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| author | Al Viro <viro@zeniv.linux.org.uk> | 2009-11-24 07:43:18 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2009-12-11 06:30:22 -0500 |
| commit | 1a0ef85f84feb13f07b604fcf5b90ef7c2b5c82f (patch) | |
| tree | 2d2ec02c42d69ffbf1c3d027cd8dbd8634754942 /mm/mremap.c | |
| parent | ecc1a8993751de4e82eb18640d631dae1f626bd6 (diff) | |
| download | lwn-1a0ef85f84feb13f07b604fcf5b90ef7c2b5c82f.tar.gz lwn-1a0ef85f84feb13f07b604fcf5b90ef7c2b5c82f.zip | |
do_mremap() untangling, part 3
Take the check for being able to expand vma in place into a separate
helper.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'mm/mremap.c')
| -rw-r--r-- | mm/mremap.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/mm/mremap.c b/mm/mremap.c index 5f346178f16f..90e422c9f410 100644 --- a/mm/mremap.c +++ b/mm/mremap.c @@ -366,6 +366,17 @@ out: return ret; } +static int vma_expandable(struct vm_area_struct *vma, unsigned long delta) +{ + unsigned long max_addr = TASK_SIZE; + if (vma->vm_next) + max_addr = vma->vm_next->vm_start; + if (max_addr - vma->vm_end < delta) + return 0; + /* we need to do arch-specific checks here */ + return 1; +} + /* * Expand (or shrink) an existing mapping, potentially moving it at the * same time (controlled by the MREMAP_MAYMOVE flag and available VM space) @@ -430,11 +441,8 @@ unsigned long do_mremap(unsigned long addr, /* old_len exactly to the end of the area.. */ if (old_len == vma->vm_end - addr) { - unsigned long max_addr = TASK_SIZE; - if (vma->vm_next) - max_addr = vma->vm_next->vm_start; /* can we just expand the current mapping? */ - if (max_addr - addr >= new_len) { + if (vma_expandable(vma, new_len - old_len)) { int pages = (new_len - old_len) >> PAGE_SHIFT; vma_adjust(vma, vma->vm_start, |