| Message ID | 53E888C3.70807@jp.fujitsu.com (mailing list archive) |
|---|---|
| State | Not Applicable |
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On 8/11/14, 2:11 AM, Satoru Takeuchi wrote: > From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> > > - Simplify and unify the description of both man and usage. > - Fix to show -m and -d is not exclusive > with "<path>|<uuid>|<device>|<label>". > - Add the description about short options for "--mounted" and > "--all-devices", "-m" and "-d" respectively. > - Move the descriptions of options to "Options" section. > > Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> > > --- > Documentation/btrfs-filesystem.txt | 22 ++++++++++++++-------- > cmds-filesystem.c | 15 ++++++++++----- > 2 files changed, 24 insertions(+), 13 deletions(-) > > diff --git a/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt > index c9c0b00..fe68496 100644 > --- a/Documentation/btrfs-filesystem.txt > +++ b/Documentation/btrfs-filesystem.txt > @@ -20,15 +20,21 @@ SUBCOMMAND > *df* <path> [<path>...]:: > Show space usage information for a mount point. > > -*show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: > -Show the btrfs filesystem with some additional info. > +*show* [-d|-m] [<path>|<uuid>|<device>|<label>]:: > +Show the structure of btrfs filesystem(s). > + > -If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows > -information of all the btrfs filesystem both mounted and unmounted. > -If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs > -filesystem(s); > -If '--all-devices' is passed, all the devices under /dev are scanned; > -otherwise the devices list is extracted from the /proc/partitions file. > +If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows > +information of all the btrfs filesystems both mounted and unmounted. that doesn't seem quite correct; # btrfs filesystem show -m does not specify '<path>|<uuid>|<device>|<label>' but it only shows mounted filesystems, not all filesystems. As I understand it, the -d and -m options control how the command finds devices; the '<path>|<uuid>|<device>|<label>' argument is used as a filter for what is found. > ++ > +The show command finds btrfs filesystems by scanning all the devices > +in /proc/partitions by default. I think I would document it something like this: show [-m|-d] [<path>|<uuid>|<device>|<label>] Show the structure of btrfs filesystem(s). By default, the show command scans all devices found in /proc/partitions. If [-d|--all-devices] is specified, all devices found under /dev are scanned. If [-m|--mounted] is specified, only mounted (btrfs?) devices are scanned. By default, the structure of all discovered filesystems is shown. If any one of [<path>|<uuid>|<device>|<label>] is specified, only filesystems matching that identifier are shown. (What seems to be missing, though, is why would the user ever choose to use '-d?') -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 8/11/14, 10:05 AM, Eric Sandeen wrote: > On 8/11/14, 2:11 AM, Satoru Takeuchi wrote: >> From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >> >> - Simplify and unify the description of both man and usage. >> - Fix to show -m and -d is not exclusive >> with "<path>|<uuid>|<device>|<label>". >> - Add the description about short options for "--mounted" and >> "--all-devices", "-m" and "-d" respectively. >> - Move the descriptions of options to "Options" section. >> >> Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >> >> --- >> Documentation/btrfs-filesystem.txt | 22 ++++++++++++++-------- >> cmds-filesystem.c | 15 ++++++++++----- >> 2 files changed, 24 insertions(+), 13 deletions(-) >> >> diff --git a/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt >> index c9c0b00..fe68496 100644 >> --- a/Documentation/btrfs-filesystem.txt >> +++ b/Documentation/btrfs-filesystem.txt >> @@ -20,15 +20,21 @@ SUBCOMMAND >> *df* <path> [<path>...]:: >> Show space usage information for a mount point. >> >> -*show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: >> -Show the btrfs filesystem with some additional