diff options
| -rw-r--r-- | utility/Makefile | 1 | ||||
| -rw-r--r-- | utility/mount-helpers.c | 74 |
2 files changed, 74 insertions, 1 deletions
diff --git a/utility/Makefile b/utility/Makefile index 128e087f..f3808987 100644 --- a/utility/Makefile +++ b/utility/Makefile @@ -187,6 +187,7 @@ ${BUILD_ROOT}/mount-encrypted: mount-encrypted.c mount-encrypted.h \ -I$(HOSTDIR)/include \ $(LDFLAGS) \ $< -o $@ $(shell $(PKG_CONFIG) --libs glib-2.0 openssl) \ + -lm \ ${BUILD_ROOT}/mount-helpers.o $(LIBS) ${BUILD_ROOT}/dev_sign_file: dev_sign_file.c $(LIBS) diff --git a/utility/mount-helpers.c b/utility/mount-helpers.c index 893d43e0..7647ffab 100644 --- a/utility/mount-helpers.c +++ b/utility/mount-helpers.c @@ -15,6 +15,7 @@ #include <string.h> #include <errno.h> #include <fcntl.h> +#include <math.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <sys/statvfs.h> @@ -38,6 +39,9 @@ static const int kLoopMajor = 7; static const int kLoopMax = 8; static const unsigned int kResizeStepSeconds = 2; static const size_t kResizeBlocks = 32768 * 10; +static const size_t kBlocksPerGroup = 32768; +static const size_t kInodeRatioDefault = 16384; +static const size_t kInodeRatioMinimum = 2048; static const gchar * const kExt4ExtendedOptions = "discard,lazy_itable_init"; int remove_tree(const char *tree) @@ -444,10 +448,68 @@ out: return sparsefd; } +/* When creating a filesystem that will grow, the inode ratio is calculated + * using the starting size not the hinted "resize" size, which means the + * number of inodes can be highly constrained on tiny starting filesystems. + * Instead, calculate what the correct inode ratio should be for a given + * filesystem based on its expected starting and ending sizes. + * + * inode-ratio_mkfs = + * + * ceil(blocks_max / group-ratio) * size_mkfs + * ------------------------------------------------------------------ + * ceil(size_max / inode-ratio_max) * ceil(blocks_mkfs / group-ratio) + */ +static size_t get_inode_ratio(size_t block_bytes_in, size_t blocks_mkfs_in, + size_t blocks_max_in) +{ + double block_bytes = (double)block_bytes_in; + double blocks_mkfs = (double)blocks_mkfs_in; + double blocks_max = (double)blocks_max_in; + + double size_max, size_mkfs, groups_max, groups_mkfs, inodes_max; + double denom, inode_ratio_mkfs; + + size_max = block_bytes * blocks_max; + size_mkfs = block_bytes * blocks_mkfs; + + groups_max = ceil(blocks_max / kBlocksPerGroup); + groups_mkfs = ceil(blocks_mkfs / kBlocksPerGroup); + + inodes_max = ceil(size_max / kInodeRatioDefault); + + denom = inodes_max * groups_mkfs; + /* Make sure we never trigger divide-by-zero. */ + if (denom == 0.0) + goto failure; + inode_ratio_mkfs = (groups_max * size_mkfs) / denom; + + /* Make sure we never calculate anything totally huge. */ + if (inode_ratio_mkfs > blocks_mkfs) + goto failure; + /* Make sure we never calculate anything totally tiny. */ + if (inode_ratio_mkfs < kInodeRatioMinimum) + goto failure; + + return (size_t)inode_ratio_mkfs; + +failure: + return kInodeRatioDefault; +} + +/* Creates an ext4 filesystem. + * device: path to block device to create filesystem on. + * block_bytes: bytes per block to use for filesystem. + * blocks_min: starting number of blocks on filesystem. + * blocks_max: largest expected size in blocks of filesystem, for growth hints. + * + * Returns 1 on success, 0 on failure. + */ int filesystem_build(const char *device, size_t block_bytes, size_t blocks_min, size_t blocks_max) { int rc = 0; + size_t inode_ratio; gchar *blocksize = g_strdup_printf("%zu", block_bytes); if (!blocksize) { @@ -474,12 +536,20 @@ int filesystem_build(const char *device, size_t block_bytes, size_t blocks_min, goto free_blocks_str; } + inode_ratio = get_inode_ratio(block_bytes, blocks_min, blocks_max); + gchar *inode_ratio_str = g_strdup_printf("%zu", inode_ratio); + if (!inode_ratio_str) { + PERROR("g_strdup_printf"); + goto free_extended; + } + const gchar *mkfs[] = { "/sbin/mkfs.ext4", "-T", "default", "-b", blocksize, "-m", "0", "-O", "^huge_file,^flex_bg", + "-i", inode_ratio_str, "-E", extended, device, blocks_str, @@ -488,7 +558,7 @@ int filesystem_build(const char *device, size_t block_bytes, size_t blocks_min, rc = (runcmd(mkfs, NULL) == 0); if (!rc) - goto free_extended; + goto free_inode_ratio_str; const gchar *tune2fs[] = { "/sbin/tune2fs", @@ -499,6 +569,8 @@ int filesystem_build(const char *device, size_t block_bytes, size_t blocks_min, }; rc = (runcmd(tune2fs, NULL) == 0); +free_inode_ratio_str: + g_free(inode_ratio_str); free_extended: g_free(extended); free_blocks_str: |