diff --git a/statinfo.c b/statinfo.c index 17bb8966c33d6d..9367ca099cd114 100644 --- a/statinfo.c +++ b/statinfo.c @@ -2,6 +2,22 @@ #include "environment.h" #include "statinfo.h" +/* + * Munge st_size into an unsigned int. + */ +static unsigned int munge_st_size(off_t st_size) { + unsigned int sd_size = st_size; + + /* + * If the file is an exact multiple of 4 GiB, modify the value so it + * doesn't get marked as racily clean (zero). + */ + if (!sd_size && st_size) + return 0x80000000; + else + return sd_size; +} + void fill_stat_data(struct stat_data *sd, struct stat *st) { sd->sd_ctime.sec = (unsigned int)st->st_ctime; @@ -12,7 +28,7 @@ void fill_stat_data(struct stat_data *sd, struct stat *st) sd->sd_ino = st->st_ino; sd->sd_uid = st->st_uid; sd->sd_gid = st->st_gid; - sd->sd_size = st->st_size; + sd->sd_size = munge_st_size(st->st_size); } int match_stat_data(const struct stat_data *sd, struct stat *st) @@ -51,7 +67,7 @@ int match_stat_data(const struct stat_data *sd, struct stat *st) changed |= INODE_CHANGED; #endif - if (sd->sd_size != (unsigned int) st->st_size) + if (sd->sd_size != munge_st_size(st->st_size)) changed |= DATA_CHANGED; return changed; diff --git a/t/t7508-status.sh b/t/t7508-status.sh index 6928fd89f5d887..6c46648e1128cc 100755 --- a/t/t7508-status.sh +++ b/t/t7508-status.sh @@ -1745,4 +1745,20 @@ test_expect_success 'slow status advice when core.untrackedCache true, and fsmon ) ' +test_expect_success EXPENSIVE 'status does not re-read unchanged 4 or 8 GiB file' ' + ( + mkdir large-file && + cd large-file && + # Files are 2 GiB, 4 GiB, and 8 GiB sparse files. + test-tool truncate file-a 0x080000000 && + test-tool truncate file-b 0x100000000 && + test-tool truncate file-c 0x200000000 && + # This will be slow. + git add file-a file-b file-c && + git commit -m "add large files" && + git diff-index HEAD file-a file-b file-c >actual && + test_must_be_empty actual + ) +' + test_done