bybrooklyn/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-04-18 06:44:00 -04:00
Code Issues Packages Projects Releases Wiki Activity

fs/ntfs3: add delayed-allocation (delalloc) support

Browse Source 
This patch implements delayed allocation (delalloc) in ntfs3 driver.

It introduces an in-memory delayed-runlist (run_da) and the helpers to
track, reserve and later convert those delayed reservations into real
clusters at writeback time. The change keeps on-disk formats untouched and
focuses on pagecache integration, correctness and safe interaction with
fallocate, truncate, and dio/iomap paths.

Key points:

- add run_da (delay-allocated run tree) and bookkeeping for delayed clusters.

- mark ranges as delalloc (DELALLOC_LCN) instead of immediately allocating.
  Actual allocation performed later (writeback / attr_set_size_ex / explicit
  flush paths).

- direct i/o / iomap paths updated to avoid dio collisions with
  delalloc: dio falls back or forces allocation of delayed blocks before
  proceeding.

- punch/collapse/truncate/fallocate check and cancel delay-alloc reservations.
  Sparse/compressed files handled specially.

- free-space checks updated (ntfs_check_free_space) to account for reserved
  delalloc clusters and MFT record budgeting.

- delayed allocations are committed on last writer (file release) and on
  explicit allocation flush paths.

Tested-by: syzbot@syzkaller.appspotmail.com
Reported-by: syzbot+2bd8e813c7f767aa9bb1@syzkaller.appspotmail.com
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
This commit is contained in:
Konstantin Komarov
2026-02-16 17:10:26 +01:00
parent c5226b96c0
commit 10d7c95af0
12 changed files with 890 additions and 348 deletions
Download Patch File Download Diff File Expand all files Collapse all files

