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devices: simplify md superblock checking code

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This commit is contained in:
David Teigland 2019-09-19 12:17:36 -05:00
parent 23774f997e
commit 00c9a788cc
1 changed files with 59 additions and 78 deletions
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137
lib/device/dev-md.c
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@ -75,7 +75,7 @@ struct ddf_header {
char padding[472]; char padding[472];
}; };
static int _dev_has_ddf_magic(struct device *dev, uint64_t devsize_sectors) static int _dev_has_ddf_magic(struct device *dev, uint64_t devsize_sectors, uint64_t *sb_offset)
{ {
struct ddf_header hdr; struct ddf_header hdr;
uint32_t crc, our_crc; uint32_t crc, our_crc;
@ -99,8 +99,7 @@ static int _dev_has_ddf_magic(struct device *dev, uint64_t devsize_sectors)
if ((cpu_to_be32(our_crc) == crc) || if ((cpu_to_be32(our_crc) == crc) ||
(cpu_to_le32(our_crc) == crc)) { (cpu_to_le32(our_crc) == crc)) {
log_debug_devs("Found md ddf magic at %llu crc %x %s", *sb_offset = off;
(unsigned long long)off, crc, dev_name(dev));
return 1; return 1;
} else { } else {
log_debug_devs("Found md ddf magic at %llu wrong crc %x disk %x %s", log_debug_devs("Found md ddf magic at %llu wrong crc %x disk %x %s",
@ -123,8 +122,7 @@ static int _dev_has_ddf_magic(struct device *dev, uint64_t devsize_sectors)
if ((cpu_to_be32(our_crc) == crc) || if ((cpu_to_be32(our_crc) == crc) ||
(cpu_to_le32(our_crc) == crc)) { (cpu_to_le32(our_crc) == crc)) {
log_debug_devs("Found md ddf magic at %llu crc %x %s", *sb_offset = off;
(unsigned long long)off, crc, dev_name(dev));
return 1; return 1;
} else { } else {
log_debug_devs("Found md ddf magic at %llu wrong crc %x disk %x %s", log_debug_devs("Found md ddf magic at %llu wrong crc %x disk %x %s",
@ -136,46 +134,6 @@ static int _dev_has_ddf_magic(struct device *dev, uint64_t devsize_sectors)
return 0; return 0;
} }
/*
* Calculate the position of the superblock.
* It is always aligned to a 4K boundary and
* depending on minor_version, it can be:
* 0: At least 8K, but less than 12K, from end of device
* 1: At start of device
* 2: 4K from start of device.
*/
typedef enum {
MD_MINOR_VERSION_MIN,
MD_MINOR_V0 = MD_MINOR_VERSION_MIN,
MD_MINOR_V1,
MD_MINOR_V2,
MD_MINOR_VERSION_MAX = MD_MINOR_V2
} md_minor_version_t;
static uint64_t _v1_sb_offset(uint64_t size, md_minor_version_t minor_version)
{
uint64_t sb_offset;
switch(minor_version) {
case MD_MINOR_V0:
sb_offset = (size - 8 * 2) & ~(4 * 2 - 1ULL);
break;
case MD_MINOR_V1:
sb_offset = 0;
break;
case MD_MINOR_V2:
sb_offset = 4 * 2;
break;
default:
log_warn(INTERNAL_ERROR "WARNING: Unknown minor version %d.",
minor_version);
return 0;
}
sb_offset <<= SECTOR_SHIFT;
return sb_offset;
}
/* /*
* _udev_dev_is_md_component() only works if * _udev_dev_is_md_component() only works if
* external_device_info_source="udev" * external_device_info_source="udev"
@ -218,7 +176,6 @@ static int _udev_dev_is_md_component(struct device *dev)
*/ */
static int _native_dev_is_md_component(struct device *dev, uint64_t *offset_found, int full) static int _native_dev_is_md_component(struct device *dev, uint64_t *offset_found, int full)
{ {
md_minor_version_t minor;
uint64_t size, sb_offset; uint64_t size, sb_offset;
int ret; int ret;
@ -234,9 +191,9 @@ static int _native_dev_is_md_component(struct device *dev, uint64_t *offset_foun
return 0; return 0;
/* /*
* Old md versions locate the magic number at the end of the device. * Some md versions locate the magic number at the end of the device.
