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disk cache: support for sector sizes other than 512 bytes

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git-svn-id: svn://kolibrios.org@5089 a494cfbc-eb01-0410-851d-a64ba20cac60
This commit is contained in:
CleverMouse 2014-09-03 12:11:19 +00:00
parent 99959f9109
commit 9d022746fd
6 changed files with 176 additions and 125 deletions
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32
kernel/trunk/blkdev/disk.inc
View File

@ -108,6 +108,7 @@ struct DISKCACHE
data dd ?
sad_size dd ?
search_start dd ?
sector_size_log dd ?
ends
; This structure represents a disk device and its media for the kernel.
@ -271,13 +272,13 @@ disk_list_mutex MUTEX
endg
iglobal
; The function 'disk_scan_partitions' needs three 512-byte buffers for
; The function 'disk_scan_partitions' needs three sector-sized buffers for
; MBR, bootsector and fs-temporary sector data. It can not use the static
; buffers always, since it can be called for two or more disks in parallel.
; However, this case is not typical. We reserve three static 512-byte buffers
; and a flag that these buffers are currently used. If 'disk_scan_partitions'
; detects that the buffers are currently used, it allocates buffers from the
; heap.
; heap. Also, the heap is used when sector size is other than 512.
; The flag is implemented as a global dword variable. When the static buffers
; are not used, the value is -1. When the static buffers are used, the value
; is normally 0 and temporarily can become greater. The function increments
@ -638,28 +639,25 @@ disk_scan_partitions:
; 1. Initialize .NumPartitions and .Partitions fields as zeros: empty list.
and [esi+DISK.NumPartitions], 0
and [esi+DISK.Partitions], 0
; 2. Currently we can work only with 512-bytes sectors. Check this restriction.
; The only exception is 2048-bytes CD/DVD, but they are not supported yet by
; this code.
cmp [esi+DISK.MediaInfo.SectorSize], 512
jz .doscan
DEBUGF 1,'K : sector size is %d, only 512 is supported\n',[esi+DISK.MediaInfo.SectorSize]
ret
.doscan:
; 3. Acquire the buffer for MBR and bootsector tests. See the comment before
; 2. Acquire the buffer for MBR and bootsector tests. See the comment before
; the 'partition_buffer_users' variable.
mov eax, [esi+DISK.MediaInfo.SectorSize]
cmp eax, 512
jnz @f
mov ebx, mbr_buffer ; assume the global buffer is free
lock inc [partition_buffer_users]
jz .buffer_acquired ; yes, it is free
lock dec [partition_buffer_users] ; no, we must allocate
stdcall kernel_alloc, 512*3
@@:
lea eax, [eax*3]
stdcall kernel_alloc, eax
test eax, eax
jz .nothing
xchg eax, ebx
.buffer_acquired:
; MBR/EBRs are organized in the chain. We use a loop over MBR/EBRs, but no
; more than MAX_NUM_PARTITION times.
; 4. Prepare things for the loop.
; 3. Prepare things for the loop.
; ebp will hold the sector number for current MBR/EBR.
; [esp] will hold the sector number for current extended partition, if there
; is one.
@ -668,6 +666,10 @@ disk_scan_partitions:
push MAX_NUM_PARTITIONS ; the counter of max MBRs to process
xor ebp, ebp ; start from sector zero
push ebp ; no extended partition yet
; 4. MBR is 512 bytes long. If sector size is less than 512 bytes,
; assume no MBR, no partitions and go to 10.
cmp [esi+DISK.MediaInfo.SectorSize], 512
jb .notmbr
.new_mbr:
; 5. Read the current sector.
; Note that 'read' callback operates with 64-bit sector numbers, so we must
@ -986,7 +988,7 @@ end virtual
; a three-sectors-sized buffer. This function saves ebx in the stack
; immediately before ebp.
mov ebx, [ebp-4] ; get buffer
add ebx, 512 ; advance over MBR data to bootsector data
add ebx, [esi+DISK.MediaInfo.SectorSize] ; advance over MBR data to bootsector data
add ebp, 8 ; ebp points to part of PARTITION structure
xor eax, eax ; first sector of the partition
call fs_read32_sys
@ -997,7 +999,7 @@ end virtual
; ebp -> first three fields of PARTITION structure, .start, .length, .disk;
; [esp] = error code after bootsector read: 0 = ok, otherwise = failed,
; ebx points to the buffer for bootsector,
; ebx+512 points to 512-bytes buffer that can be used for anything.
; ebx+[esi+DISK.MediaInfo.SectorSize] points to sector-sized buffer that can be used for anything.
call fat_create_partition
test eax, eax
jnz .success

