From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/ntfs/mft.h | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 fs/ntfs/mft.h (limited to 'fs/ntfs/mft.h') diff --git a/fs/ntfs/mft.h b/fs/ntfs/mft.h new file mode 100644 index 000000000..75a51a98d --- /dev/null +++ b/fs/ntfs/mft.h @@ -0,0 +1,91 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Defines for mft record handling in NTFS Linux kernel driver. + * + * Copyright (c) 2001-2004 Anton Altaparmakov + */ + +#ifndef _LINUX_NTFS_MFT_H +#define _LINUX_NTFS_MFT_H + +#include +#include + +#include "inode.h" + +struct mft_record *map_mft_record(struct ntfs_inode *ni); +void unmap_mft_record(struct ntfs_inode *ni); +struct mft_record *map_extent_mft_record(struct ntfs_inode *base_ni, u64 mref, + struct ntfs_inode **ntfs_ino); + +static inline void unmap_extent_mft_record(struct ntfs_inode *ni) +{ + unmap_mft_record(ni); +} + +void __mark_mft_record_dirty(struct ntfs_inode *ni); + +/* + * mark_mft_record_dirty - set the mft record and the page containing it dirty + * @ni: ntfs inode describing the mapped mft record + * + * Set the mapped (extent) mft record of the (base or extent) ntfs inode @ni, + * as well as the page containing the mft record, dirty. Also, mark the base + * vfs inode dirty. This ensures that any changes to the mft record are + * written out to disk. + * + * NOTE: Do not do anything if the mft record is already marked dirty. + */ +static inline void mark_mft_record_dirty(struct ntfs_inode *ni) +{ + if (!NInoTestSetDirty(ni)) + __mark_mft_record_dirty(ni); +} + +int ntfs_sync_mft_mirror(struct ntfs_volume *vol, const u64 mft_no, + struct mft_record *m); +int write_mft_record_nolock(struct ntfs_inode *ni, struct mft_record *m, int sync); + +/* + * write_mft_record - write out a mapped (extent) mft record + * @ni: ntfs inode describing the mapped (extent) mft record + * @m: mapped (extent) mft record to write + * @sync: if true, wait for i/o completion + * + * This is just a wrapper for write_mft_record_nolock() (see mft.c), which + * locks the page for the duration of the write. This ensures that there are + * no race conditions between writing the mft record via the dirty inode code + * paths and via the page cache write back code paths or between writing + * neighbouring mft records residing in the same page. + * + * Locking the page also serializes us against ->read_folio() if the page is not + * uptodate. + * + * On success, clean the mft record and return 0. On error, leave the mft + * record dirty and return -errno. + */ +static inline int write_mft_record(struct ntfs_inode *ni, struct mft_record *m, int sync) +{ + struct folio *folio = ni->folio; + int err; + + folio_lock(folio); + err = write_mft_record_nolock(ni, m, sync); + folio_unlock(folio); + + return err; +} + +int ntfs_mft_record_alloc(struct ntfs_volume *vol, const int mode, + struct ntfs_inode **ni, struct ntfs_inode *base_ni, + struct mft_record **ni_mrec); +int ntfs_mft_record_free(struct ntfs_volume *vol, struct ntfs_inode *ni); +int ntfs_mft_records_write(const struct ntfs_volume *vol, const u64 mref, + const s64 count, struct mft_record *b); +int ntfs_mft_record_check(const struct ntfs_volume *vol, struct mft_record *m, + u64 mft_no); +int ntfs_mft_writepages(struct address_space *mapping, + struct writeback_control *wbc); +void ntfs_mft_mark_dirty(struct folio *folio); + +#endif /* _LINUX_NTFS_MFT_H */ -- cgit v1.3.1