info. >> +*show* [-d|-m] [<path>|<uuid>|<device>|<label>]:: >> +Show the structure of btrfs filesystem(s). >> + >> -If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows >> -information of all the btrfs filesystem both mounted and unmounted. >> -If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs >> -filesystem(s); >> -If '--all-devices' is passed, all the devices under /dev are scanned; >> -otherwise the devices list is extracted from the /proc/partitions file. > >> +If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows >> +information of all the btrfs filesystems both mounted and unmounted. > > that doesn't seem quite correct; > > # btrfs filesystem show -m > > does not specify '<path>|<uuid>|<device>|<label>' but it only shows > mounted filesystems, not all filesystems. > > As I understand it, the -d and -m options control how the command > finds devices; the '<path>|<uuid>|<device>|<label>' argument is > used as a filter for what is found. > >> ++ >> +The show command finds btrfs filesystems by scanning all the devices >> +in /proc/partitions by default. > > I think I would document it something like this: > > show [-m|-d] [<path>|<uuid>|<device>|<label>] > Show the structure of btrfs filesystem(s). > > By default, the show command scans all devices found in /proc/partitions. > If [-d|--all-devices] is specified, all devices found under /dev are scanned. > If [-m|--mounted] is specified, only mounted (btrfs?) devices are scanned. > > By default, the structure of all discovered filesystems is shown. > If any one of [<path>|<uuid>|<device>|<label>] is specified, only filesystems > matching that identifier are shown. > > (What seems to be missing, though, is why would the user ever choose to use '-d?') Incidentally, there is some strange behavior here when looking for multiple filesystems which match. Make 2 filesystems w/ the same label: [root@bp-05 tmp]# btrfs filesystem label /dev/sdc1 testlabel2 [root@bp-05 tmp]# btrfs filesystem label /dev/sdc5 testlabel2 Show matching filesytems: [root@bp-05 tmp]# btrfs filesystem show testlabel2 Label: 'testlabel2' uuid: 8c6ec835-5628-439b-9749-d92f62573ce8 Total devices 1 FS bytes used 112.00KiB devid 1 size 30.00GiB used 2.04GiB path /dev/sdc5 Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 Total devices 1 FS bytes used 384.00KiB devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 Btrfs v3.14.2 That works fine, but if one is mounted: [root@bp-05 tmp]# mount /dev/sdc1 /mnt/test only the mounted filesystem is shown: [root@bp-05 tmp]# btrfs filesystem show testlabel2 Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 Total devices 1 FS bytes used 384.00KiB devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 Btrfs v3.14.2 That's unexpected. Mount the other fs, and both are shown again: [root@bp-05 tmp]# mount /dev/sdc5 /mnt/scratch [root@bp-05 tmp]# btrfs filesystem show testlabel2 Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 Total devices 1 FS bytes used 384.00KiB devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 Label: 'testlabel2' uuid: 8c6ec835-5628-439b-9749-d92f62573ce8 Total devices 1 FS bytes used 384.00KiB devid 1 size 30.00GiB used 2.04GiB path /dev/sdc5 Btrfs v3.14.2 -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Eric, (2014/08/12 2:05), Eric Sandeen wrote: > On 8/11/14, 2:11 AM, Satoru Takeuchi wrote: >> From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >> >> - Simplify and unify the description of both man and usage. >> - Fix to show -m and -d is not exclusive >> with "<path>|<uuid>|<device>|<label>". >> - Add the description about short options for "--mounted" and >> "--all-devices", "-m" and "-d" respectively. >> - Move the descriptions of options to "Options" section. >> >> Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >> >> --- >> Documentation/btrfs-filesystem.txt | 22 ++++++++++++++-------- >> cmds-filesystem.c | 15 ++++++++++----- >> 2 files changed, 24 insertions(+), 13 deletions(-) >> >> diff --git a/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt >> index c9c0b00..fe68496 100644 >> --- a/Documentation/btrfs-filesystem.txt >> +++ b/Documentation/btrfs-filesystem.txt >> @@ -20,15 +20,21 @@ SUBCOMMAND >> *df* <path> [<path>...]:: >> Show space usage information for a mount point. >> >> -*show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: >> -Show the btrfs filesystem with some additional info. >> +*show* [-d|-m] [<path>|<uuid>|<device>|<label>]:: >> +Show the structure of btrfs filesystem(s). >> + >> -If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows >> -information of all the btrfs filesystem both mounted and unmounted. >> -If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs >> -filesystem(s); >> -If '--all-devices' is passed, all the devices under /dev are scanned; >> -otherwise the devices list is extracted from the /proc/partitions file. > >> +If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows >> +information of all the btrfs filesystems both mounted and unmounted. > > that doesn't seem quite correct; > > # btrfs filesystem show -m > > does not specify '<path>|<uuid>|<device>|<label>' but it only shows > mounted filesystems, not all filesystems. Oh, I forgot to add "[" and "]". > > As I understand it, the -d and -m options control how the command > finds devices; the '<path>|<uuid>|<device>|<label>' argument is > used as a filter for what is found. Yes, my understanding is so too. > >> ++ >> +The show command finds btrfs filesystems by scanning all the devices >> +in /proc/partitions by default. > > I think I would document it something like this: > > show [-m|-d] [<path>|<uuid>|<device>|<label>] > Show the structure of btrfs filesystem(s). > > By default, the show command scans all devices found in /proc/partitions. > If [-d|--all-devices] is specified, all devices found under /dev are scanned. > If [-m|--mounted] is specified, only mounted (btrfs?) devices are scanned. > > By default, the structure of all discovered filesystems is shown. > If any one of [<path>|<uuid>|<device>|<label>] is specified, only filesystems > matching that identifier are shown. OK, I'll fix my patch based on your comment. # Of course, I'll replace "(btrfs?)" with something proper words. Can I add your "Signed-off-by" to my v2 patch? > > (What seems to be missing, though, is why would the user ever choose to use '-d?') I'm not sure. I guess, for example, in large systems, -d takes too many times for scanning all devices under /dev or something? Thank you for your comments! Satoru > > -Eric > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Eric, (2014/08/12 2:14), Eric Sandeen wrote: > On 8/11/14, 10:05 AM, Eric Sandeen wrote: >> On 8/11/14, 2:11 AM, Satoru Takeuchi wrote: >>> From: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >>> >>> - Simplify and unify the description of both man and usage. >>> - Fix to show -m and -d is not exclusive >>> with "<path>|<uuid>|<device>|<label>". >>> - Add the description about short options for "--mounted" and >>> "--all-devices", "-m" and "-d" respectively. >>> - Move the descriptions of options to "Options" section. >>> >>> Signed-off-by: Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> >>> >>> --- >>> Documentation/btrfs-filesystem.txt | 22 ++++++++++++++-------- >>> cmds-filesystem.c | 15 ++++++++++----- >>> 2 files changed, 24 insertions(+), 13 deletions(-) >>> >>> diff --git a/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt >>> index c9c0b00..fe68496 100644 >>> --- a/Documentation/btrfs-filesystem.txt >>> +++ b/Documentation/btrfs-filesystem.txt >>> @@ -20,15 +20,21 @@ SUBCOMMAND >>> *df* <path> [<path>...]:: >>> Show space usage information for a mount point. >>> >>> -*show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: >>> -Show the btrfs filesystem with some additional info. >>> +*show* [-d|-m] [<path>|<uuid>|<device>|<label>]:: >>> +Show the structure of btrfs filesystem(s). >>> + >>> -If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows >>> -information of all the btrfs filesystem both mounted and unmounted. >>> -If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs >>> -filesystem(s); >>> -If '--all-devices' is passed, all the devices