> On May 7, 2017, at 10:07 AM, Darrick J. Wong <darrick.wong@xxxxxxxxxx> wrote:
>
> Use GETFSMAP to query mounted filesystems for free space information.
> This prevents us from reporting stale free space stats if there happen
> to be uncheckpointed block bitmap updates sitting in the journal.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> configure | 2 -
> configure.ac | 1
> lib/config.h.in | 3 +
> misc/e2freefrag.c | 137 +++++++++++++++++++++++++++++++++++++++++++++++++----
> misc/fsmap.h | 89 ++++++++++++++++++++++++++++++++++
> 5 files changed, 221 insertions(+), 11 deletions(-)
> create mode 100644 misc/fsmap.h
>
> diff --git a/configure b/configure
> index 5f7b429..2d75150 100755
> --- a/configure
> +++ b/configure
> @@ -12368,7 +12368,7 @@ fi
> done
>
> fi
> -for ac_header in dirent.h errno.h execinfo.h getopt.h malloc.h mntent.h paths.h semaphore.h setjmp.h signal.h stdarg.h stdint.h stdlib.h termios.h termio.h unistd.h utime.h attr/xattr.h linux/falloc.h linux/fd.h linux/major.h linux/loop.h net/if_dl.h netinet/in.h sys/acl.h sys/disklabel.h sys/disk.h sys/file.h sys/ioctl.h sys/key.h sys/mkdev.h sys/mman.h sys/mount.h sys/prctl.h sys/resource.h sys/select.h sys/socket.h sys/sockio.h sys/stat.h sys/syscall.h sys/sysctl.h sys/sysmacros.h sys/time.h sys/types.h sys/un.h sys/wait.h
> +for ac_header in dirent.h errno.h execinfo.h getopt.h malloc.h mntent.h paths.h semaphore.h setjmp.h signal.h stdarg.h stdint.h stdlib.h termios.h termio.h unistd.h utime.h attr/xattr.h linux/falloc.h linux/fd.h linux/fsmap.h linux/major.h linux/loop.h net/if_dl.h netinet/in.h sys/acl.h sys/disklabel.h sys/disk.h sys/file.h sys/ioctl.h sys/key.h sys/mkdev.h sys/mman.h sys/mount.h sys/prctl.h sys/resource.h sys/select.h sys/socket.h sys/sockio.h sys/stat.h sys/syscall.h sys/sysctl.h sys/sysmacros.h sys/time.h sys/types.h sys/un.h sys/wait.h
> do :
> as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
> ac_fn_c_check_header_mongrel "$LINENO" "$ac_header" "$as_ac_Header" "$ac_includes_default"
> diff --git a/configure.ac b/configure.ac
> index 9da7b86..a8bc15d 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -918,6 +918,7 @@ AC_CHECK_HEADERS(m4_flatten([
> attr/xattr.h
> linux/falloc.h
> linux/fd.h
> + linux/fsmap.h
> linux/major.h
> linux/loop.h
> net/if_dl.h
> diff --git a/lib/config.h.in b/lib/config.h.in
> index bc006de..37d0c46 100644
> --- a/lib/config.h.in
> +++ b/lib/config.h.in
> @@ -244,6 +244,9 @@
> /* Define to 1 if you have the <linux/fd.h> header file. */
> #undef HAVE_LINUX_FD_H
>
> +/* Define to 1 if you have the <linux/fsmap.h> header file. */
> +#undef HAVE_LINUX_FSMAP_H
> +
> /* Define to 1 if you have the <linux/loop.h> header file. */
> #undef HAVE_LINUX_LOOP_H
>
> diff --git a/misc/e2freefrag.c b/misc/e2freefrag.c
> index 90acb7e..64ed5cd 100644
> --- a/misc/e2freefrag.c