260
kernel/trunk/blkdev/disk_cache.inc
View File

@ -118,7 +118,6 @@ end virtual
add [.sector_lo], eax
adc [.sector_hi], edx
; 5. If the cache is disabled, pass the request directly to the driver.
mov edi, [.buffer]
cmp [ebx+DISKCACHE.pointer], 0
jz .nocache
; 6. Look for sectors in the cache, sequentially from the beginning.
@ -137,13 +136,15 @@ end virtual
; release the lock and go to 7.
jc .not_found_in_cache
; The sector is found in cache.
; 6d. Copy data for the caller.
; Note that buffer in edi is advanced automatically.
mov esi, ecx
shl esi, 9
add esi, [ebx+DISKCACHE.data]
mov ecx, 512/4
; 6d. Copy data for the caller, advance [.buffer].
mov esi, edi
mov edi, [.buffer]
mov eax, 1
shl eax, cl
mov ecx, eax
shr ecx, 2
rep movsd
mov [.buffer], edi
; 6e. Advance the sector.
add [.sector_lo], 1
adc [.sector_hi], 0
@ -177,6 +178,7 @@ end virtual
; However, for extra-large requests make an upper limit:
; do not use more than half of the free memory
; or more than CACHE_MAX_ALLOC_SIZE bytes.
mov ecx, [ebx+DISKCACHE.sector_size_log]
mov ebx, [pg_data.pages_free]
shr ebx, 1
jz .nomemory
@ -184,13 +186,15 @@ end virtual
jbe @f
mov ebx, CACHE_MAX_ALLOC_SIZE shr 12
@@:
shl ebx, 12 - 9
shl ebx, 12
shr ebx, cl
jz .nomemory
cmp ebx, [.num_sectors]
jbe @f
mov ebx, [.num_sectors]
@@:
mov eax, ebx
shl eax, 9
shl eax, cl
stdcall kernel_alloc, eax
; If failed, return the appropriate error code.
test eax, eax
@ -233,28 +237,31 @@ end virtual
jz @f
mov [.error_code+.local_vars2_size], eax
@@:
; 11. Copy data for the caller.
; Note that buffer in edi is advanced automatically.
; 11. Copy data for the caller, advance .buffer.
cmp [.current_num_sectors], 0
jz .copy_done
mov ecx, [.current_num_sectors]
shl ecx, 9-2
mov ebx, [.cache+.local_vars2_size]
mov eax, [.current_num_sectors]
mov ecx, [ebx+DISKCACHE.sector_size_log]
shl eax, cl
mov esi, [.allocated_buffer]
mov edi, [.buffer+.local_vars2_size]
mov ecx, eax
shr ecx, 2
rep movsd
mov [.buffer+.local_vars2_size], edi
; 12. Copy data to the cache.
; 12a. Acquire the lock.
mov ebx, [.cache+.local_vars2_size]
mov ecx, [ebp+PARTITION.Disk]
add ecx, DISK.CacheLock
call mutex_lock
; 12b. Prepare for the loop: save edi and create a local variable that
; 12b. Prepare for the loop: create a local variable that
; stores number of sectors to be copied.
push edi
push [.current_num_sectors+4]
push [.current_num_sectors]
.store_to_cache:
; 12c. For each sector, call the lookup function with adding to the cache, if not yet.
mov eax, [.sector_lo+.local_vars2_size+8]
mov edx, [.sector_hi+.local_vars2_size+8]
mov eax, [.sector_lo+.local_vars2_size+4]
mov edx, [.sector_hi+.local_vars2_size+4]
call cache_lookup_write
test eax, eax
jnz .cache_error
@ -263,39 +270,39 @@ end virtual
; so rewrite data for the caller from the cache.
cmp [esi+CACHE_ITEM.Status], CACHE_ITEM_MODIFIED
jnz .not_modified
mov esi, ecx
shl esi, 9
add esi, [ebx+DISKCACHE.data]
mov edi, [esp+4]
mov ecx, [esp]
shl ecx, 9-2
sub edi, ecx
mov ecx, 512/4
mov esi, edi
mov edi, [.buffer+.local_vars2_size+4]
mov eax, [esp]
shl eax, cl
sub edi, eax
mov eax, 1
shl eax, cl
mov ecx, eax
shr ecx, 2
rep movsd
add [.current_buffer+8], 512
add [.current_buffer+4], eax
jmp .sector_done
.not_modified:
; 12e. For each not-modified sector,
; copy data, mark the item as not-modified copy of the disk,
; advance .current_buffer and .sector_hi:.sector_lo to the next sector.
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_COPY
mov esi, [.current_buffer+8]
mov edi, ecx
shl edi, 9
add edi, [ebx+DISKCACHE.data]
mov ecx, 512/4
mov eax, 1
shl eax, cl
mov esi, [.current_buffer+4]
mov ecx, eax
shr ecx, 2
rep movsd
mov [.current_buffer+8], esi
mov [.current_buffer+4], esi
.sector_done:
add [.sector_lo+.local_vars2_size+8], 1
adc [.sector_hi+.local_vars2_size+8], 0
