From 9f618068755b51d19b22c52bc4a2f8084946948e Mon Sep 17 00:00:00 2001 From: Jim Meyering Date: Sat, 5 Feb 2011 22:40:57 +0100 Subject: [PATCH] copy: don't let a failed lseek go undiagnosed Upon failed lseek, sparse_copy_finalize would mistakenly return true. Admittedly, that is very unlikely, since that particular lseek is attempted only if the preceding call to sparse_copy induced a hole at EOF (via lseek on the destination FD). However, now that sparse_copy has an output parameter, N_READ, there is no longer any reason to call lseek (fd, 0, SEEK_CUR), so... * src/copy.c (sparse_copy_finalize): Remove the function. (copy_reg): Call ftruncate with n_read, rather than sparse_copy_finalize with its now-unnecessary lseek. Lasse Collin spotted the bug in sparse_copy_finalize. --- src/copy.c | 18 ++---------------- 1 file changed, 2 insertions(+), 16 deletions(-) diff --git a/src/copy.c b/src/copy.c index f429c006e2..9182c1624a 100644 --- a/src/copy.c +++ b/src/copy.c @@ -233,21 +233,6 @@ sparse_copy (int src_fd, int dest_fd, char *buf, size_t buf_size, return true; } -/* If the file ends with a `hole' (i.e., if sparse_copy set wrote_hole_at_eof), - call this function to record the length of the output file. */ -static bool -sparse_copy_finalize (int dest_fd, char const *dst_name) -{ - off_t len = lseek (dest_fd, 0, SEEK_CUR); - if (0 <= len && ftruncate (dest_fd, len) < 0) - { - error (0, errno, _("truncating %s"), quote (dst_name)); - return false; - } - - return true; -} - /* Perform the O(1) btrfs clone operation, if possible. Upon success, return 0. Otherwise, return -1 and set errno. */ static inline int @@ -1000,8 +985,9 @@ copy_reg (char const *src_name, char const *dst_name, UINTMAX_MAX, &n_read, &wrote_hole_at_eof) || (wrote_hole_at_eof && - ! sparse_copy_finalize (dest_desc, dst_name))) + ftruncate (dest_desc, n_read) < 0)) { + error (0, errno, _("failed to extend %s"), quote (dst_name)); return_val = false; goto close_src_and_dst_desc; } -- 2.47.2