> +++ b/misc/e2freefrag.c
> @@ -25,11 +25,25 @@
> extern char *optarg;
> extern int optind;
> #endif
> +#if defined(HAVE_EXT2_IOCTLS) && !defined(DEBUGFS)
> +# include <sys/ioctl.h>
> +# include <sys/types.h>
> +# include <sys/stat.h>
> +# include <fcntl.h>
> +# include <limits.h>
> +#endif
>
> #include "ext2fs/ext2_fs.h"
> #include "ext2fs/ext2fs.h"
> #include "e2freefrag.h"
>
> +#if defined(HAVE_EXT2_IOCTLS) && !defined(DEBUGFS)
> +# ifdef HAVE_LINUX_FSMAP_H
> +# include <linux/fsmap.h>
> +# endif
> +# include "fsmap.h"
> +#endif
> +
> static void usage(const char *prog)
> {
> fprintf(stderr, "usage: %s [-c chunksize in kb] [-h] "
> @@ -143,8 +157,81 @@ static void scan_block_bitmap(ext2_filsys fs, struct chunk_info *info)
> update_chunk_stats(info, last_chunk_size);
> }
>
> -static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
> - FILE *f)
> +#if defined(HAVE_EXT2_IOCTLS) && !defined(DEBUGFS)
> +# define FSMAP_EXTENTS 1024
> +static int scan_online(ext2_filsys fs, struct chunk_info *info)
> +{
> + struct fsmap_head *fsmap;
> + struct fsmap *extent;
> + struct fsmap *p;
> + int fd = (intptr_t)fs->priv_data;
> + int ret;
> + int i;
> +
> + if (fd < 0)
> + return 0;
> +
> + fsmap = malloc(fsmap_sizeof(FSMAP_EXTENTS));
> + if (!fsmap) {
> + com_err(fs->device_name, errno, "while allocating memory");
> + return 0;
> + }
> +
> + memset(fsmap, 0, sizeof(*fsmap));
> + fsmap->fmh_count = FSMAP_EXTENTS;
> + fsmap->fmh_keys[1].fmr_device = UINT_MAX;
> + fsmap->fmh_keys[1].fmr_physical = ULLONG_MAX;
> + fsmap->fmh_keys[1].fmr_owner = ULLONG_MAX;
> + fsmap->fmh_keys[1].fmr_offset = ULLONG_MAX;
> + fsmap->fmh_keys[1].fmr_flags = UINT_MAX;
> +
> + while (1) {
> + ret = ioctl(fd, FS_IOC_GETFSMAP, fsmap);
> + if (ret < 0) {
> + com_err(fs->device_name, errno, "while calling fsmap");
> + free(fsmap);
> + return 0;
> + }
> +
> + /* No more extents to map, exit */
> + if (!fsmap->fmh_entries)
> + break;
> +
> + for (i = 0, extent = fsmap->fmh_recs;
> + i < fsmap->fmh_entries;
> + i++, extent++) {
> + if (!(extent->fmr_flags & FMR_OF_SPECIAL_OWNER) ||
> + extent->fmr_owner != FMR_OWN_FREE)
> + continue;
> + update_chunk_stats(info,
> + extent->fmr_length / fs->blocksize);
> + }
> +
> + p = &fsmap->fmh_recs[fsmap->fmh_entries - 1];
> + if (p->fmr_flags & FMR_OF_LAST)
> + break;
> + fsmap_advance(fsmap);
> + }
> +
> + return 1;
> +}
> +#else
> +# define scan_online(fs, info) (0)
> +#endif /* HAVE_EXT2_IOCTLS */
> +
> +static errcode_t scan_offline(ext2_filsys fs, struct chunk_info *info)
> +{
> + errcode_t retval;
> +
> + retval = ext2fs_read_block_bitmap(fs);
> + if (retval)
> + return retval;
> + scan_block_bitmap(fs, info);
> + return 0;
> +}
> +
> +static errcode_t dump_chunk_info(ext2_filsys fs, struct chunk_info *info,
> + FILE *f)
> {
> unsigned long total_chunks;
> const char *unitp = "KMGTPEZY";
