aboutsummaryrefslogtreecommitdiffstats
path: root/fs
diff options
context:
space:
mode:
authorHugh Dickins <hugh@veritas.com>2009-03-22 21:41:27 -0400
committerGreg Kroah-Hartman <gregkh@suse.de>2009-03-24 19:38:26 -0400
commit095160aee954688a9bad225952c4bee546541e19 (patch)
tree5f2ceb17b0a414da00b7173384efda8c56c1755c /fs
parentf520360d93cdc37de5d972dac4bf3bdef6a7f6a7 (diff)
sysfs: fix some bin_vm_ops errors
Commit 86c9508eb1c0ce5aa07b5cf1d36b60c54efc3d7a "sysfs: don't block indefinitely for unmapped files" in linux-next crashes the PowerMac G5 when X starts up. It's caught out by the way powerpc's pci_mmap of legacy_mem uses shmem_zero_setup(), substituting a new vma->vm_file whose private_data no longer points to the bin_buffer (substitution done because some versions of X crash if that mmap fails). The fix to this is straightforward: the original vm_file is fput() in that case, so this mmap won't block sysfs at all, so just don't switch over to bin_vm_ops if vm_file has changed. But more fixes made before realizing that was the problem:- It should not be an error if bin_page_mkwrite() finds no underlying page_mkwrite(). Check that a file already mmap'ed has the same underlying vm_ops _before_ pointing vma->vm_ops at bin_vm_ops. If the file being mmap'ed is a shmem/tmpfs file, don't fail the mmap on CONFIG_NUMA=y, just because that has a set_policy and get_policy: provide bin_set_policy, bin_get_policy and bin_migrate. Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Eric Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'fs')
-rw-r--r--fs/sysfs/bin.c89
1 files changed, 79 insertions, 10 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c
index 96cc2bf6a84e..07703d3ff4a1 100644
--- a/fs/sysfs/bin.c
+++ b/fs/sysfs/bin.c
@@ -241,9 +241,12 @@ static int bin_page_mkwrite(struct vm_area_struct *vma, struct page *page)
241 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; 241 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
242 int ret; 242 int ret;
243 243
244 if (!bb->vm_ops || !bb->vm_ops->page_mkwrite) 244 if (!bb->vm_ops)
245 return -EINVAL; 245 return -EINVAL;
246 246
247 if (!bb->vm_ops->page_mkwrite)
248 return 0;
249
247 if (!sysfs_get_active_two(attr_sd)) 250 if (!sysfs_get_active_two(attr_sd))
248 return -EINVAL; 251 return -EINVAL;
249 252
@@ -273,12 +276,78 @@ static int bin_access(struct vm_area_struct *vma, unsigned long addr,
273 return ret; 276 return ret;
274} 277}
275 278
279#ifdef CONFIG_NUMA
280static int bin_set_policy(struct vm_area_struct *vma, struct mempolicy *new)
281{
282 struct file *file = vma->vm_file;
283 struct bin_buffer *bb = file->private_data;
284 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
285 int ret;
286
287 if (!bb->vm_ops || !bb->vm_ops->set_policy)
288 return 0;
289
290 if (!sysfs_get_active_two(attr_sd))
291 return -EINVAL;
292
293 ret = bb->vm_ops->set_policy(vma, new);
294
295 sysfs_put_active_two(attr_sd);
296 return ret;
297}
298
299static struct mempolicy *bin_get_policy(struct vm_area_struct *vma,
300 unsigned long addr)
301{
302 struct file *file = vma->vm_file;
303 struct bin_buffer *bb = file->private_data;
304 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
305 struct mempolicy *pol;
306
307 if (!bb->vm_ops || !bb->vm_ops->get_policy)
308 return vma->vm_policy;
309
310 if (!sysfs_get_active_two(attr_sd))
311 return vma->vm_policy;
312
313 pol = bb->vm_ops->get_policy(vma, addr);
314
315 sysfs_put_active_two(attr_sd);
316 return pol;
317}
318
319static int bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
320 const nodemask_t *to, unsigned long flags)
321{
322 struct file *file = vma->vm_file;
323 struct bin_buffer *bb = file->private_data;
324 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
325 int ret;
326
327 if (!bb->vm_ops || !bb->vm_ops->migrate)
328 return 0;
329
330 if (!sysfs_get_active_two(attr_sd))
331 return 0;
332
333 ret = bb->vm_ops->migrate(vma, from, to, flags);
334
335 sysfs_put_active_two(attr_sd);
336 return ret;
337}
338#endif
339
276static struct vm_operations_struct bin_vm_ops = { 340static struct vm_operations_struct bin_vm_ops = {
277 .open = bin_vma_open, 341 .open = bin_vma_open,
278 .close = bin_vma_close, 342 .close = bin_vma_close,
279 .fault = bin_fault, 343 .fault = bin_fault,
280 .page_mkwrite = bin_page_mkwrite, 344 .page_mkwrite = bin_page_mkwrite,
281 .access = bin_access, 345 .access = bin_access,
346#ifdef CONFIG_NUMA
347 .set_policy = bin_set_policy,
348 .get_policy = bin_get_policy,
349 .migrate = bin_migrate,
350#endif
282}; 351};
283 352
284static int mmap(struct file *file, struct vm_area_struct *vma) 353static int mmap(struct file *file, struct vm_area_struct *vma)
@@ -287,7 +356,6 @@ static int mmap(struct file *file, struct vm_area_struct *vma)
287 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata; 356 struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
288 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr; 357 struct bin_attribute *attr = attr_sd->s_bin_attr.bin_attr;
289 struct kobject *kobj = attr_sd->s_parent->s_dir.kobj; 358 struct kobject *kobj = attr_sd->s_parent->s_dir.kobj;
290 struct vm_operations_struct *vm_ops;
291 int rc; 359 int rc;
292 360
293 mutex_lock(&bb->mutex); 361 mutex_lock(&bb->mutex);
@@ -302,24 +370,25 @@ static int mmap(struct file *file, struct vm_area_struct *vma)
302 goto out_put; 370 goto out_put;
303 371
304 rc = attr->mmap(kobj, attr, vma); 372 rc = attr->mmap(kobj, attr, vma);
305 vm_ops = vma->vm_ops;
306 vma->vm_ops = &bin_vm_ops;
307 if (rc) 373 if (rc)
308 goto out_put; 374 goto out_put;
309 375
310 rc = -EINVAL; 376 /*
311 if (bb->mmapped && bb->vm_ops != vma->vm_ops) 377 * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup()
378 * to satisfy versions of X which crash if the mmap fails: that
379 * substitutes a new vm_file, and we don't then want bin_vm_ops.
380 */
381 if (vma->vm_file != file)
312 goto out_put; 382 goto out_put;
313 383
314#ifdef CONFIG_NUMA
315 rc = -EINVAL; 384 rc = -EINVAL;
316 if (vm_ops && ((vm_ops->set_policy || vm_ops->get_policy || vm_ops->migrate))) 385 if (bb->mmapped && bb->vm_ops != vma->vm_ops)
317 goto out_put; 386 goto out_put;
318#endif
319 387
320 rc = 0; 388 rc = 0;
321 bb->mmapped = 1; 389 bb->mmapped = 1;
322 bb->vm_ops = vm_ops; 390 bb->vm_ops = vma->vm_ops;
391 vma->vm_ops = &bin_vm_ops;
323out_put: 392out_put:
324 sysfs_put_active_two(attr_sd); 393 sysfs_put_active_two(attr_sd);
325out_unlock: 394out_unlock: