diff mbox series

[7/9] btrfs: Add support for recovery for a RAID 5 btrfs profiles.

Message ID 20180927183504.18078-8-kreijack@libero.it (mailing list archive)
State New, archived
Headers show
Series [1/9] btrfs: Add support for reading a filesystem with a RAID 5 or RAID 6 profile. | expand

Commit Message

Goffredo Baroncelli Sept. 27, 2018, 6:35 p.m. UTC 
From: Goffredo Baroncelli <kreijack@inwind.it>

Add support for recovery for a RAID 5 btrfs profile. In addition
it is added some code as preparatory work for RAID 6 recovery code.

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
---
 grub-core/fs/btrfs.c | 160 +++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 155 insertions(+), 5 deletions(-)

Comments

Daniel Kiper Oct. 9, 2018, 6:20 p.m. UTC | #1 
On Thu, Sep 27, 2018 at 08:35:02PM +0200, Goffredo Baroncelli wrote:
> From: Goffredo Baroncelli <kreijack@inwind.it>
>
> Add support for recovery for a RAID 5 btrfs profile. In addition
> it is added some code as preparatory work for RAID 6 recovery code.
>
> Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
> ---
>  grub-core/fs/btrfs.c | 160 +++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 155 insertions(+), 5 deletions(-)
>
> diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
> index 554f350c5..db8df0eea 100644
> --- a/grub-core/fs/btrfs.c
> +++ b/grub-core/fs/btrfs.c
> @@ -29,6 +29,7 @@
>  #include <minilzo.h>
>  #include <grub/i18n.h>
>  #include <grub/btrfs.h>
> +#include <grub/crypto.h>
>
>  GRUB_MOD_LICENSE ("GPLv3+");
>
> @@ -665,6 +666,139 @@ btrfs_read_from_chunk (struct grub_btrfs_data *data,
>      return err;
>  }
>
> +struct raid56_buffer {
> +  void *buf;
> +  int  data_is_valid;
> +};
> +
> +static void
> +rebuild_raid5 (char *dest, struct raid56_buffer *buffers,
> +	       grub_uint64_t nstripes, grub_uint64_t csize)
> +{
> +  grub_uint64_t i;
> +  int first;
> +
> +  for(i = 0; buffers[i].data_is_valid && i < nstripes; i++);
> +
> +  if (i == nstripes)
> +    {
> +      grub_dprintf ("btrfs", "called rebuild_raid5(), but all disks are OK\n");
> +      return;
> +    }
> +
> +  grub_dprintf ("btrfs", "rebuilding RAID 5 stripe #%" PRIuGRUB_UINT64_T "\n", i);
> +
> +  for (i = 0, first = 1; i < nstripes; i++)
> +    {
> +      if (!buffers[i].data_is_valid)
> +	continue;
> +
> +      if (first) {
> +	grub_memcpy(dest, buffers[i].buf, csize);
> +	first = 0;
> +      } else
> +	grub_crypto_xor (dest, dest, buffers[i].buf, csize);
> +
> +    }
> +}
> +
> +static grub_err_t
> +raid56_read_retry (struct grub_btrfs_data *data,
> +		   struct grub_btrfs_chunk_item *chunk,
> +		   grub_uint64_t stripe_offset,
> +		   grub_uint64_t csize, void *buf)
> +{
> +  struct raid56_buffer *buffers;
> +  grub_uint64_t nstripes = grub_le_to_cpu16 (chunk->nstripes);
> +  grub_uint64_t chunk_type = grub_le_to_cpu64 (chunk->type);
> +  grub_err_t ret = GRUB_ERR_OUT_OF_MEMORY;
> +  grub_uint64_t i, failed_devices;
> +
> +  buffers = grub_zalloc (sizeof(*buffers) * nstripes);
> +  if (!buffers)
> +    goto cleanup;
> +
> +  for (i = 0; i < nstripes; i++)
> +    {
> +      buffers[i].buf = grub_zalloc (csize);
> +      if (!buffers[i].buf)
> +	goto cleanup;
> +    }
> +
> +  for (failed_devices = 0, i = 0; i < nstripes; i++)
> +    {
> +      struct grub_btrfs_chunk_stripe *stripe;
> +      grub_disk_addr_t paddr;
> +      grub_device_t dev;
> +      grub_err_t err;
> +
> +      stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1) + i;

I think that "chunk + 1" requires short comment why...

