NeilBrown: Grow: handle array going degraded during reshape.

[Martin F. Krafft]

Module: mdadm
Branch: master
Commit: d44453876eefa0aa4c6d2dc224cde3f501b051ff
URL:    http://git.debian.org/?p=pkg-mdadm/mdadm.git;a=commit;h=d44453876eefa0aa4c6d2dc224cde3f501b051ff

Author: NeilBrown <neilb at suse.de>
Date:   Fri Nov  6 13:56:05 2009 +1100

Grow: handle array going degraded during reshape.

If an array goes degraded during reshape, we need to
adjust the devices we read from so as not to back up
stale data.

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

---

 Grow.c |   41 +++++++++++++++++++++++++++++++++++------
 1 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/Grow.c b/Grow.c
index deff0e0..31007ae 100644
--- a/Grow.c
+++ b/Grow.c
@@ -1205,7 +1205,7 @@ int grow_backup(struct mdinfo *sra,
 		int *sources, unsigned long long *offsets,
 		int disks, int chunk, int level, int layout,
 		int dests, int *destfd, unsigned long long *destoffsets,
-		int part,
+		int part, int *degraded,
 		char *buf)
 {
 	/* Backup 'blocks' sectors at 'offset' on each device of the array,
@@ -1217,12 +1217,38 @@ int grow_backup(struct mdinfo *sra,
 	int odata = disks;
 	int rv = 0;
 	int i;
+	unsigned long long new_degraded;
 	//printf("offset %llu\n", offset);
 	if (level >= 4)
 		odata--;
 	if (level == 6)
 		odata--;
 	sysfs_set_num(sra, NULL, "suspend_hi", (offset + stripes * chunk/512) * odata);
+	/* Check that array hasn't become degraded, else we might backup the wrong data */
+	sysfs_get_ll(sra, NULL, "degraded", &new_degraded);
+	if (new_degraded != *degraded) {
+		/* check each device to ensure it is still working */
+		struct mdinfo *sd;
+		for (sd = sra->devs ; sd ; sd = sd->next) {
+			if (sd->disk.state & (1<<MD_DISK_FAULTY))
+				continue;
+			if (sd->disk.state & (1<<MD_DISK_SYNC)) {
+				char sbuf[20];
+				if (sysfs_get_str(sra, sd, "state", sbuf, 20) < 0 ||
+				    strstr(sbuf, "faulty") ||
+				    strstr(sbuf, "in_sync") == NULL) {
+					/* this device is dead */
+					sd->disk.state = (1<<MD_DISK_FAULTY);
+					if (sd->disk.raid_disk >= 0 &&
+					    sources[sd->disk.raid_disk] >= 0) {
+						close(sources[sd->disk.raid_disk]);
+						sources[sd->disk.raid_disk] = -1;
+					}
+				}
+			}
+		}
+		*degraded = new_degraded;
+	}
 	if (part) {
 		bsb.arraystart2 = __cpu_to_le64(offset * odata);
 		bsb.length2 = __cpu_to_le64(stripes * chunk/512 * odata);
@@ -1422,6 +1448,7 @@ static int child_grow(int afd, struct mdinfo *sra, unsigned long stripes,
 		      int dests, int *destfd, unsigned long long *destoffsets)
 {
 	char *buf;
+	int degraded = 0;
 
 	posix_memalign((void**)&buf, 4096, disks * chunk);
 	sysfs_set_num(sra, NULL, "suspend_hi", 0);
@@ -1429,7 +1456,7 @@ static int child_grow(int afd, struct mdinfo *sra, unsigned long stripes,
 	grow_backup(sra, 0, stripes,
 		    fds, offsets, disks, chunk, level, layout,
 		    dests, destfd, destoffsets,
-		    0, buf);
+		    0, &degraded, buf);
 	validate(afd, destfd[0], destoffsets[0]);
 	wait_backup(sra, 0, stripes * chunk / 512, stripes * chunk / 512,
 		    dests, destfd, destoffsets,
@@ -1449,6 +1476,7 @@ static int child_shrink(int afd, struct mdinfo *sra, unsigned long stripes,
 	char *buf;
 	unsigned long long start;
 	int rv;
+	int degraded = 0;
 
 	posix_memalign((void**)&buf, 4096, disks * chunk);
 	start = sra->component_size - stripes * chunk/512;
@@ -1464,7 +1492,7 @@ static int child_shrink(int afd, struct mdinfo *sra, unsigned long stripes,
 		    fds, offsets,
 		    disks, chunk, level, layout,
 		    dests, destfd, destoffsets,
-		    0, buf);
+		    0, &degraded, buf);
 	validate(afd, destfd[0], destoffsets[0]);
 	wait_backup(sra, start, stripes*chunk/512, 0,
 		    dests, destfd, destoffsets, 0);
@@ -1486,6 +1514,7 @@ static int child_same_size(int afd, struct mdinfo *sra, unsigned long stripes,
 	int part;
 	char *buf;
 	unsigned long long speed;
+	int degraded = 0;
 
 
 	posix_memalign((void**)&buf, 4096, disks * chunk);
@@ -1500,12 +1529,12 @@ static int child_same_size(int afd, struct mdinfo *sra, unsigned long stripes,
 		    fds, offsets,
 		    disks, chunk, level, layout,
 		    dests, destfd, destoffsets,
-		    0, buf);
+		    0, &degraded, buf);
 	grow_backup(sra, (start + stripes) * chunk/512, stripes,
 		    fds, offsets,
 		    disks, chunk, level, layout,
 		    dests, destfd, destoffsets,
-		    1, buf);
+		    1, &degraded, buf);
 	validate(afd, destfd[0], destoffsets[0]);
 	part = 0;
 	start += stripes * 2; /* where to read next */
@@ -1524,7 +1553,7 @@ static int child_same_size(int afd, struct mdinfo *sra, unsigned long stripes,
 			    fds, offsets,
 			    disks, chunk, level, layout,
 			    dests, destfd, destoffsets,
-			    part, buf);
+			    part, &degraded, buf);
 		start += stripes;
 		part = 1 - part;
 		validate(afd, destfd[0], destoffsets[0]);