under /dev are scanned; >>> -otherwise the devices list is extracted from the /proc/partitions file. >> >>> +If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows >>> +information of all the btrfs filesystems both mounted and unmounted. >> >> that doesn't seem quite correct; >> >> # btrfs filesystem show -m >> >> does not specify '<path>|<uuid>|<device>|<label>' but it only shows >> mounted filesystems, not all filesystems. >> >> As I understand it, the -d and -m options control how the command >> finds devices; the '<path>|<uuid>|<device>|<label>' argument is >> used as a filter for what is found. >> >>> ++ >>> +The show command finds btrfs filesystems by scanning all the devices >>> +in /proc/partitions by default. >> >> I think I would document it something like this: >> >> show [-m|-d] [<path>|<uuid>|<device>|<label>] >> Show the structure of btrfs filesystem(s). >> >> By default, the show command scans all devices found in /proc/partitions. >> If [-d|--all-devices] is specified, all devices found under /dev are scanned. >> If [-m|--mounted] is specified, only mounted (btrfs?) devices are scanned. >> >> By default, the structure of all discovered filesystems is shown. >> If any one of [<path>|<uuid>|<device>|<label>] is specified, only filesystems >> matching that identifier are shown. >> >> (What seems to be missing, though, is why would the user ever choose to use '-d?') > > Incidentally, there is some strange behavior here when looking for multiple filesystems which match. > > Make 2 filesystems w/ the same label: > > [root@bp-05 tmp]# btrfs filesystem label /dev/sdc1 testlabel2 > [root@bp-05 tmp]# btrfs filesystem label /dev/sdc5 testlabel2 > > Show matching filesytems: > > [root@bp-05 tmp]# btrfs filesystem show testlabel2 > Label: 'testlabel2' uuid: 8c6ec835-5628-439b-9749-d92f62573ce8 > Total devices 1 FS bytes used 112.00KiB > devid 1 size 30.00GiB used 2.04GiB path /dev/sdc5 > > Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 > Total devices 1 FS bytes used 384.00KiB > devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 > > Btrfs v3.14.2 > > That works fine, but if one is mounted: > > [root@bp-05 tmp]# mount /dev/sdc1 /mnt/test > > only the mounted filesystem is shown: > > [root@bp-05 tmp]# btrfs filesystem show testlabel2 > Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 > Total devices 1 FS bytes used 384.00KiB > devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 > > Btrfs v3.14.2 > > That's unexpected. > > Mount the other fs, and both are shown again: > > [root@bp-05 tmp]# mount /dev/sdc5 /mnt/scratch > [root@bp-05 tmp]# btrfs filesystem show testlabel2 > Label: 'testlabel2' uuid: a43cd507-02a2-46d2-a754-322cb7bdc346 > Total devices 1 FS bytes used 384.00KiB > devid 1 size 30.00GiB used 2.04GiB path /dev/sdc1 > > Label: 'testlabel2' uuid: 8c6ec835-5628-439b-9749-d92f62573ce8 > Total devices 1 FS bytes used 384.00KiB > devid 1 size 30.00GiB used 2.04GiB path /dev/sdc5 > > Btrfs v3.14.2 I'll dig into it. Thank you for let me know. Satoru > > > -Eric > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> On Aug 11, 2014, at 4:51 PM, Satoru Takeuchi <takeuchi_satoru@jp.fujitsu.com> wrote: > > Hi Eric, > ... > > > OK, I'll fix my patch based on your comment. > # Of course, I'll replace "(btrfs?)" with something proper words. I assumed it only scans btrfs but didn't know for sure :) > Can I add your "Signed-off-by" to my v2 patch? Oh, sure, if you use my text, that makes sense. thanks, -Eric >> >> (What seems to be missing, though, is why would the user ever choose to use '-d?') > > I'm not sure. I guess, for example, in large systems, -d takes too > many times for scanning all devices under /dev or something? > > Thank you for your comments! > > Satoru > >> >> -Eric > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Aug 11, 2014 at 10:05:52AM -0700, Eric Sandeen wrote:
> (What seems to be missing, though, is why would the user ever choose to use '-d?')
That's a fallback method if blkid or udev are not available. We've had
reports in the past that this functionality should not be dropped.
