Revision 1aef882f023eb7c24d6d77f001bd0ba956fdd861 authored by Linus Torvalds on 24 April 2015, 14:08:41 UTC, committed by Linus Torvalds on 24 April 2015, 14:08:41 UTC
Pull xfs update from Dave Chinner: "This update contains: - RENAME_WHITEOUT support - conversion of per-cpu superblock accounting to use generic counters - new inode mmap lock so that we can lock page faults out of truncate, hole punch and other direct extent manipulation functions to avoid racing mmap writes from causing data corruption - rework of direct IO submission and completion to solve data corruption issue when running concurrent extending DIO writes. Also solves problem of running IO completion transactions in interrupt context during size extending AIO writes. - FALLOC_FL_INSERT_RANGE support for inserting holes into a file via direct extent manipulation to avoid needing to copy data within the file - attribute block header field overflow fix for 64k block size filesystems - Lots of changes to log messaging to be more informative and concise when errors occur. Also prevent a lot of unnecessary log spamming due to cascading failures in error conditions. - lots of cleanups and bug fixes One thing of note is the direct IO fixes that we merged last week after the window opened. Even though a little late, they fix a user reported data corruption and have been pretty well tested. I figured there was not much point waiting another 2 weeks for -rc1 to be released just so I could send them to you..." * tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits) xfs: using generic_file_direct_write() is unnecessary xfs: direct IO EOF zeroing needs to drain AIO xfs: DIO write completion size updates race xfs: DIO writes within EOF don't need an ioend xfs: handle DIO overwrite EOF update completion correctly xfs: DIO needs an ioend for writes xfs: move DIO mapping size calculation xfs: factor DIO write mapping from get_blocks xfs: unlock i_mutex in xfs_break_layouts xfs: kill unnecessary firstused overflow check on attr3 leaf removal xfs: use larger in-core attr firstused field and detect overflow xfs: pass attr geometry to attr leaf header conversion functions xfs: disallow ro->rw remount on norecovery mount xfs: xfs_shift_file_space can be static xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate fs: Add support FALLOC_FL_INSERT_RANGE for fallocate xfs: Fix incorrect positive ENOMEM return xfs: xfs_mru_cache_insert() should use GFP_NOFS xfs: %pF is only for function pointers xfs: fix shadow warning in xfs_da3_root_split() ...
madvise.c
/*
* linux/mm/madvise.c
*
* Copyright (C) 1999 Linus Torvalds
* Copyright (C) 2002 Christoph Hellwig
*/
#include <linux/mman.h>
#include <linux/pagemap.h>
#include <linux/syscalls.h>
#include <linux/mempolicy.h>
#include <linux/page-isolation.h>
#include <linux/hugetlb.h>
#include <linux/falloc.h>
#include <linux/sched.h>
#include <linux/ksm.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/blkdev.h>
#include <linux/swap.h>
#include <linux/swapops.h>
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
* take mmap_sem for writing. Others, which simply traverse vmas, need
* to only take it for reading.
*/
static int madvise_need_mmap_write(int behavior)
{
switch (behavior) {
case MADV_REMOVE:
case MADV_WILLNEED:
case MADV_DONTNEED:
return 0;
default:
/* be safe, default to 1. list exceptions explicitly */
return 1;
}
}
/*
* We can potentially split a vm area into separate
* areas, each area with its own behavior.
