| Message ID | 2ff0137c-85ff-fdb8-3ae8-da599ea75200@sandeen.net (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
On 21.11.2017 18:02, Eric Sandeen wrote: > Currently the fiemap implementation of xfs_io doesn't support making ranged > queries. This patch implements two optional arguments which take the starting > offset and the length of the region to be queried. > > When the end of the requested region falls within an extent boundary then we > print the whole extent (i.e. return all the information that the kernel has given > us). When the end offset falls within a hole then the printed hole range is > truncated to the requested one since we do not have information how long the > hole is. > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> > [sandeen: simplify/rewrite ranged logic] > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > > --- > V6: <sandeen> > * Update V5 changelog re: printed extents & end of range ;) > * rename "last" to "done" > * simplify loop control by setting done=1 in inner loop for all terminal conditions > * update manpage re: behavior details for ranged queries > Reviewed-by: Nikolay Borisov <nborisov@suse.com> > V5: > * Now based on Eric's simpler approach. > * Fix printed-extent counting in print_plain & print_verbose > * Change while loop conditions to stop if full range has been mapped > > V4: > * Don't do any fiemap processing if passed offset is past EOF. Filesystems > might have custom handling for this. XFS for example pretends there is a > hole. > > * Restore offset/len handling to using the optional params at the end of > getopt and not using an additional '-r' param > > V3: > * Fixed a bug where incorrect extent index was shown if we didn't print a > hole. This was due to statically returning 2 at the end of print_(plain|verbose) > Now, the actual number of printed extents inside the 2 functions is used. > This bug is visible only with the -r parameter > > * Fixed a bug where 1 additional extent would be printed. This was a result of > the aforementioned bug fix, since now printing function can return 1 and still > have printed an extent and no hole. This can happen when you use -r parameter, > this is now fixed and a comment explaining it is put. > > * Reworked the handling of the new params by making them arguments to the > -r parameter. > > V2: > * Incorporated Daricks feedback - removed variables which weren't introduced > until the next patch as a result the build with this patch was broken. This is > fixed now > > diff --git a/io/fiemap.c b/io/fiemap.c > index bdcfacd..2f12652 100644 > --- a/io/fiemap.c > +++ b/io/fiemap.c > @@ -49,6 +49,8 @@ fiemap_help(void) > " -l -- also displays the length of each extent in 512-byte blocks.\n" > " -n -- query n extents.\n" > " -v -- Verbose information\n" > +" offset is the starting offset to map, and is optional. If offset is\n" > +" specified, mapping length may (optionally) be specified as well." > "\n")); > } > > @@ -101,6 +103,7 @@ print_verbose( > char lbuf[48]; > char bbuf[48]; > char flgbuf[16]; > + int num_printed = 0; > > llast = BTOBBT(last_logical); > lstart = BTOBBT(extent->fe_logical); > @@ -118,14 +121,15 @@ print_verbose( > flg_w, _("FLAGS")); > } > > - if (lstart != llast) { > + if (lstart > llast) { > print_hole(foff_w, boff_w, tot_w, cur_extent, 0, false, llast, > lstart); > cur_extent++; > + num_printed++; > } > > if (cur_extent == max_extents) > - return 1; > + return num_printed; > > snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", > (unsigned long long)lstart, lstart + len - 1ULL); > @@ -135,7 +139,9 @@ print_verbose( > printf("%4d: %-*s %-*s %*llu %*s\n", cur_extent, foff_w, lbuf, > boff_w, bbuf, tot_w, (unsigned long long)len, flg_w, flgbuf); > > - return 2; > + num_printed++; > + > + return num_printed; > } > > static int > @@ -149,29 +155,33 @@ print_plain( > __u64 llast; > __u64 block; > __u64 len; > + int num_printed = 0; > > llast = BTOBBT(last_logical); > lstart = BTOBBT(extent->fe_logical); > len = BTOBBT(extent->fe_length); > block = BTOBBT(extent->fe_physical); > > - if (lstart != llast) { > + if (lstart > llast) { > print_hole(0, 0, 0, cur_extent, lflag, true, llast, lstart); > cur_extent++; > + num_printed++; > } > > if (cur_extent == max_extents) > - return 1; > + return num_printed; > > printf("\t%d: [%llu..