On 2019/8/16 6:21, Jaegeuk Kim wrote: > On 08/12, Chao Yu wrote: >> On 2019/8/9 23:12, Jaegeuk Kim wrote: >>> We actually don't need to issue trim on entire disk by checking first >>> blocks having zeros. >> >> In heap mode, we locate node log header to tail end of device, should we >> consider to check block contain according to heap option? > > I wanted to check F2FS metadata mainly.
Oh, I thought you mean main area. :P > >> >> BTW, if we changed cp_ver whenever mkfs, why should we still issue trim to >> obsolete old data in node remained in image? > > For simplicity. :P I didn't get why we can assume all metadata are zeroed if first 16MB are all zero... BTW, if first 16MB are non-zero, why not just trim F2FS metadata rather than whole area? Thanks, > >> >> Thanks, >> >>> >>> Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org> >>> --- >>> v2 from v1: >>> - clean up >>> >>> mkfs/f2fs_format_utils.c | 53 ++++++++++++++++++++++++++++++++++++++-- >>> 1 file changed, 51 insertions(+), 2 deletions(-) >>> >>> diff --git a/mkfs/f2fs_format_utils.c b/mkfs/f2fs_format_utils.c >>> index 8bf128c..f2d55ad 100644 >>> --- a/mkfs/f2fs_format_utils.c >>> +++ b/mkfs/f2fs_format_utils.c >>> @@ -25,6 +25,7 @@ >>> #include <stdio.h> >>> #include <unistd.h> >>> #include <stdlib.h> >>> +#include <stdbool.h> >>> #ifndef ANDROID_WINDOWS_HOST >>> #include <sys/ioctl.h> >>> #endif >>> @@ -110,13 +111,61 @@ static int trim_device(int i) >>> return 0; >>> } >>> >>> +static bool is_wiped_device(int i) >>> +{ >>> +#ifdef WITH_ANDROID >>> + struct device_info *dev = c.devices + i; >>> + int fd = dev->fd; >>> + char *buf, *zero_buf; >>> + bool wiped = true; >>> + int nblocks = 4096; /* 16MB size */ >>> + int j; >>> + >>> + buf = malloc(F2FS_BLKSIZE); >>> + if (buf == NULL) { >>> + MSG(1, "\tError: Malloc Failed for buf!!!\n"); >>> + return false; >>> + } >>> + zero_buf = calloc(1, F2FS_BLKSIZE); >>> + if (zero_buf == NULL) { >>> + MSG(1, "\tError: Calloc Failed for zero buf!!!\n"); >>> + free(buf); >>> + return false; >>> + } >>> + >>> + if (lseek(fd, 0, SEEK_SET) < 0) { >>> + free(zero_buf); >>> + free(buf); >>> + return false; >>> + } >>> + >>> + /* check first n blocks */ >>> + for (j = 0; j < nblocks; j++) { >>> + if (read(fd, buf, F2FS_BLKSIZE) != F2FS_BLKSIZE || >>> + memcmp(buf, zero_buf, F2FS_BLKSIZE)) { >>> + wiped = false; >>> + break; >>> + } >>> + } >>> + free(zero_buf); >>> + free(buf); >>> + >>> + if (wiped) >>> + MSG(0, "Info: Found all zeros in first %d blocks\n", nblocks); >>> + return wiped; >>> +#else >>> + return false; >>> +#endif >>> +} >>> + >>> int f2fs_trim_devices(void) >>> { >>> int i; >>> >>> - for (i = 0; i < c.ndevs; i++) >>> - if (trim_device(i)) >>> + for (i = 0; i < c.ndevs; i++) { >>> + if (!is_wiped_device(i) && trim_device(i)) >>> return -1; >>> + } >>> c.trimmed = 1; >>> return 0; >>> } >>> > . > _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel