Re: [PATCH 1/2] fsx: Add fallocate collapse range operation

Lukáš Czerner
2014-04-02T15:55:16Z

On Wed, 2 Apr 2014, Lukas Czerner wrote:

> Date: Wed, 2 Apr 2014 17:33:19 +0200
> From: Lukas Czerner <lczerner@redhat.com>
> To: xfs@oss.sgi.com
> Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
> Lukas Czerner <lczerner@redhat.com>
> Subject: [PATCH 1/2] fsx: Add fallocate collapse range operation
>
> This commit adds fallocate FALLOC_FL_COLLAPSE_RANGE support for fsx.

Btw, this actually makes the fsx fail on ext4 and xfs after a while.
I was trying to find a problem in fsx itself but I think it is
actually ok. That means that we could possibly have bugs in ext4 and
xfs collapse range implementation. More eyes are needed on this!

Thanks!
-Lukas

>
> Signed-off-by: Lukas Czerner <lczerner@redhat.com>
> ---
> ltp/fsx.c | 107 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----
> 1 file changed, 100 insertions(+), 7 deletions(-)
>
> diff --git a/ltp/fsx.c b/ltp/fsx.c
> index bd1ed76..47d3ee8 100644
> --- a/ltp/fsx.c
> +++ b/ltp/fsx.c
> @@ -90,11 +90,12 @@ int logcount = 0; /* total ops */
> #define OP_MAX_LITE 4
>
> /* !lite operations */
> -#define OP_TRUNCATE 4
> -#define OP_FALLOCATE 5
> -#define OP_PUNCH_HOLE 6
> -#define OP_ZERO_RANGE 7
> -#define OP_MAX_FULL 8
> +#define OP_TRUNCATE 4
> +#define OP_FALLOCATE 5
> +#define OP_PUNCH_HOLE 6
> +#define OP_ZERO_RANGE 7
> +#define OP_COLLAPSE_RANGE 8
> +#define OP_MAX_FULL 9
>
> /* operation modifiers */
> #define OP_CLOSEOPEN 100
> @@ -111,6 +112,7 @@ char *temp_buf; /* a pointer to the current data */
> char *fname; /* name of our test file */
> int fd; /* fd for our test file */
>
> +blksize_t block_size = 0;
> off_t file_size = 0;
> off_t biggest = 0;
> char state[256];
> @@ -142,6 +144,7 @@ int mapped_writes = 1; /* -W flag disables */
> int fallocate_calls = 1; /* -F flag disables */
> int punch_hole_calls = 1; /* -H flag disables */
> int zero_range_calls = 1; /* -z flag disables */
> +int collapse_range_calls = 1; /* -C flag disables */
> int mapped_reads = 1; /* -R flag disables it */
> int fsxgoodfd = 0;
> int o_direct; /* -Z */
> @@ -321,13 +324,21 @@ logdump(void)
> prt("\t******PPPP");
> break;
> case OP_ZERO_RANGE:
> - prt("ZERO 0x%x thru 0x%x\t(0x%x bytes)",
> + prt("ZERO 0x%x thru 0x%x\t(0x%x bytes)",
> lp->args[0], lp->args[0] + lp->args[1] - 1,
> lp->args[1]);
> if (badoff >= lp->args[0] && badoff <
> lp->args[0] + lp->args[1])
> prt("\t******ZZZZ");
> break;
> + case OP_COLLAPSE_RANGE:
> + prt("COLLAPSE 0x%x thru 0x%x\t(0x%x bytes)",
> + lp->args[0], lp->args[0] + lp->args[1] - 1,
> + lp->args[1]);
> + if (badoff >= lp->args[0] && badoff <
> + lp->args[0] + lp->args[1])
> + prt("\t******CCCC");
> + break;
> case OP_SKIPPED:
> prt("SKIPPED (no operation)");
> break;
> @@ -949,6 +960,58 @@ do_zero_range(unsigned offset, unsigned length)
> }
> #endif
>
> +#ifdef FALLOC_FL_COLLAPSE_RANGE
> +void
> +do_collapse_range(unsigned offset, unsigned length)
> +{
> + unsigned end_offset;
> + int mode = FALLOC_FL_COLLAPSE_RANGE;
> +
> + if (length == 0) {
> + if (!quiet && testcalls > simulatedopcount)
> + prt("skipping zero length collapse range\n");
> + log4(OP_SKIPPED, OP_COLLAPSE_RANGE, offset, length);
> + return;
> + }
> +
> + end_offset = offset + length;
> + if ((loff_t)end_offset >= file_size) {
> + if (!quiet && testcalls > simulatedopcount)