add [.sector_lo+.local_vars2_size+4], 1
adc [.sector_hi+.local_vars2_size+4], 0
; 12f. Continue the loop 12c-12e until all sectors are read.
dec dword [esp]
jnz .store_to_cache
.cache_error:
; 12g. Restore after the loop: pop the local variable and restore edi.
; 12g. Restore after the loop: pop the local variable.
pop ecx
pop edi
; 12h. Release the lock.
mov ecx, [ebp+PARTITION.Disk]
add ecx, DISK.CacheLock
@ -328,7 +335,7 @@ end virtual
push eax ; numsectors
push [.sector_hi+4] ; startsector
push [.sector_lo+8] ; startsector
push edi ; buffer
push [.buffer+12] ; buffer
mov esi, [ebp+PARTITION.Disk]
mov al, DISKFUNC.read
call disk_call_driver
@ -440,11 +447,11 @@ end virtual
; 6c. For each sector, copy data, mark the item as modified and not saved,
; advance .current_buffer to the next sector.
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_MODIFIED
mov eax, 1
shl eax, cl
mov esi, [.cur_buffer]
mov edi, ecx
shl edi, 9
add edi, [ebx+DISKCACHE.data]
mov ecx, 512/4
mov ecx, eax
shr ecx, 2
rep movsd
mov [.cur_buffer], esi
; 6d. Remove the sector from the other cache.
@ -592,11 +599,12 @@ end virtual
jc .not_found_in_cache
.found_in_cache:
; 4c. Copy the data.
mov esi, edi
mov edi, [.buffer]
mov esi, ecx
shl esi, 9
add esi, [ebx+DISKCACHE.data]
mov ecx, 512/4
mov eax, 1
shl eax, cl
mov ecx, eax
shr ecx, 2
rep movsd
; 4d. Release the lock and return success.
mov ecx, [ebp+PARTITION.Disk]
@ -627,7 +635,10 @@ end virtual
add ecx, DISK.CacheLock
call mutex_unlock
; 7. Allocate buffer for CACHE_LEGACY_READ_SIZE sectors.
stdcall kernel_alloc, CACHE_LEGACY_READ_SIZE shl 9
mov eax, CACHE_LEGACY_READ_SIZE
mov ecx, [ebx+DISKCACHE.sector_size_log]
shl eax, cl
stdcall kernel_alloc, eax
; If failed, return the corresponding error code.
test eax, eax
jz .nomemory
@ -656,7 +667,11 @@ end virtual
; 10. Copy data for the caller.
mov esi, [.allocated_buffer]
mov edi, [.buffer+.local_vars2_size]
mov ecx, 512/4
mov ecx, [ebx+DISKCACHE.sector_size_log]
mov eax, 1
shl eax, cl
mov ecx, eax
shr ecx, 2
rep movsd
; 11. Store all sectors that were successfully read to the cache.
; 11a. Acquire the lock.
@ -671,19 +686,19 @@ end virtual
test eax, eax
jnz .cache_error
; 11c. Ignore sectors marked as modified: for them the cache is more recent that disk data.
mov eax, 1
shl eax, cl
cmp [esi+CACHE_ITEM.Status], CACHE_ITEM_MODIFIED
jnz .not_modified
add [.current_buffer], 512
add [.current_buffer], eax
jmp .sector_done
.not_modified:
; 11d. For each sector, copy data, mark the item as not-modified copy of the disk,
; advance .current_buffer and .sector_hi:.sector_lo to the next sector.
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_COPY
mov esi, [.current_buffer]
mov edi, ecx
shl edi, 9
add edi, [ebx+DISKCACHE.data]
mov ecx, 512/4
mov ecx, eax
shr ecx, 2
rep movsd
mov [.current_buffer], esi
.sector_done:
@ -721,16 +736,14 @@ end virtual
call cache_lookup_write
test eax, eax
jnz .floppy_cache_error
push ecx
push esi
; 14. Call the driver to read one sector.
push 1
push esp
push edx
push [.sector_lo+16]
shl ecx, 9
add ecx, [ebx+DISKCACHE.data]
push ecx
push edi
mov esi, [ebp+PARTITION.Disk]
mov al, DISKFUNC.read
call disk_call_driver
@ -740,10 +753,7 @@ end virtual
; 15. Get the slot and pointer to the cache item,
; change the status to not-modified copy of the disk
; and go to 4c.
pop ecx
lea esi, [ecx*sizeof.CACHE_ITEM/4]
shl esi, 2
add esi, [ebx+DISKCACHE.pointer]
pop esi
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_COPY
jmp .found_in_cache
@ -795,13 +805,14 @@ fs_write32_app:
; in: edx:eax = sector
; in: ebx -> DISKCACHE structure
; out: CF set if sector is not in cache
; out: ecx = index in cache
; out: ecx = sector_size_log
; out: esi -> sector:status
; out: edi -> sector data
proc cache_lookup_read
mov esi, [ebx+DISKCACHE.pointer]
add esi, sizeof.CACHE_ITEM
