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>

fs/btrfs/async-thread.c

@@ -20,13 +20,7 @@
 #include <linux/kthread.h>
 #include <linux/list.h>
 #include <linux/spinlock.h>
-
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
 # include <linux/freezer.h>
-#else
-# include <linux/sched.h>
-#endif
-
 #include "async-thread.h"
 
 /*

fs/btrfs/compat.h

@@ -1,9 +1,8 @@
 #ifndef _COMPAT_H_
 #define _COMPAT_H_
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,26)
-#define trylock_page(page) (!TestSetPageLocked(page))
-#endif
+#define btrfs_drop_nlink(inode) drop_nlink(inode)
+#define btrfs_inc_nlink(inode)	inc_nlink(inode)
 
 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,27)
 static inline struct dentry *d_obtain_alias(struct inode *inode)
@@ -22,39 +21,4 @@ static inline struct dentry *d_obtain_alias(struct inode *inode)
 }
 #endif
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
-static inline void btrfs_drop_nlink(struct inode *inode)
-{
-	inode->i_nlink--;
-}
-
-static inline void btrfs_inc_nlink(struct inode *inode)
-{
-	inode->i_nlink++;
-}
-#else
-# define btrfs_drop_nlink(inode) drop_nlink(inode)
-# define btrfs_inc_nlink(inode)	inc_nlink(inode)
-#endif
-
-/*
- * Even if AppArmor isn't enabled, it still has different prototypes.
- * Add more distro/version pairs here to declare which has AppArmor applied.
- */
-#if defined(CONFIG_SUSE_KERNEL)
-# if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,22)
-# define REMOVE_SUID_PATH 1
-# endif
-#endif
-
-/*
- * catch any other distros that have patched in apparmor.  This isn't
- * 100% reliable because it won't catch people that hand compile their
- * own distro kernels without apparmor compiled in.  But, it is better
- * than nothing.
- */
-#ifdef CONFIG_SECURITY_APPARMOR
-# define REMOVE_SUID_PATH 1
-#endif
-
 #endif /* _COMPAT_H_ */

fs/btrfs/crc32c.h

@@ -96,13 +96,7 @@ static inline u32 __btrfs_crc32c(u32 crc, unsigned char const *address,
  * We must workaround older implementations of crc32c_le()
  * found on older kernel versions.
  */
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
-#define btrfs_crc32c(seed, data, length) \
-	__cpu_to_le32( __btrfs_crc32c( __le32_to_cpu(seed), \
-		                      (unsigned char const *)data, length) )
-#else
 #define btrfs_crc32c(seed, data, length) \
 	__btrfs_crc32c(seed, (unsigned char const *)data, length)
 #endif
-#endif
 

fs/btrfs/ctree.h

@@ -1472,12 +1472,9 @@ static inline u32 btrfs_level_size(struct btrfs_root *root, int level) {
 	((unsigned long)(btrfs_leaf_data(leaf) + \
 	btrfs_item_offset_nr(leaf, slot)))
 
-static inline struct dentry *fdentry(struct file *file) {
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
-	return file->f_dentry;
-#else
+static inline struct dentry *fdentry(struct file *file)
+{
 	return file->f_path.dentry;
-#endif
 }
 
 /* extent-tree.c */

fs/btrfs/disk-io.c

@@ -26,11 +26,7 @@
 #include <linux/buffer_head.h> // for block_sync_page
 #include <linux/workqueue.h>
 #include <linux/kthread.h>
-#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,20)
 # include <linux/freezer.h>
-#else
-# include <linux/sched.h>
-#endif
 #include "crc32c.h"
 #include "ctree.h"
 #include "disk-io.h"
@@ -373,21 +369,11 @@ int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
 	return ret;
 }
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 static void end_workqueue_bio(struct bio *bio, int err)
-#else
-static int end_workqueue_bio(struct bio *bio,
-				   unsigned int bytes_done, int err)
-#endif
 {
 	struct end_io_wq *end_io_wq = bio->bi_private;
 	struct btrfs_fs_info *fs_info;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	if (bio->bi_size)
-		return 1;
-#endif
-
 	fs_info = end_io_wq->info;
 	end_io_wq->error = err;
 	end_io_wq->work.func = end_workqueue_fn;
@@ -397,10 +383,6 @@ static int end_workqueue_bio(struct bio *bio,
 				   &end_io_wq->work);
 	else
 		btrfs_queue_worker(&fs_info->endio_workers, &end_io_wq->work);
-
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	return 0;
-#endif
 }
 
 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
@@ -1161,9 +1143,7 @@ void btrfs_unplug_io_fn(struct backing_dev_info *bdi, struct page *page)
 
 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
 {
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 	bdi_init(bdi);
-#endif
 	bdi->ra_pages	= default_backing_dev_info.ra_pages;
 	bdi->state		= 0;
 	bdi->capabilities	= default_backing_dev_info.capabilities;
@@ -1242,11 +1222,7 @@ static void end_workqueue_fn(struct btrfs_work *work)
 	bio->bi_private = end_io_wq->private;
 	bio->bi_end_io = end_io_wq->end_io;
 	kfree(end_io_wq);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	bio_endio(bio, bio->bi_size, error);
-#else
 	bio_endio(bio, error);
-#endif
 }
 
 static int cleaner_kthread(void *arg)
@@ -1673,9 +1649,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
 
 	kfree(extent_root);
 	kfree(tree_root);
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 	bdi_destroy(&fs_info->bdi);
-#endif
 	kfree(fs_info);
 	return ERR_PTR(err);
 }
@@ -1936,9 +1910,7 @@ int close_ctree(struct btrfs_root *root)
 	btrfs_close_devices(fs_info->fs_devices);
 	btrfs_mapping_tree_free(&fs_info->mapping_tree);
 
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 	bdi_destroy(&fs_info->bdi);
-#endif
 
 	kfree(fs_info->extent_root);
 	kfree(fs_info->tree_root);

fs/btrfs/export.c

@@ -7,12 +7,6 @@
 #include "export.h"
 #include "compat.h"
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,28)
-#define FILEID_BTRFS_WITHOUT_PARENT		0x4d
-#define FILEID_BTRFS_WITH_PARENT 		0x4e
-#define FILEID_BTRFS_WITH_PARENT_ROOT 		0x4f
-#endif
-
 #define BTRFS_FID_SIZE_NON_CONNECTABLE		(offsetof(struct btrfs_fid, parent_objectid)/4)
 #define BTRFS_FID_SIZE_CONNECTABLE		(offsetof(struct btrfs_fid, parent_root_objectid)/4)
 #define BTRFS_FID_SIZE_CONNECTABLE_ROOT		(sizeof(struct btrfs_fid)/4)

fs/btrfs/extent_io.c

@@ -1397,12 +1397,7 @@ static int check_page_writeback(struct extent_io_tree *tree,
  * Scheduling is not allowed, so the extent state tree is expected
  * to have one and only one object corresponding to this IO.
  */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 static void end_bio_extent_writepage(struct bio *bio, int err)
-#else
-static int end_bio_extent_writepage(struct bio *bio,
-				   unsigned int bytes_done, int err)
-#endif
 {
 	int uptodate = err == 0;
 	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
@@ -1412,10 +1407,6 @@ static int end_bio_extent_writepage(struct bio *bio,
 	int whole_page;
 	int ret;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	if (bio->bi_size)
-		return 1;
-#endif
 	do {
 		struct page *page = bvec->bv_page;
 		tree = &BTRFS_I(page->mapping->host)->io_tree;
@@ -1461,10 +1452,8 @@ static int end_bio_extent_writepage(struct bio *bio,
 		else
 			check_page_writeback(tree, page);
 	} while (bvec >= bio->bi_io_vec);
+
 	bio_put(bio);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	return 0;
-#endif
 }
 