*/
static long madvise_behavior(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end, int behavior)
{
struct mm_struct *mm = vma->vm_mm;
int error = 0;
pgoff_t pgoff;
unsigned long new_flags = vma->vm_flags;
switch (behavior) {
case MADV_NORMAL:
new_flags = new_flags & ~VM_RAND_READ & ~VM_SEQ_READ;
break;
case MADV_SEQUENTIAL:
new_flags = (new_flags & ~VM_RAND_READ) | VM_SEQ_READ;
break;
case MADV_RANDOM:
new_flags = (new_flags & ~VM_SEQ_READ) | VM_RAND_READ;
break;
case MADV_DONTFORK:
new_flags |= VM_DONTCOPY;
break;
case MADV_DOFORK:
if (vma->vm_flags & VM_IO) {
error = -EINVAL;
goto out;
}
new_flags &= ~VM_DONTCOPY;
break;
case MADV_DONTDUMP:
new_flags |= VM_DONTDUMP;
break;
case MADV_DODUMP:
if (new_flags & VM_SPECIAL) {
error = -EINVAL;
goto out;
}
new_flags &= ~VM_DONTDUMP;
break;
case MADV_MERGEABLE:
case MADV_UNMERGEABLE:
error = ksm_madvise(vma, start, end, behavior, &new_flags);
if (error)
goto out;
break;
case MADV_HUGEPAGE:
case MADV_NOHUGEPAGE:
error = hugepage_madvise(vma, &new_flags, behavior);
if (error)
goto out;
break;
}
if (new_flags == vma->vm_flags) {
*prev = vma;
goto out;
}
pgoff = vma->vm_pgoff + ((start - vma->vm_start) >> PAGE_SHIFT);
*prev = vma_merge(mm, *prev, start, end, new_flags, vma->anon_vma,
vma->vm_file, pgoff, vma_policy(vma));
if (*prev) {
vma = *prev;
goto success;
}
*prev = vma;
if (start != vma->vm_start) {
error = split_vma(mm, vma, start, 1);
if (error)
goto out;
}
if (end != vma->vm_end) {
error = split_vma(mm, vma, end, 0);
if (error)
goto out;
}
success:
/*
* vm_flags is protected by the mmap_sem held in write mode.
*/
vma->vm_flags = new_flags;
out:
if (error == -ENOMEM)
error = -EAGAIN;
return error;
}
#ifdef CONFIG_SWAP
static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
unsigned long end, struct mm_walk *walk)
{
pte_t *orig_pte;
struct vm_area_struct *vma = walk->private;
unsigned long index;
if (pmd_none_or_trans_huge_or_clear_bad(pmd))
return 0;
for (index = start; index != end; index += PAGE_SIZE) {
pte_t pte;
swp_entry_t entry;
struct page *page;
spinlock_t *ptl;
orig_pte = pte_offset_map_lock(vma->vm_mm, pmd, start, &ptl);
pte = *(orig_pte + ((index - start) / PAGE_SIZE));
pte_unmap_unlock(orig_pte, ptl);
if (pte_present(pte) || pte_none(pte))
continue;
entry = pte_to_swp_entry(pte);
if (unlikely(non_swap_entry(entry)))
continue;
page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE,
vma, index);
if (page)
page_cache_release(page);
}
return 0;
}
static void force_swapin_readahead(struct vm_area_struct *vma,
unsigned long start, unsigned long end)
{
struct mm_walk walk = {
.mm = vma->vm_mm,
.pmd_entry = swapin_walk_pmd_entry,
.private = vma,
};
walk_page_range(start, end, &walk);
lru_add_drain(); /* Push any new pages onto the LRU now */
}
static void force_shm_swapin_readahead(struct vm_area_struct *vma,
unsigned long start, unsigned long end,
struct address_space *mapping)
{
pgoff_t index;
struct page *page;
swp_entry_t swap;
for (; start < end; start += PAGE_SIZE) {
index = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
page = find_get_entry(mapping, index);
if (!radix_tree_exceptional_entry(page)) {
if (page)
page_cache_release(page);
continue;
}
swap = radix_to_swp_entry(page);
page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
NULL, 0);
if (page)
page_cache_release(page);
}
lru_add_drain(); /* Push any new pages onto the LRU now */
}
#endif /* CONFIG_SWAP */
/*
* Schedule all required I/O operations. Do not wait for completion.
*/
static long madvise_willneed(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
struct file *file = vma->vm_file;
#ifdef CONFIG_SWAP
if (!file) {
*prev = vma;
force_swapin_readahead(vma, start, end);
return 0;
}
if (shmem_mapping(file->f_mapping)) {
*prev = vma;
force_shm_swapin_readahead(vma, start, end,
file->f_mapping);
return 0;
}
#else
if (!file)
return -EBADF;
#endif
if (IS_DAX(file_inode(file))) {
/* no bad return value, but ignore advice */
return 0;
}
*prev = vma;
start = ((start - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
if (end > vma->vm_end)
end = vma->vm_end;
end = ((end - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
force_page_cache_readahead(file->f_mapping, file, start, end - start);
return 0;
}
/*
* Application no longer needs these pages. If the pages are dirty,
* it's OK to just throw them away. The app will be more careful about
* data it wants to keep. Be sure to free swap resources too. The
* zap_page_range call sets things up for shrink_active_list to actually free
* these pages later if no one else has touched them in the meantime,
* although we could add these pages to a global reuse list for
* shrink_active_list to pick up before reclaiming other pages.
