2022-10-28 17:22:07

by Konstantin Komarov

[permalink] [raw]
Subject: [PATCH 13/14] fs/ntfs3: Improve checking of bad clusters

Added new function wnd_set_used_safe.
Load $BadClus before $AttrDef instead of before $Bitmap.

Signed-off-by: Konstantin Komarov <[email protected]>
---
fs/ntfs3/bitmap.c | 38 +++++++++++++++++++++++++++
fs/ntfs3/ntfs_fs.h | 2 ++
fs/ntfs3/run.c | 21 ++-------------
fs/ntfs3/super.c | 64 ++++++++++++++++++++++++++++------------------
4 files changed, 81 insertions(+), 44 deletions(-)

diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 6e68887597ac..c86a76dd44b9 100644
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -800,6 +800,44 @@ int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits)
return err;
}

+/*
+ * wnd_set_used_safe - Mark the bits range from bit to bit + bits as used.
+ *
+ * Unlikely wnd_set_used/wnd_set_free this function is not full trusted.
+ * It scans every bit in bitmap and marks free bit as used.
+ * @done - how many bits were marked as used.
+ *
+ * NOTE: normally *done should be 0.
+ */
+int wnd_set_used_safe(struct wnd_bitmap *wnd, size_t bit, size_t bits,
+ size_t *done)
+{
+ size_t i, from = 0, len = 0;
+ int err = 0;
+
+ *done = 0;
+ for (i = 0; i < bits; i++) {
+ if (wnd_is_free(wnd, bit + i, 1)) {
+ if (!len)
+ from = bit + i;
+ len += 1;
+ } else if (len) {
+ err = wnd_set_used(wnd, from, len);
+ *done += len;
+ len = 0;
+ if (err)
+ break;
+ }
+ }
+
+ if (len) {
+ /* last fragment. */
+ err = wnd_set_used(wnd, from, len);
+ *done += len;
+ }
+ return err;
+}
+
/*
* wnd_is_free_hlp
*
diff --git a/fs/ntfs3/ntfs_fs.h b/fs/ntfs3/ntfs_fs.h
index bc02cfb344f9..2f55993a716c 100644
--- a/fs/ntfs3/ntfs_fs.h
+++ b/fs/ntfs3/ntfs_fs.h
@@ -826,6 +826,8 @@ static inline size_t wnd_zeroes(const struct wnd_bitmap *wnd)
int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits);
int wnd_set_free(struct wnd_bitmap *wnd, size_t bit, size_t bits);
int wnd_set_used(struct wnd_bitmap *wnd, size_t bit, size_t bits);
+int wnd_set_used_safe(struct wnd_bitmap *wnd, size_t bit, size_t bits,
+ size_t *done);
bool wnd_is_free(struct wnd_bitmap *wnd, size_t bit, size_t bits);
bool wnd_is_used(struct wnd_bitmap *wnd, size_t bit, size_t bits);

diff --git a/fs/ntfs3/run.c b/fs/ntfs3/run.c
index 12d8682f33b5..a5af71cd8d14 100644
--- a/fs/ntfs3/run.c
+++ b/fs/ntfs3/run.c
@@ -1096,25 +1096,8 @@ int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,

if (down_write_trylock(&wnd->rw_lock)) {
/* Mark all zero bits as used in range [lcn, lcn+len). */
- CLST i, lcn_f = 0, len_f = 0;
-
- err = 0;
- for (i = 0; i < len; i++) {
- if (wnd_is_free(wnd, lcn + i, 1)) {
- if (!len_f)
- lcn_f = lcn + i;
- len_f += 1;
- } else if (len_f) {
- err = wnd_set_used(wnd, lcn_f, len_f);
- len_f = 0;
- if (err)
- break;
- }
- }
-
- if (len_f)
- err = wnd_set_used(wnd, lcn_f, len_f);
-
+ size_t done;
+ err = wnd_set_used_safe(wnd, lcn, len, &done);
up_write(&wnd->rw_lock);
if (err)
return err;
diff --git a/fs/ntfs3/super.c b/fs/ntfs3/super.c
index 1e2c04e48f98..d8ba6724adf1 100644
--- a/fs/ntfs3/super.c
+++ b/fs/ntfs3/super.c
@@ -921,7 +921,7 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
struct block_device *bdev = sb->s_bdev;
struct inode *inode;
struct ntfs_inode *ni;
- size_t i, tt;
+ size_t i, tt, bad_len, bad_frags;
CLST vcn, lcn, len;
struct ATTRIB *attr;
const struct VOLUME_INFO *info;
@@ -1091,30 +1091,6 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)

sbi->mft.ni = ni;

- /* Load $BadClus. */
- ref.low = cpu_to_le32(MFT_REC_BADCLUST);
- ref.seq = cpu_to_le16(MFT_REC_BADCLUST);
- inode = ntfs_iget5(sb, &ref, &NAME_BADCLUS);
- if (IS_ERR(inode)) {
- ntfs_err(sb, "Failed to load $BadClus.");
- err = PTR_ERR(inode);
- goto out;
- }
-
- ni = ntfs_i(inode);
-
- for (i = 0; run_get_entry(&ni->file.run, i, &vcn, &lcn, &len); i++) {
- if (lcn == SPARSE_LCN)
- continue;
-
- if (!sbi->bad_clusters)
- ntfs_notice(sb, "Volume contains bad blocks");
-
- sbi->bad_clusters += len;
- }
-
- iput(inode);
-
/* Load $Bitmap. */
ref.low = cpu_to_le32(MFT_REC_BITMAP);
ref.seq = cpu_to_le16(MFT_REC_BITMAP);
@@ -1152,6 +1128,44 @@ static int ntfs_fill_super(struct super_block *sb, struct fs_context *fc)
if (err)
goto out;

+ /* Load $BadClus. */
+ ref.low = cpu_to_le32(MFT_REC_BADCLUST);
+ ref.seq = cpu_to_le16(MFT_REC_BADCLUST);
+ inode = ntfs_iget5(sb, &ref, &NAME_BADCLUS);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ ntfs_err(sb, "Failed to load $BadClus (%d).", err);
+ goto out;
+ }
+
+ ni = ntfs_i(inode);
+ bad_len = bad_frags = 0;
+ for (i = 0; run_get_entry(&ni->file.run, i, &vcn, &lcn, &len); i++) {
+ if (lcn == SPARSE_LCN)
+ continue;
+
+ bad_len += len;
+ bad_frags += 1;
+ if (sb_rdonly(sb))
+ continue;
+
+ if (wnd_set_used_safe(&sbi->used.bitmap, lcn, len, &tt) || tt) {
+ /* Bad blocks marked as free in bitmap. */
+ ntfs_set_state(sbi, NTFS_DIRTY_ERROR);
+ }
+ }
+ if (bad_len) {
+ /*
+ * Notice about bad blocks.
+ * In normal cases these blocks are marked as used in bitmap.
+ * And we never allocate space in it.
+ */
+ ntfs_notice(sb,
+ "Volume contains %zu bad blocks in %zu fragments.",
+ bad_len, bad_frags);
+ }
+ iput(inode);
+
/* Load $AttrDef. */
ref.low = cpu_to_le32(MFT_REC_ATTR);
ref.seq = cpu_to_le16(MFT_REC_ATTR);
--
2.37.0