On Sat, May 13, 2017 at 07:31:43PM -0600, Andreas Dilger wrote:
>
> > 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?
oops, yes, the histogram data ought to be reset.
> > +
> > + 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.
Yes. Good point.
--D
>
> 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
>
>
>
>
>
