Add support to display slave device stats for software RAIDs.

When running tests on a device created using mdadm, the relevant
disk statistics must also come from the individual
disks that constitute the RAID, because the software RAID device
is just a virtual device.

This patch goes through the 'slaves' directory in the software
RAID device's directory in /sys/block, gets a list of all the
slave devices and creates a master-slave relationship between
the virtual device and the actual disks.

The individual slave disks' stats are displayed along with the
master's disk stats at the end of the test.

Signed-off-by: Shehjar Tikoo <shehjart@gelato.unsw.edu.au>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/diskutil.c b/diskutil.c
index 9fb31bf2be44f6c6e9f997e204a10fb6b7574aa1..b409d8efe97397ba6ce407ea6ecad7f7d59b5fa3 100644 (file)
--- a/diskutil.c
+++ b/diskutil.c
@@ -102,7 +102,129 @@ static struct disk_util *disk_util_exists(int major, int minor)
        return NULL;
 }
 
        return NULL;
 }
 

-static void disk_util_add(int majdev, int mindev, char *path)
+static int get_device_numbers(char *file_name, int *maj, int *min)
+{
+       struct stat st;
+       int majdev, mindev;
+       char tempname[PATH_MAX], *p;
+
+       if (!lstat(file_name, &st)) {
+               if (S_ISBLK(st.st_mode)) {
+                       majdev = major(st.st_rdev);
+                       mindev = minor(st.st_rdev);
+               } else if (S_ISCHR(st.st_mode)) {
+                       majdev = major(st.st_rdev);
+                       mindev = minor(st.st_rdev);
+                       if (fio_lookup_raw(st.st_rdev, &majdev, &mindev))
+                               return -1;
+               } else if (S_ISFIFO(st.st_mode))
+                       return -1;
+               else {
+                       majdev = major(st.st_dev);
+                       mindev = minor(st.st_dev);
+               }
+       } else {
+               /*
+                * must be a file, open "." in that path
+                */
+               strncpy(tempname, file_name, PATH_MAX - 1);
+               p = dirname(tempname);
+               if (stat(p, &st)) {
+                       perror("disk util stat");
+                       return -1;
+               }
+
+               majdev = major(st.st_dev);
+               mindev = minor(st.st_dev);
+       }
+
+       *min = mindev;
+       *maj = majdev;
+
+       return 0;
+}
+
+static int read_block_dev_entry(char *path, int *maj, int *min)
+{
+       char line[256], *p;
+       FILE *f;
+
+       f = fopen(path, "r");
+       if (!f) {
+               perror("open path");
+               return 1;
+       }
+
+       p = fgets(line, sizeof(line), f);
+       fclose(f);
+
+       if (!p)
+               return 1;
+
+       if (sscanf(p, "%u:%u", maj, min) != 2)
+               return 1;
+
+       return 0;
+}
+
+
+static void __init_per_file_disk_util(struct thread_data *td, int majdev,
+               int mindev, char * path);
+
+static void find_add_disk_slaves(struct thread_data *td, char *path,
+               struct disk_util *masterdu)
+{
+       DIR *dirhandle = NULL;
+       struct dirent *dirent = NULL;
+       char slavesdir[PATH_MAX], temppath[PATH_MAX], slavepath[PATH_MAX];
+       struct disk_util *slavedu = NULL;
+       int majdev, mindev;
+       ssize_t linklen;
+
+       sprintf(slavesdir, "%s/%s",path, "slaves");
+       dirhandle = opendir(slavesdir);
+       if (!dirhandle)
+               return;
+
+       while ((dirent = readdir(dirhandle)) != NULL) {
+               if (!strcmp(dirent->d_name, ".") || !strcmp(dirent->d_name, ".."))
+                       continue;
+
+               sprintf(temppath, "%s/%s", slavesdir, dirent->d_name);
+               /* Can we always assume that the slaves device entries
+                * are links to the real directories for the slave
+                * devices?
+                */
+               if ((linklen = readlink(temppath, slavepath, PATH_MAX-1)) < 0) {
+                       perror("readlink() for slave device.");
+                       return;
+               }
+               slavepath[linklen]='\0';
+
+               sprintf(temppath, "%s/%s/dev", slavesdir, slavepath);
+               if (read_block_dev_entry(temppath, &majdev, &mindev)) {
+                       perror("Error getting slave device numbers.");
+                       return;
+               }
+
+               sprintf(temppath, "%s/%s", slavesdir, slavepath);
+               __init_per_file_disk_util(td, majdev, mindev, temppath);
+               slavedu = disk_util_exists(majdev, mindev);
+
+               /* Should probably use an assert here. slavedu should
+                * always be present at this point. */
+               if (slavedu)
+                       flist_add_tail(&slavedu->slavelist, &masterdu->slaves);
+       }
+
+       closedir(dirhandle);
+       return;
+}
+
+
+
+static void disk_util_add(struct thread_data * td, int majdev, int mindev,
+               char *path)

