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authorHugh Dickins <hughd@google.com>2012-05-29 22:06:40 (GMT)
committerLinus Torvalds <torvalds@linux-foundation.org>2012-05-29 23:22:22 (GMT)
commit3f31d07571eeea18a7d34db9af21d2285b807a17 (patch)
tree04350a376ef0cbe32cf2ff11067d4a0a920fd093 /mm
parent83e4fa9c16e4af7122e31be3eca5d57881d236fe (diff)
downloadlinux-3f31d07571eeea18a7d34db9af21d2285b807a17.tar.xz
mm/fs: route MADV_REMOVE to FALLOC_FL_PUNCH_HOLE
Now tmpfs supports hole-punching via fallocate(), switch madvise_remove() to use do_fallocate() instead of vmtruncate_range(): which extends madvise(,,MADV_REMOVE) support from tmpfs to ext4, ocfs2 and xfs. There is one more user of vmtruncate_range() in our tree, staging/android's ashmem_shrink(): convert it to use do_fallocate() too (but if its unpinned areas are already unmapped - I don't know - then it would do better to use shmem_truncate_range() directly). Based-on-patch-by: Cong Wang <amwang@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Colin Cross <ccross@android.com> Cc: John Stultz <john.stultz@linaro.org> Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Andreas Dilger <adilger@dilger.ca> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Ben Myers <bpm@sgi.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/madvise.c15
1 files changed, 7 insertions, 8 deletions
diff --git a/mm/madvise.c b/mm/madvise.c
index 1ccbba5..deff1b6 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -11,8 +11,10 @@
#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>
/*
* Any behaviour which results in changes to the vma->vm_flags needs to
@@ -200,8 +202,7 @@ static long madvise_remove(struct vm_area_struct *vma,
struct vm_area_struct **prev,
unsigned long start, unsigned long end)
{
- struct address_space *mapping;
- loff_t offset, endoff;
+ loff_t offset;
int error;
*prev = NULL; /* tell sys_madvise we drop mmap_sem */
@@ -217,16 +218,14 @@ static long madvise_remove(struct vm_area_struct *vma,
if ((vma->vm_flags & (VM_SHARED|VM_WRITE)) != (VM_SHARED|VM_WRITE))
return -EACCES;
- mapping = vma->vm_file->f_mapping;
-
offset = (loff_t)(start - vma->vm_start)
+ ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
- endoff = (loff_t)(end - vma->vm_start - 1)
- + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
- /* vmtruncate_range needs to take i_mutex */
+ /* filesystem's fallocate may need to take i_mutex */
up_read(&current->mm->mmap_sem);
- error = vmtruncate_range(mapping->host, offset, endoff);
+ error = do_fallocate(vma->vm_file,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE,
+ offset, end - start);
down_read(&current->mm->mmap_sem);
return error;
}