From 363cad7f7e586b385c20e9925b4923683d46deb6 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Sat, 16 Jul 2016 21:59:22 -0700 Subject: [PATCH] f2fs: avoid memory allocation failure due to a long length We need to avoid ENOMEM due to unexpected long length. Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 48 +++++++++++++++++++++++++++++------------------- 1 file changed, 29 insertions(+), 19 deletions(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 47f1f5e36d1c..9f9cb6489997 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -1000,33 +1000,43 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode, static int __exchange_data_block(struct inode *src_inode, struct inode *dst_inode, pgoff_t src, pgoff_t dst, - int len, bool full) + pgoff_t len, bool full) { block_t *src_blkaddr; int *do_replace; + pgoff_t olen; int ret; - src_blkaddr = f2fs_kvzalloc(sizeof(block_t) * len, GFP_KERNEL); - if (!src_blkaddr) - return -ENOMEM; + while (len) { + olen = min((pgoff_t)4 * ADDRS_PER_BLOCK, len); + + src_blkaddr = f2fs_kvzalloc(sizeof(block_t) * olen, GFP_KERNEL); + if (!src_blkaddr) + return -ENOMEM; + + do_replace = f2fs_kvzalloc(sizeof(int) * olen, GFP_KERNEL); + if (!do_replace) { + kvfree(src_blkaddr); + return -ENOMEM; + } + + ret = __read_out_blkaddrs(src_inode, src_blkaddr, + do_replace, src, olen); + if (ret) + goto roll_back; + + ret = __clone_blkaddrs(src_inode, dst_inode, src_blkaddr, + do_replace, src, dst, olen, full); + if (ret) + goto roll_back; + + src += olen; + dst += olen; + len -= olen; - do_replace = f2fs_kvzalloc(sizeof(int) * len, GFP_KERNEL); - if (!do_replace) { kvfree(src_blkaddr); - return -ENOMEM; + kvfree(do_replace); } - - ret = __read_out_blkaddrs(src_inode, src_blkaddr, do_replace, src, len); - if (ret) - goto roll_back; - - ret = __clone_blkaddrs(src_inode, dst_inode, src_blkaddr, - do_replace, src, dst, len, full); - if (ret) - goto roll_back; - - kvfree(src_blkaddr); - kvfree(do_replace); return 0; roll_back: