On Wed, Jun 27, 2018 at 06:57:31PM +0300, c17828 wrote:
> From: Andreas Dilger <andreas.dilger@xxxxxxxxx>
>
> Add support for multiple-device filesystems by defining a new
> fe_device field in the fiemap_extent structure. This allows
> printing the filesystem-relative or linux block device number
> associated with each extent of a file. If a single filesystem
> extent is mirrored to multiple block devices, the fe_device
> field can be used to disambiguate the multiple copies.
>
> If the "-l" (device-logical) option is given to filefrag, then
> all extents for a particular device of a file are returned
> before returning extents for the next device. This makes it
> easier to see if extent allocation within a single device is
> contiguous, instead of returning all of the blocks of a file
> interleaved in file-logical-offset order.
>
> Change-Id: Icdefe4dbc319e6652c3d6641e1500f2cfaf63605
> Signed-off-by: Andreas Dilger <andreas.dilger@xxxxxxxxx>
> Signed-off-by: Artem Blagodarenko <artem.blagodarenko@xxxxxxxxx>
> ---
> lib/ext2fs/fiemap.h | 7 +++++-
> misc/filefrag.8.in | 5 +++-
> misc/filefrag.c | 67 +++++++++++++++++++++++++++++++++++++++++++----------
> 3 files changed, 65 insertions(+), 14 deletions(-)
>
> diff --git a/lib/ext2fs/fiemap.h b/lib/ext2fs/fiemap.h
> index a331bc12..261a0b2b 100644
> --- a/lib/ext2fs/fiemap.h
> +++ b/lib/ext2fs/fiemap.h
> @@ -19,7 +19,8 @@ struct fiemap_extent {
> __u64 fe_length; /* length in bytes for this extent */
> __u64 fe_reserved64[2];
> __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
> - __u32 fe_reserved[3];
> + __u32 fe_device; /* device number (fs-specific if FIEMAP_EXTENT_NET)*/
> + __u32 fe_reserved[2];
> };
>
> struct fiemap {
> @@ -42,6 +43,7 @@ struct fiemap {
>
> #define FIEMAP_FLAG_SYNC 0x00000001 /* sync file data before map */
> #define FIEMAP_FLAG_XATTR 0x00000002 /* map extended attribute tree */
> +#define FIEMAP_FLAG_DEVICE_ORDER 0x40000000 /* return device ordered mapping */
>
> #define FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
>
> @@ -67,4 +69,7 @@ struct fiemap {
> #define FIEMAP_EXTENT_SHARED 0x00002000 /* Space shared with other
> * files. */
>
> +/* Network filesystem flags - use a high bit, don't conflict with upstream */
> +#define FIEMAP_EXTENT_NET 0x80000000 /* Data stored remotely. */
Why does "NET" means "look for a device number"?
What's the format for fe_device? Arbitrary 32-bit cookie? Kernel
dev_t? Something else?
Is there a corresponding change for include/uapi/linux/fiemap.h? Would
be nice if we could wire that up to iomap_fiemap <hint hint>
--D
> +
> #endif /* _LINUX_FIEMAP_H */
> diff --git a/misc/filefrag.8.in b/misc/filefrag.8.in
> index 292b3b7d..fdba67f7 100644
> --- a/misc/filefrag.8.in
> +++ b/misc/filefrag.8.in
> @@ -8,7 +8,7 @@ filefrag \- report on file fragmentation
> .BI \-b blocksize
> ]
> [
> -.B \-BeksvxX
> +.B \-BeklsvxX
> ]
> [
> .I files...
> @@ -46,6 +46,9 @@ Print output in extent format, even for block-mapped files.
> .BI \-k
> Use 1024\-byte blocksize for output (identical to '\-b 1024').
> .TP
> +.B \-l
> +Extents are displayed in device-logical offset order.
> +.TP
> .B \-s
> Sync the file before requesting the mapping.
