ext4l: Add extents_status.c compilation support

Add the extent status tree implementation to the ext4l build. This
module tracks extent status in memory to support delayed allocation
and SEEK_DATA/SEEK_HOLE operations.

Changes:
- Add extents_status.o to Makefile
- Add include guard to acl.h
- Add shrinker, ktime, and ratelimit stubs to ext4_uboot.h
- Guard iomap definitions in ext4_uboot.h when iomap.h is included
- Guard dquot macros when quotaops.h is included
- Remove stub functions now provided by extents_status.c
- Add ext4_da_release_space/update_reserve_space stubs

Series-to: u-boot
Cover-letter:
ext4l: Adjust some of the smaller files (part C)
This series makes various changes to allow some of the ext4l files to
compile successfully.

It provides a basic Kconfig to allow selecting ext4l (ext4 from Linu)
instead of the existing ext4 implementation.

To reduce the large number of include/linux files somewhat and to avoid
exceesive diffs against the Linux files, a new ext4_uboot.h header is
created. This will expand over time.
END

Co-developed-by: Claude Opus 4.5 <noreply@anthropic.com>
Signed-off-by: Simon Glass <simon.glass@canonical.com>

fs/ext4l/Makefile

@@ -5,5 +5,5 @@
 
 obj-y := interface.o stub.o
 
-obj-y	+= balloc.o bitmap.o block_validity.o ext4_jbd2.o extents.o hash.o \
-		ialloc.o indirect.o
+obj-y	+= balloc.o bitmap.o block_validity.o ext4_jbd2.o extents.o \
+		extents_status.o hash.o ialloc.o indirect.o

fs/ext4l/acl.h

@@ -5,6 +5,9 @@
   (C) 2001 Andreas Gruenbacher, <a.gruenbacher@computer.org>
 */
 
+#ifndef _FS_EXT4_ACL_H
+#define _FS_EXT4_ACL_H
+
 #include <linux/posix_acl_xattr.h>
 
 #define EXT4_ACL_VERSION	0x0001
@@ -72,3 +75,4 @@ ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir)
 }
 #endif  /* CONFIG_EXT4_FS_POSIX_ACL */
 
+#endif /* _FS_EXT4_ACL_H */

fs/ext4l/ext4_uboot.h

@@ -58,10 +58,10 @@ typedef struct { atomic_t refs; } refcount_t;
 typedef int rwlock_t;
 /* spinlock_t is defined in linux/compat.h */
 
-#define read_lock(l)		do { } while (0)
-#define read_unlock(l)		do { } while (0)
-#define write_lock(l)		do { } while (0)
-#define write_unlock(l)		do { } while (0)
+#define read_lock(l)		do { (void)(l); } while (0)
+#define read_unlock(l)		do { (void)(l); } while (0)
+#define write_lock(l)		do { (void)(l); } while (0)
+#define write_unlock(l)		do { (void)(l); } while (0)
 
 /* RB tree types - stubs */
 struct rb_node {
@@ -177,7 +177,8 @@ struct dir_context {
 	loff_t pos;
 };
 
-/* iomap types */
+/* iomap types - only define if linux/iomap.h not included */
+#ifndef _LINUX_IOMAP_H
 #define IOMAP_MAPPED	0
 #define IOMAP_INLINE	1
 #define IOMAP_UNWRITTEN	2
@@ -200,6 +201,7 @@ struct iomap_ops {
 	int (*iomap_end)(struct inode *inode, loff_t pos, loff_t length,
 			 ssize_t written, unsigned flags, struct iomap *iomap);
 };
+#endif /* _LINUX_IOMAP_H */
 
 /* fiemap types */
 #define FIEMAP_FLAG_SYNC	0x00000001
@@ -313,12 +315,14 @@ extern struct user_namespace init_user_ns;
 /* Group permission - stub */
 #define in_group_p(gid)			(0)
 
