diff options
| -rw-r--r-- | NEWS | 4 | ||||
| -rw-r--r-- | src/extent-scan.c | 34 | ||||
| -rw-r--r-- | src/extent-scan.h | 3 | ||||
| -rwxr-xr-x | tests/cp/sparse-fiemap | 4 |
4 files changed, 42 insertions, 3 deletions
@@ -28,6 +28,10 @@ GNU coreutils NEWS -*- outline -*- ** Changes in behavior + cp now avoids syncing files when possible, when doing a FIEMAP copy. + The sync in only needed on Linux kernels before 2.6.38. + [The sync was introduced in coreutils-8.10] + df now aligns columns consistently, and no longer wraps entries with longer device identifiers, over two lines. diff --git a/src/extent-scan.c b/src/extent-scan.c index b9520b7fa..f10d8e0a0 100644 --- a/src/extent-scan.c +++ b/src/extent-scan.c @@ -20,15 +20,46 @@ #include <stdio.h> #include <sys/types.h> #include <sys/ioctl.h> +#include <sys/utsname.h> #include <assert.h> #include "system.h" #include "extent-scan.h" +#include "xstrtol.h" #ifndef HAVE_FIEMAP # include "fiemap.h" #endif +/* Work around Linux kernel issues on BTRFS and EXT4 before 2.6.38. + FIXME: remove in 2013, or whenever we're pretty confident + that the offending, unpatched kernels are no longer in use. */ +static bool +extent_need_sync (void) +{ + static int need_sync = -1; + + if (need_sync == -1) + { + struct utsname name; + need_sync = 0; /* No workaround by default. */ + +#ifdef __linux__ + if (uname (&name) != -1 && strncmp (name.release, "2.6.", 4) == 0) + { + unsigned long val; + if (xstrtoul (name.release + 4, NULL, 10, &val, NULL) == LONGINT_OK) + { + if (val < 38) + need_sync = 1; + } + } +#endif + } + + return need_sync; +} + /* Allocate space for struct extent_scan, initialize the entries if necessary and return it as the input argument of extent_scan_read(). */ extern void @@ -39,6 +70,7 @@ extent_scan_init (int src_fd, struct extent_scan *scan) scan->scan_start = 0; scan->initial_scan_failed = false; scan->hit_final_extent = false; + scan->fm_flags = extent_need_sync () ? FIEMAP_FLAG_SYNC : 0; } #ifdef __linux__ @@ -62,7 +94,7 @@ extent_scan_read (struct extent_scan *scan) memset (&fiemap_buf, 0, sizeof fiemap_buf); fiemap->fm_start = scan->scan_start; - fiemap->fm_flags = FIEMAP_FLAG_SYNC; + fiemap->fm_flags = scan->fm_flags; fiemap->fm_extent_count = count; fiemap->fm_length = FIEMAP_MAX_OFFSET - scan->scan_start; diff --git a/src/extent-scan.h b/src/extent-scan.h index 4724b2575..872851507 100644 --- a/src/extent-scan.h +++ b/src/extent-scan.h @@ -41,6 +41,9 @@ struct extent_scan /* Next scan start offset. */ off_t scan_start; + /* Flags to use for scan. */ + uint32_t fm_flags; + /* How many extent info returned for a scan. */ uint32_t ei_count; diff --git a/tests/cp/sparse-fiemap b/tests/cp/sparse-fiemap index 73448ecfa..bac289093 100755 --- a/tests/cp/sparse-fiemap +++ b/tests/cp/sparse-fiemap @@ -69,8 +69,8 @@ for i in $(seq 1 2 21); do -e 'for (1..'$j') { sysseek (*F, $n, 1)' \ -e '&& syswrite (*F, chr($_)x$n) or die "$!"}' > j1 || fail=1 - # Note there is an implicit sync performed by cp to - # work around bugs in EXT4 and BTRFS before Linux 2.6.38 + # Note there is an implicit sync performed by cp on Linux kernels + # before 2.6.38 to work around bugs in EXT4 and BTRFS. # Note also the -s parameter to the filefrag commands below # for the same reasons. cp --sparse=always j1 j2 || fail=1 |