ANDROID: Incremental fs: Small improvements

Rmove bc_mutex used to protect metadata chain, now that is only
read at file open time
Remove certain unused mount options

Bug: 172482559
Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: Id70e5a5d08e5de79f391e19ea97e356f39a3ed51

fs/incfs/data_mgmt.c

@@ -19,6 +19,8 @@
 #include "format.h"
 #include "integrity.h"
 
+static int incfs_scan_metadata_chain(struct data_file *df);
+
 static void log_wake_up_all(struct work_struct *work)
 {
 	struct delayed_work *dw = container_of(work, struct delayed_work, work);
@@ -240,12 +242,8 @@ struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf)
 	for (i = 0; i < ARRAY_SIZE(df->df_segments); i++)
 		data_file_segment_init(&df->df_segments[i]);
 
-	error = mutex_lock_interruptible(&bfc->bc_mutex);
-	if (error)
-		goto out;
 	error = incfs_read_file_header(bfc, &df->df_metadata_off, &df->df_id,
 				       &size, &df->df_header_flags);
-	mutex_unlock(&bfc->bc_mutex);
 
 	if (error)
 		goto out;
@@ -1373,7 +1371,7 @@ static int process_status_md(struct incfs_status *is,
 	return 0;
 }
 
-int incfs_scan_metadata_chain(struct data_file *df)
+static int incfs_scan_metadata_chain(struct data_file *df)
 {
 	struct metadata_handler *handler = NULL;
 	int result = 0;
@@ -1390,12 +1388,6 @@ int incfs_scan_metadata_chain(struct data_file *df)
 	if (!handler)
 		return -ENOMEM;
 
-	/* No writing to the backing file while it's being scanned. */
-	error = mutex_lock_interruptible(&bfc->bc_mutex);
-	if (error)
-		goto out;
-
-	/* Reading superblock */
 	handler->md_record_offset = df->df_metadata_off;
 	handler->context = df;
 	handler->handle_blockmap = process_blockmap_md;
@@ -1418,7 +1410,6 @@ int incfs_scan_metadata_chain(struct data_file *df)
 		result = error;
 	} else
 		result = records_count;
-	mutex_unlock(&bfc->bc_mutex);
 
 	if (df->df_hash_tree) {
 		int hash_block_count = get_blocks_count_for_size(
@@ -1430,7 +1421,6 @@ int incfs_scan_metadata_chain(struct data_file *df)
 	} else if (df->df_data_block_count != df->df_total_block_count)
 		result = -EINVAL;
 
-out:
 	kfree(handler);
 	return result;
 }
@@ -1443,10 +1433,6 @@ bool incfs_fresh_pending_reads_exist(struct mount_info *mi, int last_number)
 {
 	bool result = false;
 
-	/*
-	 * We could probably get away with spin locks here;
-	 * if we use atomic_read() on both these variables.
-	 */
 	spin_lock(&mi->pending_read_lock);
 	result = (mi->mi_last_pending_read_number > last_number) &&
 		(mi->mi_pending_reads_count > 0);
@@ -1461,7 +1447,6 @@ int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
 {
 	int reported_reads = 0;
 	struct pending_read *entry = NULL;
-	bool result = false;
 
 	if (!mi)
 		return -EFAULT;
@@ -1469,15 +1454,8 @@ int incfs_collect_pending_reads(struct mount_info *mi, int sn_lowerbound,
 	if (reads_size <= 0)
 		return 0;
 
-	spin_lock(&mi->pending_read_lock);
-
-	result = ((mi->mi_last_pending_read_number <= sn_lowerbound)
-		|| (mi->mi_pending_reads_count == 0));
-
-	spin_unlock(&mi->pending_read_lock);
-
-	if (result)
-		return reported_reads;
+	if (!incfs_fresh_pending_reads_exist(mi, sn_lowerbound))
+		return 0;
 
 	rcu_read_lock();
 