*
* NB: This interface discards data rather than pushes it out to swap,
* as some implementations do. This has performance implications for
* applications like large transactional databases which want to discard
* pages in anonymous maps after committing to backing store the data
* that was kept in them. There is no reason to write this data out to
* the swap area if the application is discarding it.
*
* An interface that causes the system to free clean pages and flush
* dirty pages is already available as msync(MS_INVALIDATE).
*/
static long madvise_dontneed(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
*prev = vma;
if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
return -EINVAL;
zap_page_range(vma, start, end - start, NULL);
return 0;
}
/*
* Application wants to free up the pages and associated backing store.
* This is effectively punching a hole into the middle of a file.
*/
static long madvise_remove(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
loff_t offset;
int error;
struct file *f;
*prev = NULL; /* tell sys_madvise we drop mmap_sem */
if (vma->vm_flags & (VM_LOCKED | VM_HUGETLB))
return -EINVAL;
f = vma->vm_file;
if (!f || !f->f_mapping || !f->f_mapping->host) {
return -EINVAL;
}
if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
return -EACCES;
offset = (loff_t)(start - vma->vm_start)
+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
/*
* Filesystem's fallocate may need to take i_mutex. We need to
* explicitly grab a reference because the vma (and hence the
* vma's reference to the file) can go away as soon as we drop
* mmap_sem.
*/
get_file(f);
up_read(¤t->mm->mmap_sem);
error = vfs_fallocate(f,
FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
offset, end - start);
fput(f);
down_read(¤t->mm->mmap_sem);
return error;
}
#ifdef CONFIG_MEMORY_FAILURE
/*
* Error injection support for memory error handling.
*/
static int madvise_hwpoison(int bhv, unsigned long start, unsigned long end)
{
struct page *p;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
for (; start < end; start += PAGE_SIZE <<
compound_order(compound_head(p))) {
int ret;
ret = get_user_pages_fast(start, 1, 0, &p);
if (ret != 1)
return ret;
if (PageHWPoison(p)) {
put_page(p);
continue;
}
if (bhv == MADV_SOFT_OFFLINE) {
pr_info("Soft offlining page %#lx at %#lx\n",
page_to_pfn(p), start);
ret = soft_offline_page(p, MF_COUNT_INCREASED);
if (ret)
return ret;
continue;
}
pr_info("Injecting memory failure for page %#lx at %#lx\n",
page_to_pfn(p), start);
/* Ignore return value for now */
memory_failure(page_to_pfn(p), 0, MF_COUNT_INCREASED);
}
return 0;
}
#endif
static long
madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
unsigned long start, unsigned long end, int behavior)
{
switch (behavior) {
case MADV_REMOVE:
return madvise_remove(vma, prev, start, end);
case MADV_WILLNEED:
return madvise_willneed(vma, prev, start, end);
case MADV_DONTNEED:
return madvise_dontneed(vma, prev, start, end);
default:
return madvise_behavior(vma, prev, start, end, behavior);
}
}
static int
madvise_behavior_valid(int behavior)
{
switch (behavior) {
case MADV_DOFORK:
case MADV_DONTFORK:
case MADV_NORMAL:
case MADV_SEQUENTIAL:
case MADV_RANDOM:
case MADV_REMOVE:
case MADV_WILLNEED:
case MADV_DONTNEED:
#ifdef CONFIG_KSM
case MADV_MERGEABLE:
case MADV_UNMERGEABLE:
#endif
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
case MADV_HUGEPAGE:
case MADV_NOHUGEPAGE:
#endif
case MADV_DONTDUMP:
case MADV_DODUMP:
return 1;
default:
return 0;
}
}
/*
* The madvise(2) system call.
*
* Applications can use madvise() to advise the kernel how it should
* handle paging I/O in this VM area. The idea is to help the kernel
* use appropriate read-ahead and caching techniques. The information
* provided is advisory only, and can be safely disregarded by the
* kernel without affecting the correct operation of the application.
*
* behavior values:
* MADV_NORMAL - the default behavior is to read clusters. This
* results in some read-ahead and read-behind.
* MADV_RANDOM - the system should read the minimum amount of data
* on any access, since it is unlikely that the appli-
* cation will need more than what it asks for.
* MADV_SEQUENTIAL - pages in the given range will probably be accessed
* once, so they can be aggressively read ahead, and
* can be freed soon after they are accessed.
* MADV_WILLNEED - the application is notifying the system to read
* some pages ahead.
* MADV_DONTNEED - the application is finished with the given range,
* so the kernel can free resources associated with it.
* MADV_REMOVE - the application wants to free up the given range of
* pages and associated backing store.
* MADV_DONTFORK - omit this area from child's address space when forking:
* typically, to avoid COWing pages pinned by get_user_pages().
* MADV_DOFORK - cancel MADV_DONTFORK: no longer omit this area when forking.
* MADV_MERGEABLE - the application recommends that KSM try to merge pages in
* this area with pages of identical content from other such areas.
* MADV_UNMERGEABLE- cancel MADV_MERGEABLE: no longer merge pages with others.
*
* return values:
* zero - success
* -EINVAL - start + len < 0, start is not page-aligned,
* "behavior" is not a valid value, or application
* is attempting to release locked or shared pages.
* -ENOMEM - addresses in the specified range are not currently
* mapped, or are outside the AS of the process.
* -EIO - an I/O error occurred while paging in data.
* -EBADF - map exists, but area maps something that isn't a file.
* -EAGAIN - a kernel resource was temporarily unavailable.
*/
SYSCALL_DEFINE3(madvise, unsigned long, start, size_t, len_in, int, behavior)
{
unsigned long end, tmp;
struct vm_area_struct *vma, *prev;
int unmapped_error = 0;
int error = -EINVAL;
int write;
size_t len;
struct blk_plug plug;
#ifdef CONFIG_MEMORY_FAILURE
if (behavior == MADV_HWPOISON || behavior == MADV_SOFT_OFFLINE)
return madvise_hwpoison(behavior, start, start+len_in);
#endif
if (!madvise_behavior_valid(behavior))
return error;
if (start & ~PAGE_MASK)
return error;
len = (len_in + ~PAGE_MASK) & PAGE_MASK;
/* Check to see whether len was rounded up from small -ve to zero */
if (len_in && !len)
return error;
end = start + len;
if (end < start)
return error;
error = 0;
if (end == start)
return error;
write = madvise_need_mmap_write(behavior);
if (write)
down_write(¤t->mm->mmap_sem);
else
down_read(¤t->mm->mmap_sem);
/*
* If the interval [start,end) covers some unmapped address
* ranges, just ignore them, but return -ENOMEM at the end.
* - different from the way of handling in mlock etc.
*/
vma = find_vma_prev(current->mm, start, &prev);
if (vma && start > vma->vm_start)
prev = vma;
blk_start_plug(&plug);
for (;;) {
/* Still start < end. */
error = -ENOMEM;
if (!vma)
goto out;
/* Here start < (end|vma->vm_end). */
if (start < vma->vm_start) {
unmapped_error = -ENOMEM;
start = vma->vm_start;
if (start >= end)
goto out;
}
/* Here vma->vm_start <= start < (end|vma->vm_end) */
tmp = vma->vm_end;
if (end < tmp)
tmp = end;
/* Here vma->vm_start <= start < tmp <= (end|vma->vm_end). */
error = madvise_vma(vma, &prev, start, tmp, behavior);
if (error)
goto out;
start = tmp;
if (prev && start < prev->vm_end)
start = prev->vm_end;
error = unmapped_error;
if (start >= end)
goto out;
if (prev)
vma = prev->vm_next;
else /* madvise_remove dropped mmap_sem */
vma = find_vma(current->mm, start);
}
out:
blk_finish_plug(&plug);
if (write)
up_write(¤t->mm->mmap_sem);
else
up_read(¤t->mm->mmap_sem);
return error;
}
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