[PATCH AUTOSEL 6.6 01/51] fs/ntfs3: Improve alternative boot processing

Sasha Levin
2024-02-13T00:20:54Z

[ Upstream commit c39de951282df9a60ef70664e4378d88006b2670 ]

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ntfs3/super.c | 35 +++++++++++++++++------------------
1 file changed, 17 insertions(+), 18 deletions(-)

diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index f763e3256ccc..aa3b2c262ab6 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -865,6 +865,7 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
u16 fn, ao;
u8 cluster_bits;
u32 boot_off = 0;
+ sector_t boot_block = 0;
const char *hint = "Primary boot";

/* Save original dev_size. Used with alternative boot. */
@@ -872,11 +873,11 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,

sbi->volume.blocks = dev_size >> PAGE_SHIFT;

- bh = ntfs_bread(sb, 0);
+read_boot:
+ bh = ntfs_bread(sb, boot_block);
if (!bh)
- return -EIO;
+ return boot_block ? -EINVAL : -EIO;

-check_boot:
err = -EINVAL;

/* Corrupted image; do not read OOB */
@@ -1107,26 +1108,24 @@ static int ntfs_init_from_boot(struct super_block *sb, u32 sector_size,
}

out:
- if (err == -EINVAL && !bh->b_blocknr && dev_size0 > PAGE_SHIFT) {
+ brelse(bh);
+
+ if (err == -EINVAL && !boot_block && dev_size0 > PAGE_SHIFT) {
u32 block_size = min_t(u32, sector_size, PAGE_SIZE);
u64 lbo = dev_size0 - sizeof(*boot);

- /*
- * Try alternative boot (last sector)
- */
- brelse(bh);
-
- sb_set_blocksize(sb, block_size);
- bh = ntfs_bread(sb, lbo >> blksize_bits(block_size));
- if (!bh)
- return -EINVAL;
-
+ boot_block = lbo >> blksize_bits(block_size);
boot_off = lbo & (block_size - 1);
- hint = "Alternative boot";
- dev_size = dev_size0; /* restore original size. */
- goto check_boot;
+ if (boot_block && block_size >= boot_off + sizeof(*boot)) {
+ /*
+ * Try alternative boot (last sector)
+ */
+ sb_set_blocksize(sb, block_size);
+ hint = "Alternative boot";
+ dev_size = dev_size0; /* restore original size. */
+ goto read_boot;
+ }
}
- brelse(bh);

return err;
}
--
2.43.0