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author | Pádraig Brady <P@draigBrady.com> | 2013-11-07 12:32:29 +0000 |
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committer | Pádraig Brady <P@draigBrady.com> | 2013-11-08 13:39:35 +0000 |
commit | 90181a5926e96f34b5ffff21b81a2874a846ff6f (patch) | |
tree | 6cdda1ab6f90c873542c11de9a6d1b9dab667242 /src/shred.c | |
parent | c2eaef2f57153a22b6dc075b1adc9fde1a4eb7bd (diff) | |
download | coreutils-90181a5926e96f34b5ffff21b81a2874a846ff6f.tar.xz |
shred: avoid data write pass with --size=0
* src/shred.c (dopass): Exit early to avoid redundant heap
allocation, and more importantly avoiding a file sync
when we're writting no data, as this can have side effects.
Also with --verbose, this avoids printing of "pass status"
which could be confusing as to whether data was actually written.
* tests/misc/shred-passes.sh: Ensure the status for data
passes are not written when not doing any data writes.
Diffstat (limited to 'src/shred.c')
-rw-r--r-- | src/shred.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/shred.c b/src/shred.c index 6ff8322c9..95a255a5b 100644 --- a/src/shred.c +++ b/src/shred.c @@ -378,6 +378,10 @@ dopass (int fd, char const *qname, off_t *sizep, int type, size_t soff; /* Offset into buffer for next write */ ssize_t ssize; /* Return value from write */ + /* Do nothing for --size=0 or regular empty files with --exact. */ + if (size == 0) + return 0; + /* Fill pattern buffer. Aligning it to a page so we can do direct I/O. */ size_t page_size = getpagesize (); #define PERIODIC_OUTPUT_SIZE (60 * 1024) |