-/* Quota operations - stubs */
+/* Quota operations - stubs (only define if quotaops.h not included) */
+#ifndef _LINUX_QUOTAOPS_H
 #define dquot_alloc_block_nofail(inode, nr)	({ (void)(inode); (void)(nr); 0; })
 #define dquot_initialize(inode)			({ (void)(inode); 0; })
 #define dquot_free_inode(inode)			do { (void)(inode); } while (0)
 #define dquot_alloc_inode(inode)		({ (void)(inode); 0; })
 #define dquot_drop(inode)			do { (void)(inode); } while (0)
+#endif /* _LINUX_QUOTAOPS_H */
 
 /* Trace stubs for ialloc.c */
 #define trace_ext4_load_inode_bitmap(...)	do { } while (0)
@@ -358,12 +362,13 @@ extern struct user_namespace init_user_ns;
 #define fscrypt_prepare_new_inode(dir, i, e)	({ (void)(dir); (void)(i); (void)(e); 0; })
 #define fscrypt_set_context(inode, handle)	({ (void)(inode); (void)(handle); 0; })
 
-/* ACL and security stubs */
+/* ACL and security stubs - only if acl.h won't be included */
+#ifndef _FS_EXT4_ACL_H
 #define ext4_init_acl(h, i, d)			({ (void)(h); (void)(i); (void)(d); 0; })
-#define ext4_init_security(h, i, d, q)		({ (void)(h); (void)(i); (void)(d); (void)(q); 0; })
+#endif
+/* Note: ext4_init_security is already handled in xattr.h */
 
-/* xattr stubs */
-#define __ext4_xattr_set_credits(sb, i, b, isz, cr)	({ (void)(sb); (void)(i); (void)(b); (void)(isz); (void)(cr); 0; })
+/* xattr stubs - __ext4_xattr_set_credits is declared in xattr.h */
 
 /* inode state stubs */
 #define is_bad_inode(inode)			(0)
@@ -420,7 +425,7 @@ extern struct user_namespace init_user_ns;
 #define rb_next(node)		((node)->rb_right)
 #define rb_prev(node)		((node)->rb_left)
 #define rb_insert_color(node, root)	do { } while (0)
-#define rb_erase(node, root)		do { } while (0)
+#define rb_erase(node, root)		do { (void)(node); (void)(root); } while (0)
 #define rb_link_node(node, parent, rb_link)	do { *(rb_link) = (node); } while (0)
 #define RB_EMPTY_ROOT(root)	((root)->rb_node == NULL)
 #define rbtree_postorder_for_each_entry_safe(pos, n, root, field) \
@@ -784,4 +789,67 @@ static inline int in_range(unsigned long val, unsigned long start,
 
 /* ext4_sb_bread_nofail is stubbed in interface.c */
 
+/* extents_status.c stubs */
+
+/* shrinker - memory reclaim infrastructure (stub for U-Boot) */
+struct shrink_control {
+	gfp_t gfp_mask;
+	int nid;
+	unsigned long nr_to_scan;
+	unsigned long nr_scanned;
+};
+
+struct shrinker {
+	unsigned long (*count_objects)(struct shrinker *, struct shrink_control *);
+	unsigned long (*scan_objects)(struct shrinker *, struct shrink_control *);
+	void *private_data;
+};
+
+static inline struct shrinker *shrinker_alloc(unsigned int flags,
+					      const char *fmt, ...)
+{
+	return NULL;
+}
+
+static inline void shrinker_register(struct shrinker *s)
+{
+}
+
+static inline void shrinker_free(struct shrinker *s)
+{
+}
+
+/* ktime functions */
+static inline ktime_t ktime_get(void)
+{
+	return 0;
+}
+
+static inline s64 ktime_to_ns(ktime_t kt)
+{
+	return kt;
+}
+
+static inline ktime_t ktime_sub(ktime_t a, ktime_t b)
+{
+	return a - b;
+}
+
+/* write lock variants */
+#define write_trylock(lock)		({ (void)(lock); 1; })
+
+/* percpu counter init/destroy */
+#define percpu_counter_init(fbc, val, gfp)	({ (fbc)->count = (val); 0; })
+#define percpu_counter_destroy(fbc)		do { } while (0)
+
+/* ratelimit macros */
+#define DEFAULT_RATELIMIT_INTERVAL	(5 * 1000)
+#define DEFAULT_RATELIMIT_BURST		10
+#define DEFINE_RATELIMIT_STATE(name, interval, burst) \
+	int name __attribute__((unused)) = 0
+#define __ratelimit(state)		({ (void)(state); 1; })
+
+/* seq_file tokens */
+#define SEQ_START_TOKEN			((void *)1)
+
 #endif /* __EXT4_UBOOT_H__ */