91
fs/ntfs3/ntfs_fs.h
View File

@@ -108,6 +108,7 @@ struct ntfs_mount_options {
unsigned force : 1; /* RW mount dirty volume. */
unsigned prealloc : 1; /* Preallocate space when file is growing. */
unsigned nocase : 1; /* case insensitive. */
unsigned delalloc : 1; /* delay allocation. */
};
/* Special value to unpack and deallocate. */
@@ -132,7 +133,8 @@ struct ntfs_buffers {
enum ALLOCATE_OPT {
ALLOCATE_DEF = 0, // Allocate all clusters.
ALLOCATE_MFT = 1, // Allocate for MFT.
ALLOCATE_ZERO = 2, // Zeroout new allocated clusters
ALLOCATE_ZERO = 2, // Zeroout new allocated clusters.
ALLOCATE_ONE_FR = 4, // Allocate one fragment only.
};
enum bitmap_mutex_classes {
@@ -213,7 +215,7 @@ struct ntfs_sb_info {
u32 discard_granularity;
u64 discard_granularity_mask_inv; // ~(discard_granularity_mask_inv-1)
u32 bdev_blocksize_mask; // bdev_logical_block_size(bdev) - 1;
u32 bdev_blocksize; // bdev_logical_block_size(bdev)
u32 cluster_size; // bytes per cluster
u32 cluster_mask; // == cluster_size - 1
@@ -272,6 +274,12 @@ struct ntfs_sb_info {
struct {
struct wnd_bitmap bitmap; // $Bitmap::Data
CLST next_free_lcn;
/* Total sum of delay allocated clusters in all files. */
#ifdef CONFIG_NTFS3_64BIT_CLUSTER
atomic64_t da;
#else
atomic_t da;
#endif
} used;
struct {
@@ -379,7 +387,7 @@ struct ntfs_inode {
*/
u8 mi_loaded;
/*
/*
* Use this field to avoid any write(s).
* If inode is bad during initialization - use make_bad_inode
* If inode is bad during operations - use this field
@@ -390,7 +398,14 @@ struct ntfs_inode {
struct ntfs_index dir;
struct {
struct rw_semaphore run_lock;
/* Unpacked runs from just one record. */
struct runs_tree run;
/*
* Pairs [vcn, len] for all delay allocated clusters.
* Normal file always contains delayed clusters in one fragment.
* TODO: use 2 CLST per pair instead of 3.
*/
struct runs_tree run_da;
#ifdef CONFIG_NTFS3_LZX_XPRESS
struct folio *offs_folio;
#endif
@@ -430,19 +445,32 @@ enum REPARSE_SIGN {
/* Functions from attrib.c */
int attr_allocate_clusters(struct ntfs_sb_info *sbi, struct runs_tree *run,
CLST vcn, CLST lcn, CLST len, CLST *pre_alloc,
enum ALLOCATE_OPT opt, CLST *alen, const size_t fr,
CLST *new_lcn, CLST *new_len);
struct runs_tree *run_da, CLST vcn, CLST lcn,
CLST len, CLST *pre_alloc, enum ALLOCATE_OPT opt,
CLST *alen, const size_t fr, CLST *new_lcn,
CLST *new_len);
int attr_make_nonresident(struct ntfs_inode *ni, struct ATTRIB *attr,
struct ATTR_LIST_ENTRY *le, struct mft_inode *mi,
u64 new_size, struct runs_tree *run,
struct ATTRIB **ins_attr, struct page *page);
int attr_set_size(struct ntfs_inode *ni, enum ATTR_TYPE type,
const __le16 *name, u8 name_len, struct runs_tree *run,
u64 new_size, const u64 *new_valid, bool keep_prealloc,
struct ATTRIB **ret);
int attr_set_size_ex(struct ntfs_inode *ni, enum ATTR_TYPE type,
const __le16 *name, u8 name_len, struct runs_tree *run,
u64 new_size, const u64 *new_valid, bool keep_prealloc,
struct ATTRIB **ret, bool no_da);
static inline int attr_set_size(struct ntfs_inode *ni, enum ATTR_TYPE type,
const __le16 *name, u8 name_len,
struct runs_tree *run, u64 new_size,
const u64 *new_valid, bool keep_prealloc)
{
return attr_set_size_ex(ni, type, name, name_len, run, new_size,
new_valid, keep_prealloc, NULL, false);
}
int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
CLST *len, bool *new, bool zero, void **res);
CLST *len, bool *new, bool zero, void **res,
bool no_da);
int attr_data_get_block_locked(struct ntfs_inode *ni, CLST vcn, CLST clen,
CLST *lcn, CLST *len, bool *new, bool zero,
void **res, bool no_da);
int attr_data_write_resident(struct ntfs_inode *ni, struct folio *folio);
int attr_load_runs_vcn(struct ntfs_inode *ni, enum ATTR_TYPE type,
const __le16 *name, u8 name_len, struct runs_tree *run,
@@ -590,6 +618,8 @@ int ni_rename(struct ntfs_inode *dir_ni, struct ntfs_inode *new_dir_ni,
bool ni_is_dirty(struct inode *inode);
loff_t ni_seek_data_or_hole(struct ntfs_inode *ni, loff_t offset, bool data);
int ni_write_parents(struct ntfs_inode *ni, int sync);
int ni_allocate_da_blocks(struct ntfs_inode *ni);
int ni_allocate_da_blocks_locked(struct ntfs_inode *ni);
/* Globals from fslog.c */
bool check_index_header(const struct INDEX_HDR *hdr, size_t bytes);
@@ -605,7 +635,8 @@ int ntfs_loadlog_and_replay(struct ntfs_inode *ni, struct ntfs_sb_info *sbi);
int ntfs_look_for_free_space(struct ntfs_sb_info *sbi, CLST lcn, CLST len,
CLST *new_lcn, CLST *new_len,
enum ALLOCATE_OPT opt);
bool ntfs_check_for_free_space(struct ntfs_sb_info *sbi, CLST clen, CLST mlen);
bool ntfs_check_free_space(struct ntfs_sb_info *sbi, CLST clen, CLST mlen,
bool da);
int ntfs_look_free_mft(struct ntfs_sb_info *sbi, CLST *rno, bool mft,
struct ntfs_inode *ni, struct mft_inode **mi);
void ntfs_mark_rec_free(struct ntfs_sb_info *sbi, CLST rno, bool is_mft);
@@ -831,7 +862,8 @@ void run_truncate_around(struct runs_tree *run, CLST vcn);
bool run_add_entry(struct runs_tree *run, CLST vcn, CLST lcn, CLST len,
bool is_mft);
bool run_collapse_range(struct runs_tree *run, CLST vcn, CLST len, CLST sub);
bool run_insert_range(struct runs_tree *run, CLST vcn, CLST len);
int run_insert_range(struct runs_tree *run, CLST vcn, CLST len);
int run_insert_range_da(struct runs_tree *run, CLST vcn, CLST len);
bool run_get_entry(const struct runs_tree *run, size_t index, CLST *vcn,
CLST *lcn, CLST *len);
bool run_is_mapped_full(const struct runs_tree *run, CLST svcn, CLST evcn);
@@ -851,6 +883,9 @@ int run_unpack_ex(struct runs_tree *run, struct ntfs_sb_info *sbi, CLST ino,
#endif
int run_get_highest_vcn(CLST vcn, const u8 *run_buf, u64 *highest_vcn);
int run_clone(const struct runs_tree *run, struct runs_tree *new_run);
bool run_remove_range(struct runs_tree *run, CLST vcn, CLST len, CLST *done);
CLST run_len(const struct runs_tree *run);
CLST run_get_max_vcn(const struct runs_tree *run);
/* Globals from super.c */
void *ntfs_set_shared(void *ptr, u32 bytes);
@@ -1027,6 +1062,36 @@ static inline int ntfs3_forced_shutdown(struct super_block *sb)
return test_bit(NTFS_FLAGS_SHUTDOWN_BIT, &ntfs_sb(sb)->flags);
}
/* Returns total sum of delay allocated clusters in all files. */
static inline CLST ntfs_get_da(struct ntfs_sb_info *sbi)
{
#ifdef CONFIG_NTFS3_64BIT_CLUSTER
return atomic64_read(&sbi->used.da);
#else
return atomic_read(&sbi->used.da);
#endif
}
/* Update total count of delay allocated clusters. */
static inline void ntfs_add_da(struct ntfs_sb_info *sbi, CLST da)
{
#ifdef CONFIG_NTFS3_64BIT_CLUSTER
atomic64_add(da, &sbi->used.da);
#else
atomic_add(da, &sbi->used.da);
#endif
}
/* Update total count of delay allocated clusters. */
static inline void ntfs_sub_da(struct ntfs_sb_info *sbi, CLST da)
{
#ifdef CONFIG_NTFS3_64BIT_CLUSTER
atomic64_sub(da, &sbi->used.da);
#else
atomic_sub(da, &sbi->used.da);
#endif
}
/*
* ntfs_up_cluster - Align up on cluster boundary.
*/