btrfs-progs/cmds-fi-du.c
Goffredo Baroncelli b5665d66e8 btrfs-progs: fi du: don't call lookup_path_rootid for BTRFS_EMPTY_SUBVOL_DIR_OBJECTID
When ino is BTRFS_EMPTY_SUBVOL_DIR_OBJECTID, the item is not referred to
any file-tree. So lookup_path_rootid() doesn't return any meaningful
value.

As was reported, this can be triggered by

$ btrfs sub create test1
$ btrfs sub create test1/test2
$ btrfs sub snap test1 test1.snap
$ btrfs fi du -s test1
  Total   Exclusive  Set shared  Filename
  0.00B       0.00B       0.00B  test1
$ btrfs fi du -s test1.snap
  Total   Exclusive  Set shared  Filename
ERROR: cannot check space of 'test1.snap': Inappropriate ioctl for device

Signed-off-by: Goffredo Baroncelli <kreijack@inwind.it>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-09-08 16:15:05 +02:00

614 lines
13 KiB
C

/*
* 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.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <getopt.h>
#include <fcntl.h>
#include <dirent.h>
#include <sys/ioctl.h>
#include <linux/fs.h>
#include <linux/version.h>
#include <linux/fiemap.h>
#if !defined(FIEMAP_EXTENT_SHARED) && (HAVE_OWN_FIEMAP_EXTENT_SHARED_DEFINE == 1)
#define FIEMAP_EXTENT_SHARED 0x00002000
#endif
#include "utils.h"
#include "commands.h"
#include "kerncompat.h"
#include "rbtree.h"
#include "interval_tree_generic.h"
#include "help.h"
#include "fsfeatures.h"
static int summarize = 0;
static unsigned unit_mode = UNITS_RAW;
static char path[PATH_MAX] = { 0, };
static char *pathp = path;
static char *path_max = &path[PATH_MAX - 1];
struct shared_extent {
struct rb_node rb;
u64 start; /* Start of interval */
u64 last; /* Last location _in_ interval */
u64 __subtree_last;
};
/*
* extent_tree_* functions are defined in the massive interval tree
* macro below. This serves to illustrate the api in human-readable
* terms.
*/
static void
extent_tree_insert(struct shared_extent *node, struct rb_root *root);
static void
extent_tree_remove(struct shared_extent *node, struct rb_root *root);
static struct shared_extent *
extent_tree_iter_first(struct rb_root *root,
u64 start, u64 last);
static struct shared_extent *
extent_tree_iter_next(struct shared_extent *node,
u64 start, u64 last);
#define START(node) ((node)->start)
#define LAST(node) ((node)->last)
INTERVAL_TREE_DEFINE(struct shared_extent, rb,
u64, __subtree_last,
START, LAST, static, extent_tree)
static int add_shared_extent(u64 start, u64 len, struct rb_root *root)
{
struct shared_extent *sh;
ASSERT(len != 0);
sh = calloc(1, sizeof(*sh));
if (!sh)
return -ENOMEM;
sh->start = start;
sh->last = (start + len - 1);
extent_tree_insert(sh, root);
return 0;
}
static void cleanup_shared_extents(struct rb_root *root)
{
struct shared_extent *s;
struct shared_extent *tmp;
if (!root)
return;
s = extent_tree_iter_first(root, 0, -1ULL);
while (s) {
tmp = extent_tree_iter_next(s, 0, -1ULL);
extent_tree_remove(s, root);
free(s);
s = tmp;
}
}
#define dbgprintf(...)
/*
* Find all extents which overlap 'n', calculate the space
* covered by them and remove those nodes from the tree.
