ocfs: simplify symlink handling

seeing that "fast" symlinks still get allocation + copy, we might as
well simply switch them to pagecache-based variant of ->follow_link();
just need an appropriate ->readpage() for them...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c
index 735514c..d89e08a 100644 (file)
--- a/fs/ocfs2/inode.c
+++ b/fs/ocfs2/inode.c
@@ -273,11 +273,13 @@ void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
        inode->i_gid = le32_to_cpu(fe->i_gid);
 
        /* Fast symlinks will have i_size but no allocated clusters. */
-       if (S_ISLNK(inode->i_mode) && !fe->i_clusters)
+       if (S_ISLNK(inode->i_mode) && !fe->i_clusters) {
                inode->i_blocks = 0;
-       else
+               inode->i_mapping->a_ops = &ocfs2_fast_symlink_aops;
+       } else {
                inode->i_blocks = ocfs2_inode_sector_count(inode);
-       inode->i_mapping->a_ops = &ocfs2_aops;
+               inode->i_mapping->a_ops = &ocfs2_aops;
+       }
        inode->i_atime.tv_sec = le64_to_cpu(fe->i_atime);
        inode->i_atime.tv_nsec = le32_to_cpu(fe->i_atime_nsec);
        inode->i_mtime.tv_sec = le64_to_cpu(fe->i_mtime);
@@ -331,10 +333,7 @@ void ocfs2_populate_inode(struct inode *inode, struct ocfs2_dinode *fe,
                    OCFS2_I(inode)->ip_dir_lock_gen = 1;
                    break;
            case S_IFLNK:
-                   if (ocfs2_inode_is_fast_symlink(inode))
-                       inode->i_op = &ocfs2_fast_symlink_inode_operations;
-                   else
-                       inode->i_op = &ocfs2_symlink_inode_operations;
+                   inode->i_op = &ocfs2_symlink_inode_operations;
                    i_size_write(inode, le64_to_cpu(fe->i_size));
                    break;
            default:

diff --git a/fs/ocfs2/namei.c b/fs/ocfs2/namei.c
index a9856e3..9f39c64 100644 (file)
--- a/fs/ocfs2/namei.c
+++ b/fs/ocfs2/namei.c
@@ -1724,15 +1724,16 @@ static int ocfs2_symlink(struct inode *dir,
        fe = (struct ocfs2_dinode *) new_fe_bh->b_data;
        inode->i_rdev = 0;
        newsize = l - 1;
+       inode->i_op = &ocfs2_symlink_inode_operations;
        if (l > ocfs2_fast_symlink_chars(sb)) {
                u32 offset = 0;
 
-               inode->i_op = &ocfs2_symlink_inode_operations;
                status = dquot_alloc_space_nodirty(inode,
                    ocfs2_clusters_to_bytes(osb->sb, 1));
                if (status)
                        goto bail;
                did_quota = 1;
+               inode->i_mapping->a_ops = &ocfs2_aops;
                status = ocfs2_add_inode_data(osb, inode, &offset, 1, 0,
                                              new_fe_bh,
                                              handle, data_ac, NULL,
@@ -1750,7 +1751,7 @@ static int ocfs2_symlink(struct inode *dir,
                i_size_write(inode, newsize);
                inode->i_blocks = ocfs2_inode_sector_count(inode);
        } else {
-               inode->i_op = &ocfs2_fast_symlink_inode_operations;
+               inode->i_mapping->a_ops = &ocfs2_fast_symlink_aops;
                memcpy((char *) fe->id2.i_symlink, symname, l);
                i_size_write(inode, newsize);
                inode->i_blocks = 0;

diff --git a/fs/ocfs2/symlink.c b/fs/ocfs2/symlink.c
index 5d22872..f1fbb4b 100644 (file)
--- a/fs/ocfs2/symlink.c
+++ b/fs/ocfs2/symlink.c
@@ -54,101 +54,40 @@
 #include "buffer_head_io.h"
 
 
-static char *ocfs2_fast_symlink_getlink(struct inode *inode,
-                                       struct buffer_head **bh)
+static int ocfs2_fast_symlink_readpage(struct file *unused, struct page *page)
 {
-       int status;
-       char *link = NULL;
+       struct inode *inode = page->mapping->host;
+       struct buffer_head *bh;
+       int status = ocfs2_read_inode_block(inode, &bh);
        struct ocfs2_dinode *fe;
+       const char *link;
+       void *kaddr;
+       size_t len;
 
-       status = ocfs2_read_inode_block(inode, bh);
        if (status < 0) {
                mlog_errno(status);
-               link = ERR_PTR(status);
-               goto bail;
+               return status;
        }
 
