From 9d6023a856a1c4f84415dff59b0d5459cc8768db Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Thu, 27 Feb 2020 15:05:48 -0500 Subject: [PATCH] libxfs: use FALLOC_FL_ZERO_RANGE in libxfs_device_zero I had a request from someone who cared about mkfs speed over a slower network block device to look into using faster zeroing methods, particularly for the log, during mkfs. Using FALLOC_FL_ZERO_RANGE is faster in this case than writing a bunch of zeros across a wire. Signed-off-by: Eric Sandeen Reviewed-by: Christoph Hellwig Signed-off-by: Eric Sandeen --- include/builddefs.in | 3 +++ include/linux.h | 22 ++++++++++++++++++++++ libxfs/rdwr.c | 15 +++++++++++---- 3 files changed, 36 insertions(+), 4 deletions(-) diff --git a/include/builddefs.in b/include/builddefs.in index 4700b52..1dd27f7 100644 --- a/include/builddefs.in +++ b/include/builddefs.in @@ -144,6 +144,9 @@ endif ifeq ($(HAVE_GETFSMAP),yes) PCFLAGS+= -DHAVE_GETFSMAP endif +ifeq ($(HAVE_FALLOCATE),yes) +PCFLAGS += -DHAVE_FALLOCATE +endif LIBICU_LIBS = @libicu_LIBS@ LIBICU_CFLAGS = @libicu_CFLAGS@ diff --git a/include/linux.h b/include/linux.h index 8f3c32b..57726bb 100644 --- a/include/linux.h +++ b/include/linux.h @@ -20,6 +20,10 @@ #include #include #include +#include +#if defined(HAVE_FALLOCATE) +#include +#endif #ifdef OVERRIDE_SYSTEM_FSXATTR # define fsxattr sys_fsxattr #endif @@ -164,6 +168,24 @@ static inline void platform_mntent_close(struct mntent_cursor * cursor) endmntent(cursor->mtabp); } +#if defined(FALLOC_FL_ZERO_RANGE) +static inline int +platform_zero_range( + int fd, + xfs_off_t start, + size_t len) +{ + int ret; + + ret = fallocate(fd, FALLOC_FL_ZERO_RANGE, start, len); + if (!ret) + return 0; + return -errno; +} +#else +#define platform_zero_range(fd, s, l) (-EOPNOTSUPP) +#endif + /* * Check whether we have to define FS_IOC_FS[GS]ETXATTR ourselves. These * are a copy of the definitions moved to linux/uapi/fs.h in the 4.5 kernel, diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c index 0d9d720..e2d9d79 100644 --- a/libxfs/rdwr.c +++ b/libxfs/rdwr.c @@ -61,8 +61,18 @@ libxfs_device_zero(struct xfs_buftarg *btp, xfs_daddr_t start, uint len) { xfs_off_t start_offset, end_offset, offset; ssize_t zsize, bytes; + size_t len_bytes; char *z; - int fd; + int error, fd; + + fd = libxfs_device_to_fd(btp->dev); + start_offset = LIBXFS_BBTOOFF64(start); + + /* try to use special zeroing methods, fall back to writes if needed */ + len_bytes = LIBXFS_BBTOOFF64(len); + error = platform_zero_range(fd, start_offset, len_bytes); + if (!error) + return 0; zsize = min(BDSTRAT_SIZE, BBTOB(len)); if ((z = memalign(libxfs_device_alignment(), zsize)) == NULL) { @@ -73,9 +83,6 @@ libxfs_device_zero(struct xfs_buftarg *btp, xfs_daddr_t start, uint len) } memset(z, 0, zsize); - fd = libxfs_device_to_fd(btp->dev); - start_offset = LIBXFS_BBTOOFF64(start); - if ((lseek(fd, start_offset, SEEK_SET)) < 0) { fprintf(stderr, _("%s: %s seek to offset %llu failed: %s\n"), progname, __FUNCTION__, -- 2.9.5