filesetup: make random generator block auto-switch on huge files

[fio.git] / filesetup.c

diff --git a/filesetup.c b/filesetup.c
index 10fc4150804b8fadce1a4af7cb856828796ca1f8..881aeee8f8bf2b94649046181d9892d7050face8 100644 (file)
--- a/filesetup.c
+++ b/filesetup.c
@@ -65,7 +65,9 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
                }
        }
 
-       flags = O_WRONLY | O_CREAT;
+       flags = O_WRONLY;
+       if (td->o.allow_create)
+               flags |= O_CREAT;
        if (new_layout)
                flags |= O_TRUNC;
 
@@ -76,7 +78,13 @@ static int extend_file(struct thread_data *td, struct fio_file *f)
        dprint(FD_FILE, "open file %s, flags %x\n", f->file_name, flags);
        f->fd = open(f->file_name, flags, 0644);
        if (f->fd < 0) {
-               td_verror(td, errno, "open");
+               int err = errno;
+
+               if (err == ENOENT && !td->o.allow_create)
+                       log_err("fio: file creation disallowed by "
+                                       "allow_file_create=0\n");
+               else
+                       td_verror(td, err, "open");
                return 1;
        }
 
@@ -259,11 +267,13 @@ error:
 static unsigned long long get_rand_file_size(struct thread_data *td)
 {
        unsigned long long ret, sized;
+       uint64_t frand_max;
        unsigned long r;
 
+       frand_max = rand_max(&td->file_size_state);
        r = __rand(&td->file_size_state);
        sized = td->o.file_size_high - td->o.file_size_low;
-       ret = (unsigned long long) ((double) sized * (r / (FRAND_MAX + 1.0)));
+       ret = (unsigned long long) ((double) sized * (r / (frand_max + 1.0)));
        ret += td->o.file_size_low;
        ret -= (ret % td->o.rw_min_bs);
        return ret;
@@ -539,7 +549,7 @@ int generic_open_file(struct thread_data *td, struct fio_file *f)
        }
        if (td->o.sync_io)
                flags |= O_SYNC;
-       if (td->o.create_on_open)
+       if (td->o.create_on_open && td->o.allow_create)
                flags |= O_CREAT;
 skip_flags:
        if (f->filetype != FIO_TYPE_FILE)
@@ -550,7 +560,7 @@ open_again:
                if (!read_only)
                        flags |= O_RDWR;
 
-               if (f->filetype == FIO_TYPE_FILE)
+               if (f->filetype == FIO_TYPE_FILE && td->o.allow_create)
                        flags |= O_CREAT;
 
                if (is_std)
@@ -722,7 +732,7 @@ static unsigned long long get_fs_free_counts(struct thread_data *td)
                fm = flist_entry(n, struct fio_mount, list);
                flist_del(&fm->list);
 
-               sz = get_fs_size(fm->base);
+               sz = get_fs_free_size(fm->base);
                if (sz && sz != -1ULL)
                        ret += sz;
 
@@ -1041,6 +1051,43 @@ static int init_rand_distribution(struct thread_data *td)
        return 1;
 }
 
+/*
+ * Check if the number of blocks exceeds the randomness capability of
+ * the selected generator. Tausworthe is 32-bit, the others are fullly
+ * 64-bit capable.
+ */
+static int check_rand_gen_limits(struct thread_data *td, struct fio_file *f,
+                                uint64_t blocks)
+{
+       if (blocks <= FRAND32_MAX)
+               return 0;
+       if (td->o.random_generator != FIO_RAND_GEN_TAUSWORTHE)
+               return 0;
+
+       /*
+        * If the user hasn't specified a random generator, switch
+        * to tausworthe64 with informational warning. If the user did
+        * specify one, just warn.
+        */
+       log_info("fio: file %s exceeds 32-bit tausworthe random generator.\n",
+                       f->file_name);
+
+       if (!fio_option_is_set(&td->o, random_generator)) {
+               log_info("fio: Switching to tausworthe64. Use the "
+                        "random_generator= option to get rid of this "
+                        " warning.\n");
+               td->o.random_generator = FIO_RAND_GEN_TAUSWORTHE64;
+               return 0;
+       }
+
+       /*
+        * Just make this information to avoid breaking scripts.
+        */
+       log_info("fio: Use the random_generator= option to switch to lfsr or "
+                        "tausworthe64.\n");
+       return 0;
+}
+
 int init_random_map(struct thread_data *td)
 {
        unsigned long long blocks;
@@ -1057,6 +1104,9 @@ int init_random_map(struct thread_data *td)
 
                blocks = fsize / (unsigned long long) td->o.rw_min_bs;
 
+               if (check_rand_gen_limits(td, f, blocks))
+                       return 1;
+
                if (td->o.random_generator == FIO_RAND_GEN_LFSR) {
                        unsigned long seed;
 
@@ -1262,7 +1312,7 @@ int add_file(struct thread_data *td, const char *fname, int numjob, int inc)
        dprint(FD_FILE, "add file %s\n", fname);
 
        if (td->o.directory)
-               len = set_name_idx(file_name, td->o.directory, numjob);
+               len = set_name_idx(file_name, PATH_MAX, td->o.directory, numjob);
 
        sprintf(file_name + len, "%s", fname);