diff options
| author | Damien Le Moal <damien.lemoal@wdc.com> | 2020-03-20 21:36:54 +0900 |
|---|---|---|
| committer | Damien Le Moal <damien.lemoal@wdc.com> | 2020-03-25 11:28:26 +0900 |
| commit | ccf4ad7da0d9c30a962a116cb55bcd7d8c44b0fe (patch) | |
| tree | 7dd69481e52106a8dceeaad3ee2157d34e640ce7 /Documentation | |
| parent | 0dda2ddb7ded1395189e95d43106469687c07795 (diff) | |
zonfs: Fix handling of read-only zones
The write pointer of zones in the read-only consition is defined as
invalid by the SCSI ZBC and ATA ZAC specifications. It is thus not
possible to determine the correct size of a read-only zone file on
mount. Fix this by handling read-only zones in the same manner as
offline zones by disabling all accesses to the zone (read and write)
and initializing the inode size of the read-only zone to 0).
For zones found to be in the read-only condition at runtime, only
disable write access to the zone and keep the size of the zone file to
its last updated value to allow the user to recover previously written
data.
Also fix zonefs documentation file to reflect this change.
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/filesystems/zonefs.txt | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/Documentation/filesystems/zonefs.txt b/Documentation/filesystems/zonefs.txt index d54fa98ac158..78813c34ec47 100644 --- a/Documentation/filesystems/zonefs.txt +++ b/Documentation/filesystems/zonefs.txt @@ -258,11 +258,11 @@ conditions. | option | condition | size read write read write | +--------------+-----------+-----------------------------------------+ | | good | fixed yes no yes yes | - | remount-ro | read-only | fixed yes no yes no | + | remount-ro | read-only | as is yes no yes no | | (default) | offline | 0 no no no no | +--------------+-----------+-----------------------------------------+ | | good | fixed yes no yes yes | - | zone-ro | read-only | fixed yes no yes no | + | zone-ro | read-only | as is yes no yes no | | | offline | 0 no no no no | +--------------+-----------+-----------------------------------------+ | | good | 0 no no yes yes | @@ -270,7 +270,7 @@ conditions. | | offline | 0 no no no no | +--------------+-----------+-----------------------------------------+ | | good | fixed yes yes yes yes | - | repair | read-only | fixed yes no yes no | + | repair | read-only | as is yes no yes no | | | offline | 0 no no no no | +--------------+-----------+-----------------------------------------+ @@ -307,8 +307,16 @@ condition changes. The defined behaviors are as follow: * zone-offline * repair -The I/O error actions defined for each behavior are detailed in the previous -section. +The run-time I/O error actions defined for each behavior are detailed in the +previous section. Mount time I/O errors will cause the mount operation to fail. +The handling of read-only zones also differs between mount-time and run-time. +If a read-only zone is found at mount time, the zone is always treated in the +same manner as offline zones, that is, all accesses are disabled and the zone +file size set to 0. This is necessary as the write pointer of read-only zones +is defined as invalib by the ZBC and ZAC standards, making it impossible to +discover the amount of data that has been written to the zone. In the case of a +read-only zone discovered at run-time, as indicated in the previous section. +the size of the zone file is left unchanged from its last updated value. Zonefs User Space Tools ======================= |