On Fri, Sep 06, 2024 at 02:56:06PM -0400, Brian Foster wrote: > The fallocate unshare mode flag modifies traditional preallocate > mode to unshare any shared extents backing the target range. Without > the unshare flag, preallocate mode simply assures that blocks are > physically allocated, regardless of whether they might be shared. > Unshare mode behaves the same as preallocate mode outside of the > shared extent case. > > Since unshare is fundamentally a modifier to preallocate mode, > enable it via an operation flag. Similar to keep size mode, select > it randomly for fallocate operations and track it via a flag and > string combination for operation logging and replay. > > Unshare is mainly used for filesystems that support reflink, but the > operation is equivalent to preallocate mode for non-shared ranges, > so enable it by default. Filesystems that do not support the > fallocate flag (such as those that might not support reflink) will > fail the test operation and disable unshare calls at runtime. Also > provide a new command line option to explicitly disable unshare > calls. > > Signed-off-by: Brian Foster <bfoster@xxxxxxxxxx> > --- > > Hi all, > > A couple quick notes.. > > First, this applies on top of the currently pending EOF pollution > patches [1] to fsx. The patchset [1] has been merged, thanks for doing that. > > Second, this triggers multiple new test failures in my initial tests > that I've not fully diagnosed. I'm not necessarily sure that we want to > hold off on added test coverage for that reason, but I'd like to at > least be sure this isn't due to this patch doing something blatantly > wrong. > > That said, this has also uncovered one or two unshare related issues, so > I'm posting this slightly prematurely in order to share it and hopefully > get some review.. > > Brian > > [1] https://lore.kernel.org/fstests/20240828181534.41054-1-bfoster@xxxxxxxxxx/ > > ltp/fsx.c | 59 ++++++++++++++++++++++++++++++++++++++++++------------- > 1 file changed, 45 insertions(+), 14 deletions(-) > > diff --git a/ltp/fsx.c b/ltp/fsx.c > index 1ba1bf65..003990db 100644 > --- a/ltp/fsx.c > +++ b/ltp/fsx.c > @@ -45,9 +45,14 @@ > > #define NUMPRINTCOLUMNS 32 /* # columns of data to print on each line */ > > -/* Operation flags */ > - > -enum opflags { FL_NONE = 0, FL_SKIPPED = 1, FL_CLOSE_OPEN = 2, FL_KEEP_SIZE = 4 }; > +/* Operation flags (bitmask) */ > +enum opflags { > + FL_NONE = 0, > + FL_SKIPPED = 1, > + FL_CLOSE_OPEN = 2, > + FL_KEEP_SIZE = 4, > + FL_UNSHARE = 8 > +}; > > /* > * A log entry is an operation and a bunch of arguments. > @@ -167,6 +172,7 @@ int seed = 1; /* -S flag */ > int mapped_writes = 1; /* -W flag disables */ > int fallocate_calls = 1; /* -F flag disables */ > int keep_size_calls = 1; /* -K flag disables */ > +int unshare_calls = 1; /* -u 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 */ > @@ -543,6 +549,8 @@ logdump(void) > fprintf(logopsf, " keep_size"); > if (lp->flags & FL_CLOSE_OPEN) > fprintf(logopsf, " close_open"); > + if (lp->flags & FL_UNSHARE) > + fprintf(logopsf, " unshare"); > if (overlap) > fprintf(logopsf, " *"); > fprintf(logopsf, "\n"); > @@ -1879,15 +1887,25 @@ do_copy_range(unsigned offset, unsigned length, unsigned dest) > #ifdef HAVE_LINUX_FALLOC_H > /* fallocate is basically a no-op unless extending, then a lot like a truncate */ > void > -do_preallocate(unsigned offset, unsigned length, int keep_size) > +do_preallocate(unsigned offset, unsigned length, int keep_size, int unshare) > { > unsigned end_offset; > + enum opflags opflags = FL_NONE; > + int mode = 0; > + > + if (keep_size) { > + opflags |= FL_KEEP_SIZE; > + mode |= FALLOC_FL_KEEP_SIZE; > + } > + if (unshare) { > + opflags |= FL_UNSHARE; > + mode |= FALLOC_FL_UNSHARE_RANGE; The FALLOC_FL_UNSHARE_RANGE is not a new flag, but it might be not old enough. The first commit about the FALLOC_FL_UNSHARE_RANGE is: commit 409332b65d3ed8cfa7a8030f1e9d52f372219642 Author: Lukas Czerner <lczerner@xxxxxxxxxx> Date: Thu Mar 13 19:07:42 2014 +1100 fs: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate So "#ifdef FALLOC_FL_UNSHARE_RANGE" maybe needed. Thanks, Zorro > + } > > if (length == 0) { > if (!quiet && testcalls > simulatedopcount) > prt("skipping zero length fallocate\n"); > - log4(OP_FALLOCATE, offset, length, FL_SKIPPED | > - (keep_size ? FL_KEEP_SIZE : FL_NONE)); > + log4(OP_FALLOCATE, offset, length, FL_SKIPPED | opflags); > return; > } > > @@ -1905,8 +1923,7 @@ do_preallocate(unsigned offset, unsigned length, int keep_size) > * 1: extending prealloc > * 2: interior prealloc > */ > - log4(OP_FALLOCATE, offset, length, > - keep_size ? FL_KEEP_SIZE : FL_NONE); > + log4(OP_FALLOCATE, offset, length, opflags); > > if (end_offset > file_size) { > memset(good_buf + file_size, '\0', end_offset - file_size); > @@ -1921,7 +1938,7 @@ do_preallocate(unsigned offset, unsigned length, int keep_size) > end_offset <= monitorend))) > prt("%lld falloc\tfrom 0x%x to 0x%x (0x%x bytes)\n", testcalls, > offset, offset + length, length); > - if (fallocate(fd, keep_size ? FALLOC_FL_KEEP_SIZE : 0, (loff_t)offset, (loff_t)length) == -1) { > + if (fallocate(fd, mode, (loff_t)offset, (loff_t)length) == -1) { > prt("fallocate: 0x%x to 0x%x\n", offset, offset + length); > prterr("do_preallocate: fallocate"); > report_failure(161); > @@ -1929,7 +1946,7 @@ do_preallocate(unsigned offset, unsigned length, int keep_size) > } > #else > void > -do_preallocate(unsigned offset, unsigned length, int keep_size) > +do_preallocate(unsigned offset, unsigned length, int keep_size, int unshare) > { > return; > } > @@ -2095,6 +2112,8 @@ read_op(struct log_entry *log_entry) > log_entry->flags |= FL_KEEP_SIZE; > else if (strcmp(str, "close_open") == 0) > log_entry->flags |= FL_CLOSE_OPEN; > + else if (strcmp(str, "unshare") == 0) > + log_entry->flags |= FL_UNSHARE; > else if (strcmp(str, "*") == 0) > ; /* overlap marker; ignore */ > else > @@ -2161,6 +2180,7 @@ test(void) > unsigned long rv; > unsigned long op; > int keep_size = 0; > + int unshare = 0; > > if (simulatedopcount > 0 && testcalls == simulatedopcount) > writefileimage(); > @@ -2190,6 +2210,7 @@ test(void) > offset2 = log_entry.args[2]; > closeopen = !!(log_entry.flags & FL_CLOSE_OPEN); > keep_size = !!(log_entry.flags & FL_KEEP_SIZE); > + unshare = !!(log_entry.flags & FL_UNSHARE); > goto have_op; > } > return 0; > @@ -2219,8 +2240,12 @@ test(void) > size = random() % maxfilelen; > break; > case OP_FALLOCATE: > - if (fallocate_calls && size && keep_size_calls) > - keep_size = random() % 2; > + if (fallocate_calls && size) { > + if (keep_size_calls) > + keep_size = random() % 2; > + if (unshare_calls) > + unshare = random() % 2; > + } > break; > case OP_ZERO_RANGE: > if (zero_range_calls && size && keep_size_calls) > @@ -2334,7 +2359,7 @@ have_op: > > case OP_FALLOCATE: > TRIM_OFF_LEN(offset, size, maxfilelen); > - do_preallocate(offset, size, keep_size); > + do_preallocate(offset, size, keep_size, unshare); > break; > > case OP_PUNCH_HOLE: > @@ -2469,6 +2494,7 @@ usage(void) > -r readbdy: 4096 would make reads page aligned (default 1)\n\ > -s style: 1 gives smaller truncates (default 0)\n\ > -t truncbdy: 4096 would make truncates page aligned (default 1)\n\ > + -u Do not use unshare range\n\ > -w writebdy: 4096 would make writes page aligned (default 1)\n\ > -x: preallocate file space before starting, XFS only\n\ > -y: synchronize changes to a file\n" > @@ -2853,7 +2879,7 @@ main(int argc, char **argv) > setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */ > > while ((ch = getopt_long(argc, argv, > - "0b:c:de:fg:i:j:kl:m:no:p:qr:s:t:w:xyABD:EFJKHzCILN:OP:RS:UWXZ", > + "0b:c:de:fg:i:j:kl:m:no:p:qr:s:t:uw:xyABD:EFJKHzCILN:OP:RS:UWXZ", > longopts, NULL)) != EOF) > switch (ch) { > case 'b': > @@ -2952,6 +2978,9 @@ main(int argc, char **argv) > if (truncbdy <= 0) > usage(); > break; > + case 'u': > + unshare_calls = 0; > + break; > case 'w': > writebdy = getnum(optarg, &endp); > if (writebdy <= 0) > @@ -3242,6 +3271,8 @@ main(int argc, char **argv) > fallocate_calls = test_fallocate(0); > if (keep_size_calls) > keep_size_calls = test_fallocate(FALLOC_FL_KEEP_SIZE); > + if (unshare_calls) > + unshare_calls = test_fallocate(FALLOC_FL_UNSHARE_RANGE); > if (punch_hole_calls) > punch_hole_calls = test_fallocate(FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE); > if (zero_range_calls) > -- > 2.45.0 > >