-       fe = (struct ocfs2_dinode *) (*bh)->b_data;
+       fe = (struct ocfs2_dinode *) bh->b_data;
        link = (char *) fe->id2.i_symlink;
-bail:
-
-       return link;
-}
-
-static int ocfs2_readlink(struct dentry *dentry,
-                         char __user *buffer,
-                         int buflen)
-{
-       int ret;
-       char *link;
-       struct buffer_head *bh = NULL;
-       struct inode *inode = dentry->d_inode;
-
-       link = ocfs2_fast_symlink_getlink(inode, &bh);
-       if (IS_ERR(link)) {
-               ret = PTR_ERR(link);
-               goto out;
-       }
-
-       /*
-        * Without vfsmount we can't update atime now,
-        * but we will update atime here ultimately.
-        */
-       ret = vfs_readlink(dentry, buffer, buflen, link);
-
+       /* will be less than a page size */
+       len = strnlen(link, ocfs2_fast_symlink_chars(inode->i_sb));
+       kaddr = kmap_atomic(page);
+       memcpy(kaddr, link, len + 1);
+       kunmap_atomic(kaddr);
+       SetPageUptodate(page);
+       unlock_page(page);
        brelse(bh);
-out:
-       if (ret < 0)
-               mlog_errno(ret);
-       return ret;
+       return 0;
 }
 
-static void *ocfs2_fast_follow_link(struct dentry *dentry,
-                                   struct nameidata *nd)
-{
-       int status = 0;
-       int len;
-       char *target, *link = ERR_PTR(-ENOMEM);
-       struct inode *inode = dentry->d_inode;
-       struct buffer_head *bh = NULL;
-
-       BUG_ON(!ocfs2_inode_is_fast_symlink(inode));
-       target = ocfs2_fast_symlink_getlink(inode, &bh);
-       if (IS_ERR(target)) {
-               status = PTR_ERR(target);
-               mlog_errno(status);
-               goto bail;
-       }
-
-       /* Fast symlinks can't be large */
-       len = strnlen(target, ocfs2_fast_symlink_chars(inode->i_sb));
-       link = kzalloc(len + 1, GFP_NOFS);
-       if (!link) {
-               status = -ENOMEM;
-               mlog_errno(status);
-               goto bail;
-       }
-
-       memcpy(link, target, len);
-
-bail:
-       nd_set_link(nd, status ? ERR_PTR(status) : link);
-       brelse(bh);
-
-       if (status)
-               mlog_errno(status);
-       return NULL;
-}
-
-static void ocfs2_fast_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
-{
-       char *link = nd_get_link(nd);
-       if (!IS_ERR(link))
-               kfree(link);
-}
+const struct address_space_operations ocfs2_fast_symlink_aops = {
+       .readpage               = ocfs2_fast_symlink_readpage,
+};
 
 const struct inode_operations ocfs2_symlink_inode_operations = {
-       .readlink       = page_readlink,
+       .readlink       = generic_readlink,
        .follow_link    = page_follow_link_light,
        .put_link       = page_put_link,
        .getattr        = ocfs2_getattr,
@@ -159,15 +98,3 @@ const struct inode_operations ocfs2_symlink_inode_operations = {
        .removexattr    = generic_removexattr,
        .fiemap         = ocfs2_fiemap,
 };
-const struct inode_operations ocfs2_fast_symlink_inode_operations = {
-       .readlink       = ocfs2_readlink,
-       .follow_link    = ocfs2_fast_follow_link,
-       .put_link       = ocfs2_fast_put_link,
-       .getattr        = ocfs2_getattr,
-       .setattr        = ocfs2_setattr,
-       .setxattr       = generic_setxattr,
-       .getxattr       = generic_getxattr,
-       .listxattr      = ocfs2_listxattr,
-       .removexattr    = generic_removexattr,
-       .fiemap         = ocfs2_fiemap,
-};

diff --git a/fs/ocfs2/symlink.h b/fs/ocfs2/symlink.h
index 65a6c9c..71ee424 100644 (file)
--- a/fs/ocfs2/symlink.h
+++ b/fs/ocfs2/symlink.h
@@ -27,7 +27,7 @@
 #define OCFS2_SYMLINK_H
 
 extern const struct inode_operations ocfs2_symlink_inode_operations;
-extern const struct inode_operations ocfs2_fast_symlink_inode_operations;
+extern const struct address_space_operations ocfs2_fast_symlink_aops;
 
 /*
  * Test whether an inode is a fast symlink.