Jeff Liu
2013-Aug-02 10:52 UTC
[Ocfs2-devel] [PATCH RESEND] ocfs2: fix NULL pointer dereference in ocfs2_duplicate_clusters_by_page
From: Tiger Yang <tiger.yang at oracle.com> Since ocfs2_cow_file_pos will invoke ocfs2_refcount_icow 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. [Jeff: rebased patch against linux-next tree] Cc: Joel Becker <jlbec at evilplan.org> Cc: Mark Fasheh <mfasheh at suse.com> Acked-by: Tao Ma <tm at tao.ma> Tested-by: David Weber <wb at munzinger.de> Signed-off-by: Tiger Yang <tiger.yang at oracle.com> Signed-off-by: Jie Liu <jeff.liu 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 79736a2..2abf97b 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -1757,7 +1757,7 @@ 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 41000f2..3261d71 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); @@ -2078,7 +2078,7 @@ 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 f1fc172..452068b 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 998b17e..aefe414 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_inode(file); - 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_inode(file); 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, -- 1.7.9.5