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authorMark Fasheh <mfasheh@suse.de>2016-01-20 13:49:27 -0800
committerDavid Sterba <dsterba@suse.com>2016-03-14 13:42:47 +0100
commitbc23667bd24ef5f76d5357200c462b66d2d21974 (patch)
treecce8516fb15a9f48e0b7650675885f77b2541088 /cmds-fi-du.c
parenta2e7ff1eae45ad77d80d31d8b793021364573a74 (diff)
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btrfs-progs: fi du: Calculate space shared by each directory arguments file set
Here we define each file set as those found by a recursive search of a single directory argument to btrfs fi du. This isn't as simple as adding up shared extents - they may be shared with each other, and may also overlap. This patch uses an interval tree to store shared extents we find while fiemapping files. After collecting them, a 'set shared' count is calculated by summing (without overlap) each shared region discovered. This is then displayed to the user as 'set shared'. Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'cmds-fi-du.c')
-rw-r--r--cmds-fi-du.c272
1 files changed, 236 insertions, 36 deletions
diff --git a/cmds-fi-du.c b/cmds-fi-du.c
index b413b61..836d357 100644
--- a/cmds-fi-du.c
+++ b/cmds-fi-du.c
@@ -34,12 +34,162 @@
#include "kerncompat.h"
#include "rbtree.h"
+#include "interval_tree_generic.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;
+
+ BUG_ON(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 dprintf(...)
+
+/*
+ * 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;
+
+ dprintf("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;
+
+ dprintf(" (%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);
+
+ dprintf("; 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. Specifcally, 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;
@@ -112,7 +262,21 @@ static int inode_seen(u64 ino, u64 subvol)
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);
+ }
}
const char * const cmd_filesystem_du_usage[] = {
@@ -130,7 +294,7 @@ const char * const cmd_filesystem_du_usage[] = {
* 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 dirfd, const char *filename,
+static int du_calc_file_space(int fd, struct rb_root *shared_extents,
uint64_t *ret_total, uint64_t *ret_shared)
{
char buf[16384];
@@ -142,28 +306,19 @@ static int du_calc_file_space(int dirfd, const char *filename,
int last = 0;
int rc;
u64 ext_len;
- int fd;
u64 file_total = 0;
u64 file_shared = 0;
u32 flags;
memset(fiemap, 0, sizeof(struct fiemap));
- fd = openat(dirfd, filename, O_RDONLY);
- if (fd == -1) {
- ret = errno;
- fprintf(stderr, "ERROR: can't access '%s': %s\n",
- filename, strerror(ret));
- return ret;
- }
-
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_close;
+ goto out;
}
/* If 0 extents are returned, then more ioctls are not needed */
@@ -181,8 +336,17 @@ static int du_calc_file_space(int dirfd, const char *filename,
continue;
file_total += ext_len;
- if (flags & FIEMAP_EXTENT_SHARED)
+ 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 +
@@ -193,28 +357,27 @@ static int du_calc_file_space(int dirfd, const char *filename,
*ret_shared = file_shared;
ret = 0;
-out_close:
- close(fd);
+out:
return ret;
}
struct du_dir_ctxt {
uint64_t bytes_total;
uint64_t 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, uint64_t *ret_total,
+static int du_add_file(const char *filename, int dirfd,
+ struct rb_root *shared_extents, uint64_t *ret_total,
uint64_t *ret_shared, int top_level);
-static int du_walk_dir(struct du_dir_ctxt *ctxt)
+static int du_walk_dir(struct du_dir_ctxt *ctxt, struct rb_root *shared_extents)
{
- int fd, ret, type;
- DIR *dirstream = NULL;
+ int ret, type;
struct dirent *entry;
-
- fd = open_file_or_dir(path, &dirstream);
- if (fd < 0)
- return fd;
+ DIR *dirstream = ctxt->dirstream;
ret = 0;
do {
@@ -232,8 +395,9 @@ static int du_walk_dir(struct du_dir_ctxt *ctxt)
tot = shr = 0;
ret = du_add_file(entry->d_name,
- dirfd(dirstream), &tot,
- &shr, 0);
+ dirfd(dirstream),
+ shared_extents, &tot, &shr,
+ 0);
if (ret)
break;
@@ -243,19 +407,21 @@ static int du_walk_dir(struct du_dir_ctxt *ctxt)
}
} while (entry != NULL);
- close_file_or_dir(fd, dirstream);
return ret;
}
-static int du_add_file(const char *filename, int dirfd, uint64_t *ret_total,
+static int du_add_file(const char *filename, int dirfd,
+ struct rb_root *shared_extents, uint64_t *ret_total,
uint64_t *ret_shared, int top_level)
{
int ret, len = strlen(filename);
char *pathtmp;
struct stat st;
- struct du_dir_ctxt dir;
+ struct du_dir_ctxt dir = INIT_DU_DIR_CTXT;
+ int is_dir = 0;
uint64_t file_total = 0;
uint64_t file_shared = 0;
+ u64 dir_set_shared = 0;
u64 subvol;
int fd;
DIR *dirstream = NULL;
@@ -300,26 +466,57 @@ static int du_add_file(const char *filename, int dirfd, uint64_t *ret_total,
goto out_close;
if (S_ISREG(st.st_mode)) {
- ret = du_calc_file_space(dirfd, filename, &file_total,
+ ret = du_calc_file_space(fd, shared_extents, &file_total,
&file_shared);
if (ret)
goto out_close;
} else if (S_ISDIR(st.st_mode)) {
- memset(&dir, 0, sizeof(dir));
+ 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;
- ret = du_walk_dir(&dir);
+ dir.dirstream = dirstream;
+ ret = du_walk_dir(&dir, root);
*pathp = '\0';
- if (ret)
+ 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) {
- printf("%s\t%s\t%s\n", pretty_size_mode(file_total, unit_mode),
- pretty_size_mode((file_total - file_shared), unit_mode),
- path);
+ u64 excl = file_total - file_shared;
+
+ if (top_level) {
+ u64 set_shared = file_shared;
+
+ if (is_dir)
+ set_shared = dir_set_shared;
+
+ printf("%s\t%s\t%s\t%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("%s\t%s\t\t\t%s\n",
+ pretty_size_mode(file_total, unit_mode),
+ pretty_size_mode(excl, unit_mode), path);
+ }
}
if (ret_total)
@@ -369,15 +566,18 @@ int cmd_filesystem_du(int argc, char **argv)
if (check_argc_min(argc - optind, 1))
usage(cmd_filesystem_du_usage);
- printf("total\texclusive\tfilename\n");
+ printf("total\texclusive\tset shared\tfilename\n");
for (i = optind; i < argc; i++) {
- ret = du_add_file(argv[i], AT_FDCWD, NULL, NULL, 1);
+ ret = du_add_file(argv[i], AT_FDCWD, NULL, NULL, NULL, 1);
if (ret) {
fprintf(stderr, "ERROR: can't check space of '%s': %s\n",
argv[i], strerror(ret));
error = 1;
}
+
+ /* reset hard-link detection for each argument */
+ clear_seen_inodes();
}
return error;