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fstype: make copy of first sector in /env to avoid unaligned reads on the disk (for devfs)

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devfs crypto partitions do not support unaligned reads,
so we make a copy of the first in /env/block and then
slice it to find filesystem signatures.

thanks mykhal for reporting the issue.
This commit is contained in:
cinap_lenrek 2018-02-07 18:18:32 +01:00
parent 650e5db5a2
commit d8999511e0
1 changed files with 6 additions and 6 deletions
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12
rc/bin/fstype
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@ -6,15 +6,16 @@ if(~ $"m 01CD00101){
echo 9660
exit
}
dd -if $1 -count 1 >/env/block >[2]/dev/null
fn fat {
m=`{dd -if $1 -bs 1 -count 3 -skip $2 >[2]/dev/null}
m=`{dd -if /env/block -bs 1 -count 3 -skip $1 >[2]/dev/null}
~ $"m FAT
}
if(fat $1 54 || fat $1 82){
if(fat 54 || fat 82){
echo dos
exit
}
m=`{dd -if $1 -bs 4 -count 1 >[2]/dev/null | xd | sed 's,0000000 ,,;q'}
m=`{dd -if /env/block -bs 4 -count 1 >[2]/dev/null | xd | sed 's,0000000 ,,;q'}
if(~ $"m 529ab12b){
echo paqfs
exit
@ -23,13 +24,12 @@ if(~ $"m 011ce50d){
echo hjfs
exit
}
m=`{dd -if $1 -bs 16 -count 1 -skip 16 >[2]/dev/null}
m=`{dd -if /env/block -bs 16 -count 1 -skip 16 >[2]/dev/null}
if(~ $"m 'kfs wren device'){
echo kfs
exit
}
dd -if $1 -count 1 >[2]/dev/null | \
awk '
</env/block awk '
/^(blocksize|daddrbits|daddrbits|indirblks|dirblks|namelen)/{p[$1]=$2}
END{
ca["fs", "blocksize"] = 4*1024