> .TP
> diff --git a/misc/filefrag.c b/misc/filefrag.c
> index 9c57ab93..78e13076 100644
> --- a/misc/filefrag.c
> +++ b/misc/filefrag.c
> @@ -54,14 +54,16 @@ int verbose = 0;
> int blocksize; /* Use specified blocksize (default 1kB) */
> int sync_file = 0; /* fsync file before getting the mapping */
> int xattr_map = 0; /* get xattr mapping */
> -int force_bmap; /* force use of FIBMAP instead of FIEMAP */
> +int force_bmap; /* force use of FIBMAP instead of FIEMAP */
> int force_extent; /* print output in extent format always */
> +int device_offset; /* extents report device-relative offsets */
> int logical_width = 8;
> int physical_width = 10;
> const char *ext_fmt = "%4d: %*llu..%*llu: %*llu..%*llu: %6llu: %s\n";
> const char *hex_fmt = "%4d: %*llx..%*llx: %*llx..%*llx: %6llx: %s\n";
>
> -#define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
> +#define FILEFRAG_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR |\
> + FIEMAP_FLAG_DEVICE_ORDER)
>
> #define FIBMAP _IO(0x00, 1) /* bmap access */
> #define FIGETBSZ _IO(0x00, 2) /* get the block size used for bmap */
> @@ -120,10 +122,10 @@ static void print_extent_header(void)
> {
> printf(" ext: %*s %*s length: %*s flags:\n",
> logical_width * 2 + 3,
> - "logical_offset:",
> + device_offset ? "device_logical:" : "logical_offset:",
> physical_width * 2 + 3, "physical_offset:",
> - physical_width + 1,
> - "expected:");
> + device_offset ? 5 : physical_width + 1,
> + device_offset ? " dev:" : "expected:");
> }
>
> static void print_flag(__u32 *flags, __u32 mask, char *buf, const char *name)
> @@ -159,11 +161,11 @@ static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
> physical_blk = fm_extent->fe_physical >> blk_shift;
> }
>
> - if (expected)
> - sprintf(flags, ext_fmt == hex_fmt ? "%*llx: " : "%*llu: ",
> + if (device_offset)
> + sprintf(flags, "%04x: ", fm_extent->fe_device);
> + else if (expected)
> + sprintf(flags, ext_fmt == hex_fmt ? "%*llx:" : "%*llu: ",
> physical_width, expected >> blk_shift);
> - else
> - sprintf(flags, "%.*s ", physical_width, " ");
>
> fe_flags = fm_extent->fe_flags;
> print_flag(&fe_flags, FIEMAP_EXTENT_LAST, flags, "last,");
> @@ -177,6 +179,8 @@ static void print_extent_info(struct fiemap_extent *fm_extent, int cur_ex,
> print_flag(&fe_flags, FIEMAP_EXTENT_UNWRITTEN, flags, "unwritten,");
> print_flag(&fe_flags, FIEMAP_EXTENT_MERGED, flags, "merged,");
> print_flag(&fe_flags, FIEMAP_EXTENT_SHARED, flags, "shared,");
> + print_flag(&fe_flags, FIEMAP_EXTENT_NET, flags, "net,");
> +
> /* print any unknown flags as hex values */
> for (mask = 1; fe_flags != 0 && mask != 0; mask <<= 1) {
> char hex[6];
> @@ -217,6 +221,7 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents,
> unsigned int i;
> int fiemap_header_printed = 0;
> int tot_extents = 0, n = 0;
> + int previous_device = 0;
> int last = 0;
> int rc;
>
> @@ -228,6 +233,12 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents,
> if (xattr_map)
> flags |= FIEMAP_FLAG_XATTR;
>
> + if (device_offset) {
