[Ocfs2-devel] [PATCH] ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page
Tiger Yang
tiger.yang at oracle.com
Thu Sep 27 23:57:02 PDT 2012
Since ocfs2_cow_file_pos will invoke ocfs2_refcount_cow with a NULL
as the struct file pointer, it finally result in a null pointer
dereference in ocfs2_duplicate_clusters_by_page.
This patch replace file pointer with inode pointer in
cow_duplicate_clusters to fix this issue.
Signed-off-by: Tiger Yang <tiger.yang at oracle.com>
---
fs/ocfs2/aops.c | 2 +-
fs/ocfs2/file.c | 6 ++--
fs/ocfs2/move_extents.c | 2 +-
fs/ocfs2/refcounttree.c | 53 +++++++---------------------------------------
fs/ocfs2/refcounttree.h | 6 ++--
5 files changed, 16 insertions(+), 53 deletions(-)
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 6577432..8cc8cad 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1755,7 +1755,7 @@ try_again:
goto out;
} else if (ret == 1) {
clusters_need = wc->w_clen;
- ret = ocfs2_refcount_cow(inode, filp, di_bh,
+ ret = ocfs2_refcount_cow(inode, di_bh,
wc->w_cpos, wc->w_clen, UINT_MAX);
if (ret) {
mlog_errno(ret);
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 46a1f6d..e26cd20 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -370,7 +370,7 @@ static int ocfs2_cow_file_pos(struct inode *inode,
if (!(ext_flags & OCFS2_EXT_REFCOUNTED))
goto out;
- return ocfs2_refcount_cow(inode, NULL, fe_bh, cpos, 1, cpos+1);
+ return ocfs2_refcount_cow(inode, fe_bh, cpos, 1, cpos+1);
out:
return status;
@@ -899,7 +899,7 @@ static int ocfs2_zero_extend_get_range(struct inode *inode,
zero_clusters = last_cpos - zero_cpos;
if (needs_cow) {
- rc = ocfs2_refcount_cow(inode, NULL, di_bh, zero_cpos,
+ rc = ocfs2_refcount_cow(inode, di_bh, zero_cpos,
zero_clusters, UINT_MAX);
if (rc) {
mlog_errno(rc);
@@ -2097,7 +2097,7 @@ static int ocfs2_prepare_inode_for_refcount(struct inode *inode,
*meta_level = 1;
- ret = ocfs2_refcount_cow(inode, file, di_bh, cpos, clusters, UINT_MAX);
+ ret = ocfs2_refcount_cow(inode, di_bh, cpos, clusters, UINT_MAX);
if (ret)
mlog_errno(ret);
out:
diff --git a/fs/ocfs2/move_extents.c b/fs/ocfs2/move_extents.c
index 6083432..8519926 100644
--- a/fs/ocfs2/move_extents.c
+++ b/fs/ocfs2/move_extents.c
@@ -69,7 +69,7 @@ static int __ocfs2_move_extent(handle_t *handle,
u64 ino = ocfs2_metadata_cache_owner(context->et.et_ci);
u64 old_blkno = ocfs2_clusters_to_blocks(inode->i_sb, p_cpos);
- ret = ocfs2_duplicate_clusters_by_page(handle, context->file, cpos,
+ ret = ocfs2_duplicate_clusters_by_page(handle, inode, cpos,
p_cpos, new_p_cpos, len);
if (ret) {
mlog_errno(ret);
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 30a0550..2d1bb91 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -49,7 +49,6 @@
struct ocfs2_cow_context {
struct inode *inode;
- struct file *file;
u32 cow_start;
u32 cow_len;
struct ocfs2_extent_tree data_et;
@@ -66,7 +65,7 @@ struct ocfs2_cow_context {
u32 *num_clusters,
unsigned int *extent_flags);
int (*cow_duplicate_clusters)(handle_t *handle,
- struct file *file,
+ struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
};
@@ -2922,14 +2921,12 @@ static int ocfs2_clear_cow_buffer(handle_t *handle, struct buffer_head *bh)
}
int ocfs2_duplicate_clusters_by_page(handle_t *handle,
- struct file *file,
+ struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len)
{
int ret = 0, partial;
- struct inode *inode = file->f_path.dentry->d_inode;
- struct ocfs2_caching_info *ci = INODE_CACHE(inode);
- struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
+ struct super_block *sb = inode->i_sb;
u64 new_block = ocfs2_clusters_to_blocks(sb, new_cluster);
struct page *page;
pgoff_t page_index;
@@ -2973,13 +2970,6 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
if (PAGE_CACHE_SIZE <= OCFS2_SB(sb)->s_clustersize)
BUG_ON(PageDirty(page));
- if (PageReadahead(page)) {
- page_cache_async_readahead(mapping,
- &file->f_ra, file,
- page, page_index,
- readahead_pages);
- }
-
if (!PageUptodate(page)) {
ret = block_read_full_page(page, ocfs2_get_block);
if (ret) {
@@ -2999,7 +2989,8 @@ int ocfs2_duplicate_clusters_by_page(handle_t *handle,
}
}
- ocfs2_map_and_dirty_page(inode, handle, from, to,
+ ocfs2_map_and_dirty_page(inode,
+ handle, from, to,
page, 0, &new_block);
mark_page_accessed(page);
unlock:
@@ -3015,12 +3006,11 @@ unlock:
}
int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
- struct file *file,
+ struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len)
{
int ret = 0;
- struct inode *inode = file->f_path.dentry->d_inode;
struct super_block *sb = inode->i_sb;
struct ocfs2_caching_info *ci = INODE_CACHE(inode);
int i, blocks = ocfs2_clusters_to_blocks(sb, new_len);
@@ -3145,7 +3135,7 @@ static int ocfs2_replace_clusters(handle_t *handle,
/*If the old clusters is unwritten, no need to duplicate. */
if (!(ext_flags & OCFS2_EXT_UNWRITTEN)) {
- ret = context->cow_duplicate_clusters(handle, context->file,
+ ret = context->cow_duplicate_clusters(handle, context->inode,
cpos, old, new, len);
if (ret) {
mlog_errno(ret);
@@ -3423,35 +3413,12 @@ static int ocfs2_replace_cow(struct ocfs2_cow_context *context)
return ret;
}
-static void ocfs2_readahead_for_cow(struct inode *inode,
- struct file *file,
- u32 start, u32 len)
-{
- struct address_space *mapping;
- pgoff_t index;
- unsigned long num_pages;
- int cs_bits = OCFS2_SB(inode->i_sb)->s_clustersize_bits;
-
- if (!file)
- return;
-
- mapping = file->f_mapping;
- num_pages = (len << cs_bits) >> PAGE_CACHE_SHIFT;
- if (!num_pages)
- num_pages = 1;
-
- index = ((loff_t)start << cs_bits) >> PAGE_CACHE_SHIFT;
- page_cache_sync_readahead(mapping, &file->f_ra, file,
- index, num_pages);
-}
-
/*
* Starting at cpos, try to CoW write_len clusters. Don't CoW
* past max_cpos. This will stop when it runs into a hole or an
* unrefcounted extent.
*/
static int ocfs2_refcount_cow_hunk(struct inode *inode,
- struct file *file,
struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos)
{
@@ -3480,8 +3447,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
BUG_ON(cow_len == 0);
- ocfs2_readahead_for_cow(inode, file, cow_start, cow_len);
-
context = kzalloc(sizeof(struct ocfs2_cow_context), GFP_NOFS);
if (!context) {
ret = -ENOMEM;
@@ -3503,7 +3468,6 @@ static int ocfs2_refcount_cow_hunk(struct inode *inode,
context->ref_root_bh = ref_root_bh;
context->cow_duplicate_clusters = ocfs2_duplicate_clusters_by_page;
context->get_clusters = ocfs2_di_get_clusters;
- context->file = file;
ocfs2_init_dinode_extent_tree(&context->data_et,
INODE_CACHE(inode), di_bh);
@@ -3532,7 +3496,6 @@ out:
* clusters between cpos and cpos+write_len are safe to modify.
*/
int ocfs2_refcount_cow(struct inode *inode,
- struct file *file,
struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos)
{
@@ -3552,7 +3515,7 @@ int ocfs2_refcount_cow(struct inode *inode,
num_clusters = write_len;
if (ext_flags & OCFS2_EXT_REFCOUNTED) {
- ret = ocfs2_refcount_cow_hunk(inode, file, di_bh, cpos,
+ ret = ocfs2_refcount_cow_hunk(inode, di_bh, cpos,
num_clusters, max_cpos);
if (ret) {
mlog_errno(ret);
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index 7754608..6422bbc 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -53,7 +53,7 @@ int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
int *credits,
int *ref_blocks);
int ocfs2_refcount_cow(struct inode *inode,
- struct file *filep, struct buffer_head *di_bh,
+ struct buffer_head *di_bh,
u32 cpos, u32 write_len, u32 max_cpos);
typedef int (ocfs2_post_refcount_func)(struct inode *inode,
@@ -85,11 +85,11 @@ int ocfs2_refcount_cow_xattr(struct inode *inode,
u32 cpos, u32 write_len,
struct ocfs2_post_refcount *post);
int ocfs2_duplicate_clusters_by_page(handle_t *handle,
- struct file *file,
+ struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
int ocfs2_duplicate_clusters_by_jbd(handle_t *handle,
- struct file *file,
+ struct inode *inode,
u32 cpos, u32 old_cluster,
u32 new_cluster, u32 new_len);
int ocfs2_cow_sync_writeback(struct super_block *sb,
--
1.7.4.4
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