%llu]: %llu..%llu", cur_extent, > (unsigned long long)lstart, lstart + len - 1ULL, > (unsigned long long)block, block + len - 1ULL); > > + num_printed++; > + > if (lflag) > printf(_(" %llu blocks\n"), (unsigned long long)len); > else > printf("\n"); > - return 2; > + return num_printed; > } > > /* > @@ -222,7 +232,7 @@ fiemap_f( > char **argv) > { > struct fiemap *fiemap; > - int last = 0; > + int done = 0; > int lflag = 0; > int vflag = 0; > int fiemap_flags = FIEMAP_FLAG_SYNC; > @@ -235,9 +245,15 @@ fiemap_f( > int boff_w = 16; > int tot_w = 5; /* 5 since its just one number */ > int flg_w = 5; > - __u64 last_logical = 0; > + __u64 last_logical = 0; /* last extent offset handled */ > + off64_t start_offset = 0; /* mapping start */ > + off64_t length = -1LL; /* mapping length */ > + off64_t range_end = -1LL; /* mapping end*/ > + size_t fsblocksize, fssectsize; > struct stat st; > > + init_cvtnum(&fsblocksize, &fssectsize); > + > while ((c = getopt(argc, argv, "aln:v")) != EOF) { > switch (c) { > case 'a': > @@ -257,6 +273,27 @@ fiemap_f( > } > } > > + /* Range start (optional) */ > + if (optind < argc) { > + start_offset = cvtnum(fsblocksize, fssectsize, argv[optind]); > + if (start_offset < 0) { > + printf("non-numeric offset argument -- %s\n", argv[optind]); > + return 0; > + } > + last_logical = start_offset; > + optind++; > + } > + > + /* Range length (optional if range start was specified) */ > + if (optind < argc) { > + length = cvtnum(fsblocksize, fssectsize, argv[optind]); > + if (length < 0) { > + printf("non-numeric len argument -- %s\n", argv[optind]); > + return 0; > + } > + range_end = start_offset + length; > + } > + > map_size = sizeof(struct fiemap) + > (EXTENT_BATCH * sizeof(struct fiemap_extent)); > fiemap = malloc(map_size); > @@ -269,12 +306,11 @@ fiemap_f( > > printf("%s:\n", file->name); > > - while (!last && (cur_extent != max_extents)) { > - > + while (!done) { > memset(fiemap, 0, map_size); > fiemap->fm_flags = fiemap_flags; > fiemap->fm_start = last_logical; > - fiemap->fm_length = -1LL; > + fiemap->fm_length = range_end - last_logical; > fiemap->fm_extent_count = EXTENT_BATCH; > > ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap); > @@ -314,13 +350,23 @@ fiemap_f( > cur_extent += num_printed; > last_logical = extent->fe_logical + extent->fe_length; > > + /* Kernel has told us there are no more extents */ > if (extent->fe_flags & FIEMAP_EXTENT_LAST) { > - last = 1; > + done = 1; > + break; > + } > + > + /* We have exhausted the requested range */ > + if (last_logical >= range_end) { > + done = 1; > break; > } > > - if (cur_extent == max_extents) > + /* We have printed requested nr of extents */ > + if (cur_extent == max_extents) { > + done = 1; > break; > + } > } > } > > @@ -336,9 +382,12 @@ fiemap_f( > return 0; > } > > - if (cur_extent && last_logical < st.st_size) > + /* Print last hole to EOF or to end of requested range */ > + range_end = min((uint64_t)range_end, st.st_size); > + > + if (cur_extent && last_logical < range_end) > print_hole(foff_w, boff_w, tot_w, cur_extent, lflag, !vflag, > - BTOBBT(last_logical), BTOBBT(st.st_size)); > + BTOBBT(last_logical), BTOBBT(range_end)); > > out: > free(fiemap); > @@ -353,7 +402,7 @@ fiemap_init(void) > fiemap_cmd.argmin = 0; > fiemap_cmd.argmax = -1; > fiemap_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK; > - fiemap_cmd.args = _("[-alv] [-n nx]"); > + fiemap_cmd.args = _("[-alv] [-n nx] [offset [len]]"); > fiemap_cmd.oneline = _("print block mapping for a file"); > fiemap_cmd.help = fiemap_help; > > diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8 > index 9bf1a47..fabf92f 100644 > --- a/man/man8/xfs_io.8 > +++ b/man/man8/xfs_io.8 > @@ -304,11 +304,23 @@ Prints the block mapping for the current open file. Refer to the > .BR xfs_bmap (8) > manual page for complete documentation. > .TP > -.BI "fiemap [ \-alv ] [ \-n " nx " ]" > +.BI "fiemap [ \-alv ] [ \-n " nx " ] [ " offset " [ " len " ]]" > Prints the block mapping for the current open file using the fiemap > ioctl. Options behave as described in the > .BR xfs_bmap (8) > manual page. > +.PP > +.RS > +Optionally, this command also supports passing the start offset > +from where to begin the mapping and the length of that region. > +The kernel will return any full extents which intersect with the requested > +range, and the > +.B fiemap > +command will print them in their entirety. If the requested range starts > +or ends in a hole, > +.B fiemap > +will print the hole, truncated to the requested range. > +.RE > .TP > .BI "fsmap [ \-d | \-l | \-r ] [ \-m | \-v ] [ \-n " nx " ] [ " start " ] [ " end " ] > Prints the mapping of disk blocks used by the filesystem hosting the current > -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 21.11.2017 18:02, Eric Sandeen wrote: > Currently the fiemap implementation of xfs_io doesn't support making ranged > queries. This patch implements two optional arguments which take the starting > offset and the length of the region to be queried. > > When the end of the requested region falls within an extent boundary then we > print the whole extent (i.e. return all the information that the kernel has given > us). When the end offset falls within a hole then the printed hole range is > truncated to the requested one since we do not have information how long the > hole is. > > Signed-off-by: Nikolay Borisov <nborisov@suse.com> > [sandeen: simplify/rewrite ranged logic] > Signed-off-by: Eric Sandeen <sandeen@redhat.com> > Ping on that, is ther anything stopping it from being merged? > --- > V6: <sandeen> > * Update V5 changelog re: printed extents & end of range ;) > * rename "last" to "done" > * simplify loop control by setting done=1 in inner loop for all terminal conditions > * update manpage re: behavior details for ranged queries > > V5: > * Now based on Eric's simpler approach. > * Fix printed-extent counting in print_plain & print_verbose > * Change while loop conditions to stop if full range has been mapped > > V4: > * Don't do any fiemap processing if passed offset is past EOF. Filesystems > might have custom handling for this. XFS for example pretends there is a > hole. > > * Restore offset/len handling to using the optional params at the end of > getopt and not using an additional '-r' param > > V3: > * Fixed a bug where incorrect extent index was shown if we didn't print a > hole. This was due to statically returning 2 at the end of print_(plain|verbose) > Now, the actual number of printed extents inside the 2 functions is used. > This bug is visible only with the -r parameter > > * Fixed a bug where 1 additional extent would be printed. This was a result of > the aforementioned bug fix, since now printing function can return 1 and still > have printed an extent and no hole. This can happen when you use -r parameter, > this is now fixed and a comment explaining it is put. > > * Reworked the handling of the new params by making them arguments to the > -r parameter. > > V2: > * Incorporated Daricks feedback - removed variables which weren't introduced > until the next patch as a result the build with this patch was broken. This is > fixed now > > diff --git a/io/fiemap.c b/io/fiemap.c > index bdcfacd..2f12652 100644 > --- a/io/fiemap.c > +++ b/io/fiemap.c > @@ -49,6 +49,8 @@ fiemap_help(void) > " -l -- also displays the length of each extent in 512-byte blocks.\n" > " -n -- query n extents.\n" > " -v -- Verbose information\n" > +" offset is the starting offset to map, and is optional. If offset is\n" > +" specified, mapping length may (optionally) be specified as well." > "\n")); > } > > @@ -101,6 +103,7 @@ print_verbose( > char lbuf[48]; > char bbuf[48]; > char flgbuf[16]; > + int num_printed = 0; > > llast = BTOBBT(last_logical); > lstart = BTOBBT(extent->fe_logical); > @@ -118,14 +121,15 @@ print_verbose( > flg_w, _("FLAGS")); > } > > - if (lstart != llast) { > + if (lstart > llast) { > print_hole(foff_w, boff_w, tot_w, cur_extent, 0, false, llast, > lstart); > cur_extent++; > + num_printed++; > } > > if (cur_extent == max_extents) > - return 1; > + return num_printed; > > snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", > (unsigned long long)lstart, lstart + len - 1ULL); > @@ -135,7 +139,9 @@ print_verbose( > printf("%4d: %-*s %-*s %*llu %*s\n", cur_extent, foff_w, lbuf, > boff_w, bbuf, tot_w, (unsigned long long)len, flg_w, flgbuf); > > - return 2; > + num_printed++; > + > + return num_printed; > } > > static int > @@ -149,29 +155,33 @@ print_plain( > __u64 llast; > __u64 block; > __u64 len; > + int num_printed = 0; > > llast = BTOBBT(last_logical); > lstart = BTOBBT(extent->fe_logical); > len = BTOBBT(extent->fe_length); > block = BTOBBT(extent->fe_physical); > > - if (lstart != llast) { > + if (lstart > llast) { > print_hole(0, 0, 0, cur_extent, lflag, true, llast, lstart); > cur_extent++; > + num_printed++; > } > > if (cur_extent == max_extents) > - return 1; > + return num_printed; > > printf("\t%d: [%llu..%llu]: %llu..%llu", cur_extent, > (unsigned long long)lstart, lstart + len - 1ULL, > (unsigned long long)block, block + len - 1ULL); > > + num_printed++; > + > if (lflag) > printf(_(" %llu blocks\n"), (unsigned long long)len); > else > printf("\n"); > - return 2; > + return num_printed; > } > > /* > @@ -222,7 +232,7 @@ fiemap_f( > char **argv) > { > struct fiemap *fiemap; > - int last = 0; > + int done = 0; > int lflag = 0; > int vflag = 0; > int fiemap_flags = FIEMAP_FLAG_SYNC; > @@ -235,9 +245,15 @@ fiemap_f( > int boff_w = 16; > int tot_w = 5; /* 5 since its just one number */ > int flg_w = 5; > - __u64 last_logical = 0; > + __u64 last_logical = 0; /* last extent offset handled */ > + off64_t start_offset = 0; /* mapping start */ > + off64_t length = -1LL; /* mapping length */ > + off64_t range_end = -1LL; /* mapping end*/ > + size_t fsblocksize, fssectsize; > struct stat st; > > + init_cvtnum(&fsblocksize, &fssectsize); > + > while ((c = getopt(argc, argv, "aln:v")) != EOF) { > switch (c) { > case 'a': > @@ -257,6 +273,27 @@ fiemap_f( > } > } > > + /* Range start (optional) */ > + if (optind < argc) { > + start_offset = cvtnum(fsblocksize, fssectsize, argv[optind]); > + if (start_offset < 0) { > + printf("non-numeric offset argument -- %s\n", argv[optind]); > + return 0; > + } > + last_logical = start_offset; > + optind++; > + } > + > + /* Range length (optional if range start was specified) */ > + if (optind < argc) { > + length = cvtnum(fsblocksize, fssectsize, argv[optind]); > + if (length < 0) { > + printf("non-numeric len argument -- %s\n", argv[optind]); > + return 0; > + } > + range_end = start_offset + length; > + } > + > map_size = sizeof(struct fiemap) + > (EXTENT_BATCH * sizeof(struct fiemap_extent)); > fiemap = malloc(map_size); > @@ -269,12 +306,11 @@ fiemap_f( > > printf("%s:\n", file->name); > > - while (!last && (cur_extent != max_extents)) { > - > + while (!done) { > memset(fiemap, 0, map_size); > fiemap->fm_flags = fiemap_flags; > fiemap->fm_start = last_logical; > - fiemap->fm_length = -1LL; > + fiemap->fm_length = range_end - last_logical; > fiemap->fm_extent_count = EXTENT_BATCH; > > ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap); > @@ -314,13 +350,23 @@ fiemap_f( > cur_extent += num_printed; > last_logical = extent->fe_logical + extent->fe_length; > > + /* Kernel has told us there are no more extents */ > if (extent->fe_flags & FIEMAP_EXTENT_LAST) { > - last = 1; > + done = 1; > + break; > + } > + > + /* We have exhausted the requested range */ > + if (last_logical >= range_end) { > + done = 1; > break; > } > > - if (cur_extent == max_extents) > + /* We have printed requested nr of extents */ > + if (cur_extent == max_extents) { > + done = 1; > break; > + } > } > } > > @@ -336,9 +382,12 @@ fiemap_f( > return 0; > } > > - if (cur_extent && last_logical < st.st_size) > + /* Print last hole to EOF or to end of requested range */ > + range_end = min((uint64_t)range_end, st.st_size); > + > + if (cur_extent && last_logical < range_end) > print_hole(foff_w, boff_w, tot_w, cur_extent, lflag, !vflag, > - BTOBBT(last_logical), BTOBBT(st.st_size)); > + BTOBBT(last_logical), BTOBBT(range_end)); > > out: > free(fiemap); > @@ -353,7 +402,7 @@ fiemap_init(void) > fiemap_cmd.argmin = 0; > fiemap_cmd.argmax = -1; > fiemap_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK; > - fiemap_cmd.args = _("[-alv] [-n nx]"); > + fiemap_cmd.args = _("[-alv] [-n nx] [offset [len]]"); > fiemap_cmd.oneline = _("print block mapping for a file"); > fiemap_cmd.help = fiemap_help; > > diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8 > index 9bf1a47..fabf92f 100644 > --- a/man/man8/xfs_io.8 > +++ b/man/man8/xfs_io.8 > @@ -304,11 +304,23 @@ Prints the block mapping for the current open file. Refer to the > .BR xfs_bmap (8) > manual page for complete documentation. > .TP > -.BI "fiemap [ \-alv ] [ \-n " nx " ]" > +.BI "fiemap [ \-alv ] [ \-n " nx " ] [ " offset " [ " len " ]]" > Prints the block mapping for the current open file using the fiemap > ioctl. Options behave as described in the > .BR xfs_bmap (8) > manual page. > +.PP > +.RS > +Optionally, this command also supports passing the start offset > +from where to begin the mapping and the length of that region. > +The kernel will return any full extents which intersect with the requested > +range, and the > +.B fiemap > +command will print them in their entirety. If the requested range starts > +or ends in a hole, > +.B fiemap > +will print the hole, truncated to the requested range. > +.RE > .TP > .BI "fsmap [ \-d | \-l | \-r ] [ \-m | \-v ] [ \-n " nx " ] [ " start " ] [ " end " ] > Prints the mapping of disk blocks used by the filesystem hosting the current > -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/io/fiemap.c b/io/fiemap.c index bdcfacd..2f12652 100644 --- a/io/fiemap.c +++ b/io/fiemap.c @@ -49,6 +49,8 @@ fiemap_help(void) " -l -- also displays the length of each extent in 512-byte blocks.\n" " -n -- query n extents.\n" " -v -- Verbose information\n" +" offset is the starting offset to map, and is optional. If offset is\n" +" specified, mapping length may (optionally) be specified as well." "\n")); } @@ -101,6 +103,7 @@ print_verbose( char lbuf[48]; char bbuf[48]; char flgbuf[16]; + int num_printed = 0; llast = BTOBBT(last_logical); lstart = BTOBBT(extent->fe_logical); @@ -118,14 +121,15 @@ print_verbose( flg_w, _("FLAGS")); } - if (lstart != llast) { + if (lstart > llast) { print_hole(foff_w, boff_w, tot_w, cur_extent, 0, false, llast, lstart); cur_extent++; + num_printed++; } if (cur_extent == max_extents) - return 1; + return num_printed; snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", (unsigned long long)lstart, lstart + len - 1ULL); @@ -135,7 +139,9 @@ print_verbose( printf("%4d: %-*s %-*s %*llu %*s\n", cur_extent, foff_w, lbuf, boff_w, bbuf, tot_w, (unsigned long long)len, flg_w, flgbuf); - return 2; + num_printed++; + + return num_printed; } static int @@ -149,29 +155,33 @@ print_plain( __u64 llast; __u64 block; __u64 len; + int num_printed = 0; llast = BTOBBT(last_logical); lstart = BTOBBT(extent->fe_logical); len = BTOBBT(extent->fe_length); block = BTOBBT(extent->fe_physical); - if (lstart != llast) { + if (lstart > llast) { print_hole(0, 0, 0, cur_extent, lflag, true, llast, lstart); cur_extent++; + num_printed++; } if (cur_extent == max_extents) - return 1; + return num_printed; printf("\t%d: [%llu..%llu]: %llu..