 /*
@@ -1478,12 +1467,7 @@ static int end_bio_extent_writepage(struct bio *bio,
  * Scheduling is not allowed, so the extent state tree is expected
  * to have one and only one object corresponding to this IO.
  */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 static void end_bio_extent_readpage(struct bio *bio, int err)
-#else
-static int end_bio_extent_readpage(struct bio *bio,
-				   unsigned int bytes_done, int err)
-#endif
 {
 	int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
@@ -1493,11 +1477,6 @@ static int end_bio_extent_readpage(struct bio *bio,
 	int whole_page;
 	int ret;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	if (bio->bi_size)
-		return 1;
-#endif
-
 	do {
 		struct page *page = bvec->bv_page;
 		tree = &BTRFS_I(page->mapping->host)->io_tree;
@@ -1556,34 +1535,21 @@ static int end_bio_extent_readpage(struct bio *bio,
 	} while (bvec >= bio->bi_io_vec);
 
 	bio_put(bio);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	return 0;
-#endif
 }
 
 /*
  * IO done from prepare_write is pretty simple, we just unlock
  * the structs in the extent tree when done, and set the uptodate bits
  * as appropriate.
  */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,23)
 static void end_bio_extent_preparewrite(struct bio *bio, int err)
-#else
-static int end_bio_extent_preparewrite(struct bio *bio,
-				       unsigned int bytes_done, int err)
-#endif
 {
 	const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 	struct bio_vec *bvec = bio->bi_io_vec + bio->bi_vcnt - 1;
 	struct extent_io_tree *tree;
 	u64 start;
 	u64 end;
 
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	if (bio->bi_size)
-		return 1;
-#endif
-
 	do {
 		struct page *page = bvec->bv_page;
 		tree = &BTRFS_I(page->mapping->host)->io_tree;
@@ -1607,9 +1573,6 @@ static int end_bio_extent_preparewrite(struct bio *bio,
 	} while (bvec >= bio->bi_io_vec);
 
 	bio_put(bio);
-#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,23)
-	return 0;
-#endif
 }
 
 static struct bio *
@@ -2079,12 +2042,6 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 	return 0;
 }
 
-#if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,22)
-/* Taken directly from 2.6.23 with a mod for a lockpage hook */
-typedef int (*writepage_t)(struct page *page, struct writeback_control *wbc,
-                                void *data);
-#endif
-
 /**
  * write_cache_pages - walk the list of dirty pages of the given address space and write all of them.
  * @mapping: address space structure to write
@@ -2201,10 +2158,9 @@ int extent_write_cache_pages(struct extent_io_tree *tree,
 	}
 	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
 		mapping->writeback_index = index;
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
+
 	if (wbc->range_cont)
 		wbc->range_start = index << PAGE_CACHE_SHIFT;
-#endif
 	return ret;
 }
 EXPORT_SYMBOL(extent_write_cache_pages);
@@ -2560,18 +2516,10 @@ static inline struct page *extent_buffer_page(struct extent_buffer *eb,
 	 * by increasing the reference count.  So we know the page must
 	 * be in the radix tree.
 	 */
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 	rcu_read_lock();
-#else
-	read_lock_irq(&mapping->tree_lock);
-#endif
 	p = radix_tree_lookup(&mapping->page_tree, i);
-
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 	rcu_read_unlock();
-#else
-	read_unlock_irq(&mapping->tree_lock);
-#endif
+
 	return p;
 }
 
@@ -2773,21 +2721,13 @@ int clear_extent_buffer_dirty(struct extent_io_tree *tree,
 			}
 		}
 		clear_page_dirty_for_io(page);
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 		spin_lock_irq(&page->mapping->tree_lock);
-#else
-		read_lock_irq(&page->mapping->tree_lock);
-#endif
 		if (!PageDirty(page)) {
 			radix_tree_tag_clear(&page->mapping->page_tree,
 						page_index(page),
 						PAGECACHE_TAG_DIRTY);
 		}
-#if LINUX_VERSION_CODE > KERNEL_VERSION(2,6,26)
 		spin_unlock_irq(&page->mapping->tree_lock);
-#else
-		read_unlock_irq(&page->mapping->tree_lock);
-#endif
 		unlock_page(page);
 	}
 	return 0;