> +
> +      paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset;
> +      grub_dprintf ("btrfs", "reading paddr %" PRIxGRUB_UINT64_T
> +                    " from stripe ID %" PRIxGRUB_UINT64_T "\n", paddr,
> +                    stripe->device_id);
> +
> +      dev = find_device (data, stripe->device_id);
> +      if (!dev)
> +	{
> +	  buffers[i].data_is_valid = 0;
> +	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " FAILED (dev ID %"
> +			PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
> +	  failed_devices++;
> +	  continue;
> +	}
> +
> +      err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
> +			    paddr & (GRUB_DISK_SECTOR_SIZE - 1),
> +			    csize, buffers[i].buf);
> +      if (err == GRUB_ERR_NONE)
> +	{
> +	  buffers[i].data_is_valid = 1;
> +	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " Ok (dev ID %"
> +			PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
> +	}
> +      else
> +	{
> +	  buffers[i].data_is_valid = 0;
> +	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T
> +			" FAILED (dev ID %" PRIxGRUB_UINT64_T ")\n", i,
> +			stripe->device_id);
> +	  failed_devices++;
> +	}
> +    }
> +
> +  if (failed_devices > 1 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5))
> +    {
> +      grub_dprintf ("btrfs",
> +		    "not enough disks for RAID 5: total %" PRIuGRUB_UINT64_T
> +		    ", missing %" PRIuGRUB_UINT64_T "\n",
> +		    nstripes, failed_devices);
> +      ret = GRUB_ERR_READ_ERROR;
> +      goto cleanup;
> +    }
> +  else
> +    grub_dprintf ("btrfs",
> +		  "enough disks for RAID 5 rebuilding: total %"
> +		  PRIuGRUB_UINT64_T ", missing %" PRIuGRUB_UINT64_T "\n",
> +		  nstripes, failed_devices);
> +
> +  /* if these are enough, try to rebuild the data */
> +  if (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5)
> +    rebuild_raid5 (buf, buffers, nstripes, csize);
> +  else
> +    grub_dprintf ("btrfs", "called rebuild_raid6(), NOT IMPLEMENTED\n");
> +
> +  ret = GRUB_ERR_NONE;
> + cleanup:
> +  if (buffers)
> +    for (i = 0; i < nstripes; i++)
> +	grub_free(buffers[i].buf);
> +  grub_free(buffers);
> +
> +  return ret;
> +}
> +
>  static grub_err_t
>  grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
>  			 void *buf, grub_size_t size, int recursion_depth)
> @@ -742,6 +876,10 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
>  	grub_uint16_t nstripes;
>  	unsigned redundancy = 1;
>  	unsigned i, j;
> +	int is_raid56;
> +
> +	is_raid56 = !!(grub_le_to_cpu64 (chunk->type) &
> +		       GRUB_BTRFS_CHUNK_TYPE_RAID5);
>
>  	if (grub_le_to_cpu64 (chunk->size) <= off)
>  	  {
> @@ -922,17 +1060,29 @@ grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
>  	    grub_dprintf ("btrfs", "reading laddr 0x%" PRIxGRUB_UINT64_T "\n",
>  			  addr);
>
> -	    for (i = 0; i < redundancy; i++)
> +	    if (!is_raid56)

Why not "if (is_raid56)"? This looks more natural here.

> +	      for (i = 0; i < redundancy; i++)
> +		{
> +		  err = btrfs_read_from_chunk (data, chunk, stripen,
> +					       stripe_offset,
> +					       i,     /* redundancy */
> +					       csize, buf);
> +		  if (!err)
> +		    break;
> +		  grub_errno = GRUB_ERR_NONE;
> +		}
> +	    else
>  	      {
>  		err = btrfs_read_from_chunk (data, chunk, stripen,
>  					     stripe_offset,
> -					     i,     /* redundancy */
> +					     0,     /* no mirror */
>  					     csize, buf);
> -		if (!err)
> -		  break;
>  		grub_errno = GRUB_ERR_NONE;
> +		if (err != GRUB_ERR_NONE)

Please be consistent and use "if (err)" here.

