ANDROID: fs: add vendor hook to collect IO statistics

Add vendor hook to get metainfo of direct/buffered read and write.
Determine hot files in each performance-sensitive user scenario.

Bug: 380502059
Change-Id: Ie7604852df637d6664afd72e87bd6d4b14bbc2a2
Signed-off-by: Rui Chen <chenrui9@honor.com>

drivers/android/vendor_hooks.c

@@ -422,6 +422,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_delayacct_compact_start);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_delayacct_compact_end);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_delayacct_wpcopy_start);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_delayacct_wpcopy_end);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_io_statistics);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_usb_dev_suspend);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_usb_dev_resume);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_sound_usb_support_cpu_suspend);

fs/direct-io.c

@@ -38,6 +38,9 @@
 #include <linux/uio.h>
 #include <linux/atomic.h>
 #include <linux/prefetch.h>
+#ifndef __GENKSYMS__
+#include <trace/hooks/mm.h>
+#endif
 
 #include "internal.h"
 
@@ -1053,6 +1056,12 @@ do_holes:
 				put_page(page);
 				goto out;
 			}
+
+			trace_android_vh_io_statistics(dio->inode->i_mapping,
+					sdio->block_in_file >> sdio->blkfactor,
+					this_chunk_blocks >> sdio->blkfactor,
+					iov_iter_rw(sdio->iter) == READ, true);
+
 			sdio->next_block_for_io += this_chunk_blocks;
 
 			sdio->block_in_file += this_chunk_blocks;

fs/iomap/direct-io.c

@@ -12,6 +12,9 @@
 #include <linux/backing-dev.h>
 #include <linux/uio.h>
 #include <linux/task_io_accounting_ops.h>
+#ifndef __GENKSYMS__
+#include <trace/hooks/mm.h>
+#endif
 #include "trace.h"
 
 #include "../internal.h"
@@ -320,6 +323,9 @@ static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
 			goto out;
 		}
 
+		trace_android_vh_io_statistics(inode->i_mapping, pos >> inode->i_blkbits,
+					nr_pages, !(dio->flags & IOMAP_DIO_WRITE), true);
+
 		bio = iomap_dio_alloc_bio(iter, dio, nr_pages, bio_opf);
 		fscrypt_set_bio_crypt_ctx(bio, inode, pos >> inode->i_blkbits,
 					  GFP_KERNEL);

include/trace/hooks/mm.h

@@ -18,6 +18,10 @@ DECLARE_RESTRICTED_HOOK(android_rvh_shmem_get_folio,
 			TP_PROTO(struct shmem_inode_info *info, struct folio **folio),
 			TP_ARGS(info, folio), 2);
 
+DECLARE_HOOK(android_vh_io_statistics,
+	TP_PROTO(struct address_space *mapping, unsigned int index,
+		unsigned int nr_page, bool read, bool direct),
+	TP_ARGS(mapping, index, nr_page, read, direct));
 DECLARE_RESTRICTED_HOOK(android_rvh_set_gfp_zone_flags,
 			TP_PROTO(unsigned int *flags),	/* gfp_t *flags */
 			TP_ARGS(flags), 1);

mm/filemap.c

@@ -3892,6 +3892,7 @@ again:
 			if (unlikely(status < 0))
 				break;
 		}
+		trace_android_vh_io_statistics(mapping, page->index, 1, false, false);
 		cond_resched();
 
 		if (unlikely(status == 0)) {

mm/readahead.c

@@ -256,6 +256,7 @@ void page_cache_ra_unbounded(struct readahead_control *ractl,
 			continue;
 		}
 
+		trace_android_vh_io_statistics(mapping, index + i, 1, true, false);
 		folio = filemap_alloc_folio(gfp_mask, 0);
 		if (!folio)
 			break;