61 lines
966 B
C
61 lines
966 B
C
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#include <u.h>
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#include <libc.h>
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#include <diskfs.h>
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typedef struct DiskPart DiskPart;
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struct DiskPart
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{
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Disk disk;
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Disk *subdisk;
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u64int offset;
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u64int size;
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};
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static Block*
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diskpartread(Disk *dd, u32int len, u64int offset)
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{
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DiskPart *d = (DiskPart*)dd;
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if(offset+len > d->size){
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werrstr("read past region %llud + %lud > %llud", offset, len, d->size);
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return nil;
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}
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return diskread(d->subdisk, len, offset+d->offset);
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}
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static int
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diskpartsync(Disk *dd)
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{
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DiskPart *d = (DiskPart*)dd;
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return disksync(d->subdisk);
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}
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static void
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diskpartclose(Disk *dd)
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{
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DiskPart *d = (DiskPart*)dd;
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diskclose(d->subdisk);
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free(d);
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}
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Disk*
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diskpart(Disk *subdisk, u64int size, u64int offset)
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{
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DiskPart *d;
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d = mallocz(sizeof(DiskPart), 1);
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if(d == nil)
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return nil;
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d->subdisk = subdisk;
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d->offset = offset;
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d->size = size;
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d->disk._read = diskpartread;
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d->disk._sync = diskpartsync;
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d->disk._close = diskpartclose;
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return &d->disk;
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}
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