> +		  err = raid56_read_retry (data, chunk, stripe_offset,
> +					   csize, buf);
>  	      }
> -	    if (i != redundancy)
> +	    if (err == GRUB_ERR_NONE)

if (!err) please...

Daniel
diff mbox series

Patch

diff --git a/grub-core/fs/btrfs.c b/grub-core/fs/btrfs.c
index 554f350c5..db8df0eea 100644
--- a/grub-core/fs/btrfs.c
+++ b/grub-core/fs/btrfs.c
@@ -29,6 +29,7 @@ 
 #include <minilzo.h>
 #include <grub/i18n.h>
 #include <grub/btrfs.h>
+#include <grub/crypto.h>
 
 GRUB_MOD_LICENSE ("GPLv3+");
 
@@ -665,6 +666,139 @@  btrfs_read_from_chunk (struct grub_btrfs_data *data,
     return err;
 }
 
+struct raid56_buffer {
+  void *buf;
+  int  data_is_valid;
+};
+
+static void
+rebuild_raid5 (char *dest, struct raid56_buffer *buffers,
+	       grub_uint64_t nstripes, grub_uint64_t csize)
+{
+  grub_uint64_t i;
+  int first;
+
+  for(i = 0; buffers[i].data_is_valid && i < nstripes; i++);
+
+  if (i == nstripes)
+    {
+      grub_dprintf ("btrfs", "called rebuild_raid5(), but all disks are OK\n");
+      return;
+    }
+
+  grub_dprintf ("btrfs", "rebuilding RAID 5 stripe #%" PRIuGRUB_UINT64_T "\n", i);
+
+  for (i = 0, first = 1; i < nstripes; i++)
+    {
+      if (!buffers[i].data_is_valid)
+	continue;
+
+      if (first) {
+	grub_memcpy(dest, buffers[i].buf, csize);
+	first = 0;
+      } else
+	grub_crypto_xor (dest, dest, buffers[i].buf, csize);
+
+    }
+}
+
+static grub_err_t
+raid56_read_retry (struct grub_btrfs_data *data,
+		   struct grub_btrfs_chunk_item *chunk,
+		   grub_uint64_t stripe_offset,
+		   grub_uint64_t csize, void *buf)
+{
+  struct raid56_buffer *buffers;
+  grub_uint64_t nstripes = grub_le_to_cpu16 (chunk->nstripes);
+  grub_uint64_t chunk_type = grub_le_to_cpu64 (chunk->type);
+  grub_err_t ret = GRUB_ERR_OUT_OF_MEMORY;
+  grub_uint64_t i, failed_devices;
+
+  buffers = grub_zalloc (sizeof(*buffers) * nstripes);
+  if (!buffers)
+    goto cleanup;
+
+  for (i = 0; i < nstripes; i++)
+    {
+      buffers[i].buf = grub_zalloc (csize);
+      if (!buffers[i].buf)
+	goto cleanup;
+    }
+
+  for (failed_devices = 0, i = 0; i < nstripes; i++)
+    {
+      struct grub_btrfs_chunk_stripe *stripe;
+      grub_disk_addr_t paddr;
+      grub_device_t dev;
+      grub_err_t err;
+
+      stripe = (struct grub_btrfs_chunk_stripe *) (chunk + 1) + i;
+
+      paddr = grub_le_to_cpu64 (stripe->offset) + stripe_offset;
+      grub_dprintf ("btrfs", "reading paddr %" PRIxGRUB_UINT64_T
+                    " from stripe ID %" PRIxGRUB_UINT64_T "\n", paddr,
+                    stripe->device_id);
+
+      dev = find_device (data, stripe->device_id);
+      if (!dev)
+	{
+	  buffers[i].data_is_valid = 0;
+	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " FAILED (dev ID %"
+			PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
+	  failed_devices++;
+	  continue;
+	}
+
+      err = grub_disk_read (dev->disk, paddr >> GRUB_DISK_SECTOR_BITS,
+			    paddr & (GRUB_DISK_SECTOR_SIZE - 1),
+			    csize, buffers[i].buf);
+      if (err == GRUB_ERR_NONE)
+	{
+	  buffers[i].data_is_valid = 1;
+	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T " Ok (dev ID %"
+			PRIxGRUB_UINT64_T ")\n", i, stripe->device_id);
+	}
+      else
+	{
+	  buffers[i].data_is_valid = 0;
+	  grub_dprintf ("btrfs", "stripe %" PRIuGRUB_UINT64_T
+			" FAILED (dev ID %" PRIxGRUB_UINT64_T ")\n", i,
+			stripe->device_id);
+	  failed_devices++;
+	}
+    }
+
+  if (failed_devices > 1 && (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5))
+    {
+      grub_dprintf ("btrfs",
+		    "not enough disks for RAID 5: total %" PRIuGRUB_UINT64_T
+		    ", missing %" PRIuGRUB_UINT64_T "\n",
+		    nstripes, failed_devices);
+      ret = GRUB_ERR_READ_ERROR;
+      goto cleanup;
+    }
+  else
+    grub_dprintf ("btrfs",
+		  "enough disks for RAID 5 rebuilding: total %"
+		  PRIuGRUB_UINT64_T ", missing %" PRIuGRUB_UINT64_T "\n",
+		  nstripes, failed_devices);
+
+  /* if these are enough, try to rebuild the data */
+  if (chunk_type & GRUB_BTRFS_CHUNK_TYPE_RAID5)
+    rebuild_raid5 (buf, buffers, nstripes, csize);
+  else
+    grub_dprintf ("btrfs", "called rebuild_raid6(), NOT IMPLEMENTED\n");
+
+  ret = GRUB_ERR_NONE;
+ cleanup:
+  if (buffers)
+    for (i = 0; i < nstripes; i++)
+	grub_free(buffers[i].buf);
+  grub_free(buffers);
+
+  return ret;
+}
+
 static grub_err_t
 grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
 			 void *buf, grub_size_t size, int recursion_depth)
@@ -742,6 +876,10 @@  grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
 	grub_uint16_t nstripes;
 	unsigned redundancy = 1;
 	unsigned i, j;
+	int is_raid56;
+
+	is_raid56 = !!(grub_le_to_cpu64 (chunk->type) &
+		       GRUB_BTRFS_CHUNK_TYPE_RAID5);
 
