORRUPTED;
+               }
+               inode_set_cached_link(inode, link, inode->i_size);
+       }
+       return 0;
 }
 
 static int erofs_read_inode(struct inode *inode)