@@ -647,6 +647,17 @@ struct ext2_super_block {
#define EXT3_JNL_BACKUP_BLOCKS 1
/*
+ * A Next3 'big' journal needs to accomodate extra snapshot COW credits.
+ * Default journal size accomodates maximum possible COW credits.
+ * Minimum required journal size accomodates the avarage COW credits.
+ */
+#define EXT3_DEF_JOURNAL_BLOCKS 32768
+#define NEXT3_AVG_COW_CREDITS 16
+#define NEXT3_MAX_COW_CREDITS 24
+#define NEXT3_MIN_JOURNAL_BLOCKS (EXT3_DEF_JOURNAL_BLOCKS*NEXT3_AVG_COW_CREDITS)
+#define NEXT3_DEF_JOURNAL_BLOCKS (EXT3_DEF_JOURNAL_BLOCKS*NEXT3_MAX_COW_CREDITS)
+
+/*
* Feature set definitions
*/
@@ -1245,6 +1245,8 @@ extern errcode_t ext2fs_add_journal_device(ext2_filsys fs,
extern errcode_t ext2fs_add_journal_inode(ext2_filsys fs, blk_t size,
int flags);
extern int ext2fs_default_journal_size(__u64 blocks);
+extern int ext2fs_big_journal_size(int factor, __u64 blocks);
+extern int ext2fs_check_journal_size(ext2_filsys fs);
/* openfs.c */
extern errcode_t ext2fs_open(const char *name, int flags, int superblock,
@@ -400,6 +400,47 @@ int ext2fs_default_journal_size(__u64 blocks)
return 32768;
}
+/*
+ * Big journal is up to X times bigger than the default journal
+ * to accomodate snapshot COW credits in transactions.
+ * journal size is restricted to 1/32 of the filesystem size
+ */
+int ext2fs_big_journal_size(int factor, __u64 blocks)
+{
+ int mega_blocks = blocks >> 20;
+ if (!mega_blocks)
+ return ext2fs_default_journal_size(blocks);
+
+ if (mega_blocks < factor)
+ /* 32K/1M = 1/32 of filesystem size */
+ return EXT3_DEF_JOURNAL_BLOCKS*mega_blocks;
+
+ /* X times bigger than the default journal */
+ return EXT3_DEF_JOURNAL_BLOCKS*factor;
+}
+
+/*
+ * Return the number of blocks in the journal inode
+ */
+int ext2fs_check_journal_size(ext2_filsys fs)
+{
+ struct ext2_inode j_inode;
+ int j_blocks;
+
+ if (!(fs->super->s_feature_compat &
+ EXT3_FEATURE_COMPAT_HAS_JOURNAL) ||
+ !fs->super->s_journal_inum)
+ return 0;
+
+ if (ext2fs_read_inode(fs, fs->super->s_journal_inum, &j_inode))
+ return -1;
+
+ /* read journal inode size */
+ j_blocks = j_inode.i_size >> EXT2_BLOCK_SIZE_BITS(fs->super);
+
+ return j_blocks;
+}
+
/*
* This function adds a journal device to a filesystem
*/
@@ -903,6 +903,9 @@ static char **parse_fs_type(const char *fs_type,
ext_type = "ext2";
else if (!strcmp(program_name, "mke3fs"))
ext_type = "ext3";
+ else if (!strcmp(program_name, "mkfs.next3") ||
+ !strcmp(program_name, "mkn3fs"))
+ ext_type = "ext3";
else if (progname) {
ext_type = strrchr(progname, '/');
if (ext_type)
@@ -1164,6 +1167,15 @@ static void PRS(int argc, char *argv[])
if (!strcmp(program_name, "mkfs.ext3") ||
!strcmp(program_name, "mke3fs"))
journal_size = -1;
+
+ /* If called as mkfs.next3: */
+ if (!strcmp(program_name, "mkfs.next3") ||
+ !strcmp(program_name, "mkn3fs")) {
+ /* 1. create a big journal */
+ journal_size = -NEXT3_MAX_COW_CREDITS;
+ /* 2. use system page size as block size */
+ blocksize = sys_page_size;
+ }
}
while ((c = getopt (argc, argv,
@@ -222,6 +222,20 @@ void parse_journal_opts(const char *opts)
journal_size = strtoul(arg, &p, 0);
if (*p)
journal_usage++;
+ } else if (strcmp(token, "big") == 0) {
+ /* Create a big journal for Next3 */
+ journal_size = -NEXT3_MAX_COW_CREDITS;
+ continue;
+ } else if (strcmp(token, "bigger") == 0) {
+ /* Create a journal bigger than default */
+ if (!arg) {
+ journal_usage++;
+ continue;
+ }
+ journal_size = -strtoul(arg, &p, 0);
+ if (*p)
+ journal_usage++;
+ continue;
} else if (strcmp(token, "v1_superblock") == 0) {
journal_flags |= EXT2_MKJOURNAL_V1_SUPER;
continue;
@@ -235,6 +249,8 @@ void parse_journal_opts(const char *opts)
"\tis set off by an equals ('=') sign.\n\n"
"Valid journal options are:\n"
"\tsize=<journal size in megabytes>\n"
+ "\tbig (Next3 big journal size)\n"
+ "\tbigger=<X times bigger than default size>\n"
"\tdevice=<journal device>\n\n"
"The journal size must be between "
"1024 and 10240000 filesystem blocks.\n\n"), stderr);
@@ -263,6 +279,20 @@ unsigned int figure_journal_size(int size, ext2_filsys fs)
return 0;
}
+ if (size < -1) {
+ /* bigger journal requested */
+ j_blocks = ext2fs_big_journal_size(-size, fs->super->s_blocks_count);
+ if (j_blocks < EXT3_DEF_JOURNAL_BLOCKS*(-size)) {
+ fputs(_("\nFilesystem too small for requested "
+ "journal size. "), stderr);
+ if (j_blocks < 0) {
+ fputs(_("Aborting.\n"), stderr);
+ exit(1);
+ }
+ fputs(_("Creating a smaller journal.\n"), stderr);
+ }
+ }
+
if (size > 0) {
j_blocks = size * 1024 / (fs->blocksize / 1024);
if (j_blocks < 1024 || j_blocks > 10240000) {
Next3 transactions reserve up to 24 times more credits than Ext3 transactions for the same operation. On mke2fs and tune2fs, if the '-J big' option is used to create a journal, increase the default journal size by a factor of 24. Signed-off-by: Amir Goldstein <amir73il@users.sf.net> --- lib/ext2fs/ext2_fs.h | 11 +++++++++++ lib/ext2fs/ext2fs.h | 2 ++ lib/ext2fs/mkjournal.c | 41 +++++++++++++++++++++++++++++++++++++++++ misc/mke2fs.c | 12 ++++++++++++ misc/util.c | 30 ++++++++++++++++++++++++++++++ 5 files changed, 96 insertions(+), 0 deletions(-)