 	if (grub_le_to_cpu64 (chunk->size) <= off)
 	  {
@@ -922,17 +1060,29 @@  grub_btrfs_read_logical (struct grub_btrfs_data *data, grub_disk_addr_t addr,
 	    grub_dprintf ("btrfs", "reading laddr 0x%" PRIxGRUB_UINT64_T "\n",
 			  addr);
 
-	    for (i = 0; i < redundancy; i++)
+	    if (!is_raid56)
+	      for (i = 0; i < redundancy; i++)
+		{
+		  err = btrfs_read_from_chunk (data, chunk, stripen,
+					       stripe_offset,
+					       i,     /* redundancy */
+					       csize, buf);
+		  if (!err)
+		    break;
+		  grub_errno = GRUB_ERR_NONE;
+		}
+	    else
 	      {
 		err = btrfs_read_from_chunk (data, chunk, stripen,
 					     stripe_offset,
-					     i,     /* redundancy */
+					     0,     /* no mirror */
 					     csize, buf);
-		if (!err)
-		  break;
 		grub_errno = GRUB_ERR_NONE;
+		if (err != GRUB_ERR_NONE)
+		  err = raid56_read_retry (data, chunk, stripe_offset,
+					   csize, buf);
 	      }
-	    if (i != redundancy)
+	    if (err == GRUB_ERR_NONE)
 	      break;
 	  }
 	if (err)