From 9b6e817d022fd44fe99db92f00d4b18ac2d8f429 Mon Sep 17 00:00:00 2001 From: Gerhard Heift Date: Thu, 30 Jan 2014 16:24:00 +0100 Subject: [PATCH] btrfs: tree_search, copy_to_sk: return needed size on EOVERFLOW If an item in tree_search is too large to be stored in the given buffer, return the needed size (including the header). Signed-off-by: Gerhard Heift Signed-off-by: Chris Mason Acked-by: David Sterba --- fs/btrfs/ioctl.c | 24 +++++++++++++++--------- 1 file changed, 15 insertions(+), 9 deletions(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 6e09fc1c1c18..3d89fd888399 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1957,7 +1957,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key, struct btrfs_ioctl_search_key *sk, - size_t buf_size, + size_t *buf_size, char *buf, unsigned long *sk_offset, int *num_found) @@ -1990,7 +1990,7 @@ static noinline int copy_to_sk(struct btrfs_root *root, if (!key_in_sk(key, sk)) continue; - if (sizeof(sh) + item_len > buf_size) { + if (sizeof(sh) + item_len > *buf_size) { if (*num_found) { ret = 1; goto out; @@ -2001,11 +2001,12 @@ static noinline int copy_to_sk(struct btrfs_root *root, * handle -EOVERFLOW */ + *buf_size = sizeof(sh) + item_len; item_len = 0; ret = -EOVERFLOW; } - if (sizeof(sh) + item_len + *sk_offset > buf_size) { + if (sizeof(sh) + item_len + *sk_offset > *buf_size) { ret = 1; goto out; } @@ -2056,7 +2057,7 @@ out: static noinline int search_ioctl(struct inode *inode, struct btrfs_ioctl_search_key *sk, - size_t buf_size, + size_t *buf_size, char *buf) { struct btrfs_root *root; @@ -2067,8 +2068,10 @@ static noinline int search_ioctl(struct inode *inode, int num_found = 0; unsigned long sk_offset = 0; - if (buf_size < sizeof(struct btrfs_ioctl_search_header)) + if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) { + *buf_size = sizeof(struct btrfs_ioctl_search_header); return -EOVERFLOW; + } path = btrfs_alloc_path(); if (!path) @@ -2121,9 +2124,10 @@ err: static noinline int btrfs_ioctl_tree_search(struct file *file, void __user *argp) { - struct btrfs_ioctl_search_args *args; - struct inode *inode; - int ret; + struct btrfs_ioctl_search_args *args; + struct inode *inode; + int ret; + size_t buf_size; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -2132,8 +2136,10 @@ static noinline int btrfs_ioctl_tree_search(struct file *file, if (IS_ERR(args)) return PTR_ERR(args); + buf_size = sizeof(args->buf); + inode = file_inode(file); - ret = search_ioctl(inode, &args->key, sizeof(args->buf), args->buf); + ret = search_ioctl(inode, &args->key, &buf_size, args->buf); /* * In the origin implementation an overflow is handled by returning a -- 2.20.1