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* grub-core/fs/zfs/zfs.c (read_device): Add ability to sustain a single

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drive failure on both raidz and raidz2.
This commit is contained in:
Vladimir 'phcoder' Serbinenko 2011-11-02 23:28:25 +01:00
parent aca5aefc7c
commit 177440046d
2 changed files with 71 additions and 34 deletions
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5
ChangeLog
View file

@ -1,3 +1,8 @@
2011-11-02 Vladimir Serbinenko <phcoder@gmail.com>
* grub-core/fs/zfs/zfs.c (read_device): Add ability to sustain a single
drive failure on both raidz and raidz2.
2011-11-02 Vladimir Serbinenko <phcoder@gmail.com>
Fix RAIDZ(2) for >= 5 devices.

94
grub-core/fs/zfs/zfs.c
View file

@ -850,6 +850,14 @@ scan_devices (struct grub_zfs_data *data)
return GRUB_ERR_NONE;
}
static inline void
xor (grub_uint64_t *a, const grub_uint64_t *b, grub_size_t s)
{
s /= sizeof (grub_uint64_t);
while (s--)
*a++ ^= *b++;
}
static grub_err_t
read_device (grub_uint64_t offset, struct grub_zfs_device_desc *desc,
grub_size_t len, void *buf)
@ -889,40 +897,26 @@ read_device (grub_uint64_t offset, struct grub_zfs_device_desc *desc,
unsigned c = 0;
grub_uint64_t high;
grub_uint64_t devn;
grub_uint64_t redundancy_strip = 0, m;
grub_uint64_t redundancy_strip2 = 0;
grub_uint32_t s;
grub_uint64_t m;
grub_uint32_t s, orig_s;
void *orig_buf = buf;
grub_size_t orig_len = len;
void *recovery_buf = NULL;
grub_size_t recovery_len = 0;
if (desc->nparity < 1 || desc->nparity > 2)
return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,
"raidz%d is not supported", desc->nparity);
s = (((len + (1 << desc->ashift) - 1) >> desc->ashift)
orig_s = (((len + (1 << desc->ashift) - 1) >> desc->ashift)
+ (desc->n_children - desc->nparity) - 1);
s = orig_s;
high = grub_divmod64 ((offset >> desc->ashift),
desc->n_children, &m);
switch (desc->nparity)
{
case 1:
redundancy_strip = m;
redundancy_strip += ((offset >> (desc->ashift + 11)) & 1);
if (redundancy_strip == desc->n_children)
redundancy_strip = 0;
redundancy_strip2 = redundancy_strip;
break;
case 2:
redundancy_strip = m;
redundancy_strip2 = m + 1;
if (redundancy_strip2 == desc->n_children)
redundancy_strip2 = 0;
break;
}
grub_dprintf ("zfs", "rs = %x, %llx\n",
(int) redundancy_strip,
(unsigned long long) high);
if (desc->nparity == 2)
c = 2;
while (len > 0)
{
grub_size_t csize;
@ -930,15 +924,12 @@ read_device (grub_uint64_t offset, struct grub_zfs_device_desc *desc,
grub_err_t err;
bsize = s / (desc->n_children - desc->nparity);
while (1)
{
if (desc->nparity == 1
&& ((offset >> (desc->ashift + 11)) & 1) == c)
c++;
high = grub_divmod64 ((offset >> desc->ashift) + c,
desc->n_children, &devn);
if (devn != redundancy_strip && devn != redundancy_strip2)
break;
c++;
}
csize = bsize << desc->ashift;
if (csize > len)
csize = len;
@ -953,6 +944,13 @@ read_device (grub_uint64_t offset, struct grub_zfs_device_desc *desc,
| (offset & ((1 << desc->ashift) - 1)),
&desc->children[devn],
csize, buf);
/* No raidz2 recovery yet. */
if (err && recovery_len == 0)
{
recovery_buf = buf;
recovery_len = csize;
grub_errno = err = 0;
}
if (err)
return err;
@ -961,9 +959,43 @@ read_device (grub_uint64_t offset, struct grub_zfs_device_desc *desc,
buf = (char *) buf + csize;
len -= csize;
}
if (recovery_buf)
{
grub_err_t err;
high = grub_divmod64 ((offset >> desc->ashift)
+
((desc->nparity == 1)
&& ((offset >> (desc->ashift + 11)) & 1)),
desc->n_children, &devn);
err = read_device ((high << desc->ashift)
| (offset & ((1 << desc->ashift) - 1)),
&desc->children[devn],
recovery_len, recovery_buf);
if (err)
return err;
buf = orig_buf;
len = orig_len;
s = orig_s;
while (len > 0)
{
grub_size_t csize;
csize = ((s / (desc->n_children - desc->nparity))
<< desc->ashift);
if (csize > len)
csize = len;
if (buf != recovery_buf)
xor (recovery_buf, buf,
csize < recovery_len ? csize : recovery_len);
s--;
buf = (char *) buf + csize;
len -= csize;
}
}
return GRUB_ERR_NONE;
}
}
return grub_error (GRUB_ERR_BAD_FS, "unsupported device type");
}