From 90f446f9b04ab820a99b9408e68c01dc6b57056c Mon Sep 17 00:00:00 2001 From: rpm-build Date: Mon, 28 Jul 2014 08:10:10 +0200 Subject: [PATCH 2/9] vfat-like FS & sparse (still downstream) Fix extracting sparse files to a file system like vfat, when ftruncate may fail to grow the size of a file. Still downstram, (do we need this now? ftruncate & vfat works is now OK). Resolves: #179507 Upstream bugreport: http://lists.gnu.org/archive/html/bug-tar/2006-02/msg00000.html --- src/system.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/src/system.c b/src/system.c index 9414233..37e9a3e 100644 --- a/src/system.c +++ b/src/system.c @@ -243,8 +243,25 @@ sys_compare_links (struct stat *link_data, struct stat *stat_data) int sys_truncate (int fd) { + struct stat st; off_t pos = lseek (fd, (off_t) 0, SEEK_CUR); - return pos < 0 ? -1 : ftruncate (fd, pos); + + if ( pos < 0) + return -1; + + if ( ftruncate(fd, pos) && errno == EPERM ) { + /* wrapper around ftruncate: + * ftruncate may fail to grow the size of a file with some OS and filesystem + * combinations. Linux and vfat/fat is one example. If this is the case do + * a write to grow the file to the desired length. + */ + if( (fstat( fd, &st ) == -1) || + (st.st_size >= pos) || + (lseek( fd, pos - 1, SEEK_SET) == (off_t)-1) || + (write( fd, "\0", 1) == -1) ) + return -1; + } + return 0; } /* Return nonzero if NAME is the name of a regular file, or if the file -- 1.9.3