> + flags |= FIEMAP_FLAG_DEVICE_ORDER;
> + memset(fm_ext, 0, sizeof(struct fiemap_extent));
> + }
> +
> +retry_wo_device_order:
> do {
> fiemap->fm_length = ~0ULL;
> fiemap->fm_flags = flags;
> @@ -242,6 +253,10 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents,
> "flags %x\n",
> fiemap->fm_flags);
> fiemap_incompat_printed = 1;
> + } else if (rc == EBADR && (fiemap->fm_flags &
> + FIEMAP_FLAG_DEVICE_ORDER)) {
> + flags &= ~FIEMAP_FLAG_DEVICE_ORDER;
> + goto retry_wo_device_order;
> }
> return rc;
> }
> @@ -260,6 +275,9 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents,
> fm_last.fe_length;
> expected = fm_last.fe_physical +
> fm_ext[i].fe_logical - fm_last.fe_logical;
> + if (previous_device != fm_ext[i].fe_device)
> + previous_device = fm_ext[i].fe_device;
> +
> if (fm_ext[i].fe_logical != 0 &&
> fm_ext[i].fe_physical != expected &&
> fm_ext[i].fe_physical != expected_dense) {
> @@ -278,8 +296,20 @@ static int filefrag_fiemap(int fd, int blk_shift, int *num_extents,
> n++;
> }
>
> - fiemap->fm_start = (fm_ext[i - 1].fe_logical +
> - fm_ext[i - 1].fe_length);
> + /* For DEVICE_ORDER mappings, if EXTENT_LAST not yet found then
> + * fm_start needs to be the same as it was for earlier ioctl.
> + * The first extent is used to pass the end offset and device
> + * of the last FIEMAP call. Otherwise, we ask for extents
> + * starting from where the last mapping ended. */
> + if (flags & FIEMAP_FLAG_DEVICE_ORDER) {
> + fm_ext[0].fe_logical = fm_ext[i - 1].fe_logical +
> + fm_ext[i - 1].fe_length;
> + fm_ext[0].fe_device = fm_ext[i - 1].fe_device;
> + fiemap->fm_start = 0;
> + } else {
> + fiemap->fm_start = fm_ext[i - 1].fe_logical +
> + fm_ext[i - 1].fe_length;
> + }
> } while (last == 0);
>
> *num_extents = tot_extents;
> @@ -303,6 +333,8 @@ static int filefrag_fibmap(int fd, int blk_shift, int *num_extents,
> memset(&fm_ext, 0, sizeof(fm_ext));
> memset(&fm_last, 0, sizeof(fm_last));
> if (force_extent) {
> + memset(&fm_ext, 0, sizeof(fm_ext));
> + fm_ext.fe_device = st->st_dev;
> fm_ext.fe_flags = FIEMAP_EXTENT_MERGED;
> }
>
> @@ -437,6 +469,13 @@ static int frag_report(const char *filename)
> is_ext2 = 1;
> }
>
> + /* Check if filesystem is Lustre. Always print in extent format
> + * with 1kB blocks, using the device-relative logical offsets. */
> + if (fsinfo.f_type == LUSTRE_SUPER_MAGIC) {
> + device_offset = 1;
> + blocksize = blocksize ?: 1024;
> + }
> +
> if (is_ext2) {
> long cylgroups = div_ceil(fsinfo.f_blocks, blksize * 8);
>
> @@ -524,10 +563,11 @@ int main(int argc, char**argv)
> char **cpp;
> int rc = 0, c;
>
> - while ((c = getopt(argc, argv, "Bb::eksvxX")) != EOF) {
> + while ((c = getopt(argc, argv, "Bb::eklsvxX")) != EOF) {
> switch (c) {
> case 'B':
> force_bmap++;
> + force_extent = 0;
> break;
> case 'b':
> if (optarg) {
> @@ -567,6 +607,9 @@ int main(int argc, char**argv)
> case 'k':
> blocksize = 1024;
> break;
> + case 'l':
> + device_offset++;
> + break;
> case 's':
> sync_file++;
> break;
> --
> 2.14.3
>
