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authorHugh Dickins <hughd@google.com>2011-07-25 17:12:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2011-07-25 20:57:10 -0700
commit8a549bea51138be2126a2cc6aabe8f17ef66b79b (patch)
treedc6e0afdf59808238dd44c685d897da98852fca5 /mm
parent85821aab39b3403a8b5731812a930b78684d1642 (diff)
mm: tidy vmtruncate_range and related functions
Use consistent variable names in truncate_pagecache(), truncate_setsize(), vmtruncate() and vmtruncate_range(). unmap_mapping_range() and vmtruncate_range() have mismatched interfaces: don't change either, but make the vmtruncates more precise about what they expect unmap_mapping_range() to do. vmtruncate_range() is currently called only with page-aligned start and end+1: can handle unaligned start, but unaligned end+1 would hit BUG_ON in truncate_inode_pages_range() (lacks partial clearing of the end page). Signed-off-by: Hugh Dickins <hughd@google.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/truncate.c31
1 files changed, 17 insertions, 14 deletions
diff --git a/mm/truncate.c b/mm/truncate.c
index 003c6c685fc..c924764e2ce 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -531,8 +531,8 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
/**
* truncate_pagecache - unmap and remove pagecache that has been truncated
* @inode: inode
- * @old: old file offset
- * @new: new file offset
+ * @oldsize: old file size
+ * @newsize: new file size
*
* inode's new i_size must already be written before truncate_pagecache
* is called.
@@ -544,9 +544,10 @@ EXPORT_SYMBOL_GPL(invalidate_inode_pages2);
* situations such as writepage being called for a page that has already
* had its underlying blocks deallocated.
*/
-void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
+void truncate_pagecache(struct inode *inode, loff_t oldsize, loff_t newsize)
{
struct address_space *mapping = inode->i_mapping;
+ loff_t holebegin = round_up(newsize, PAGE_SIZE);
/*
* unmap_mapping_range is called twice, first simply for
@@ -557,9 +558,9 @@ void truncate_pagecache(struct inode *inode, loff_t old, loff_t new)
* truncate_inode_pages finishes, hence the second
* unmap_mapping_range call must be made for correctness.
*/
- unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
- truncate_inode_pages(mapping, new);
- unmap_mapping_range(mapping, new + PAGE_SIZE - 1, 0, 1);
+ unmap_mapping_range(mapping, holebegin, 0, 1);
+ truncate_inode_pages(mapping, newsize);
+ unmap_mapping_range(mapping, holebegin, 0, 1);
}
EXPORT_SYMBOL(truncate_pagecache);
@@ -589,29 +590,31 @@ EXPORT_SYMBOL(truncate_setsize);
/**
* vmtruncate - unmap mappings "freed" by truncate() syscall
* @inode: inode of the file used
- * @offset: file offset to start truncating
+ * @newsize: file offset to start truncating
*
* This function is deprecated and truncate_setsize or truncate_pagecache
* should be used instead, together with filesystem specific block truncation.
*/
-int vmtruncate(struct inode *inode, loff_t offset)
+int vmtruncate(struct inode *inode, loff_t newsize)
{
int error;
- error = inode_newsize_ok(inode, offset);
+ error = inode_newsize_ok(inode, newsize);
if (error)
return error;
- truncate_setsize(inode, offset);
+ truncate_setsize(inode, newsize);
if (inode->i_op->truncate)
inode->i_op->truncate(inode);
return 0;
}
EXPORT_SYMBOL(vmtruncate);
-int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
+int vmtruncate_range(struct inode *inode, loff_t lstart, loff_t lend)
{
struct address_space *mapping = inode->i_mapping;
+ loff_t holebegin = round_up(lstart, PAGE_SIZE);
+ loff_t holelen = 1 + lend - holebegin;
/*
* If the underlying filesystem is not going to provide
@@ -623,10 +626,10 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
mutex_lock(&inode->i_mutex);
inode_dio_wait(inode);
- unmap_mapping_range(mapping, offset, (end - offset), 1);
- inode->i_op->truncate_range(inode, offset, end);
+ unmap_mapping_range(mapping, holebegin, holelen, 1);
+ inode->i_op->truncate_range(inode, lstart, lend);
/* unmap again to remove racily COWed private pages */
- unmap_mapping_range(mapping, offset, (end - offset), 1);
+ unmap_mapping_range(mapping, holebegin, holelen, 1);
mutex_unlock(&inode->i_mutex);
return 0;