geom_label: Partially reinstate old sysinstall(8) workaround
This partially reverts commit af433832f7
.
Since such bogus disklabels still exist in the wild, we now probe for a
disklabel to decide whether to ignore the UFS partition or not; if there
is a label then we use the old behaviour, and if there isn't one then we
use the new behaviour.
Reviewed by: cy, mckusick
Differential Revision: https://reviews.freebsd.org/D31068
This commit is contained in:
parent
b684d812fc
commit
e77ef47d36
@ -32,6 +32,7 @@ __FBSDID("$FreeBSD$");
|
||||
|
||||
#include <sys/param.h>
|
||||
#include <sys/systm.h>
|
||||
#include <sys/disklabel.h>
|
||||
#include <sys/malloc.h>
|
||||
#include <sys/vnode.h>
|
||||
|
||||
@ -48,6 +49,81 @@ __FBSDID("$FreeBSD$");
|
||||
#define G_LABEL_UFS_VOLUME 0
|
||||
#define G_LABEL_UFS_ID 1
|
||||
|
||||
/*
|
||||
* G_LABEL_UFS_CMP returns true if difference between provider mediasize
|
||||
* and filesystem size is less than G_LABEL_UFS_MAXDIFF sectors
|
||||
*/
|
||||
#define G_LABEL_UFS_CMP(prov, fsys, size) \
|
||||
( abs( ((fsys)->size) - ( (prov)->mediasize / (fsys)->fs_fsize )) \
|
||||
< G_LABEL_UFS_MAXDIFF )
|
||||
#define G_LABEL_UFS_MAXDIFF 0x100
|
||||
|
||||
/*
|
||||
* For providers that look like disklabels we need to check if the file system
|
||||
* size is almost equal to the provider's size, because sysinstall(8) used to
|
||||
* bogusly put the first partition at offset 0 instead of 16, and glabel/ufs
|
||||
* would find a file system on the slice instead of the partition.
|
||||
*
|
||||
* In addition, media size can be a bit bigger than file system size. For
|
||||
* instance, mkuzip can append bytes to align data to large sector size (it
|
||||
* improves compression rates).
|
||||
*/
|
||||
static bool
|
||||
g_label_ufs_ignore_bsdlabel_slice(struct g_consumer *cp,
|
||||
struct fs *fs)
|
||||
{
|
||||
struct g_provider *pp;
|
||||
u_char *buf;
|
||||
uint32_t magic1, magic2;
|
||||
int error;
|
||||
|
||||
pp = cp->provider;
|
||||
|
||||
/*
|
||||
* If the expected provider size for the filesystem matches the
|
||||
* real provider size then don't ignore this filesystem.
|
||||
*/
|
||||
if (G_LABEL_UFS_CMP(pp, fs, fs_providersize))
|
||||
return (false);
|
||||
|
||||
/*
|
||||
* If the filesystem size matches the real provider size then
|
||||
* don't ignore this filesystem.
|
||||
*/
|
||||
if (fs->fs_magic == FS_UFS1_MAGIC ?
|
||||
G_LABEL_UFS_CMP(pp, fs, fs_old_size) :
|
||||
G_LABEL_UFS_CMP(pp, fs, fs_size))
|
||||
return (false);
|
||||
|
||||
/*
|
||||
* Provider is bigger than expected; probe to see if there's a
|
||||
* disklabel. Adapted from g_part_bsd_probe.
|
||||
*/
|
||||
|
||||
/* Check if the superblock overlaps where the disklabel lives. */
|
||||
if (fs->fs_sblockloc < pp->sectorsize * 2)
|
||||
return (false);
|
||||
|
||||
/* Sanity-check the provider. */
|
||||
if (pp->sectorsize < sizeof(struct disklabel) ||
|
||||
pp->mediasize < BBSIZE)
|
||||
return (false);
|
||||
if (BBSIZE % pp->sectorsize)
|
||||
return (false);
|
||||
|
||||
/* Check that there's a disklabel. */
|
||||
buf = g_read_data(cp, pp->sectorsize, pp->sectorsize, &error);
|
||||
if (buf == NULL)
|
||||
return (false);
|
||||
magic1 = le32dec(buf + 0);
|
||||
magic2 = le32dec(buf + 132);
|
||||
g_free(buf);
|
||||
if (magic1 == DISKMAGIC && magic2 == DISKMAGIC)
|
||||
return (true);
|
||||
|
||||
return (false);
|
||||
}
|
||||
|
||||
/*
|
||||
* Try to find a superblock on the provider. If successful, look for a volume
|
||||
* label and create an appropriate provider based on that.
|
||||
@ -78,6 +154,9 @@ g_label_ufs_taste_common(struct g_consumer *cp, char *label, size_t size, int wh
|
||||
} else {
|
||||
goto out;
|
||||
}
|
||||
/* Check if this should be ignored for compatibility. */
|
||||
if (g_label_ufs_ignore_bsdlabel_slice(cp, fs))
|
||||
goto out;
|
||||
G_LABEL_DEBUG(1, "%s file system detected on %s.",
|
||||
fs->fs_magic == FS_UFS1_MAGIC ? "UFS1" : "UFS2", pp->name);
|
||||
switch (what) {
|
||||
|
Loading…
Reference in New Issue
Block a user