@@ -1609,9 +1587,3 @@ int incfs_collect_logged_reads(struct mount_info *mi,
 	return dst_idx;
 }
 
-bool incfs_equal_ranges(struct mem_range lhs, struct mem_range rhs)
-{
-	if (lhs.len != rhs.len)
-		return false;
-	return memcmp(lhs.data, rhs.data, lhs.len) == 0;
-}

fs/incfs/data_mgmt.h

@@ -41,7 +41,7 @@ struct same_file_record {
 	enum LOG_RECORD_TYPE type : 2; /* SAME_FILE */
 	u32 block_index : 30;
 	u32 relative_ts_us; /* max 2^32 us ~= 1 hour (1:11:30) */
-} __packed; /* 12 bytes */
+} __packed; /* 8 bytes */
 
 struct same_file_next_block {
 	enum LOG_RECORD_TYPE type : 2; /* SAME_FILE_NEXT_BLOCK */
@@ -102,8 +102,6 @@ struct mount_options {
 	unsigned int readahead_pages;
 	unsigned int read_log_pages;
 	unsigned int read_log_wakeup_count;
-	bool no_backing_file_cache;
-	bool no_backing_file_readahead;
 	bool report_uid;
 };
 
@@ -326,8 +324,6 @@ struct dentry *incfs_lookup_dentry(struct dentry *parent, const char *name);
 struct data_file *incfs_open_data_file(struct mount_info *mi, struct file *bf);
 void incfs_free_data_file(struct data_file *df);
 
-int incfs_scan_metadata_chain(struct data_file *df);
-
 struct dir_file *incfs_open_dir_file(struct mount_info *mi, struct file *bf);
 void incfs_free_dir_file(struct dir_file *dir);
 
@@ -448,6 +444,4 @@ static inline int get_blocks_count_for_size(u64 size)
 	return 1 + (size - 1) / INCFS_DATA_FILE_BLOCK_SIZE;
 }
 
-bool incfs_equal_ranges(struct mem_range lhs, struct mem_range rhs);
-
 #endif /* _INCFS_DATA_MGMT_H */

fs/incfs/format.c

@@ -40,7 +40,7 @@ void incfs_free_bfc(struct backing_file_context *bfc)
 	kfree(bfc);
 }
 
-loff_t incfs_get_end_offset(struct file *f)
+static loff_t incfs_get_end_offset(struct file *f)
 {
 	/*
 	 * This function assumes that file size and the end-offset
@@ -503,29 +503,6 @@ int incfs_write_hash_block_to_backing_file(struct backing_file_context *bfc,
 	return write_to_bf(bfc, &bm_entry, sizeof(bm_entry), bm_entry_off);
 }
 
-/* Initialize a new image in a given backing file. */
-int incfs_make_empty_backing_file(struct backing_file_context *bfc,
-				  incfs_uuid_t *uuid, u64 file_size)
-{
-	int result = 0;
-
-	if (!bfc || !bfc->bc_file)
-		return -EFAULT;
-
-	result = mutex_lock_interruptible(&bfc->bc_mutex);
-	if (result)
-		goto out;
-
-	result = truncate_backing_file(bfc, 0);
-	if (result)
-		goto out;
-
-	result = incfs_write_fh_to_backing_file(bfc, uuid, file_size);
-out:
-	mutex_unlock(&bfc->bc_mutex);
-	return result;
-}
-
 int incfs_read_blockmap_entry(struct backing_file_context *bfc, int block_index,
 			loff_t bm_base_off,
 			struct incfs_blockmap_entry *bm_entry)
@@ -579,7 +556,6 @@ int incfs_read_file_header(struct backing_file_context *bfc,
 	if (!bfc || !first_md_off)
 		return -EFAULT;
 
-	LOCK_REQUIRED(bfc->bc_mutex);
 	bytes_read = incfs_kread(bfc->bc_file, &fh, sizeof(fh), 0);
 	if (bytes_read < 0)
 		return bytes_read;
@@ -627,8 +603,6 @@ int incfs_read_next_metadata_record(struct backing_file_context *bfc,
 	if (!bfc || !handler)
 		return -EFAULT;
 
