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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-15 22:55:52 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-03-15 22:55:52 +0300 |
| commit | 34d5a4b336e7e4c247d532a841d05367357197f8 (patch) | |
| tree | c07c789d1a075d460c4effad4acddb1f4fdfee9f /include | |
| parent | ec181b7f30bdae2fbbba1c0dd76aeaad89c7963e (diff) | |
| parent | 8d67743653dce5a0e7aa500fcccb237cde7ad88e (diff) | |
| download | linux-34d5a4b336e7e4c247d532a841d05367357197f8.tar.xz | |
Merge tag 'locking-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull futex fix from Thomas Gleixner:
"Fix for yet another subtle futex issue.
The futex code used ihold() to prevent inodes from vanishing, but
ihold() does not guarantee inode persistence. Replace the inode
pointer with a per boot, machine wide, unique inode identifier.
The second commit fixes the breakage of the hash mechanism which
causes a 100% performance regression"
* tag 'locking-urgent-2020-03-15' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Unbreak futex hashing
futex: Fix inode life-time issue
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/fs.h | 1 | ||||
| -rw-r--r-- | include/linux/futex.h | 17 |
2 files changed, 11 insertions, 7 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 3cd4fe6b845e..abedbffe2c9e 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -698,6 +698,7 @@ struct inode { struct rcu_head i_rcu; }; atomic64_t i_version; + atomic64_t i_sequence; /* see futex */ atomic_t i_count; atomic_t i_dio_count; atomic_t i_writecount; diff --git a/include/linux/futex.h b/include/linux/futex.h index 5cc3fed27d4c..b70df27d7e85 100644 --- a/include/linux/futex.h +++ b/include/linux/futex.h @@ -31,23 +31,26 @@ struct task_struct; union futex_key { struct { + u64 i_seq; unsigned long pgoff; - struct inode *inode; - int offset; + unsigned int offset; } shared; struct { + union { + struct mm_struct *mm; + u64 __tmp; + }; unsigned long address; - struct mm_struct *mm; - int offset; + unsigned int offset; } private; struct { + u64 ptr; unsigned long word; - void *ptr; - int offset; + unsigned int offset; } both; }; -#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = NULL } } +#define FUTEX_KEY_INIT (union futex_key) { .both = { .ptr = 0ULL } } #ifdef CONFIG_FUTEX enum { |