fs/ext4l/extents_status.c

@@ -1741,6 +1741,7 @@ int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
 		    max->vfs_inode.i_ino, max->i_es_all_nr, max->i_es_shk_nr,
 		    div_u64(es_stats->es_stats_max_scan_time, 1000));
 
+	(void)es_stats;  /* Used only by seq_printf which is stubbed */
 	return 0;
 }
 

fs/ext4l/stub.c

@@ -248,12 +248,7 @@ struct ext4_sb_info;
 struct ext4_es_tree;
 struct extent_status;
 
-int ext4_es_cache_extent(struct inode *inode, unsigned long lblk,
-			 unsigned long len, unsigned long long pblk,
-			 unsigned int status)
-{
-	return 0;
-}
+/* ext4_es_cache_extent is now in extents_status.c */
 
 int ext4_issue_zeroout(struct inode *inode, unsigned long long lblk,
 		       unsigned long long pblk, unsigned long long len)
@@ -261,13 +256,15 @@ int ext4_issue_zeroout(struct inode *inode, unsigned long long lblk,
 	return 0;
 }
 
-void ext4_es_insert_extent(struct inode *inode, unsigned long lblk,
-			   unsigned long len, unsigned long long pblk,
-			   unsigned int status)
+/* ext4_es_insert_extent is now in extents_status.c */
+
+/* ext4_remove_pending is now in extents_status.c */
+
+void ext4_da_release_space(struct inode *inode, int to_free)
 {
 }
 
-void ext4_remove_pending(struct inode *inode, unsigned long lblk)
+void ext4_da_update_reserve_space(struct inode *inode, int used, int quota_claim)
 {
 }
 
@@ -306,10 +303,7 @@ int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
 	return 0;
 }
 
-int ext4_is_pending(struct inode *inode, unsigned long lblk)
-{
-	return 0;
-}
+/* ext4_is_pending is now in extents_status.c */
 
 int ext4_meta_trans_blocks(struct inode *inode, int lblk, int pblk)
 {
@@ -355,24 +349,11 @@ void ext4_truncate_page_cache_block_range(struct inode *inode, loff_t start,
 /* ext4_iomap_report_ops - just a symbol needed for linking */
 char ext4_iomap_report_ops;
 
-int ext4_es_lookup_extent(struct inode *inode, unsigned long lblk,
-			  unsigned long *next_lblk, void *es)
-{
-	return 0;
-}
+/* ext4_es_lookup_extent is now in extents_status.c */
 
-int ext4_es_remove_extent(struct inode *inode, unsigned long lblk,
-			  unsigned long len)
-{
-	return 0;
-}
+/* ext4_es_remove_extent is now in extents_status.c */
 
-int ext4_es_find_extent_range(struct inode *inode, void *matching_fn,
-			      unsigned long lblk, unsigned long end,
-			      void *es)
-{
-	return 0;
-}
+/* ext4_es_find_extent_range is now in extents_status.c */
 
 void ext4_mb_mark_bb(struct super_block *sb, unsigned long long block,
 		     int len, int state)