*/
static u64 count_unique_bytes(struct rb_root *root, struct shared_extent *n)
{
struct shared_extent *tmp;
u64 wstart = n->start;
u64 wlast = n->last;
dbgprintf("Count overlaps:");
do {
/*
* Expand our search window based on the lastest
* overlapping extent. Doing this will allow us to
* find all possible overlaps
*/
if (wstart > n->start)
wstart = n->start;
if (wlast < n->last)
wlast = n->last;
dbgprintf(" (%llu, %llu)", n->start, n->last);
tmp = n;
n = extent_tree_iter_next(n, wstart, wlast);
extent_tree_remove(tmp, root);
free(tmp);
} while (n);
dbgprintf("; wstart: %llu wlast: %llu total: %llu\n", wstart,
wlast, wlast - wstart + 1);
return wlast - wstart + 1;
}
/*
* What we want to do here is get a count of shared bytes within the
* set of extents we have collected. Specifically, we don't want to
* count any byte more than once, so just adding them up doesn't
* work.
*
* For each set of overlapping extents we find the lowest start and
* highest end. From there we have the actual number of bytes which is
* shared across all of the extents in our set. A sum of each sets
* extent length is returned.
*/
static void count_shared_bytes(struct rb_root *root, u64 *ret_cnt)
{
u64 count = 0;
struct shared_extent *s = extent_tree_iter_first(root,
0, -1ULL);
if (!s)
goto out;
while (s) {
/*
* Find all extents which overlap 's', calculate the space
* covered by them and remove those nodes from the tree.
*/
count += count_unique_bytes(root, s);
/*
* Since count_unique_bytes will be emptying the tree,
* we can grab the first node here
*/
s = extent_tree_iter_first(root, 0, -1ULL);
}
BUG_ON(!RB_EMPTY_ROOT(root));
out:
*ret_cnt = count;
}
/* Track which inodes we've seen for the purposes of hardlink detection. */
struct seen_inode {
struct rb_node i_node;
u64 i_ino;
u64 i_subvol;
};
static struct rb_root seen_inodes = RB_ROOT;
static int cmp_si(struct seen_inode *si, u64 ino, u64 subvol)
{
if (ino < si->i_ino)
return -1;
else if (ino > si->i_ino)
return 1;
if (subvol < si->i_subvol)
return -1;
else if (subvol > si->i_subvol)
return 1;
return 0;
}
static int mark_inode_seen(u64 ino, u64 subvol)
{
int cmp;
struct rb_node **p = &seen_inodes.rb_node;
struct rb_node *parent = NULL;
struct seen_inode *si;
while (*p) {
parent = *p;
si = rb_entry(parent, struct seen_inode, i_node);
cmp = cmp_si(si, ino, subvol);
if (cmp < 0)
p = &(*p)->rb_left;
else if (cmp > 0)
p = &(*p)->rb_right;
else
return -EEXIST;
}
si = calloc(1, sizeof(*si));
if (!si)
return -ENOMEM;
si->i_ino = ino;
si->i_subvol = subvol;
rb_link_node(&si->i_node, parent, p);
rb_insert_color(&si->i_node, &seen_inodes);
return 0;
}
static int inode_seen(u64 ino, u64 subvol)
{
int cmp;
struct rb_node *n = seen_inodes.rb_node;
struct seen_inode *si;
while (n) {
si = rb_entry(n, struct seen_inode, i_node);
cmp = cmp_si(si, ino, subvol);
if (cmp < 0)
n = n->rb_left;
else if (cmp > 0)
n = n->rb_right;
else
return -EEXIST;
}
return 0;
}
static void clear_seen_inodes(void)
{
struct rb_node *n = rb_first(&seen_inodes);
struct seen_inode *si;
while (n) {
si = rb_entry(n, struct seen_inode, i_node);
rb_erase(&si->i_node, &seen_inodes);
free(si);
n = rb_first(&seen_inodes);
}
}
/*
* Inline extents are skipped because they do not take data space,
* delalloc and unknown are skipped because we do not know how much
* space they will use yet.