mov ecx, 1
mov edi, 1
.hdreadcache:
@ -812,14 +823,17 @@ proc cache_lookup_read
jne .nohdcache
cmp [esi+CACHE_ITEM.SectorHi], edx
jne .nohdcache
mov ecx, [ebx+DISKCACHE.sector_size_log]
shl edi, cl
add edi, [ebx+DISKCACHE.data]
clc
ret
.nohdcache:
add esi, sizeof.CACHE_ITEM
inc ecx
cmp ecx, [ebx+DISKCACHE.sad_size]
inc edi
cmp edi, [ebx+DISKCACHE.sad_size]
jbe .hdreadcache
stc
ret
@ -832,8 +846,8 @@ endp
; in: ebx -> DISKCACHE structure
; in: ebp -> PARTITION structure
; out: eax = error code
; out: ecx = index in cache
; out: esi -> sector:status
; out: edi -> sector data
proc cache_lookup_write
call cache_lookup_read
jnc .return0
@ -874,6 +888,10 @@ proc cache_lookup_write
popd [esi+CACHE_ITEM.SectorLo]
popd [esi+CACHE_ITEM.SectorHi]
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_EMPTY
mov edi, ecx
mov ecx, [ebx+DISKCACHE.sector_size_log]
shl edi, cl
add edi, [ebx+DISKCACHE.data]
.return0:
xor eax, eax ; success
ret
@ -902,7 +920,7 @@ virtual at esp
.sequential dd ?
; boolean variable, 1 if the current chain is sequential in the cache,
; 0 if additional buffer is needed to perform the operation
.chain_start_pos dd ? ; slot of chain start item
.chain_start_pos dd ? ; data of chain start item
.chain_start_ptr dd ? ; pointer to chain start item
.chain_size dd ? ; chain size (thanks, C.O.)
.iteration_size dd ?
@ -951,6 +969,9 @@ end virtual
mov eax, [ebx+DISKCACHE.sad_size]
sub eax, [.size_left]
inc eax
mov ecx, [ebx+DISKCACHE.sector_size_log]
shl eax, cl
add eax, [ebx+DISKCACHE.data]
mov [.chain_start_pos], eax
mov [.chain_size], 0
mov [.sequential], 1
@ -978,7 +999,7 @@ end virtual
; before returning to 6b; if there is a sequential block indeed, this saves some
; time instead of many full-fledged lookups.
mov [.sequential], 0
mov [.chain_start_pos], ecx
mov [.chain_start_pos], edi
.look_backward:
; 6e. For each sector, update chain start pos/ptr, decrement sector number,
; look at the previous item.
@ -1001,7 +1022,9 @@ end virtual
; ...expand the chain one sector backwards and continue the loop at 6e.
; Otherwise, advance to step 7 if the previous item describes the correct sector
; but is not modified, and return to step 6b otherwise.
dec [.chain_start_pos]
mov edi, 1
shl edi, cl
sub [.chain_start_pos], edi
jmp .look_backward
.found_chain_start:
; 7. Expand the chain forward.
@ -1046,14 +1069,11 @@ end virtual
; 9. Write a sequential chain to disk.
; 9a. Pass the entire chain to the driver.
mov eax, [.chain_start_ptr]
mov edx, [.chain_start_pos]
shl edx, 9
add edx, [ebx+DISKCACHE.data]
lea ecx, [.chain_size]
push ecx ; numsectors
pushd [eax+CACHE_ITEM.SectorHi] ; startsector
pushd [eax+CACHE_ITEM.SectorLo] ; startsector
push edx ; buffer
push [.chain_start_pos+12] ; buffer
mov esi, [ebp+PARTITION.Disk]
mov al, DISKFUNC.write
call disk_call_driver
@ -1088,13 +1108,15 @@ end virtual
jbe @f
mov eax, CACHE_MAX_ALLOC_SIZE shr 12
@@:
shl eax, 12 - 9
shl eax, 12
shr eax, cl
jz .nomemory
cmp eax, [.chain_size]
jbe @f
mov eax, [.chain_size]
@@:
mov [.iteration_size], eax
shl eax, 9
shl eax, cl
stdcall kernel_alloc, eax
test eax, eax
jz .nomemory
@ -1123,10 +1145,13 @@ end virtual
; 13b. For each sector, copy the data.
; Note that edi is advanced automatically.
mov esi, [.chain_start_pos+24]
shl esi, 9
add esi, [ebx+DISKCACHE.data]
mov ecx, 512/4
mov ecx, [ebx+DISKCACHE.sector_size_log]
mov eax, 1
shl eax, cl
mov ecx, eax
shr ecx, 2
rep movsd
mov ecx, eax ; keep for 13e
; 13c. Mark the item as not-modified.
mov esi, [.chain_start_ptr+24]
mov [esi+CACHE_ITEM.Status], CACHE_ITEM_COPY
@ -1145,7 +1170,7 @@ end virtual
jnz .no_forward
; 13e. Increment position/pointer to the chain and
; continue the loop.
inc [.chain_start_pos+24]
add [.chain_start_pos+24], ecx
mov [.chain_start_ptr+24], esi
dec dword [esp]
jnz .copy_loop
@ -1153,11 +1178,13 @@ end virtual
