This is a simple interface to test the new readahead-facility. You can trigger a readahead in the kernel for a given tree and key range. The default is to read the full extent tree. You can also specify to wait on it to finish (-w), or choose the traditional tree walk (-t) instead.
Signed-off-by: Arne Jansen <[email protected]> --- Makefile | 5 +- btrfs-reada.c | 180 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ioctl.h | 16 +++++ 3 files changed, 200 insertions(+), 1 deletions(-) create mode 100644 btrfs-reada.c diff --git a/Makefile b/Makefile index 6e6f6c6..3d6ec54 100644 --- a/Makefile +++ b/Makefile @@ -18,7 +18,7 @@ LIBS=-luuid progs = btrfsctl mkfs.btrfs btrfs-debug-tree btrfs-show btrfs-vol btrfsck \ btrfs \ - btrfs-map-logical + btrfs-map-logical btrfs-reada # make C=1 to enable sparse ifdef C @@ -62,6 +62,9 @@ btrfs-debug-tree: $(objects) debug-tree.o btrfs-zero-log: $(objects) btrfs-zero-log.o gcc $(CFLAGS) -o btrfs-zero-log $(objects) btrfs-zero-log.o $(LDFLAGS) $(LIBS) +btrfs-reada: $(objects) btrfs-reada.o + gcc $(CFLAGS) -o btrfs-reada $(objects) btrfs-reada.o $(LDFLAGS) $(LIBS) + btrfstune: $(objects) btrfstune.o gcc $(CFLAGS) -o btrfstune $(objects) btrfstune.o $(LDFLAGS) $(LIBS) diff --git a/btrfs-reada.c b/btrfs-reada.c new file mode 100644 index 0000000..b495017 --- /dev/null +++ b/btrfs-reada.c @@ -0,0 +1,180 @@ +/* + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will 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 to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> +#include <sys/types.h> +#include <dirent.h> +#include <sys/stat.h> +#include <unistd.h> +#include <fcntl.h> +#include <libgen.h> +#include <limits.h> +#include <uuid/uuid.h> +#include <ctype.h> + + +#include "kerncompat.h" +#include "btrfs_cmds.h" +#include "version.h" +#include "ioctl.h" +#include "ctree.h" + +static int open_file_or_dir(const char *fname) +{ + int ret; + struct stat st; + DIR *dirstream; + int fd; + + ret = stat(fname, &st); + if (ret < 0) + return -1; + + if (S_ISDIR(st.st_mode)) { + dirstream = opendir(fname); + if (!dirstream) + return -2; + fd = dirfd(dirstream); + } else { + fd = open(fname, O_RDWR); + } + if (fd < 0) + return -3; + + return fd; +} + +void usage(void) +{ + printf("usage: btrfs-reada [-w] <mntpnt> [<tree> [<start> [<end>]]]\n"); + printf(" <start|end>: max|<num>[:<num>[:<num>]]\n"); + printf(" <tree>: csum|extent|<num>\n"); + printf(" -w: wait\n"); + printf(" -t: read tree the old fashioned way\n"); + exit(1); +} + +void parse_key(struct btrfs_key *key, char *p) +{ + char *n; + + if (strcmp(p, "max") == 0) { + key->objectid = -1LL; + key->type = -1; + key->offset = -1LL; + return; + } + memset(key, 0, sizeof(*key)); + n = strtok(p, ":"); + if (n == NULL) + usage(); + key->objectid = atoll(n); + + n = strtok(p, ":"); + if (n == NULL) + return; + key->type = atoi(n); + + n = strtok(p, ":"); + if (n == NULL) + return; + key->offset = atoll(n); +} + +int main(int argc, char *argv[]) +{ + char *mntpnt; + int fdmnt; + int res; + struct btrfs_ioctl_reada_args reada_args; + u64 tree = BTRFS_EXTENT_TREE_OBJECTID; + int wait = 0; + int trad = 0; + struct btrfs_key start = { 0, 0, 0}; + struct btrfs_key end = { -1LL, -1, -1LL}; + + while (1) { + int c = getopt(argc, argv, "wth"); + if (c < 0) + break; + switch (c) { + case 'w': + wait = 1; + break; + case 't': + trad = 1; + break; + case 'h': + default: + usage(); + } + } + + if (optind < argc) { + mntpnt = argv[optind++]; + } else { + usage(); + exit(1); + } + if (optind < argc) { + char *p = argv[optind++]; + if (strcmp(p, "extent") == 0) { + tree = BTRFS_EXTENT_TREE_OBJECTID; + } else if (strcmp(p, "csum") == 0) { + tree = BTRFS_CSUM_TREE_OBJECTID; + } else { + tree = atoll(p); + if (tree == 0) { + printf("inval tree\n"); + usage(); + } + } + } + if (optind < argc) + parse_key(&start, argv[optind++]); + if (optind < argc) + parse_key(&end, argv[optind++]); + + fdmnt = open_file_or_dir(mntpnt); + if (fdmnt < 0) { + fprintf(stderr, "ERROR: can't access '%s'\n", mntpnt); + return 12; + } + + memset(&reada_args, 0, sizeof(reada_args)); + reada_args.flags = 0; + if (wait) + reada_args.flags |= BTRFS_READA_IOC_FLAGS_WAIT; + if (trad) + reada_args.flags |= BTRFS_READA_IOC_FLAGS_TRAD; + reada_args.tree = tree; + reada_args.start_objectid = start.objectid; + reada_args.start_type = start.type; + reada_args.start_offset = start.offset; + reada_args.end_objectid = end.objectid; + reada_args.end_type = end.type; + reada_args.end_offset = end.offset; + res = ioctl(fdmnt, BTRFS_IOC_READA_TEST, &reada_args); + if (res) + printf("ioctl return %d, %s\n", res, strerror(errno)); + + return 0; +} + diff --git a/ioctl.h b/ioctl.h index 776d7a9..0d90edc 100644 --- a/ioctl.h +++ b/ioctl.h @@ -132,6 +132,20 @@ struct btrfs_ioctl_space_args { struct btrfs_ioctl_space_info spaces[0]; }; +#define BTRFS_READA_IOC_FLAGS_WAIT 1 +#define BTRFS_READA_IOC_FLAGS_TRAD 2 +struct btrfs_ioctl_reada_args { + __u64 flags; + __u64 tree; + __u64 start_objectid; + __u8 start_type; + __u64 start_offset; + __u64 end_objectid; + __u8 end_type; + __u64 end_offset; + __u64 unused[100]; +}; + #define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \ struct btrfs_ioctl_vol_args) #define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \ @@ -169,4 +183,6 @@ struct btrfs_ioctl_space_args { #define BTRFS_IOC_DEFAULT_SUBVOL _IOW(BTRFS_IOCTL_MAGIC, 19, u64) #define BTRFS_IOC_SPACE_INFO _IOWR(BTRFS_IOCTL_MAGIC, 20, \ struct btrfs_ioctl_space_args) +#define BTRFS_IOC_READA_TEST _IOW(BTRFS_IOCTL_MAGIC, 99, \ + struct btrfs_ioctl_reada_args) #endif -- 1.7.3.4 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
