Remove Btrfs compat code for older kernels

Btrfs had compatibility code for kernels back to 2.6.18.  These have
been removed, and will be maintained in a separate backport
git tree from now on.

Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 133 deletions

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index adb169d739ce..48a3dc030807 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -2073,104 +2073,6 @@ err:
         return ret;
 }
 
-/* Kernels earlier than 2.6.28 still have the NFS deadlock where nfsd
-   will call the file system's ->lookup() method from within its
-   filldir callback, which in turn was called from the file system's
-   ->readdir() method. And will deadlock for many file systems. */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
-
-struct nfshack_dirent {
-        u64             ino;
-        loff_t          offset;
-        int             namlen;
-        unsigned int    d_type;
-        char            name[];
-};
-
-struct nfshack_readdir {
-        char            *dirent;
-        size_t          used;
-        int             full;
-};
-
-
-
-static int btrfs_nfshack_filldir(void *__buf, const char *name, int namlen,
-                              loff_t offset, u64 ino, unsigned int d_type)
-{
-        struct nfshack_readdir *buf = __buf;
-        struct nfshack_dirent *de = (void *)(buf->dirent + buf->used);
-        unsigned int reclen;
-
-        reclen = ALIGN(sizeof(struct nfshack_dirent) + namlen, sizeof(u64));
-        if (buf->used + reclen > PAGE_SIZE) {
-                buf->full = 1;
-                return -EINVAL;
-        }
-
-        de->namlen = namlen;
-        de->offset = offset;
-        de->ino = ino;
-        de->d_type = d_type;
-        memcpy(de->name, name, namlen);
-        buf->used += reclen;
-
-        return 0;
-}
-
-static int btrfs_nfshack_readdir(struct file *file, void *dirent,
-                                 filldir_t filldir)
-{
-        struct nfshack_readdir buf;
-        struct nfshack_dirent *de;
-        int err;
-        int size;
-        loff_t offset;
-
-        buf.dirent = (void *)__get_free_page(GFP_KERNEL);
-        if (!buf.dirent)
-                return -ENOMEM;
-
-        offset = file->f_pos;
-
-        do {
-                unsigned int reclen;
-
-                buf.used = 0;
-                buf.full = 0;
-                err = btrfs_real_readdir(file, &buf, btrfs_nfshack_filldir);
-                if (err)
-                        break;
-
-                size = buf.used;
-
-                if (!size)
-                        break;
-
-                de = (struct nfshack_dirent *)buf.dirent;
-                while (size > 0) {
-                        offset = de->offset;
-
-                        if (filldir(dirent, de->name, de->namlen, de->offset,
-                                    de->ino, de->d_type))
-                                goto done;
-                        offset = file->f_pos;
-
-                        reclen = ALIGN(sizeof(*de) + de->namlen,
-                                       sizeof(u64));
-                        size -= reclen;
-                        de = (struct nfshack_dirent *)((char *)de + reclen);
-                }
-        } while (buf.full);
-
- done:
-        free_page((unsigned long)buf.dirent);
-        file->f_pos = offset;
-
-        return err;
-}
-#endif
-
 int btrfs_write_inode(struct inode *inode, int wait)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
@@ -3311,13 +3213,8 @@ unsigned long btrfs_force_ra(struct address_space *mapping,
 {
         pgoff_t req_size = last_index - offset + 1;
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
-        offset = page_cache_readahead(mapping, ra, file, offset, req_size);
-        return offset;
-#else
         page_cache_sync_readahead(mapping, ra, file, offset, req_size);
         return offset + req_size;
-#endif
 }
 
 struct inode *btrfs_alloc_inode(struct super_block *sb)
@@ -3373,14 +3270,7 @@ void btrfs_destroy_inode(struct inode *inode)
         kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
 }
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 static void init_once(void *foo)
-#elif LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
-static void init_once(struct kmem_cache * cachep, void *foo)
-#else
-static void init_once(void * foo, struct kmem_cache * cachep,
-                      unsigned long flags)
-#endif
 {
         struct btrfs_inode *ei = (struct btrfs_inode *) foo;
 
@@ -3403,22 +3293,10 @@ void btrfs_destroy_cachep(void)
 
 struct kmem_cache *btrfs_cache_create(const char *name, size_t size,
                                        unsigned long extra_flags,
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
-                                       void (*ctor)(void *)
-#elif LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
-                                       void (*ctor)(struct kmem_cache *, void *)
-#else
-                                       void (*ctor)(void *, struct kmem_cache *,
-                                                    unsigned long)
-#endif
-                                     )
+                                       void (*ctor)(void *))
 {
         return kmem_cache_create(name, size, 0, (SLAB_RECLAIM_ACCOUNT |
-                                 SLAB_MEM_SPREAD | extra_flags), ctor
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
-                                 ,NULL
-#endif
-                                );
+                                 SLAB_MEM_SPREAD | extra_flags), ctor);
 }
 
 int btrfs_init_cachep(void)
@@ -3666,12 +3544,7 @@ static int btrfs_set_page_dirty(struct page *page)
         return __set_page_dirty_nobuffers(page);
 }
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 static int btrfs_permission(struct inode *inode, int mask)
-#else
-static int btrfs_permission(struct inode *inode, int mask,
-                            struct nameidata *nd)
-#endif
 {
         if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
                 return -EACCES;
@@ -3702,11 +3575,7 @@ static struct inode_operations btrfs_dir_ro_inode_operations = {
 static struct file_operations btrfs_dir_file_operations = {
         .llseek         = generic_file_llseek,
         .read           = generic_read_dir,
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
-        .readdir        = btrfs_nfshack_readdir,
-#else /* NFSd readdir/lookup deadlock is fixed */
         .readdir        = btrfs_real_readdir,
-#endif
         .unlocked_ioctl = btrfs_ioctl,
 #ifdef CONFIG_COMPAT
         .compat_ioctl   = btrfs_ioctl,