> + prt("skipping collapse range behind EOF\n");
> + log4(OP_SKIPPED, OP_COLLAPSE_RANGE, offset, length);
> + return;
> + }
> +
> + log4(OP_COLLAPSE_RANGE, offset, length, 0);
> +
> + if (testcalls <= simulatedopcount)
> + return;
> +
> + if ((progressinterval && testcalls % progressinterval == 0) ||
> + (debug && (monitorstart == -1 || monitorend == -1 ||
> + end_offset <= monitorend))) {
> + prt("%lu collapse\tfrom 0x%x to 0x%x, (0x%x bytes)\n", testcalls,
> + offset, offset+length, length);
> + }
> + if (fallocate(fd, mode, (loff_t)offset, (loff_t)length) == -1) {
> + prt("collapse range: %x to %x\n", offset, length);
> + prterr("do_collapse_range: fallocate");
> + report_failure(161);
> + }
> +
> + memmove(good_buf + offset, good_buf + end_offset,
> + file_size - end_offset);
> + file_size -= length;
> +}
> +
> +#else
> +void
> +do_collapse_range(unsigned offset, unsigned length)
> +{
> + return;
> +}
> +#endif
> +
> #ifdef HAVE_LINUX_FALLOC_H
> /* fallocate is basically a no-op unless extending, then a lot like a truncate */
> void
> @@ -1123,6 +1186,12 @@ test(void)
> goto out;
> }
> break;
> + case OP_COLLAPSE_RANGE:
> + if (!collapse_range_calls) {
> + log4(OP_SKIPPED, OP_COLLAPSE_RANGE, offset, size);
> + goto out;
> + }
> + break;
> }
>
> switch (op) {
> @@ -1165,6 +1234,16 @@ test(void)
> TRIM_OFF_LEN(offset, size, file_size);
> do_zero_range(offset, size);
> break;
> + case OP_COLLAPSE_RANGE:
> + TRIM_OFF_LEN(offset, size, file_size - 1);
> + offset = offset & ~(block_size - 1);
> + size = size & ~(block_size - 1);
> + if (size == 0) {
> + log4(OP_SKIPPED, OP_COLLAPSE_RANGE, offset, size);
> + goto out;
> + }
> + do_collapse_range(offset, size);
> + break;
> default:
> prterr("test: unknown operation");
> report_failure(42);
> @@ -1225,6 +1304,9 @@ usage(void)
> #ifdef FALLOC_FL_ZERO_RANGE
> " -z: Do not use zero range calls\n"
> #endif
> +#ifdef FALLOC_FL_COLLAPSE_RANGE
> +" -C: Do not use collapse range calls\n"
> +#endif
> " -L: fsxLite - no file creations & no file size changes\n\
> -N numops: total # operations to do (default infinity)\n\
> -O: use oplen (see -o flag) for every op (default random)\n\
> @@ -1399,6 +1481,7 @@ main(int argc, char **argv)
> char *endp;
> char goodfile[1024];
> char logfile[1024];
> + struct stat statbuf;
>
> goodfile[0] = 0;
> logfile[0] = 0;
> @@ -1410,7 +1493,7 @@ main(int argc, char **argv)
>
> setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */
>
> - while ((ch = getopt(argc, argv, "b:c:dfl:m:no:p:qr:s:t:w:xyAD:FHzLN:OP:RS:WZ"))
> + while ((ch = getopt(argc, argv, "b:c:dfl:m:no:p:qr:s:t:w:xyAD:FHzCLN:OP:RS:WZ"))
> != EOF)
> switch (ch) {
> case 'b':
> @@ -1513,6 +1596,9 @@ main(int argc, char **argv)
> case 'z':
> zero_range_calls = 0;
> break;
> + case 'C':
> + collapse_range_calls = 0;
> + break;
> case 'L':
> lite = 1;
> break;
> @@ -1579,6 +1665,11 @@ main(int argc, char **argv)
> prterr(fname);
> exit(91);
> }
> + if (fstat(fd, &statbuf)) {
> + prterr("check_size: fstat");
> + exit(91);
> + }
> + block_size = statbuf.st_blksize;
> #ifdef XFS
> if (prealloc) {
> xfs_flock64_t resv = { 0 };
> @@ -1665,6 +1756,8 @@ main(int argc, char **argv)
> FALLOC_FL_KEEP_SIZE);
> if (zero_range_calls)
> zero_range_calls = test_fallocate(FALLOC_FL_ZERO_RANGE);
> + if (collapse_range_calls)
> + collapse_range_calls = test_fallocate(FALLOC_FL_COLLAPSE_RANGE);
>
> while (numops == -1 || numops--)
> test();
>