 {
        struct disk_util *du, *__du;
        struct flist_head *entry;
 {
        struct disk_util *du, *__du;
        struct flist_head *entry;


@@ -117,6 +239,8 @@ static void disk_util_add(int majdev, int mindev, char *path)
        du->sysfs_root = path;
        du->major = majdev;
        du->minor = mindev;
        du->sysfs_root = path;
        du->major = majdev;
        du->minor = mindev;

+       INIT_FLIST_HEAD(&du->slavelist);
+       INIT_FLIST_HEAD(&du->slaves);

 
        flist_for_each(entry, &disk_list) {
                __du = flist_entry(entry, struct disk_util, list);
 
        flist_for_each(entry, &disk_list) {
                __du = flist_entry(entry, struct disk_util, list);


@@ -136,37 +260,21 @@ static void disk_util_add(int majdev, int mindev, char *path)
        get_io_ticks(du, &du->last_dus);
 
        flist_add_tail(&du->list, &disk_list);
        get_io_ticks(du, &du->last_dus);
 
        flist_add_tail(&du->list, &disk_list);

+       find_add_disk_slaves(td, path, du);

 }
 
 }
 

+

 static int check_dev_match(int majdev, int mindev, char *path)
 {
        int major, minor;
 static int check_dev_match(int majdev, int mindev, char *path)
 {
        int major, minor;

-       char line[256], *p;
-       FILE *f;

 
 

-       f = fopen(path, "r");
-       if (!f) {
-               perror("open path");
+       if (read_block_dev_entry(path, &major, &minor))

                return 1;
                return 1;

-       }
-
-       p = fgets(line, sizeof(line), f);
-       if (!p) {
-               fclose(f);
-               return 1;
-       }
-
-       if (sscanf(p, "%u:%u", &major, &minor) != 2) {
-               fclose(f);
-               return 1;
-       }

 
        if (majdev == major && mindev == minor) {
 
        if (majdev == major && mindev == minor) {

-               fclose(f);

                return 0;
        }
 
                return 0;
        }
 

-       fclose(f);

        return 1;
 }
 
        return 1;
 }
 


@@ -222,46 +330,51 @@ static int find_block_dir(int majdev, int mindev, char *path, int link_ok)
        return found;
 }
 
        return found;
 }
 

-static void __init_disk_util(struct thread_data *td, struct fio_file *f)
+
+static void __init_per_file_disk_util(struct thread_data *td, int majdev,
+               int mindev, char * path)

 {
        struct stat st;
 {
        struct stat st;

-       char foo[PATH_MAX], tmp[PATH_MAX];
-       struct disk_util *du;
-       int mindev, majdev;
+       char tmp[PATH_MAX];

        char *p;
 
        char *p;
 

-       if (!lstat(f->file_name, &st)) {
-               if (S_ISBLK(st.st_mode)) {
-                       majdev = major(st.st_rdev);
-                       mindev = minor(st.st_rdev);
-               } else if (S_ISCHR(st.st_mode)) {
-                       majdev = major(st.st_rdev);
-                       mindev = minor(st.st_rdev);
-                       if (fio_lookup_raw(st.st_rdev, &majdev, &mindev))
-                               return;
-               } else if (S_ISFIFO(st.st_mode))
-                       return;
-               else {
-                       majdev = major(st.st_dev);
-                       mindev = minor(st.st_dev);
-               }
-       } else {
-               /*
-                * must be a file, open "." in that path
-                */
-               strncpy(foo, f->file_name, PATH_MAX - 1);
-               p = dirname(foo);
-               if (stat(p, &st)) {
-                       perror("disk util stat");
+       /*
+        * If there's a ../queue/ directory there, we are inside a partition.
+        * Check if that is the case and jump back. For loop/md/dm etc we
+        * are already in the right spot.
+        */
+       sprintf(tmp, "%s/../queue", path);
+       if (!stat(tmp, &st)) {
+               p = dirname(path);
+               sprintf(tmp, "%s/queue", p);
+               if (stat(tmp, &st)) {
+                       log_err("unknown sysfs layout\n");

                        return;
                }
                        return;
                }

-
-               majdev = major(st.st_dev);
-               mindev = minor(st.st_dev);
+               strncpy(tmp, p, PATH_MAX - 1);
+               sprintf(path, "%s", tmp);

