Commit 516dffdcd8827a40532798602830dfcfc672294c
Committed by
Linus Torvalds
1 parent
7b965e0884
Exists in
master
and in
39 other branches
[PATCH] Fix get_unmapped_area and fsync for hugetlb shm segments
This patch provides the following hugetlb-related fixes to the recent stacked shm files changes: - Update is_file_hugepages() so it will reconize hugetlb shm segments. - get_unmapped_area must be called with the nested file struct to handle the sfd->file->f_ops->get_unmapped_area == NULL case. - The fsync f_op must be wrapped since it is specified in the hugetlbfs f_ops. This is based on proposed fixes from Eric Biederman that were debugged and tested by me. Without it, attempting to use hugetlb shared memory segments on powerpc (and likely ia64) will kill your box. Signed-off-by: Adam Litke <agl@us.ibm.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Acked-by: William Irwin <bill.irwin@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 3 changed files with 38 additions and 7 deletions Side-by-side Diff
include/linux/hugetlb.h
... | ... | @@ -4,6 +4,7 @@ |
4 | 4 | #ifdef CONFIG_HUGETLB_PAGE |
5 | 5 | |
6 | 6 | #include <linux/mempolicy.h> |
7 | +#include <linux/shm.h> | |
7 | 8 | #include <asm/tlbflush.h> |
8 | 9 | |
9 | 10 | struct ctl_table; |
... | ... | @@ -168,7 +169,12 @@ |
168 | 169 | |
169 | 170 | static inline int is_file_hugepages(struct file *file) |
170 | 171 | { |
171 | - return file->f_op == &hugetlbfs_file_operations; | |
172 | + if (file->f_op == &hugetlbfs_file_operations) | |
173 | + return 1; | |
174 | + if (is_file_shm_hugepages(file)) | |
175 | + return 1; | |
176 | + | |
177 | + return 0; | |
172 | 178 | } |
173 | 179 | |
174 | 180 | static inline void set_file_hugepages(struct file *file) |
include/linux/shm.h
... | ... | @@ -96,11 +96,16 @@ |
96 | 96 | |
97 | 97 | #ifdef CONFIG_SYSVIPC |
98 | 98 | long do_shmat(int shmid, char __user *shmaddr, int shmflg, unsigned long *addr); |
99 | +extern int is_file_shm_hugepages(struct file *file); | |
99 | 100 | #else |
100 | 101 | static inline long do_shmat(int shmid, char __user *shmaddr, |
101 | 102 | int shmflg, unsigned long *addr) |
102 | 103 | { |
103 | 104 | return -ENOSYS; |
105 | +} | |
106 | +static inline int is_file_shm_hugepages(struct file *file) | |
107 | +{ | |
108 | + return 0; | |
104 | 109 | } |
105 | 110 | #endif |
106 | 111 |
ipc/shm.c
... | ... | @@ -285,21 +285,41 @@ |
285 | 285 | return 0; |
286 | 286 | } |
287 | 287 | |
288 | -#ifndef CONFIG_MMU | |
288 | +static int shm_fsync(struct file *file, struct dentry *dentry, int datasync) | |
289 | +{ | |
290 | + int (*fsync) (struct file *, struct dentry *, int datasync); | |
291 | + struct shm_file_data *sfd = shm_file_data(file); | |
292 | + int ret = -EINVAL; | |
293 | + | |
294 | + fsync = sfd->file->f_op->fsync; | |
295 | + if (fsync) | |
296 | + ret = fsync(sfd->file, sfd->file->f_path.dentry, datasync); | |
297 | + return ret; | |
298 | +} | |
299 | + | |
289 | 300 | static unsigned long shm_get_unmapped_area(struct file *file, |
290 | 301 | unsigned long addr, unsigned long len, unsigned long pgoff, |
291 | 302 | unsigned long flags) |
292 | 303 | { |
293 | 304 | struct shm_file_data *sfd = shm_file_data(file); |
294 | - return sfd->file->f_op->get_unmapped_area(sfd->file, addr, len, pgoff, | |
295 | - flags); | |
305 | + return get_unmapped_area(sfd->file, addr, len, pgoff, flags); | |
296 | 306 | } |
297 | -#else | |
298 | -#define shm_get_unmapped_area NULL | |
299 | -#endif | |
300 | 307 | |
308 | +int is_file_shm_hugepages(struct file *file) | |
309 | +{ | |
310 | + int ret = 0; | |
311 | + | |
312 | + if (file->f_op == &shm_file_operations) { | |
313 | + struct shm_file_data *sfd; | |
314 | + sfd = shm_file_data(file); | |
315 | + ret = is_file_hugepages(sfd->file); | |
316 | + } | |
317 | + return ret; | |
318 | +} | |
319 | + | |
301 | 320 | static const struct file_operations shm_file_operations = { |
302 | 321 | .mmap = shm_mmap, |
322 | + .fsync = shm_fsync, | |
303 | 323 | .release = shm_release, |
304 | 324 | .get_unmapped_area = shm_get_unmapped_area, |
305 | 325 | }; |