sysfs: allow sysfs_read to detect and drop removed disks

All operations that rely on loading from an existing container (like
--add) will fail after a disk has been removed.  Provide an option to
skip missing / offline disks rather than abort.  We attempt to do this
in the load_super_{imsm,ddf}_all cases when mdmon is running i.e. we
already have a consitent version of the metadata running in the system.
Otherwise, we fail as normal and let the administrator fix up the
container.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

diff --git a/mdadm.h b/mdadm.h
index 5be3affe073a9c2e425c1116543bd6c86d9d12fa..f8f3685963ecc980967457213ee795b15a434709 100644 (file)
--- a/mdadm.h
+++ b/mdadm.h
@@ -334,22 +334,24 @@ extern int map_lock(struct map_ent **melp);
 extern void map_unlock(struct map_ent **melp);
 
 /* various details can be requested */
 extern void map_unlock(struct map_ent **melp);
 
 /* various details can be requested */

-#define        GET_LEVEL       1
-#define        GET_LAYOUT      2
-#define        GET_COMPONENT   4
-#define        GET_CHUNK       8
-#define GET_CACHE      16
-#define        GET_MISMATCH    32
-#define        GET_VERSION     64
-#define        GET_DISKS       128
-#define        GET_DEGRADED    256
-#define        GET_SAFEMODE    512
-
-#define        GET_DEVS        1024 /* gets role, major, minor */
-#define        GET_OFFSET      2048
-#define        GET_SIZE        4096
-#define        GET_STATE       8192
-#define        GET_ERROR       16384
+enum sysfs_read_flags {
+       GET_LEVEL       = (1 << 0),
+       GET_LAYOUT      = (1 << 1),
+       GET_COMPONENT   = (1 << 2),
+       GET_CHUNK       = (1 << 3),
+       GET_CACHE       = (1 << 4),
+       GET_MISMATCH    = (1 << 5),
+       GET_VERSION     = (1 << 6),
+       GET_DISKS       = (1 << 7),
+       GET_DEGRADED    = (1 << 8),
+       GET_SAFEMODE    = (1 << 9),
+       GET_DEVS        = (1 << 10), /* gets role, major, minor */
+       GET_OFFSET      = (1 << 11),
+       GET_SIZE        = (1 << 12),
+       GET_STATE       = (1 << 13),
+       GET_ERROR       = (1 << 14),
+       SKIP_GONE_DEVS  = (1 << 15),
+};

 
 /* If fd >= 0, get the array it is open on,
  * else use devnum. >=0 -> major9. <0.....
 
 /* If fd >= 0, get the array it is open on,
  * else use devnum. >=0 -> major9. <0.....

diff --git a/super-ddf.c b/super-ddf.c
index f621f4df3922ac43b5932a16a7e40cc982006538..6c75998e90703566b79b6d787d65276a6a24264b 100644 (file)
--- a/super-ddf.c
+++ b/super-ddf.c
@@ -2734,8 +2734,14 @@ static int load_super_ddf_all(struct supertype *st, int fd,
        int seq;
        char nm[20];
        int dfd;
        int seq;
        char nm[20];
        int dfd;

+       int devnum = fd2devnum(fd);
+       enum sysfs_read_flags flags;

 
 

-       sra = sysfs_read(fd, 0, GET_LEVEL|GET_VERSION|GET_DEVS|GET_STATE);
+       flags = GET_LEVEL|GET_VERSION|GET_DEVS|GET_STATE;
+       if (mdmon_running(devnum))
+               flags |= SKIP_GONE_DEVS;
+
+       sra = sysfs_read(fd, 0, flags);

        if (!sra)
                return 1;
        if (sra->array.major_version != -1 ||
        if (!sra)
                return 1;
        if (sra->array.major_version != -1 ||

diff --git a/super-intel.c b/super-intel.c
index f55d707667b17baa47b31172eea02a8e8f78ffa6..dd69cb133f03961341d89df0b780baa316b9ba17 100644 (file)
--- a/super-intel.c
+++ b/super-intel.c
@@ -1976,9 +1976,14 @@ static int load_super_imsm_all(struct supertype *st, int fd, void **sbp,
        int rv;
        int devnum = fd2devnum(fd);
        int retry;
        int rv;
        int devnum = fd2devnum(fd);
        int retry;

+       enum sysfs_read_flags flags;

 
 

-       /* check if this disk is a member of an active array */
-       sra = sysfs_read(fd, 0, GET_LEVEL|GET_VERSION|GET_DEVS|GET_STATE);
+       flags = GET_LEVEL|GET_VERSION|GET_DEVS|GET_STATE;
+       if (mdmon_running(devnum))
+               flags |= SKIP_GONE_DEVS;
+
+       /* check if 'fd' an opened container */
+       sra = sysfs_read(fd, 0, flags);

        if (!sra)
                return 1;
 
        if (!sra)
                return 1;
 

diff --git a/sysfs.c b/sysfs.c
index b9fd3da95d37a80bb303583cf4bf0eb78ebf34e2..2dad7d3fd8c9969aefc636ce46213576aa4e85b1 100644 (file)
--- a/sysfs.c
+++ b/sysfs.c
@@ -272,18 +272,34 @@ struct mdinfo *sysfs_read(int fd, int devnum, unsigned long options)
                        }
                        
                }
                        }
                        
                }

-               dev->next = sra->devs;
-               sra->devs = dev;
-

                strcpy(dev->sys_name, de->d_name);
                dev->disk.raid_disk = strtoul(buf, &ep, 10);
                if (*ep) dev->disk.raid_disk = -1;
 
                strcpy(dbase, "block/dev");
                strcpy(dev->sys_name, de->d_name);
                dev->disk.raid_disk = strtoul(buf, &ep, 10);
                if (*ep) dev->disk.raid_disk = -1;
 
                strcpy(dbase, "block/dev");

-               if (load_sys(fname, buf))
-                       goto abort;
+               if (load_sys(fname, buf)) {
+                       free(dev);
+                       if (options & SKIP_GONE_DEVS)
+                               continue;
+                       else
+                               goto abort;
+               }

                sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 
                sscanf(buf, "%d:%d", &dev->disk.major, &dev->disk.minor);
 

+               /* special case check for block devices that can go 'offline' */
+               if (options & SKIP_GONE_DEVS) {
+                       strcpy(dbase, "block/device/state");
+                       if (load_sys(fname, buf) == 0 &&
+                           strncmp(buf, "offline", 7) == 0) {
+                               free(dev);
+                               continue;
+                       }
+               }
+
+               /* finally add this disk to the array */
+               dev->next = sra->devs;
+               sra->devs = dev;
+

                if (options & GET_OFFSET) {
                        strcpy(dbase, "offset");
                        if (load_sys(fname, buf))
                if (options & GET_OFFSET) {
                        strcpy(dbase, "offset");
                        if (load_sys(fname, buf))