*/
#define SKIP_FLAGS (FIEMAP_EXTENT_UNKNOWN|FIEMAP_EXTENT_DELALLOC|FIEMAP_EXTENT_DATA_INLINE)
static int du_calc_file_space(int fd, struct rb_root *shared_extents,
u64 *ret_total, u64 *ret_shared)
{
char buf[16384];
struct fiemap *fiemap = (struct fiemap *)buf;
struct fiemap_extent *fm_ext = &fiemap->fm_extents[0];
int count = (sizeof(buf) - sizeof(*fiemap)) /
sizeof(struct fiemap_extent);
unsigned int i, ret;
int last = 0;
int rc;
u64 ext_len;
u64 file_total = 0;
u64 file_shared = 0;
u32 flags;
memset(fiemap, 0, sizeof(struct fiemap));
do {
fiemap->fm_length = ~0ULL;
fiemap->fm_extent_count = count;
rc = ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap);
if (rc < 0) {
ret = -errno;
goto out;
}
/* If 0 extents are returned, then more ioctls are not needed */
if (fiemap->fm_mapped_extents == 0)
break;
for (i = 0; i < fiemap->fm_mapped_extents; i++) {
ext_len = fm_ext[i].fe_length;
flags = fm_ext[i].fe_flags;
if (flags & FIEMAP_EXTENT_LAST)
last = 1;
if (flags & SKIP_FLAGS)
continue;
if (ext_len == 0) {
warning("extent %llu has length 0, skipping",
(unsigned long long)fm_ext[i].fe_physical);
continue;
}
file_total += ext_len;
if (flags & FIEMAP_EXTENT_SHARED) {
file_shared += ext_len;
if (shared_extents) {
ret = add_shared_extent(fm_ext[i].fe_physical,
ext_len,
shared_extents);
if (ret)
goto out;
}
}
}
fiemap->fm_start = (fm_ext[i - 1].fe_logical +
fm_ext[i - 1].fe_length);
} while (last == 0);
*ret_total = file_total;
*ret_shared = file_shared;
ret = 0;
out:
return ret;
}
struct du_dir_ctxt {
u64 bytes_total;
u64 bytes_shared;
DIR *dirstream;
struct rb_root shared_extents;
};
#define INIT_DU_DIR_CTXT (struct du_dir_ctxt) { 0ULL, 0ULL, NULL, RB_ROOT }
static int du_add_file(const char *filename, int dirfd,
struct rb_root *shared_extents, u64 *ret_total,
u64 *ret_shared, int top_level);
static int du_walk_dir(struct du_dir_ctxt *ctxt, struct rb_root *shared_extents)
{
int ret, type;
struct dirent *entry;
DIR *dirstream = ctxt->dirstream;
ret = 0;
do {
u64 tot, shr;
errno = 0;
entry = readdir(dirstream);
if (entry) {
if (strcmp(entry->d_name, ".") == 0
|| strcmp(entry->d_name, "..") == 0)
continue;
type = entry->d_type;
if (type == DT_REG || type == DT_DIR) {
tot = shr = 0;
ret = du_add_file(entry->d_name,
dirfd(dirstream),
shared_extents, &tot, &shr,
0);
if (ret == -ENOTTY) {
ret = 0;
continue;
} else if (ret) {
fprintf(stderr,
"failed to walk dir/file: %s :%s\n",
entry->d_name, strerror(-ret));
break;
}
ctxt->bytes_total += tot;
ctxt->bytes_shared += shr;
}
}
} while (entry != NULL);
return ret;
}
static int du_add_file(const char *filename, int dirfd,
struct rb_root *shared_extents, u64 *ret_total,
u64 *ret_shared, int top_level)
{
int ret, len = strlen(filename);
char *pathtmp;
struct stat st;
struct du_dir_ctxt dir = INIT_DU_DIR_CTXT;
int is_dir = 0;
u64 file_total = 0;
u64 file_shared = 0;
u64 dir_set_shared = 0;
int fd;
DIR *dirstream = NULL;
ret = fstatat(dirfd, filename, &st, 0);
if (ret)
return -errno;
if (!S_ISREG(st.st_mode) && !S_ISDIR(st.st_mode))
return 0;
if (len > (path_max - pathp)) {
error("path too long: %s %s", path, filename);
return -ENAMETOOLONG;
}
pathtmp = pathp;
if (pathp == path)
ret = sprintf(pathp, "%s", filename);
else
ret = sprintf(pathp, "/%s", filename);
pathp += ret;
fd = open_file_or_dir3(path, &dirstream, O_RDONLY);
if (fd < 0) {
ret = -errno;
goto out;
}
/*
* If st.st_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ==2, there is no any
* related tree
*/
if (st.st_ino != BTRFS_EMPTY_SUBVOL_DIR_OBJECTID) {
u64 subvol;
ret = lookup_path_rootid(fd, &subvol);
if (ret)
goto out_close;
if (inode_seen(st.st_ino, subvol))
goto out_close;
ret = mark_inode_seen(st.st_ino, subvol);
if (ret)
goto out_close;
}
if (S_ISREG(st.st_mode)) {
ret = du_calc_file_space(fd, shared_extents, &file_total,
&file_shared);
if (ret)
goto out_close;
} else if (S_ISDIR(st.st_mode)) {
struct rb_root *root = shared_extents;
/*
* We collect shared extents in an rb_root, the top
* level caller will not pass a root down, so use the
* one on our dir context.
