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-rw-r--r--mm/shmem.c32
1 files changed, 24 insertions, 8 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index d9fc277..65c148e 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -457,7 +457,7 @@ static void shmem_free_pages(struct list_head *next)
} while (next);
}
-static void shmem_truncate(struct inode *inode)
+static void shmem_truncate_range(struct inode *inode, loff_t start, loff_t end)
{
struct shmem_inode_info *info = SHMEM_I(inode);
unsigned long idx;
@@ -475,18 +475,27 @@ static void shmem_truncate(struct inode *inode)
long nr_swaps_freed = 0;
int offset;
int freed;
+ int punch_hole = 0;
inode->i_ctime = inode->i_mtime = CURRENT_TIME;
- idx = (inode->i_size + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ idx = (start + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
if (idx >= info->next_index)
return;
spin_lock(&info->lock);
info->flags |= SHMEM_TRUNCATE;
- limit = info->next_index;
- info->next_index = idx;
+ if (likely(end == (loff_t) -1)) {
+ limit = info->next_index;
+ info->next_index = idx;
+ } else {
+ limit = (end + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
+ if (limit > info->next_index)
+ limit = info->next_index;
+ punch_hole = 1;
+ }
+
topdir = info->i_indirect;
- if (topdir && idx <= SHMEM_NR_DIRECT) {
+ if (topdir && idx <= SHMEM_NR_DIRECT && !punch_hole) {
info->i_indirect = NULL;
nr_pages_to_free++;
list_add(&topdir->lru, &pages_to_free);
@@ -573,11 +582,12 @@ static void shmem_truncate(struct inode *inode)
set_page_private(subdir, page_private(subdir) - freed);
if (offset)
spin_unlock(&info->lock);
- BUG_ON(page_private(subdir) > offset);
+ if (!punch_hole)
+ BUG_ON(page_private(subdir) > offset);
}
if (offset)
offset = 0;
- else if (subdir) {
+ else if (subdir && !page_private(subdir)) {
dir[diroff] = NULL;
nr_pages_to_free++;
list_add(&subdir->lru, &pages_to_free);
@@ -594,7 +604,7 @@ done2:
* Also, though shmem_getpage checks i_size before adding to
* cache, no recheck after: so fix the narrow window there too.
*/
- truncate_inode_pages(inode->i_mapping, inode->i_size);
+ truncate_inode_pages_range(inode->i_mapping, start, end);
}
spin_lock(&info->lock);
@@ -614,6 +624,11 @@ done2:
}
}
+static void shmem_truncate(struct inode *inode)
+{
+ shmem_truncate_range(inode, inode->i_size, (loff_t)-1);
+}
+
static int shmem_notify_change(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
@@ -2083,6 +2098,7 @@ static struct file_operations shmem_file_operations = {
static struct inode_operations shmem_inode_operations = {
.truncate = shmem_truncate,
.setattr = shmem_notify_change,
+ .truncate_range = shmem_truncate_range,
};
static struct inode_operations shmem_dir_inode_operations = {