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Kernel: Fix ext2 fileystem super block backups 

Check if rev >= 1 sets sparse superblock feature instead of assuming it
is set
This commit is contained in:
Bananymous 2026-01-11 15:24:10 +02:00
parent 4e3831e380
commit c9a8f5b456
1 changed files with 12 additions and 13 deletions
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25
kernel/kernel/FS/Ext2/FileSystem.cpp
View File

@ -1,4 +1,5 @@
#include <BAN/ScopeGuard.h>
#include <BAN/Sort.h>
#include <kernel/FS/Ext2/FileSystem.h>
#include <kernel/Lock/LockGuard.h>
@ -127,7 +128,7 @@ namespace Kernel
{
auto block_buffer = TRY(m_buffer_manager.get_buffer());
if (superblock().rev_level == Ext2::Enum::GOOD_OLD_REV)
if ((superblock().rev_level == Ext2::Enum::GOOD_OLD_REV) || !(m_superblock.feature_ro_compat & Ext2::Enum::FEATURE_RO_COMPAT_SPARSE_SUPER))
{
// In revision 0 all blockgroups contain superblock backup
TRY(m_superblock_backups.reserve(number_of_block_groups - 1));
@ -148,6 +149,8 @@ namespace Kernel
// We don't really care if this succeeds or not
(void)m_superblock_backups.shrink_to_fit();
BAN::sort::sort(m_superblock_backups.begin(), m_superblock_backups.end());
}
for (uint32_t bg : m_superblock_backups)
@ -488,14 +491,7 @@ namespace Kernel
TRY(read_block(bgd_location.block, bgd_buffer));
auto& bgd = *(Ext2::BlockGroupDescriptor*)(bgd_buffer.data() + bgd_location.offset);
const uint32_t inode_byte_offset = inode_index * superblock().inode_size;
BlockLocation location
{
.block = inode_byte_offset / block_size + bgd.inode_table,
.offset = inode_byte_offset % block_size
};
const auto bgd = bgd_buffer.span().slice(bgd_location.offset).as<Ext2::BlockGroupDescriptor>();
#if EXT2_VERIFY_INODE
const uint32_t inode_bitmap_block = bgd.inode_bitmap;
@ -503,14 +499,18 @@ namespace Kernel
// NOTE: we can reuse the bgd_buffer since it is not needed anymore
auto& inode_bitmap = bgd_buffer;
read_block(inode_bitmap_block, inode_bitmap.span());
TRY(read_block(inode_bitmap_block, inode_bitmap));
const uint32_t byte = inode_index / 8;
const uint32_t bit = inode_index % 8;
ASSERT(inode_bitmap[byte] & (1 << bit));
#endif
return location;
const uint32_t inode_byte_offset = inode_index * superblock().inode_size;
return BlockLocation {
.block = inode_byte_offset / block_size + bgd.inode_table,
.offset = inode_byte_offset % block_size
};
}
Ext2FS::BlockLocation Ext2FS::locate_block_group_descriptior(uint32_t group_index)
@ -525,8 +525,7 @@ namespace Kernel
// Block Group Descriptor table is in the block after superblock
const uint32_t bgd_byte_offset = (superblock().first_data_block + 1) * block_size + sizeof(Ext2::BlockGroupDescriptor) * group_index;
return
{
return BlockLocation {
.block = bgd_byte_offset / block_size,
.offset = bgd_byte_offset % block_size
};