Commit 3d6bcae8 authored by Ondrej Kozina's avatar Ondrej Kozina Committed by Milan Broz

reencrypt: use fsync instead of O_DIRECT flag

O_DIRECT operations directed towards filesystem are problematic:
There's no sane way how to detect specific filesystem requirements
for such operations.

This patch is replacing O_DIRECT flag with O_SYNC flag for all
open() calls related to reencrypt log. The O_SYNC flag is used
when --use-fsync option is detected.

Man page is modified accordingly.
parent b8beedb6
......@@ -158,13 +158,15 @@ WARNING: This is destructive operation and cannot be reverted.
.B "\-\-use-directio"
Use direct-io (O_DIRECT) for all read/write data operations.
Use direct-io (O_DIRECT) for all read/write data operations related
to block device undergoing reencryption.
Useful if direct-io operations perform better than normal buffered
operations (e.g. in virtual environments).
.B "\-\-use-fsync"
Use fsync call after every written block.
Use fsync call after every written block. This applies for reencryption
log files as well.
.B "\-\-write-log"
Update log file after every block write. This can slow down reencryption
......@@ -76,7 +76,7 @@ struct reenc_ctx {
char crypt_path_org[PATH_MAX];
char crypt_path_new[PATH_MAX];
int log_fd;
char *log_buf;
char log_buf[SECTOR_SIZE];
struct {
char *password;
......@@ -351,13 +351,11 @@ static void close_log(struct reenc_ctx *rc)
log_dbg("Closing LUKS reencryption log file %s.", rc->log_file);
if (rc->log_fd != -1)
rc->log_buf = NULL;
static int open_log(struct reenc_ctx *rc)
int flags = opt_directio ? O_DIRECT : 0;
int flags = opt_fsync ? O_SYNC : 0;
rc->log_fd = open(rc->log_file, O_RDWR|O_EXCL|O_CREAT|flags, S_IRUSR|S_IWUSR);
if (rc->log_fd != -1) {
......@@ -371,12 +369,6 @@ static int open_log(struct reenc_ctx *rc)
if (rc->log_fd == -1)
return -EINVAL;
if (posix_memalign((void *)&rc->log_buf, alignment(rc->log_fd), SECTOR_SIZE)) {
log_err(_("Allocation of aligned memory failed.\n"));
return -ENOMEM;
if (!rc->in_progress && write_log(rc) < 0) {
return -EIO;
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