%llu", cur_extent, (unsigned long long)lstart, lstart + len - 1ULL, (unsigned long long)block, block + len - 1ULL); + num_printed++; + if (lflag) printf(_(" %llu blocks\n"), (unsigned long long)len); else printf("\n"); - return 2; + return num_printed; } /* @@ -222,7 +232,7 @@ fiemap_f( char **argv) { struct fiemap *fiemap; - int last = 0; + int done = 0; int lflag = 0; int vflag = 0; int fiemap_flags = FIEMAP_FLAG_SYNC; @@ -235,9 +245,15 @@ fiemap_f( int boff_w = 16; int tot_w = 5; /* 5 since its just one number */ int flg_w = 5; - __u64 last_logical = 0; + __u64 last_logical = 0; /* last extent offset handled */ + off64_t start_offset = 0; /* mapping start */ + off64_t length = -1LL; /* mapping length */ + off64_t range_end = -1LL; /* mapping end*/ + size_t fsblocksize, fssectsize; struct stat st; + init_cvtnum(&fsblocksize, &fssectsize); + while ((c = getopt(argc, argv, "aln:v")) != EOF) { switch (c) { case 'a': @@ -257,6 +273,27 @@ fiemap_f( } } + /* Range start (optional) */ + if (optind < argc) { + start_offset = cvtnum(fsblocksize, fssectsize, argv[optind]); + if (start_offset < 0) { + printf("non-numeric offset argument -- %s\n", argv[optind]); + return 0; + } + last_logical = start_offset; + optind++; + } + + /* Range length (optional if range start was specified) */ + if (optind < argc) { + length = cvtnum(fsblocksize, fssectsize, argv[optind]); + if (length < 0) { + printf("non-numeric len argument -- %s\n", argv[optind]); + return 0; + } + range_end = start_offset + length; + } + map_size = sizeof(struct fiemap) + (EXTENT_BATCH * sizeof(struct fiemap_extent)); fiemap = malloc(map_size); @@ -269,12 +306,11 @@ fiemap_f( printf("%s:\n", file->name); - while (!last && (cur_extent != max_extents)) { - + while (!done) { memset(fiemap, 0, map_size); fiemap->fm_flags = fiemap_flags; fiemap->fm_start = last_logical; - fiemap->fm_length = -1LL; + fiemap->fm_length = range_end - last_logical; fiemap->fm_extent_count = EXTENT_BATCH; ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap); @@ -314,13 +350,23 @@ fiemap_f( cur_extent += num_printed; last_logical = extent->fe_logical + extent->fe_length; + /* Kernel has told us there are no more extents */ if (extent->fe_flags & FIEMAP_EXTENT_LAST) { - last = 1; + done = 1; + break; + } + + /* We have exhausted the requested range */ + if (last_logical >= range_end) { + done = 1; break; } - if (cur_extent == max_extents) + /* We have printed requested nr of extents */ + if (cur_extent == max_extents) { + done = 1; break; + } } } @@ -336,9 +382,12 @@ fiemap_f( return 0; } - if (cur_extent && last_logical < st.st_size) + /* Print last hole to EOF or to end of requested range */ + range_end = min((uint64_t)range_end, st.st_size); + + if (cur_extent && last_logical < range_end) print_hole(foff_w, boff_w, tot_w, cur_extent, lflag, !vflag, - BTOBBT(last_logical), BTOBBT(st.st_size)); + BTOBBT(last_logical), BTOBBT(range_end)); out: free(fiemap); @@ -353,7 +402,7 @@ fiemap_init(void) fiemap_cmd.argmin = 0; fiemap_cmd.argmax = -1; fiemap_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK; - fiemap_cmd.args = _("[-alv] [-n nx]"); + fiemap_cmd.args = _("[-alv] [-n nx] [offset [len]]"); fiemap_cmd.oneline = _("print block mapping for a file"); fiemap_cmd.help = fiemap_help; diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8 index 9bf1a47..fabf92f 100644 --- a/man/man8/xfs_io.8 +++ b/man/man8/xfs_io.8 @@ -304,11 +304,23 @@ Prints the block mapping for the current open file. Refer to the .BR xfs_bmap (8) manual page for complete documentation. .TP -.BI "fiemap [ \-alv ] [ \-n " nx " ]" +.BI "fiemap [ \-alv ] [ \-n " nx " ] [ " offset " [ " len " ]]" Prints the block mapping for the current open file using the fiemap ioctl. Options behave as described in the .BR xfs_bmap (8) manual page. +.PP +.RS +Optionally, this command also supports passing the start offset +from where to begin the mapping and the length of that region. +The kernel will return any full extents which intersect with the requested +range, and the +.B fiemap +command will print them in their entirety. If the requested range starts +or ends in a hole, +.B fiemap +will print the hole, truncated to the requested range. +.RE .TP .BI "fsmap [ \-d | \-l | \-r ] [ \-m | \-v ] [ \-n " nx " ] [ " start " ] [ " end " ] Prints the mapping of disk blocks used by the filesystem hosting the current