Add 'restart' arg to various functions used for reshaping.

When we restart an array in the middle of a reshape, we reuse a lot of
the code for starting the reshape, but it needs to know that
circumstances are slightly different.

So add a 'restart' arg which is used:
 - skip checking and adding spares
 - activate the array (rather than start reshape)
 - allow the backup file to already exist

Signed-off-by: NeilBrown <neilb@suse.de>

diff --git a/Grow.c b/Grow.c
index 7665684733290aa9ebe31372422db9ca764fca4a..19ad1805e4ad9841e3b979a55db4615c098fd89d 100644 (file)
--- a/Grow.c
+++ b/Grow.c
@@ -792,7 +792,8 @@ int reshape_open_backup_file(char *backup_file,
                             char *devname,
                             long blocks,
                             int *fdlist,
-                            unsigned long long *offsets)
+                            unsigned long long *offsets,
+                            int restart)
 {
        /* Return 1 on success, 0 on any form of failure */
        /* need to check backup file is large enough */
@@ -801,7 +802,7 @@ int reshape_open_backup_file(char *backup_file,
        unsigned int dev;
        int i;
 
-       *fdlist = open(backup_file, O_RDWR|O_CREAT|O_EXCL,
+       *fdlist = open(backup_file, O_RDWR|O_CREAT|(restart ? O_TRUNC : O_EXCL),
                       S_IRUSR | S_IWUSR);
        *offsets = 8 * 512;
        if (*fdlist < 0) {
@@ -1245,7 +1246,8 @@ char *analyse_change(struct mdinfo *info, struct reshape *re)
 
 static int reshape_array(char *container, int fd, char *devname,
                         struct supertype *st, struct mdinfo *info,
-                        int force, char *backup_file, int quiet, int forked);
+                        int force, char *backup_file, int quiet, int forked,
+                        int restart);
 static int reshape_container(char *container, int cfd, char *devname,
                             struct supertype *st, 
                             struct mdinfo *info,
@@ -1564,7 +1566,7 @@ int Grow_reshape(char *devname, int fd, int quiet, char *backup_file,
                }
                sync_metadata(st);
                rv = reshape_array(container, fd, devname, st, &info, force,
-                                  backup_file, quiet, 0);
+                                  backup_file, quiet, 0, 0);
                frozen = 0;
        }
 release:
@@ -1576,7 +1578,8 @@ release:
 static int reshape_array(char *container, int fd, char *devname,
                         struct supertype *st, struct mdinfo *info,
                         int force,
-                        char *backup_file, int quiet, int forked)
+                        char *backup_file, int quiet, int forked,
+                        int restart)
 {
        struct reshape reshape;
        int spares_needed;
@@ -1607,6 +1610,13 @@ static int reshape_array(char *container, int fd, char *devname,
                dprintf("Canot get array information.\n");
                goto release;
        }
+
+       if (restart) {
+               /* reshape already started. just skip to monitoring the reshape */
+               if (reshape.backup_blocks == 0)
+                       return 0;
+               goto started;
+       }
        spares_needed = max(reshape.before.data_disks,
                            reshape.after.data_disks)
                + reshape.parity - array.raid_disks;
@@ -1752,7 +1762,7 @@ static int reshape_array(char *container, int fd, char *devname,
         *   -  request the shape change.
         *   -  fork to handle backup etc.
         */
-
+started:
        /* Check that we can hold all the data */
        get_dev_size(fd, NULL, &array_size);
        if (reshape.new_size < (array_size/512)) {
@@ -1829,7 +1839,7 @@ static int reshape_array(char *container, int fd, char *devname,
        } else {
                if (!reshape_open_backup_file(backup_file, fd, devname,
                                              (signed)blocks,
-                                             fdlist+d, offsets+d)) {
+                                             fdlist+d, offsets+d, restart)) {
                        goto release;
                }
                d++;
@@ -1861,7 +1871,9 @@ static int reshape_array(char *container, int fd, char *devname,
 
        sra->new_chunk = info->new_chunk;
        
-       if (info->array.chunk_size == info->new_chunk &&
+       if (info->reshape_active)
+               /* nothing needed here */;
+       else if (info->array.chunk_size == info->new_chunk &&
            reshape.before.layout == reshape.after.layout &&
            st->ss->external == 0) {
                array.raid_disks = reshape.after.data_disks + reshape.parity;
@@ -1908,6 +1920,8 @@ static int reshape_array(char *container, int fd, char *devname,
        }
 
        start_reshape(sra);
+       if (restart)
+               sysfs_set_str(sra, NULL, "array_state", "active");
 
        /* Now we just need to kick off the reshape and watch, while
         * handling backups of the data...
@@ -2121,7 +2135,7 @@ int reshape_container(char *container, int cfd, char *devname,
 
                rv = reshape_array(container, fd, adev, st,
                                   content, force,
-                                  backup_file, quiet, 1);
+                                  backup_file, quiet, 1, 0);
                close(fd);
                if (rv)
                        break;
@@ -3160,7 +3174,7 @@ int Grow_continue(int mdfd, struct supertype *st, struct mdinfo *info,
        int err = sysfs_set_str(info, NULL, "array_state", "readonly");
        if (err)
                return err;
-       return reshape_array(NULL, mdfd, "array", st, info, 1, backup_file, 0, 0);
+       return reshape_array(NULL, mdfd, "array", st, info, 1, backup_file, 0, 0, 1);
 }
 
 

diff --git a/mdadm.h b/mdadm.h
index f67120e5865b8adc36c68c64b71f529394b026db..a1a12bc70c01c076bd2008e220c876de94a4fb5f 100644 (file)
--- a/mdadm.h
+++ b/mdadm.h
@@ -492,7 +492,8 @@ extern int reshape_open_backup_file(char *backup,
                                    char *devname,
                                    long blocks,
                                    int *fdlist,
-                                   unsigned long long *offsets);
+                                   unsigned long long *offsets,
+                                   int restart);
 extern unsigned long compute_backup_blocks(int nchunk, int ochunk,
                                           unsigned int ndata, unsigned int odata);