> @@ -152,8 +239,6 @@ static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
> unsigned long start = 0, end;
> int i, retval = 0;
>
> - scan_block_bitmap(fs, info);
> -
> fprintf(f, "Total blocks: %llu\nFree blocks: %u (%0.1f%%)\n",
> ext2fs_blocks_count(fs->super), fs->super->s_free_blocks_count,
> (double)fs->super->s_free_blocks_count * 100 /
> @@ -215,8 +300,17 @@ static errcode_t get_chunk_info(ext2_filsys fs, struct chunk_info *info,
>
> static void close_device(char *device_name, ext2_filsys fs)
> {
> - int retval = ext2fs_close_free(&fs);
> +#ifndef DEBUGFS
> + int mount_fd;
> +#endif
> + int retval;
>
> +#ifndef DEBUGFS
> + mount_fd = (intptr_t)fs->priv_data;
> + if (mount_fd >= 0)
> + close(mount_fd);
> +#endif
> + retval = ext2fs_close_free(&fs);
> if (retval)
> com_err(device_name, retval, "while closing the filesystem.\n");
> }
> @@ -228,18 +322,19 @@ static void collect_info(ext2_filsys fs, struct chunk_info *chunk_info, FILE *f)
> fprintf(f, "Device: %s\n", fs->device_name);
> fprintf(f, "Blocksize: %u bytes\n", fs->blocksize);
>
> - retval = ext2fs_read_block_bitmap(fs);
> + init_chunk_info(fs, chunk_info);
Should init_chunk_info() be called inside both scan_online() and scan_offline(),
so that it is reset if scan_online() fails internally for some reason?
> +
> + if (!scan_online(fs, chunk_info))
> + retval = scan_offline(fs, chunk_info);
> if (retval) {
> com_err(fs->device_name, retval, "while reading block bitmap");
> close_device(fs->device_name, fs);
> exit(1);
> }
>
> - init_chunk_info(fs, chunk_info);
> -
> - retval = get_chunk_info(fs, chunk_info, f);
> + retval = dump_chunk_info(fs, chunk_info, f);
> if (retval) {
> - com_err(fs->device_name, retval, "while collecting chunk info");
> + com_err(fs->device_name, retval, "while dumping chunk info");
> close_device(fs->device_name, fs);
> exit(1);
> }
> @@ -250,6 +345,11 @@ static void open_device(char *device_name, ext2_filsys *fs)
> {
> int retval;
> int flag = EXT2_FLAG_FORCE | EXT2_FLAG_64BITS;
> +#ifdef HAVE_EXT2_IOCTLS
> + int mount_flags;
> + int mount_fd;
> + char mntpoint[PATH_MAX + 1];
> +#endif
>
> retval = ext2fs_open(device_name, flag, 0, 0, unix_io_manager, fs);
> if (retval) {
> @@ -257,6 +357,23 @@ static void open_device(char *device_name, ext2_filsys *fs)
> exit(1);
> }
> (*fs)->default_bitmap_type = EXT2FS_BMAP64_RBTREE;
> + (*fs)->priv_data = (void *)-1;
> +
> +#ifdef HAVE_EXT2_IOCTLS
> + retval = ext2fs_check_mount_point(device_name, &mount_flags,
> + mntpoint, PATH_MAX);
> + if (retval) {
> + com_err(device_name, retval, "while checking mount status");
> + return;
> + }
> + if (mount_flags & EXT2_MF_MOUNTED) {
> + mount_fd = open(mntpoint, O_RDONLY);
Should this all be done inside scan_online(), since it isn't needed for use
by scan_offline()? That also avoids the need to pass the open mount point
fd via ->priv_data.
