Signed-off-by: Jan Kara <jack@xxxxxxxx>
---
misc/tune2fs.8.in | 5 +++
misc/tune2fs.c | 110 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 115 insertions(+)
diff --git a/misc/tune2fs.8.in b/misc/tune2fs.8.in
index 4373fc49b255..922705329112 100644
--- a/misc/tune2fs.8.in
+++ b/misc/tune2fs.8.in
@@ -236,6 +236,11 @@ program.
This superblock setting is only honored in 2.6.35+ kernels;
and not at all by the ext2 and ext3 file system drivers.
.TP
+.BI reserved_inodes= number_of_reserved_inodes
+Set the number of inodes reserved for system files. This number must be
+at least 10. Currently 10 is enough but future features may require additional
+reserved inodes. Reserving more inodes requires full file system scan so it
+can take a long time.
.B test_fs
Set a flag in the filesystem superblock indicating that it may be
mounted using experimental kernel code, such as the ext4dev filesystem.
diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index e7e5ccde25c2..873a7e2b08c2 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -92,6 +92,7 @@ static char *features_cmd;
static char *mntopts_cmd;
static int stride, stripe_width;
static int stride_set, stripe_width_set;
+static unsigned long new_first_ino;
static char *extended_cmd;
static unsigned long new_inode_size;
static char *ext_mount_opts;
@@ -2300,6 +2301,42 @@ static int parse_extended_opts(ext2_filsys fs, const char *opts)
continue;
}
ext_mount_opts = strdup(arg);
+ } else if (!strcmp(token, "reserved_inodes")) {
+ if (!arg) {
+ r_usage++;
+ continue;
+ }
+ new_first_ino = strtoul(arg, &p, 0);
+ if (*p || new_first_ino == ULONG_MAX) {
+ fprintf(stderr,
+ _("Invalid number of reserved inodes "
+ "%s\n"),
+ arg);
+ r_usage++;
+ continue;
+ }
+ /* Ino 0 is invalid so bump by 1... */
+ new_first_ino++;
+ if (new_first_ino < EXT2_GOOD_OLD_FIRST_INO) {
+ fprintf(stderr,
+ _("Too few reserved inodes "
+ "%s (must be at least %u)\n"),
+ arg, EXT2_GOOD_OLD_FIRST_INO - 1);
+ r_usage++;
+ continue;
+ }
+ if (new_first_ino > fs->super->s_inodes_count) {
+ fprintf(stderr,
+ _("Too many reserved inodes %s "
+ "(must be at most %u)\n"),
+ arg, fs->super->s_inodes_count - 1);
+ r_usage++;
+ continue;
+ }
+ /*
+ * Here should go further feature tests to disallow
+ * admin to free used system inode
+ */
} else
r_usage++;
}
@@ -2314,6 +2351,7 @@ static int parse_extended_opts(ext2_filsys fs, const char *opts)
"\tmount_opts=<extended default mount options>\n"
"\tstride=<RAID per-disk chunk size in blocks>\n"
"\tstripe_width=<RAID stride*data disks in blocks>\n"
+ "\treserved_inodes=<number of reserved inodes>\n"
"\ttest_fs\n"
"\t^test_fs\n"));
free(buf);
@@ -2988,6 +3026,75 @@ fs_update_journal_user(struct ext2_super_block *sb, __u8 old_uuid[UUID_SIZE])
return 0;
}
+/* Zero range of inodes and mark them as free / used */
+static errcode_t zero_inodes_range(ext2_filsys fs, ext2_ino_t start,
+ ext2_ino_t end, int inuse)
+{
+ char *inode;
+ int length = EXT2_INODE_SIZE(fs->super);
+ ext2_ino_t ino;
+ errcode_t retval;
+
+ retval = ext2fs_get_memzero(length, &inode);
+ if (retval)
+ return retval;
+
+ for (ino = start; ino <= end; ino++) {
+ ext2fs_inode_alloc_stats(fs, ino, inuse);
+ retval = ext2fs_write_inode_full(fs, ino,
+ (struct ext2_inode *)inode,
+ length);
+ if (retval)
+ break;
+ }
+ ext2fs_free_mem(inode);
+
+ return retval;
+}
+
+static errcode_t update_reserved_inodes(ext2_filsys fs)
+{
+ errcode_t retval = 0;
+ ext2fs_inode_bitmap imap;
+ ext2_ino_t ino, first_ino = fs->super->s_first_ino;
+
+ if (new_first_ino == first_ino)
+ return 0;
+
+ /* Group descriptors will need writing as well */
+ fs->flags &= ~EXT2_FLAG_SUPER_ONLY;
+
+ /* Freeing reserved inodes is easy */
+ if (new_first_ino < first_ino) {
+ retval = zero_inodes_range(fs, new_first_ino, first_ino - 1,
+ -1);
+ if (retval)
+ return retval;
+ goto out;
+ }
+
+ retval = ext2fs_allocate_inode_bitmap(fs, "inodes to move", &imap);
+ if (retval)
+ return retval;
+
+ for (ino = fs->super->s_first_ino; ino < new_first_ino; ino++)
+ ext2fs_mark_inode_bitmap2(imap, ino);
+
+ retval = ext2fs_move_inodes(fs, imap);
+ ext2fs_free_inode_bitmap(imap);
+ if (retval)
+ return retval;
+
+ retval = zero_inodes_range(fs, first_ino, new_first_ino - 1, +1);
+ if (retval)
+ return retval;
+out:
+ fs->super->s_first_ino = new_first_ino;
+ ext2fs_mark_super_dirty(fs);
+
+ return 0;
+}
+
int main(int argc, char **argv)
{
errcode_t retval;
@@ -3413,6 +3520,9 @@ retry_open:
}
}
+ if (new_first_ino)
+ update_reserved_inodes(fs);
+
if (rewrite_checksums)
rewrite_metadata_checksums(fs);
--
2.1.4
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
