X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=filesetup.c;h=ae7f8171305507d9a28417cb5afb74181cc4c655;hp=eb28826698811058a317fa6544b92bd8f388a368;hb=08c44a557efc1cf301c39b5a81f8db4ccd7baa2d;hpb=f70afaca743f2971312d9928f069a9ea7daeccf7

diff --git a/filesetup.c b/filesetup.c
index eb288266..ae7f8171 100644
--- a/filesetup.c
+++ b/filesetup.c
@@ -130,6 +130,9 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
 	}
 #endif /* CONFIG_POSIX_FALLOCATE */
 
+	/*
+	 * If our jobs don't require regular files initially, we're done.
+	 */
 	if (!new_layout)
 		goto done;
 
@@ -375,11 +378,33 @@ static int get_file_size(struct thread_data *td, struct fio_file *f)
 	else if (f->filetype == FIO_TYPE_CHAR)
 		ret = char_size(td, f);
 	else
-		f->real_file_size = -1;
+		f->real_file_size = -1ULL;
 
+	/*
+	 * Leave ->real_file_size with 0 since it could be expectation
+	 * of initial setup for regular files.
+	 */
 	if (ret)
 		return ret;
 
+	/*
+	 * If ->real_file_size is -1, a conditional for the message
+	 * "offset extends end" is always true, but it makes no sense,
+	 * so just return the same value here.
+	 */
+	if (f->real_file_size == -1ULL) {
+		log_info("%s: failed to get file size of %s\n", td->o.name,
+					f->file_name);
+		return 1;
+	}
+
+	if (td->o.start_offset && f->file_offset == 0)
+		dprint(FD_FILE, "offset of file %s not initialized yet\n",
+					f->file_name);
+	/*
+	 * ->file_offset normally hasn't been initialized yet, so this
+	 * is basically always false.
+	 */
 	if (f->file_offset > f->real_file_size) {
 		log_err("%s: offset extends end (%llu > %llu)\n", td->o.name,
 					(unsigned long long) f->file_offset,
@@ -498,9 +523,6 @@ int file_lookup_open(struct fio_file *f, int flags)
 	__f = lookup_file_hash(f->file_name);
 	if (__f) {
 		dprint(FD_FILE, "found file in hash %s\n", f->file_name);
-		/*
-		 * racy, need the __f->lock locked
-		 */
 		f->lock = __f->lock;
 		from_hash = 1;
 	} else {
@@ -652,6 +674,10 @@ open_again:
 	return 0;
 }
 
+/*
+ * This function i.e. get_file_size() is the default .get_file_size
+ * implementation of majority of I/O engines.
+ */
 int generic_get_file_size(struct thread_data *td, struct fio_file *f)
 {
 	return get_file_size(td, f);
@@ -667,7 +693,7 @@ static int get_file_sizes(struct thread_data *td)
 	int err = 0;
 
 	for_each_file(td, f, i) {
-		dprint(FD_FILE, "get file size for %p/%d/%p\n", f, i,
+		dprint(FD_FILE, "get file size for %p/%d/%s\n", f, i,
 								f->file_name);
 
 		if (td_io_get_file_size(td, f)) {
@@ -679,6 +705,13 @@ static int get_file_sizes(struct thread_data *td)
 			clear_error(td);
 		}
 
+		/*
+		 * There are corner cases where we end up with -1 for
+		 * ->real_file_size due to unsupported file type, etc.
+		 * We then just set to size option value divided by number
+		 * of files, similar to the way file ->io_size is set.
+		 * stat(2) failure doesn't set ->real_file_size to -1.
+		 */
 		if (f->real_file_size == -1ULL && td->o.size)
 			f->real_file_size = td->o.size / td->o.nr_files;
 	}
@@ -795,7 +828,9 @@ int setup_files(struct thread_data *td)
 		goto done;
 
 	/*
-	 * if ioengine defines a setup() method, it's responsible for
+	 * Find out physical size of files or devices for this thread,
+	 * before we determine I/O size and range of our targets.
+	 * If ioengine defines a setup() method, it's responsible for
 	 * opening the files and setting f->real_file_size to indicate
 	 * the valid range for that file.
 	 */
@@ -836,7 +871,7 @@ int setup_files(struct thread_data *td)
 
 	/*
 	 * Calculate per-file size and potential extra size for the
-	 * first files, if needed.
+	 * first files, if needed (i.e. if we don't have a fixed size).
 	 */
 	if (!o->file_size_low && o->nr_files) {
 		uint64_t all_fs;
@@ -858,9 +893,17 @@ int setup_files(struct thread_data *td)
 	for_each_file(td, f, i) {
 		f->file_offset = get_start_offset(td, f);
 
+		/*
+		 * Update ->io_size depending on options specified.
+		 * ->file_size_low being 0 means filesize option isn't set.
+		 * Non zero ->file_size_low equals ->file_size_high means
+		 * filesize option is set in a fixed size format.
+		 * Non zero ->file_size_low not equals ->file_size_high means
+		 * filesize option is set in a range format.
+		 */
 		if (!o->file_size_low) {
 			/*
-			 * no file size range given, file size is equal to
+			 * no file size or range given, file size is equal to
 			 * total size divided by number of files. If that is
 			 * zero, set it to the real file size. If the size
 			 * doesn't divide nicely with the min blocksize,
@@ -943,7 +986,9 @@ int setup_files(struct thread_data *td)
 	}
 
 	/*
-	 * See if we need to extend some files
+	 * See if we need to extend some files, typically needed when our
+	 * target regular files don't exist yet, but our jobs require them
+	 * initially due to read I/Os.
 	 */
 	if (need_extend) {
 		temp_stall_ts = 1;
@@ -996,8 +1041,8 @@ int setup_files(struct thread_data *td)
 	 * stored entries.
 	 */
 	if (!o->read_iolog_file) {
-		if (o->io_limit)
-			td->total_io_size = o->io_limit * o->loops;
+		if (o->io_size)
+			td->total_io_size = o->io_size * o->loops;
 		else
 			td->total_io_size = o->size * o->loops;
 	}