Cheers, Andreas
> + if (mount_fd < 0)
> + com_err(mntpoint, errno, "while opening mount point");
> + else
> + (*fs)->priv_data = (void *)(intptr_t)mount_fd;
> + }
> +#endif
> }
> #endif
>
> diff --git a/misc/fsmap.h b/misc/fsmap.h
> new file mode 100644
> index 0000000..e9590aa
> --- /dev/null
> +++ b/misc/fsmap.h
> @@ -0,0 +1,89 @@
> +/*
> + * Copyright (c) 2017 Oracle.
> + * All Rights Reserved.
> + *
> + * Author: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it would be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write the Free Software Foundation,
> + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
> + */
> +#ifndef FSMAP_H_
> +#define FSMAP_H_
> +
> +/* FS_IOC_GETFSMAP ioctl definitions */
> +#ifndef FS_IOC_GETFSMAP
> +struct fsmap {
> + __u32 fmr_device; /* device id */
> + __u32 fmr_flags; /* mapping flags */
> + __u64 fmr_physical; /* device offset of segment */
> + __u64 fmr_owner; /* owner id */
> + __u64 fmr_offset; /* file offset of segment */
> + __u64 fmr_length; /* length of segment */
> + __u64 fmr_reserved[3]; /* must be zero */
> +};
> +
> +struct fsmap_head {
> + __u32 fmh_iflags; /* control flags */
> + __u32 fmh_oflags; /* output flags */
> + __u32 fmh_count; /* # of entries in array incl. input */
> + __u32 fmh_entries; /* # of entries filled in (output). */
> + __u64 fmh_reserved[6]; /* must be zero */
> +
> + struct fsmap fmh_keys[2]; /* low and high keys for the mapping search */
> + struct fsmap fmh_recs[]; /* returned records */
> +};
> +
> +/* Size of an fsmap_head with room for nr records. */
> +static inline size_t
> +fsmap_sizeof(
> + unsigned int nr)
> +{
> + return sizeof(struct fsmap_head) + nr * sizeof(struct fsmap);
> +}
> +
> +/* Start the next fsmap query at the end of the current query results. */
> +static inline void
> +fsmap_advance(
> + struct fsmap_head *head)
> +{
> + head->fmh_keys[0] = head->fmh_recs[head->fmh_entries - 1];
> +}
> +
> +/* fmh_iflags values - set by FS_IOC_GETFSMAP caller in the header. */
> +/* no flags defined yet */
> +#define FMH_IF_VALID 0
> +
> +/* fmh_oflags values - returned in the header segment only. */
> +#define FMH_OF_DEV_T 0x1 /* fmr_device values will be dev_t */
> +
> +/* fmr_flags values - returned for each non-header segment */
> +#define FMR_OF_PREALLOC 0x1 /* segment = unwritten pre-allocation */
> +#define FMR_OF_ATTR_FORK 0x2 /* segment = attribute fork */
> +#define FMR_OF_EXTENT_MAP 0x4 /* segment = extent map */
> +#define FMR_OF_SHARED 0x8 /* segment = shared with another file */
> +#define FMR_OF_SPECIAL_OWNER 0x10 /* owner is a special value */
> +#define FMR_OF_LAST 0x20 /* segment is the last in the FS */
> +
> +/* Each FS gets to define its own special owner codes. */
> +#define FMR_OWNER(type, code) (((__u64)type << 32) | \
> + ((__u64)code & 0xFFFFFFFFULL))
> +#define FMR_OWNER_TYPE(owner) ((__u32)((__u64)owner >> 32))
> +#define FMR_OWNER_CODE(owner) ((__u32)(((__u64)owner & 0xFFFFFFFFULL)))
> +#define FMR_OWN_FREE FMR_OWNER(0, 1) /* free space */
> +#define FMR_OWN_UNKNOWN FMR_OWNER(0, 2) /* unknown owner */
> +#define FMR_OWN_METADATA FMR_OWNER(0, 3) /* metadata */
> +
> +#define FS_IOC_GETFSMAP _IOWR('X', 59, struct fsmap_head)
> +#endif /* FS_IOC_GETFSMAP */
> +
> +#endif
Cheers, Andreas
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