b48542d914
Not all services involved in block I/O go through VM to access the blocks they need. As a result, the blocks in VM may become stale, possibly causing corruption when the stale copy is restored by a service that does go through VM later on. This patch restores support for forgetting cached blocks that belong to a particular device, and makes the relevant file systems use this functionality 1) when requested by VFS through REQ_FLUSH, and 2) upon unmount. Change-Id: I0758c5ed8fe4b5ba81d432595d2113175776aff8
77 lines
1.8 KiB
C
77 lines
1.8 KiB
C
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#include "syslib.h"
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#include <string.h>
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#include <assert.h>
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#include <sys/mman.h>
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#include <minix/vm.h>
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#include <minix/sysutil.h>
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#include <machine/vmparam.h>
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int vm_cachecall(message *m, int call, void *addr, u32_t dev, u64_t dev_offset,
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u64_t ino, u64_t ino_offset, u32_t *flags, int blocksize)
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{
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if(blocksize % PAGE_SIZE)
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panic("blocksize %d should be a multiple of pagesize %d\n",
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blocksize, PAGE_SIZE);
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if(ino_offset % PAGE_SIZE)
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panic("inode offset %lld should be a multiple of pagesize %d\n",
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ino_offset, PAGE_SIZE);
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if(dev_offset % PAGE_SIZE)
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panic("dev offset offset %lld should be a multiple of pagesize %d\n",
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dev_offset, PAGE_SIZE);
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memset(m, 0, sizeof(*m));
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assert(dev != NO_DEV);
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m->m_u.m_vmmcp.dev_offset_pages = dev_offset/PAGE_SIZE;
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m->m_u.m_vmmcp.ino_offset_pages = ino_offset/PAGE_SIZE;
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m->m_u.m_vmmcp.ino = ino;
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m->m_u.m_vmmcp.block = addr;
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m->m_u.m_vmmcp.flags_ptr = flags;
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m->m_u.m_vmmcp.dev = dev;
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m->m_u.m_vmmcp.pages = blocksize / PAGE_SIZE;
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m->m_u.m_vmmcp.flags = 0;
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return _taskcall(VM_PROC_NR, call, m);
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}
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void *vm_map_cacheblock(u32_t dev, u64_t dev_offset,
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u64_t ino, u64_t ino_offset, u32_t *flags, int blocksize)
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{
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message m;
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if(vm_cachecall(&m, VM_MAPCACHEPAGE, NULL, dev, dev_offset,
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ino, ino_offset, flags, blocksize) != OK)
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return MAP_FAILED;
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return m.m_u.m_vmmcp_reply.addr;
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}
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int vm_set_cacheblock(void *block, u32_t dev, u64_t dev_offset,
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u64_t ino, u64_t ino_offset, u32_t *flags, int blocksize)
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{
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message m;
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return vm_cachecall(&m, VM_SETCACHEPAGE, block, dev, dev_offset,
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ino, ino_offset, flags, blocksize);
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}
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int
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vm_clear_cache(u32_t dev)
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{
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message m;
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assert(dev != NO_DEV);
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memset(&m, 0, sizeof(m));
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m.m_u.m_vmmcp.dev = dev;
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return _taskcall(VM_PROC_NR, VM_CLEARCACHE, &m);
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}
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