.no_forward:
; 13f. Call the lookup function without adding to the cache.
; Update position/pointer with returned value.
; Note: for the last sector in the chain, ecx/esi may contain
; Note: for the last sector in the chain, edi/esi may contain
; garbage; we are not going to use them in this case.
push edi
call cache_lookup_read
mov [.chain_start_pos+24], ecx
mov [.chain_start_ptr+24], esi
mov [.chain_start_pos+28], edi
mov [.chain_start_ptr+28], esi
pop edi
dec dword [esp]
jnz .copy_loop
.copy_done:
@ -1203,13 +1230,32 @@ endp
; is most useful example of a non-trivial adjustment.
; esi = pointer to DISK structure
disk_init_cache:
; 1. Calculate the suggested cache size.
; 1a. Get the size of free physical memory in pages.
; 1. Verify sector size. The code requires it to be a power of 2 not less than 4.
; In the name of sanity check that sector size is not too small or too large.
bsf ecx, [esi+DISK.MediaInfo.SectorSize]
jz .invalid_sector_size
mov eax, 1
shl eax, cl
cmp eax, [esi+DISK.MediaInfo.SectorSize]
jnz .invalid_sector_size
cmp ecx, 6
jb .invalid_sector_size
cmp ecx, 14
jbe .normal_sector_size
.invalid_sector_size:
DEBUGF 1,'K : sector size %x is invalid\n',[esi+DISK.MediaInfo.SectorSize]
xor eax, eax
ret
.normal_sector_size:
mov [esi+DISK.SysCache.sector_size_log], ecx
mov [esi+DISK.AppCache.sector_size_log], ecx
; 2. Calculate the suggested cache size.
; 2a. Get the size of free physical memory in pages.
mov eax, [pg_data.pages_free]
; 1b. Use the value to calculate the size.
; 2b. Use the value to calculate the size.
shl eax, 12 - 5 ; 1/32 of it in bytes
and eax, -8*4096 ; round down to the multiple of 8 pages
; 1c. Force lower and upper limits.
; 2c. Force lower and upper limits.
cmp eax, 1024*1024
jb @f
mov eax, 1024*1024
@ -1218,7 +1264,7 @@ disk_init_cache:
ja @f
mov eax, 128*1024
@@:
; 1d. Give a chance to the driver to adjust the size.
; 2d. Give a chance to the driver to adjust the size.
push eax
mov al, DISKFUNC.adjust_cache_size
call disk_call_driver
@ -1226,16 +1272,16 @@ disk_init_cache:
mov [esi+DISK.cache_size], eax
test eax, eax
jz .nocache
; 2. Allocate memory for the cache.
; 2a. Call the allocator.
; 3. Allocate memory for the cache.
; 3a. Call the allocator.
stdcall kernel_alloc, eax
test eax, eax
jnz @f
; 2b. If it failed, say a message and return with eax = 0.
; 3b. If it failed, say a message and return with eax = 0.
dbgstr 'no memory for disk cache'
jmp .nothing
@@:
; 3. Fill two DISKCACHE structures.
; 4. Fill two DISKCACHE structures.
mov [esi+DISK.SysCache.pointer], eax
lea ecx, [esi+DISK.CacheLock]
call mutex_init
@ -1252,9 +1298,7 @@ disk_init_cache:
mov [esi+DISK.AppCache.pointer], edx
mov eax, [esi+DISK.SysCache.data_size]
push ebx
call calculate_for_hd64
pop ebx
call calculate_cache_slots
add eax, [esi+DISK.SysCache.pointer]
mov [esi+DISK.SysCache.data], eax
mov [esi+DISK.SysCache.sad_size], ecx
@ -1267,9 +1311,7 @@ disk_init_cache:
pop edi
mov eax, [esi+DISK.AppCache.data_size]
push ebx
call calculate_for_hd64
pop ebx
call calculate_cache_slots
add eax, [esi+DISK.AppCache.pointer]
mov [esi+DISK.AppCache.data], eax
mov [esi+DISK.AppCache.sad_size], ecx
@ -1281,9 +1323,9 @@ disk_init_cache:
rep stosd
pop edi
; 4. Return with nonzero al.
; 5. Return with nonzero al.
mov al, 1
; 5. Return.
; 6. Return.
.nothing:
ret
; No caching is required for this driver. Zero cache pointers and return with
@ -1294,18 +1336,16 @@ disk_init_cache:
mov al, 1
ret
calculate_for_hd64:
calculate_cache_slots:
push eax
mov ebx, eax
shr eax, 9
lea eax, [eax*3]
shl eax, 2
sub ebx, eax
shr ebx, 9
mov ecx, ebx
shl ebx, 9
mov ecx, [esi+DISK.MediaInfo.SectorSize]
add ecx, sizeof.CACHE_ITEM
xor edx, edx
div ecx
mov ecx, eax
imul eax, [esi+DISK.MediaInfo.SectorSize]
sub [esp], eax
pop eax
sub eax, ebx
dec ecx
ret