-	LOCK_REQUIRED(bfc->bc_mutex);
-
 	if (handler->md_record_offset == 0)
 		return -EPERM;
 

fs/incfs/format.h

@@ -292,8 +292,6 @@ struct metadata_handler {
 #define INCFS_MAX_METADATA_RECORD_SIZE \
 	sizeof_field(struct metadata_handler, md_buffer)
 
-loff_t incfs_get_end_offset(struct file *f);
-
 /* Backing file context management */
 struct backing_file_context *incfs_alloc_bfc(struct file *backing_file);
 
@@ -329,9 +327,6 @@ int incfs_write_status_to_backing_file(struct backing_file_context *bfc,
 				       u32 data_blocks_written,
 				       u32 hash_blocks_written);
 
-int incfs_make_empty_backing_file(struct backing_file_context *bfc,
-				  incfs_uuid_t *uuid, u64 file_size);
-
 /* Reading stuff */
 int incfs_read_file_header(struct backing_file_context *bfc,
 			   loff_t *first_md_off, incfs_uuid_t *uuid,

fs/incfs/pseudo_files.c

@@ -336,6 +336,13 @@ retry_deleg:
 	return error;
 }
 
+static bool incfs_equal_ranges(struct mem_range lhs, struct mem_range rhs)
+{
+	if (lhs.len != rhs.len)
+		return false;
+	return memcmp(lhs.data, rhs.data, lhs.len) == 0;
+}
+
 static bool is_pseudo_filename(struct mem_range name)
 {
 	if (incfs_equal_ranges(pending_reads_file_name_range, name))

fs/incfs/vfs.c

@@ -153,8 +153,6 @@ struct inode_search {
 enum parse_parameter {
 	Opt_read_timeout,
 	Opt_readahead_pages,
-	Opt_no_backing_file_cache,
-	Opt_no_backing_file_readahead,
 	Opt_rlog_pages,
 	Opt_rlog_wakeup_cnt,
 	Opt_report_uid,
@@ -164,8 +162,6 @@ enum parse_parameter {
 static const match_table_t option_tokens = {
 	{ Opt_read_timeout, "read_timeout_ms=%u" },
 	{ Opt_readahead_pages, "readahead=%u" },
-	{ Opt_no_backing_file_cache, "no_bf_cache=%u" },
-	{ Opt_no_backing_file_readahead, "no_bf_readahead=%u" },
 	{ Opt_rlog_pages, "rlog_pages=%u" },
 	{ Opt_rlog_wakeup_cnt, "rlog_wakeup_cnt=%u" },
 	{ Opt_report_uid, "report_uid" },
@@ -210,16 +206,6 @@ static int parse_options(struct mount_options *opts, char *str)
 				return -EINVAL;
 			opts->readahead_pages = value;
 			break;
-		case Opt_no_backing_file_cache:
-			if (match_int(&args[0], &value))
-				return -EINVAL;
-			opts->no_backing_file_cache = (value != 0);
-			break;
-		case Opt_no_backing_file_readahead:
-			if (match_int(&args[0], &value))
-				return -EINVAL;
-			opts->no_backing_file_readahead = (value != 0);
-			break;
 		case Opt_rlog_pages:
 			if (match_int(&args[0], &value))
 				return -EINVAL;
@@ -1675,10 +1661,6 @@ static int show_options(struct seq_file *m, struct dentry *root)
 		seq_printf(m, ",rlog_wakeup_cnt=%u",
 			   mi->mi_options.read_log_wakeup_count);
 	}
-	if (mi->mi_options.no_backing_file_cache)
-		seq_puts(m, ",no_bf_cache");
-	if (mi->mi_options.no_backing_file_readahead)
-		seq_puts(m, ",no_bf_readahead");
 	if (mi->mi_options.report_uid)
 		seq_puts(m, ",report_uid");
 	return 0;