On Monday 19 October 2015 17:05:02 Maxim Perevedentsev wrote: > This call provides the way to get minimum size of filesystem. > This is needed for shrinking. The return units are bytes. > > --- > daemon/Makefile.am | 1 + > daemon/daemon.h | 1 + > daemon/fs-min-size.c | 46 ++++++++++++++++++++++++++++++++ > daemon/ntfs.c | 75 > ++++++++++++++++++++++++++++++++++++++++++++++++++++ > generator/actions.ml | 16 +++++++++++ > po/POTFILES | 1 + > src/MAX_PROC_NR | 2 +- > 7 files changed, 141 insertions(+), 1 deletion(-) > create mode 100644 daemon/fs-min-size.c > > diff --git a/daemon/Makefile.am b/daemon/Makefile.am > index 4ea3c88..0a01a24 100644 > --- a/daemon/Makefile.am > +++ b/daemon/Makefile.am > @@ -116,6 +116,7 @@ guestfsd_SOURCES = \ > findfs.c \ > fill.c \ > find.c \ > + fs-min-size.c \
Hm not really convinced by the file name chosen, but I cannot find better options. "size.c"? "fs-size.c"? > fsck.c \ > fstrim.c \ > glob.c \ > diff --git a/daemon/daemon.h b/daemon/daemon.h > index 508691a..a690152 100644 > --- a/daemon/daemon.h > +++ b/daemon/daemon.h > @@ -283,6 +283,7 @@ extern int btrfs_set_uuid_random (const char *device); > /*-- in ntfs.c --*/ > extern char *ntfs_get_label (const char *device); > extern int ntfs_set_label (const char *device, const char *label); > +extern int64_t ntfs_min_size (const char *device); > > /*-- in swap.c --*/ > extern int swap_set_uuid (const char *device, const char *uuid); > diff --git a/daemon/fs-min-size.c b/daemon/fs-min-size.c > new file mode 100644 > index 0000000..9c107d1 > --- /dev/null > +++ b/daemon/fs-min-size.c > @@ -0,0 +1,46 @@ > +/* libguestfs - the guestfsd daemon > + * Copyright (C) 2015 Maxim Perevedentsev [email protected] > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License as published by > + * the Free Software Foundation; either version 2 of the License, or > + * (at your option) any later version. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program; if not, write to the Free Software > + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 > USA. > + */ > + > +#include <config.h> > + > +#include <stdio.h> > +#include <stdlib.h> > +#include <unistd.h> > + > +#include "daemon.h" > +#include "actions.h" > + > +int64_t > +do_vfs_min_size(const mountable_t *mountable) I'd be slightly more verbose here, and call the action like "vfs_minimum_size". (also a minor style nitpick: missing space between function name and the bracket, and in other few places in this patch) > +{ > + int64_t r; > + > + /* How we set the label depends on the filesystem type. */ > + CLEANUP_FREE char *vfs_type = do_vfs_type (mountable); > + if (vfs_type == NULL) > + return -1; > + > + else if (STREQ (vfs_type, "ntfs")) > + r = ntfs_min_size (mountable->device); > + > + else > + NOT_SUPPORTED (-1, "don't know how to get minimum size of '%s' > filesystems", > + vfs_type); The documentation might better explicitly mention that unsupported filesystems will give ENOTSUP as errno on failure. > + > + return r; > +} > diff --git a/daemon/ntfs.c b/daemon/ntfs.c > index 1ead159..b9a645a 100644 > --- a/daemon/ntfs.c > +++ b/daemon/ntfs.c > @@ -153,6 +153,81 @@ do_ntfsresize_size (const char *device, int64_t size) > return do_ntfsresize (device, size, 0); > } > > +int64_t > +ntfs_min_size (const char *device) > +{ > + CLEANUP_FREE char *err = NULL, *out = NULL; > + CLEANUP_FREE_STRING_LIST char **lines = NULL; > + int r; > + size_t i; > + char *p; > + int64_t ret, volume_size = 0; The scope of "ret" could be reduced to only the if below where it is used. > + const char *size_pattern = "You might resize at ", > + *full_pattern = "Volume is full", > + *cluster_size_pattern = "Cluster size", > + *volume_size_pattern = "Current volume