2
kernel/trunk/fs/ext2/ext2.asm
View File

@ -59,6 +59,8 @@ endp
;---------------------------------------------------------------------
proc ext2_create_partition
push ebx
cmp dword [esi+DISK.MediaInfo.SectorSize], 512
jnz .fail
mov eax, 2 ; Superblock starts at 1024-bytes.
add ebx, 512 ; Get pointer to fs-specific buffer.

3
kernel/trunk/fs/fat.inc
View File

@ -154,6 +154,9 @@ fat_create_partition.return0:
xor eax, eax
ret
fat_create_partition:
; sector size must be 512
cmp dword [esi+DISK.MediaInfo.SectorSize], 512
jnz .return0
; bootsector must have been successfully read
cmp dword [esp+4], 0
jnz .return0

2
kernel/trunk/fs/ntfs.inc
View File

@ -152,6 +152,8 @@ ntfs_test_bootsec:
ret
proc ntfs_create_partition
cmp dword [esi+DISK.MediaInfo.SectorSize], 512
jnz .nope
mov edx, dword [ebp+PARTITION.Length]
cmp dword [esp+4], 0
jz .boot_read_ok

2
kernel/trunk/fs/xfs.asm
View File

@ -25,6 +25,8 @@ include 'xfs.inc'
; returns 0 (not XFS or invalid) / pointer to partition structure
xfs_create_partition:
push ebx ecx edx esi edi
cmp dword [esi+DISK.MediaInfo.SectorSize], 512
jnz .error
cmp dword[ebx + xfs_sb.sb_magicnum], XFS_SB_MAGIC ; signature
jne .error