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path: root/fs/ntfs3/run.c
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2026-02-16fs/ntfs3: add delayed-allocation (delalloc) supportKonstantin Komarov
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>
2026-01-15ntfs3: fix circular locking dependency in run_unpack_exSzymon Wilczek
Syzbot reported a circular locking dependency between wnd->rw_lock (sbi->used.bitmap) and ni->file.run_lock. The deadlock scenario: 1. ntfs_extend_mft() takes ni->file.run_lock then wnd->rw_lock. 2. run_unpack_ex() takes wnd->rw_lock then tries to acquire ni->file.run_lock inside ntfs_refresh_zone(). This creates an AB-BA deadlock. Fix this by using down_read_trylock() instead of down_read() when acquiring run_lock in run_unpack_ex(). If the lock is contended, skip ntfs_refresh_zone() - the MFT zone will be refreshed on the next MFT operation. This breaks the circular dependency since we never block waiting for run_lock while holding wnd->rw_lock. Reported-by: syzbot+d27edf9f96ae85939222@syzkaller.appspotmail.com Tested-by: syzbot+d27edf9f96ae85939222@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d27edf9f96ae85939222 Signed-off-by: Szymon Wilczek <swilczek.lx@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2025-11-17fs/ntfs3: correct attr_collapse_range when file is too fragmentedKonstantin Komarov
Fix incorrect VCN adjustments in attr_collapse_range() that caused filesystem errors or corruption on very fragmented NTFS files when performing collapse-range operations. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2025-10-17fs/ntfs3: fix mount failure for sparse runs in run_unpack()Konstantin Komarov
Some NTFS volumes failed to mount because sparse data runs were not handled correctly during runlist unpacking. The code performed arithmetic on the special SPARSE_LCN64 marker, leading to invalid LCN values and mount errors. Add an explicit check for the case described above, marking the run as sparse without applying arithmetic. Fixes: 736fc7bf5f68 ("fs: ntfs3: Fix integer overflow in run_unpack()") Cc: stable@vger.kernel.org Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2025-09-10fs: ntfs3: Fix integer overflow in run_unpack()Vitaly Grigoryev
The MFT record relative to the file being opened contains its runlist, an array containing information about the file's location on the physical disk. Analysis of all Call Stack paths showed that the values of the runlist array, from which LCNs are calculated, are not validated before run_unpack function. The run_unpack function decodes the compressed runlist data format from MFT attributes (for example, $DATA), converting them into a runs_tree structure, which describes the mapping of virtual clusters (VCN) to logical clusters (LCN). The NTFS3 subsystem also has a shortcut for deleting files from MFT records - in this case, the RUN_DEALLOCATE command is sent to the run_unpack input, and the function logic provides that all data transferred to the runlist about file or directory is deleted without creating a runs_tree structure. Substituting the runlist in the $DATA attribute of the MFT record for an arbitrary file can lead either to access to arbitrary data on the disk bypassing access checks to them (since the inode access check occurs above) or to destruction of arbitrary data on the disk. Add overflow check for addition operation. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 4342306f0f0d ("fs/ntfs3: Add file operations and implementation") Signed-off-by: Vitaly Grigoryev <Vitaly.Grigoryev@kaspersky.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2024-11-01fs/ntfs3: Accumulated refactoring changesKonstantin Komarov
Changes made to improve readability and debuggability. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2024-11-01fs/ntfs3: Fix case when unmarked clusters intersect with zoneKonstantin Komarov
Reported-by: syzbot+7f3761b790fa41d0f3d5@syzkaller.appspotmail.com Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2024-09-03fs/ntfs3: Make checks in run_unpack more clearKonstantin Komarov
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2023-07-03fs/ntfs3: Code formattingKonstantin Komarov
clang-format-15 was used to format code according kernel's .clang-format. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2023-03-27fs/ntfs3: Code formatting and refactoringKonstantin Komarov
