Hi Alan,

Here comes a patch which fixes the totally broken symlink support in
shm/swapfs. It is additional to my former patches for read and write
support.

It survives now a parallel kernel make on my 8way.

Greetings
                Christoph

diff -uNr 2.4.0-shm_vm_locked-truncate-rw-swapfs/mm/shmem.c 
2.4.0-shm_vm_locked-truncate-rw-swapfs-symlink/mm/shmem.c
--- 2.4.0-shm_vm_locked-truncate-rw-swapfs/mm/shmem.c   Sat Jan 13 13:22:59 2001
+++ 2.4.0-shm_vm_locked-truncate-rw-swapfs-symlink/mm/shmem.c   Sat Jan 13 16:29:53 
+2001
@@ -39,6 +39,7 @@
 static struct inode_operations shmem_inode_operations;
 static struct file_operations shmem_dir_operations;
 static struct inode_operations shmem_dir_inode_operations;
+static struct inode_operations shmem_symlink_inode_operations;
 static struct vm_operations_struct shmem_vm_ops;
 
 LIST_HEAD (shmem_inodes);
@@ -127,7 +128,7 @@
 
        spin_lock (&info->lock);
        index = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-       if (index >= info->max_index)
+       if (index > info->max_index)
                goto out;
 
        start = shmem_truncate_part (info->i_direct, SHMEM_NR_DIRECT, index, &freed);
@@ -419,7 +420,7 @@
                        inode->i_fop = &shmem_dir_operations;
                        break;
                case S_IFLNK:
-                       inode->i_op = &page_symlink_inode_operations;
+                       inode->i_op = &shmem_symlink_inode_operations;
                        break;
                }
                spin_lock (&shmem_ilock);
@@ -787,14 +788,63 @@
 static int shmem_symlink(struct inode * dir, struct dentry *dentry, const char * 
symname)
 {
        int error;
+       int len;
+       struct inode *inode;
+       struct page *page;
+       char *kaddr;
 
        error = shmem_mknod(dir, dentry, S_IFLNK | S_IRWXUGO, 0);
-       if (!error) {
-               int l = strlen(symname)+1;
-               struct inode *inode = dentry->d_inode;
-               error = block_symlink(inode, symname, l);
-       }
-       return error;
+       if (error)
+               return error;
+
+       len = strlen(symname);
+       if (len > PAGE_SIZE)
+               return -ENAMETOOLONG;
+               
+       inode = dentry->d_inode;
+       down(&inode->i_sem);
+       page = shmem_getpage_locked(inode, 0);
+       if (IS_ERR(page))
+               goto fail;
+       kaddr = kmap(page);
+       memcpy(kaddr, symname, len);
+       kunmap(page);
+       inode->i_size = len;
+       SetPageDirty(page);
+       UnlockPage(page);
+       page_cache_release(page);
+       up(&inode->i_sem);
+       return 0;
+fail:
+       up(&inode->i_sem);
+       return PTR_ERR(page);
+}
+
+static int shmem_readlink(struct dentry *dentry, char *buffer, int buflen)
+{
+       struct page * page;
+       int res = shmem_getpage(dentry->d_inode, 0, &page);
+
+       if (res)
+               return res;
+
+       res = vfs_readlink(dentry,buffer,buflen, kmap(page));
+       kunmap(page);
+       page_cache_release(page);
+       return res;
+}
+
+static int shmem_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+       struct page * page;
+       int res = shmem_getpage(dentry->d_inode, 0, &page);
+       if (res)
+               return res;
+
+       res = vfs_follow_link(nd, kmap(page));
+       kunmap(page);
+       page_cache_release(page);
+       return res;
 }
 
 static int shmem_parse_options(char *options, int *mode, unsigned long * blocks, 
unsigned long *inodes)
@@ -912,6 +962,12 @@
 
 static struct inode_operations shmem_inode_operations = {
        truncate:       shmem_truncate,
+};
+
+static struct inode_operations shmem_symlink_inode_operations = {
+       truncate:       shmem_truncate,
+       readlink:       shmem_readlink,
+       follow_link:    shmem_follow_link,
 };
 
 static struct file_operations shmem_dir_operations = {

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