        }
 
        }
 

-       dprint(FD_DISKUTIL, "%s belongs to maj/min %d/%d\n", f->file_name,
-                                                       majdev, mindev);
+       if (td->o.ioscheduler && !td->sysfs_root)
+               td->sysfs_root = strdup(path);
+
+       disk_util_add(td, majdev, mindev, path);
+}
+
+
+
+static void init_per_file_disk_util(struct thread_data *td, char * filename)
+{
+
+       char foo[PATH_MAX];
+       struct disk_util *du;
+       int mindev, majdev;
+
+       if(get_device_numbers(filename, &majdev, &mindev))
+               return;
+
+       dprint(FD_DISKUTIL, "%s belongs to maj/min %d/%d\n", filename, majdev,
+                       mindev);

 
        du = disk_util_exists(majdev, mindev);
        if (du) {
 
        du = disk_util_exists(majdev, mindev);
        if (du) {


@@ -287,27 +400,13 @@ static void __init_disk_util(struct thread_data *td, struct fio_file *f)
        if (!find_block_dir(majdev, mindev, foo, 1))
                return;
 
        if (!find_block_dir(majdev, mindev, foo, 1))
                return;
 

-       /*
-        * If there's a ../queue/ directory there, we are inside a partition.
-        * Check if that is the case and jump back. For loop/md/dm etc we
-        * are already in the right spot.
-        */
-       sprintf(tmp, "%s/../queue", foo);
-       if (!stat(tmp, &st)) {
-               p = dirname(foo);
-               sprintf(tmp, "%s/queue", p);
-               if (stat(tmp, &st)) {
-                       log_err("unknown sysfs layout\n");
-                       return;
-               }
-               strncpy(tmp, p, PATH_MAX - 1);
-               sprintf(foo, "%s", tmp);
-       }
+       __init_per_file_disk_util(td, majdev, mindev, foo);

 
 

-       if (td->o.ioscheduler && !td->sysfs_root)
-               td->sysfs_root = strdup(foo);
+}

 
 

-       disk_util_add(majdev, mindev, foo);
+static void __init_disk_util(struct thread_data *td, struct fio_file *f)
+{
+       return init_per_file_disk_util(td, f->file_name);

 }
 
 void init_disk_util(struct thread_data *td)
 }
 
 void init_disk_util(struct thread_data *td)


@@ -343,6 +442,17 @@ void show_disk_util(void)
                if (util > 100.0)
                        util = 100.0;
 
                if (util > 100.0)
                        util = 100.0;
 

+               /* If this node is the slave of a master device, as
+                * happens in case of software RAIDs, inward-indent
+                * this stats line to reflect a master-slave
+                * relationship. Because the master device gets added
+                * before the slave devices, we can safely assume that
+                * the master's stats line has been displayed in a
+                * previous iteration of this loop.
+                */
+               if(!flist_empty(&du->slavelist))
+                       log_info("  ");
+

                log_info("  %s: ios=%u/%u, merge=%u/%u, ticks=%u/%u, "
                         "in_queue=%u, util=%3.2f%%\n", du->name,
                                                dus->ios[0], dus->ios[1],
                log_info("  %s: ios=%u/%u, merge=%u/%u, ticks=%u/%u, "
                         "in_queue=%u, util=%3.2f%%\n", du->name,
                                                dus->ios[0], dus->ios[1],

diff --git a/fio.h b/fio.h
index 9131792f6548b8fc916349b1f62d1242e8cd6f67..63cd83f5e1be23d4548739a682947667f131533e 100644 (file)
--- a/fio.h
+++ b/fio.h
@@ -753,6 +753,10 @@ struct disk_util_stat {
  */
 struct disk_util {
        struct flist_head list;
  */
 struct disk_util {
        struct flist_head list;

+       /* If this disk is a slave, hook it into the master's
+        * list using this head.
+        */
+       struct flist_head slavelist;

 
        char *name;
        char *sysfs_root;
 
        char *name;
        char *sysfs_root;


@@ -762,6 +766,15 @@ struct disk_util {
        struct disk_util_stat dus;
        struct disk_util_stat last_dus;
 
        struct disk_util_stat dus;
        struct disk_util_stat last_dus;
 

+       /* For software raids, this entry maintains pointers to the
+        * entries for the slave devices. The disk_util entries for
+        * the slaves devices should primarily be maintained through
+        * the disk_list list, i.e. for memory allocation and
+        * de-allocation, etc. Whereas this list should be used only
+        * for aggregating a software RAID's disk util figures.
+        */
+       struct flist_head slaves;
+

        unsigned long msec;
        struct timeval time;
 };
        unsigned long msec;
        struct timeval time;
 };