*/
if (top_level)
root = &dir.shared_extents;
is_dir = 1;
dir.dirstream = dirstream;
ret = du_walk_dir(&dir, root);
*pathp = '\0';
if (ret) {
if (top_level)
cleanup_shared_extents(root);
goto out_close;
}
file_total = dir.bytes_total;
file_shared = dir.bytes_shared;
if (top_level)
count_shared_bytes(root, &dir_set_shared);
}
if (!summarize || top_level) {
u64 excl = file_total - file_shared;
if (top_level) {
u64 set_shared = file_shared;
if (is_dir)
set_shared = dir_set_shared;
printf("%10s %10s %10s %s\n",
pretty_size_mode(file_total, unit_mode),
pretty_size_mode(excl, unit_mode),
pretty_size_mode(set_shared, unit_mode),
path);
} else {
printf("%10s %10s %10s %s\n",
pretty_size_mode(file_total, unit_mode),
pretty_size_mode(excl, unit_mode),
"-", path);
}
}
if (ret_total)
*ret_total = file_total;
if (ret_shared)
*ret_shared = file_shared;
out_close:
close_file_or_dir(fd, dirstream);
out:
/* reset path to just before this element */
pathp = pathtmp;
return ret;
}
const char * const cmd_filesystem_du_usage[] = {
"btrfs filesystem du [options] <path> [<path>..]",
"Summarize disk usage of each file.",
"-s|--summarize display only a total for each argument",
HELPINFO_UNITS_LONG,
NULL
};
int cmd_filesystem_du(int argc, char **argv)
{
int ret = 0, err = 0;
int i;
u32 kernel_version;
unit_mode = get_unit_mode_from_arg(&argc, argv, 1);
while (1) {
static const struct option long_options[] = {
{ "summarize", no_argument, NULL, 's'},
{ NULL, 0, NULL, 0 }
};
int c = getopt_long(argc, argv, "s", long_options, NULL);
if (c < 0)
break;
switch (c) {
case 's':
summarize = 1;
break;
default:
usage(cmd_filesystem_du_usage);
}
}
if (check_argc_min(argc - optind, 1))
usage(cmd_filesystem_du_usage);
kernel_version = get_running_kernel_version();
if (kernel_version < KERNEL_VERSION(2,6,33)) {
warning(
"old kernel version detected, shared space will be reported as exclusive\n"
"due to missing support for FIEMAP_EXTENT_SHARED flag");
}
printf("%10s %10s %10s %s\n", "Total", "Exclusive", "Set shared",
"Filename");
for (i = optind; i < argc; i++) {
ret = du_add_file(argv[i], AT_FDCWD, NULL, NULL, NULL, 1);
if (ret) {
error("cannot check space of '%s': %s", argv[i],
strerror(-ret));
err = 1;
}
/* reset hard-link detection for each argument */
clear_seen_inodes();
}
return err;
}