Implement atomic write support to help fuzz atomic writes with fsx. Suggested-by: Ritesh Harjani (IBM) Signed-off-by: Ojaswin Mujoo --- ltp/fsx.c | 109 +++++++++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 104 insertions(+), 5 deletions(-) diff --git a/ltp/fsx.c b/ltp/fsx.c index 163b9453..ea39ca29 100644 --- a/ltp/fsx.c +++ b/ltp/fsx.c @@ -40,6 +40,7 @@ #include #endif #include +#include "statx.h" #ifndef MAP_FILE # define MAP_FILE 0 @@ -49,6 +50,10 @@ #define RWF_DONTCACHE 0x80 #endif +#ifndef RWF_ATOMIC +#define RWF_ATOMIC 0x40 +#endif + #define NUMPRINTCOLUMNS 32 /* # columns of data to print on each line */ /* Operation flags (bitmask) */ @@ -110,6 +115,7 @@ enum { OP_READ_DONTCACHE, OP_WRITE, OP_WRITE_DONTCACHE, + OP_WRITE_ATOMIC, OP_MAPREAD, OP_MAPWRITE, OP_MAX_LITE, @@ -200,6 +206,11 @@ int uring = 0; int mark_nr = 0; int dontcache_io = 1; int hugepages = 0; /* -h flag */ +int do_atomic_writes = 1; /* -a flag disables */ + +/* User for atomic writes */ +int awu_min = 0; +int awu_max = 0; /* Stores info needed to periodically collapse hugepages */ struct hugepages_collapse_info { @@ -288,6 +299,7 @@ static const char *op_names[] = { [OP_READ_DONTCACHE] = "read_dontcache", [OP_WRITE] = "write", [OP_WRITE_DONTCACHE] = "write_dontcache", + [OP_WRITE_ATOMIC] = "write_atomic", [OP_MAPREAD] = "mapread", [OP_MAPWRITE] = "mapwrite", [OP_TRUNCATE] = "truncate", @@ -422,6 +434,7 @@ logdump(void) prt("\t***RRRR***"); break; case OP_WRITE_DONTCACHE: + case OP_WRITE_ATOMIC: case OP_WRITE: prt("WRITE 0x%x thru 0x%x\t(0x%x bytes)", lp->args[0], lp->args[0] + lp->args[1] - 1, @@ -1073,6 +1086,25 @@ update_file_size(unsigned offset, unsigned size) file_size = offset + size; } +static int is_power_of_2(unsigned n) { + return ((n & (n - 1)) == 0); +} + +/* + * Round down n to nearest power of 2. + * If n is already a power of 2, return n; + */ +static int rounddown_pow_of_2(int n) { + int i = 0; + + if (is_power_of_2(n)) + return n; + + for (; (1 << i) < n; i++); + + return 1 << (i - 1); +} + void dowrite(unsigned offset, unsigned size, int flags) { @@ -1081,6 +1113,27 @@ dowrite(unsigned offset, unsigned size, int flags) offset -= offset % writebdy; if (o_direct) size -= size % writebdy; + if (flags & RWF_ATOMIC) { + /* atomic write len must be inbetween awu_min and awu_max */ + if (size < awu_min) + size = awu_min; + if (size > awu_max) + size = awu_max; + + /* atomic writes need power-of-2 sizes */ + size = rounddown_pow_of_2(size); + + /* atomic writes need naturally aligned offsets */ + offset -= offset % size; + + /* Skip the write if we are crossing max filesize */ + if ((offset + size) > maxfilelen) { + if (!quiet && testcalls > simulatedopcount) + prt("skipping atomic write past maxfilelen\n"); + log4(OP_WRITE_ATOMIC, offset, size, FL_SKIPPED); + return; + } + } if (size == 0) { if (!quiet && testcalls > simulatedopcount && !o_direct) prt("skipping zero size write\n"); @@ -1088,7 +1141,10 @@ dowrite(unsigned offset, unsigned size, int flags) return; } - log4(OP_WRITE, offset, size, FL_NONE); + if (flags & RWF_ATOMIC) + log4(OP_WRITE_ATOMIC, offset, size, FL_NONE); + else + log4(OP_WRITE, offset, size, FL_NONE); gendata(original_buf, good_buf, offset, size); if (offset + size > file_size) { @@ -1108,8 +1164,9 @@ dowrite(unsigned offset, unsigned size, int flags) (monitorstart == -1 || (offset + size > monitorstart && (monitorend == -1 || offset <= monitorend)))))) - prt("%lld write\t0x%x thru\t0x%x\t(0x%x bytes)\tdontcache=%d\n", testcalls, - offset, offset + size - 1, size, (flags & RWF_DONTCACHE) != 0); + prt("%lld write\t0x%x thru\t0x%x\t(0x%x bytes)\tdontcache=%d atomic_wr=%d\n", testcalls, + offset, offset + size - 1, size, (flags & RWF_DONTCACHE) != 0, + (flags & RWF_ATOMIC) != 0); iret = fsxwrite(fd, good_buf + offset, size, offset, flags); if (iret != size) { if (iret == -1) @@ -1785,6 +1842,30 @@ do_dedupe_range(unsigned offset, unsigned length, unsigned dest) } #endif +int test_atomic_writes(void) { + int ret; + struct statx stx; + + ret = xfstests_statx(AT_FDCWD, fname, 0, STATX_WRITE_ATOMIC, &stx); + if (ret < 0) { + fprintf(stderr, "main: Statx failed with %d." + " Failed to determine atomic write limits, " + " disabling!\n", ret); + return 0; + } + + if (stx.stx_attributes & STATX_ATTR_WRITE_ATOMIC && + stx.stx_atomic_write_unit_min > 0) { + awu_min = stx.stx_atomic_write_unit_min; + awu_max = stx.stx_atomic_write_unit_max; + return 1; + } + + fprintf(stderr, "main: IO Stack does not support " + "atomic writes, disabling!\n"); + return 0; +} + #ifdef HAVE_COPY_FILE_RANGE int test_copy_range(void) @@ -2356,6 +2437,12 @@ have_op: goto out; } break; + case OP_WRITE_ATOMIC: + if (!do_atomic_writes) { + log4(OP_WRITE_ATOMIC, offset, size, FL_SKIPPED); + goto out; + } + break; } switch (op) { @@ -2385,6 +2472,11 @@ have_op: dowrite(offset, size, 0); break; + case OP_WRITE_ATOMIC: + TRIM_OFF_LEN(offset, size, maxfilelen); + dowrite(offset, size, RWF_ATOMIC); + break; + case OP_MAPREAD: TRIM_OFF_LEN(offset, size, file_size); domapread(offset, size); @@ -2511,13 +2603,14 @@ void usage(void) { fprintf(stdout, "usage: %s", - "fsx [-dfhknqxyzBEFHIJKLORWXZ0]\n\ + "fsx [-adfhknqxyzBEFHIJKLORWXZ0]\n\ [-b opnum] [-c Prob] [-g filldata] [-i logdev] [-j logid]\n\ [-l flen] [-m start:end] [-o oplen] [-p progressinterval]\n\ [-r readbdy] [-s style] [-t truncbdy] [-w writebdy]\n\ [-A|-U] [-D startingop] [-N numops] [-P dirpath] [-S seed]\n\ [--replay-ops=opsfile] [--record-ops[=opsfile]] [--duration=seconds]\n\ ... fname\n\ + -a: disable atomic writes\n\ -b opnum: beginning operation number (default 1)\n\ -c P: 1 in P chance of file close+open at each op (default infinity)\n\ -d: debug output for all operations\n\ @@ -3059,9 +3152,13 @@ main(int argc, char **argv) setvbuf(stdout, (char *)0, _IOLBF, 0); /* line buffered stdout */ while ((ch = getopt_long(argc, argv, - "0b:c:de:fg:hi:j:kl:m:no:p:qr:s:t:uw:xyABD:EFJKHzCILN:OP:RS:UWXZ", + "0ab:c:de:fg:hi:j:kl:m:no:p:qr:s:t:uw:xyABD:EFJKHzCILN:OP:RS:UWXZ", longopts, NULL)) != EOF) switch (ch) { + case 'a': + prt("main(): Atomic writes disabled\n"); + do_atomic_writes = 0; + break; case 'b': simulatedopcount = getnum(optarg, &endp); if (!quiet) @@ -3475,6 +3572,8 @@ main(int argc, char **argv) exchange_range_calls = test_exchange_range(); if (dontcache_io) dontcache_io = test_dontcache_io(); + if (do_atomic_writes) + do_atomic_writes = test_atomic_writes(); while (keep_running()) if (!test()) -- 2.49.0