Added minor refactoring. Added and fixed some comments. In some places, the code has been reformatted to fit into 80 columns. clang-format-12 was used to format code according kernel's .clang-format. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-11-14fs/ntfs3: Improve checking of bad clustersKonstantin Komarov
Added new function wnd_set_used_safe. Load $BadClus before $AttrDef instead of before $Bitmap. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-11-14fs/ntfs3: Check fields while readingKonstantin Komarov
Added new functions index_hdr_check and index_buf_check. Now we check all stuff for correctness while reading from disk. Also fixed bug with stale nfs data. Reported-by: van fantasy <g1042620637@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-08-03fs/ntfs3: Refactoring attr_punch_hole to restore after errorsKonstantin Komarov
Added comments to code Added new function run_clone to make a copy of run Added done and undo labels for restoring after errors Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-08-03fs/ntfs3: Check possible errors in run_pack in advanceKonstantin Komarov
Checking in advance speeds things up in some cases. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-08-03fs/ntfs3: Added comments to frecord functionsKonstantin Komarov
Added some comments in frecord.c for more context. Also changed run_lookup to static because it's an internal function. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-07-05fs/ntfs3: Remove duplicated assignment to variable rColin Ian King
The assignment to variable r is duplicated, the second assignment is redundant and can be removed. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2022-06-28fs/ntfs3: Fallocate (FALLOC_FL_INSERT_RANGE) implementationKonstantin Komarov
Add functions for inserting hole in file and inserting range in run. Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-09-13fs/ntfs3: Remove unneeded header files from c filesKari Argillander
We have lot of unnecessary headers in these files. Remove them so that we help compiler a little bit. Signed-off-by: Kari Argillander <kari.argillander@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-08-30fs/ntfs3: Restyle comments to better align with kernel-docKari Argillander
Capitalize comments and end with period for better reading. Also function comments are now little more kernel-doc style. This way we can easily convert them to kernel-doc style if we want. Note that these are not yet complete with this style. Example function comments start with /* and in kernel-doc style they start /**. Use imperative mood in function descriptions. Change words like ntfs -> NTFS, linux -> Linux. Use "we" not "I" when commenting code. Signed-off-by: Kari Argillander <kari.argillander@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-08-27fs/ntfs3: Do not use driver own alloc wrappersKari Argillander
Problem with these wrapper is that we cannot take off example GFP_NOFS flag. It is not recomended use those in all places. Also if we change one driver specific wrapper to kernel wrapper then it would look really weird. People should be most familiar with kernel wrappers so let's just use those ones. Driver specific alloc wrapper also confuse some static analyzing tools, good example is example kernels checkpatch tool. After we converter these to kernel specific then warnings is showed. Following Coccinelle script was used to automate changing. virtual patch @alloc depends on patch@ expression x; expression y; @@ ( - ntfs_malloc(x) + kmalloc(x, GFP_NOFS) | - ntfs_zalloc(x) + kzalloc(x, GFP_NOFS) | - ntfs_vmalloc(x) + kvmalloc(x, GFP_NOFS) | - ntfs_free(x) + kfree(x) | - ntfs_vfree(x) + kvfree(x) | - ntfs_memdup(x, y) + kmemdup(x, y, GFP_NOFS) ) Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Kari Argillander <kari.argillander@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-08-27fs/ntfs3: Use linux/log2 is_power_of_2 functionKari Argillander
We do not need our own implementation for this function in this driver. It is much better to use generic one. Signed-off-by: Kari Argillander <kari.argillander@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-08-27fs/ntfs3: Fix various spelling mistakesColin Ian King
There is a spelling mistake in a ntfs_err error message. Also fix various spelling mistakes in comments. Signed-off-by: Colin Ian King <colin.king@canonical.com> Reviewed-by: Kari Argillander <kari.argillander@gmail.com> Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
2021-08-13fs/ntfs3: Add file operations and implementationKonstantin Komarov
This adds file operations and implementation Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>