size:"; > + int is_full = 0; > + int32_t cluster_size = 0; > + > + /* FS may be marked for check, so force ntfsresize */ > + r = command (&out, &err, str_ntfsresize, "--info", "-ff", device, NULL); > + > + lines = split_lines (out); > + if (lines == NULL) > + return -1; > + > + if (verbose) { > + for (i = 0; lines[i] != NULL; ++i) > + fprintf (stderr, "ntfs_min_size: lines[%zu] = \"%s\"\n", i, lines[i]); > + } > + > + if (r == -1) { > + /* If volume is full, ntfsresize returns error. */ > + for (i = 0; lines[i] != NULL; ++i) { > + if (strstr (lines[i], full_pattern)) Better use STRPREFIX here, which is what we use all around libguestfs. > + is_full = 1; > + else if ((p = strstr (lines[i], cluster_size_pattern))) { > + if (sscanf (p + strlen(cluster_size_pattern), > + "%*[ ]:%" SCNd32, &cluster_size) != 1) { > + reply_with_error("Cannot parse cluster size"); > + return -1; > + } > + } > + else if ((p = strstr (lines[i], volume_size_pattern))) { > + if (sscanf (p + strlen(volume_size_pattern), > + "%" SCNd64, &volume_size) != 1) { > + reply_with_error("Cannot parse volume size"); > + return -1; > + } It sounds like these scans of the lines could be done using the analyze_line helper in btrfs.c (which would need to be moved as common code in guestfd.c). This way, the parsing of numbers could use xstrtoul/xstrtoull (see btrfs.c:do_btrfs_subvolume_list) instead of sscanf. > + } > + } > + if (is_full) { > + /* Ceil to cluster size */ > + if (cluster_size == 0) { > + reply_with_error("Bad cluster size"); > + return -1; > + } > + return (volume_size + cluster_size - 1) / cluster_size * cluster_size; Can you please explain (e.g. in a comment) what is this calculation for? > + } > + > + reply_with_error ("%s", err); > + return -1; > + } > + > + for (i = 0; lines[i] != NULL; ++i) { > + if ((p = strstr (lines[i], size_pattern))) { > + if (sscanf (p + strlen(size_pattern), "%" SCNd64, &ret) != 1) { > + reply_with_error("Cannot parse minimum size"); > + return -1; Same notes as above wrt using analyze_line and xstrtoul. > + } > + return ret; > + } > + } > + > + reply_with_error("Minimum size not found. Check output format:\n%s", out); > + return -1; > +} > + > /* Takes optional arguments, consult optargs_bitmask. */ > int > do_ntfsfix (const char *device, int clearbadsectors) > diff --git a/generator/actions.ml b/generator/actions.ml > index 274ef3f..0646a16 100644 > --- a/generator/actions.ml > +++ b/generator/actions.ml > @@ -12765,6 +12765,22 @@ Get the estimated minimum filesystem size of an > ext2/3/4 filesystem in blocks. > > See also L<resize2fs(8)>." }; > > + { defaults with > + name = "vfs_min_size"; added = (1, 31, 18); > + style = RInt64 "sizeinbytes", [Mountable "mountable"], []; > + proc_nr = Some 458; > + tests = [ > + InitPartition, IfAvailable "ntfsprogs", TestRun( > + [["mkfs"; "ntfs"; "/dev/sda1"; ""; "NOARG"; ""; ""; "NOARG"]; > + ["vfs_min_size"; "/dev/sda1"]]), []; > + ]; > + shortdesc = "get minimum filesystem size"; > + longdesc = "\ > +Get the minimum size of filesystem in bytes. > +This is the minimum possible size for filesystem shrinking. > + > +See also L<ntfsresize(8)>." }; > + > ] > > (* Non-API meta-commands available only in guestfish. > diff --git a/po/POTFILES b/po/POTFILES > index cd2c437..d90772a 100644 > --- a/po/POTFILES > +++ b/po/POTFILES > @@ -49,6 +49,7 @@ daemon/file.c > daemon/fill.c > daemon/find.c > daemon/findfs.c > +daemon/fs-min-size.c > daemon/fsck.c > daemon/fstrim.c > daemon/glob.c > diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR > index de2a00c..c92ddb6 100644 > --- a/src/MAX_PROC_NR > +++ b/src/MAX_PROC_NR > @@ -1 +1 @@ > -457 > +458 > -- Thanks, -- Pino Toscano
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