* Those checks can't be satisfied with the initial bcache data, and * Those checks can't be satisfied with the initial scan data, and
* would require an extra read i/o at the end of every device. Issuing * require an extra read i/o at the end of every device. Issuing
* an extra read to every device in every command, just to check for * an extra read to every device in every command, just to check for
* the old md format is a bad tradeoff. * the old md format is a bad tradeoff.
* *
@ -247,54 +204,78 @@ static int _native_dev_is_md_component(struct device *dev, uint64_t *offset_foun
* and set it for commands that could possibly write to an md dev * and set it for commands that could possibly write to an md dev
* (pvcreate/vgcreate/vgextend). * (pvcreate/vgcreate/vgextend).
*/ */
/*
* md superblock version 1.1 at offset 0 from start
*/
if (_dev_has_md_magic(dev, 0)) {
log_debug_devs("Found md magic number at offset 0 of %s.", dev_name(dev));
ret = 1;
goto out;
}
/*
* md superblock version 1.2 at offset 4KB from start
*/
if (_dev_has_md_magic(dev, 4096)) {
log_debug_devs("Found md magic number at offset 4096 of %s.", dev_name(dev));
ret = 1;
goto out;
}
if (!full) { if (!full) {
sb_offset = 0;
if (_dev_has_md_magic(dev, sb_offset)) {
log_debug_devs("Found md magic number at offset 0 of %s.", dev_name(dev));
ret = 1;
goto out;
}
sb_offset = 8 << SECTOR_SHIFT;
if (_dev_has_md_magic(dev, sb_offset)) {
log_debug_devs("Found md magic number at offset %d of %s.", (int)sb_offset, dev_name(dev));
ret = 1;
goto out;
}
ret = 0; ret = 0;
goto out; goto out;
} }
/* Version 0.90.0 */ /*
/* superblock at 64KB from end of device */ * Handle superblocks at the end of the device.
*/
/*
* md superblock version 0 at 64KB from end of device
* (after end is aligned to 64KB)
*/
sb_offset = MD_NEW_SIZE_SECTORS(size) << SECTOR_SHIFT; sb_offset = MD_NEW_SIZE_SECTORS(size) << SECTOR_SHIFT;
if (_dev_has_md_magic(dev, sb_offset)) { if (_dev_has_md_magic(dev, sb_offset)) {
log_debug_devs("Found md magic number at offset %llu of %s.", (unsigned long long)sb_offset, dev_name(dev));
ret = 1; ret = 1;
goto out; goto out;
} }
minor = MD_MINOR_VERSION_MIN; /*
* md superblock version 1.0 at 8KB from end of device
*/
/* Version 1, try v1.0 -> v1.2 */ sb_offset = ((size - 8 * 2) & ~(4 * 2 - 1ULL)) << SECTOR_SHIFT;
do { if (_dev_has_md_magic(dev, sb_offset)) {
/* superblock at start or 4K from start */ log_debug_devs("Found md magic number at offset %llu of %s.", (unsigned long long)sb_offset, dev_name(dev));
sb_offset = _v1_sb_offset(size, minor); ret = 1;
if (_dev_has_md_magic(dev, sb_offset)) { goto out;
ret = 1; }
goto out;
} /*
} while (++minor <= MD_MINOR_VERSION_MAX); * md imsm superblock 1K from end of device
*/
/* superblock 1K from end of device */
if (_dev_has_imsm_magic(dev, size)) { if (_dev_has_imsm_magic(dev, size)) {
log_debug_devs("Found md imsm magic number at offset %llu of %s.", (unsigned long long)sb_offset, dev_name(dev));
sb_offset = 1024;
ret = 1; ret = 1;
goto out; goto out;
} }
/* superblock 512 bytes from end, or 128KB from end */ /*
if (_dev_has_ddf_magic(dev, size)) { * md ddf superblock 512 bytes from end, or 128KB from end
*/
if (_dev_has_ddf_magic(dev, size, &sb_offset)) {
log_debug_devs("Found md ddf magic number at offset %llu of %s.", (unsigned long long)sb_offset, dev_name(dev));
ret = 1; ret = 1;
goto out; goto out;
} }