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On 8/19/14, 10:10 AM, David Sterba wrote: > On Mon, Aug 11, 2014 at 10:05:52AM -0700, Eric Sandeen wrote: >> (What seems to be missing, though, is why would the user ever choose to use '-d?') > > That's a fallback method if blkid or udev are not available. We've had > reports in the past that this functionality should not be dropped. Seems like using /proc/partitions would make more sense in that case than a recursive scan of every file under /dev, wouldn't it? Any details on those reports? I'm just wondering when you might possibly have success looking deep into the /dev tree if you didn't have success in /proc/partitions. It looks like the functionality was added with: commit 0dbd99fb3e117cd5f87eda492b6b4fab1b5bea23 Author: Goffredo Baroncelli <kreijack@inwind.it> Date: Wed Jun 15 21:55:25 2011 +0200 Scan the devices listed in /proc/partitions During the commands: - btrfs filesystem show - btrfs device scan the devices "scanned" are extracted from /proc/partitions. This should avoid to scan devices not suitable for a btrfs filesystem like cdrom and floppy or to scan not existant devices. The old behavior (scan all the block devices under /dev) may be forced passing the "--all-devices" switch. but I'm not sure why it was preserved. It just seems a bit bizarre to have so many ways to get the same info. Thanks, -Eric -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tue, Aug 19, 2014 at 10:33:44AM -0500, Eric Sandeen wrote: > Seems like using /proc/partitions would make more sense in that case > than a recursive scan of every file under /dev, wouldn't it? > Any details on those reports? It does make sense. > I'm just wondering when you might possibly have success looking deep > into the /dev tree if you didn't have success in /proc/partitions. I haven't figured out any advantage of /dev. > It just seems a bit bizarre to have so many ways to get the same info. I think keeping blkid as default and /proc/filesystems as fallback should cover the usecases. This meanas that the option -d stays, and the scanning method can be changed to BTRFS_SCAN_PROC (fi show and dev scan). -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" 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/Documentation/btrfs-filesystem.txt b/Documentation/btrfs-filesystem.txt index c9c0b00..fe68496 100644 --- a/Documentation/btrfs-filesystem.txt +++ b/Documentation/btrfs-filesystem.txt @@ -20,15 +20,21 @@ SUBCOMMAND *df* <path> [<path>...]:: Show space usage information for a mount point. -*show* [--mounted|--all-devices|<path>|<uuid>|<device>|<label>]:: -Show the btrfs filesystem with some additional info. +*show* [-d|-m] [<path>|<uuid>|<device>|<label>]:: +Show the structure of btrfs filesystem(s). + -If no option nor <path>|<uuid>|<device>|<label> is passed, btrfs shows -information of all the btrfs filesystem both mounted and unmounted. -If '--mounted' is passed, it would probe btrfs kernel to list mounted btrfs -filesystem(s); -If '--all-devices' is passed, all the devices under /dev are scanned; -otherwise the devices list is extracted from the /proc/partitions file. +If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows +information of all the btrfs filesystems both mounted and unmounted. ++ +The show command finds btrfs filesystems by scanning all the devices +in /proc/partitions by default. ++ +`Options` ++ +-d|--alldevices:::: +scan all the devices under /dev +-m|--mounted:::: +scan only mounted filesystems *sync* <path>:: Force a sync for the filesystem identified by <path>. diff --git a/cmds-filesystem.c b/cmds-filesystem.c index 38011e5..5a80a98 100644 --- a/cmds-filesystem.c +++ b/cmds-filesystem.c @@ -578,11 +578,16 @@ out: } static const char * const cmd_show_usage[] = { - "btrfs filesystem show [options] [<path>|<uuid>|<device>|label]", - "Show the structure of a filesystem", - "-d|--all-devices show only disks under /dev containing btrfs filesystem", - "-m|--mounted show only mounted btrfs", - "If no argument is given, structure of all present filesystems is shown.", + "btrfs filesystem show [-d|-m] [<path>|<uuid>|<device>|<label>]", + "Show the structure of btrfs filesystem(s).", + "If none of '<path>|<uuid>|<device>|<label>' is passed, btrfs shows", + "information of all the btrfs filesystems both mounted and unmounted.", + "", + "The show command finds btrfs filesystems by scanning all the devices", + "in /proc/partitions by default.", + "", + "-d|--all-devices scan all the devices under /dev", + "-m|--mounted scan only mounted filesystems", NULL };