Commit 4c5fd3b7 authored by Randy Dunlap's avatar Randy Dunlap Committed by Damien Le Moal

zonefs: fix documentation typos etc.

Fix typos, spellos, etc. in zonefs.txt.
Signed-off-by: default avatarRandy Dunlap <rdunlap@infradead.org>
Cc: Damien Le Moal <Damien.LeMoal@wdc.com>
Reviewed-by: default avatarChaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Signed-off-by: default avatarDamien Le Moal <damien.lemoal@wdc.com>
parent 11a48a5a
...@@ -134,7 +134,7 @@ Sequential zone files can only be written sequentially, starting from the file ...@@ -134,7 +134,7 @@ Sequential zone files can only be written sequentially, starting from the file
end, that is, write operations can only be append writes. Zonefs makes no end, that is, write operations can only be append writes. Zonefs makes no
attempt at accepting random writes and will fail any write request that has a attempt at accepting random writes and will fail any write request that has a
start offset not corresponding to the end of the file, or to the end of the last start offset not corresponding to the end of the file, or to the end of the last
write issued and still in-flight (for asynchrnous I/O operations). write issued and still in-flight (for asynchronous I/O operations).
Since dirty page writeback by the page cache does not guarantee a sequential Since dirty page writeback by the page cache does not guarantee a sequential
write pattern, zonefs prevents buffered writes and writeable shared mappings write pattern, zonefs prevents buffered writes and writeable shared mappings
...@@ -142,7 +142,7 @@ on sequential files. Only direct I/O writes are accepted for these files. ...@@ -142,7 +142,7 @@ on sequential files. Only direct I/O writes are accepted for these files.
zonefs relies on the sequential delivery of write I/O requests to the device zonefs relies on the sequential delivery of write I/O requests to the device
implemented by the block layer elevator. An elevator implementing the sequential implemented by the block layer elevator. An elevator implementing the sequential
write feature for zoned block device (ELEVATOR_F_ZBD_SEQ_WRITE elevator feature) write feature for zoned block device (ELEVATOR_F_ZBD_SEQ_WRITE elevator feature)
must be used. This type of elevator (e.g. mq-deadline) is the set by default must be used. This type of elevator (e.g. mq-deadline) is set by default
for zoned block devices on device initialization. for zoned block devices on device initialization.
There are no restrictions on the type of I/O used for read operations in There are no restrictions on the type of I/O used for read operations in
...@@ -196,7 +196,7 @@ additional conditions that result in I/O errors. ...@@ -196,7 +196,7 @@ additional conditions that result in I/O errors.
may still happen in the case of a partial failure of a very large direct I/O may still happen in the case of a partial failure of a very large direct I/O
operation split into multiple BIOs/requests or asynchronous I/O operations. operation split into multiple BIOs/requests or asynchronous I/O operations.
If one of the write request within the set of sequential write requests If one of the write request within the set of sequential write requests
issued to the device fails, all write requests after queued after it will issued to the device fails, all write requests queued after it will
become unaligned and fail. become unaligned and fail.
* Delayed write errors: similarly to regular block devices, if the device side * Delayed write errors: similarly to regular block devices, if the device side
...@@ -207,7 +207,7 @@ additional conditions that result in I/O errors. ...@@ -207,7 +207,7 @@ additional conditions that result in I/O errors.
causing all data to be dropped after the sector that caused the error. causing all data to be dropped after the sector that caused the error.
All I/O errors detected by zonefs are notified to the user with an error code All I/O errors detected by zonefs are notified to the user with an error code
return for the system call that trigered or detected the error. The recovery return for the system call that triggered or detected the error. The recovery
actions taken by zonefs in response to I/O errors depend on the I/O type (read actions taken by zonefs in response to I/O errors depend on the I/O type (read
vs write) and on the reason for the error (bad sector, unaligned writes or zone vs write) and on the reason for the error (bad sector, unaligned writes or zone
condition change). condition change).
...@@ -222,7 +222,7 @@ condition change). ...@@ -222,7 +222,7 @@ condition change).
* A zone condition change to read-only or offline also always triggers zonefs * A zone condition change to read-only or offline also always triggers zonefs
I/O error recovery. I/O error recovery.
Zonefs minimal I/O error recovery may change a file size and a file access Zonefs minimal I/O error recovery may change a file size and file access
permissions. permissions.
* File size changes: * File size changes:
...@@ -237,7 +237,7 @@ permissions. ...@@ -237,7 +237,7 @@ permissions.
A file size may also be reduced to reflect a delayed write error detected on A file size may also be reduced to reflect a delayed write error detected on
fsync(): in this case, the amount of data effectively written in the zone may fsync(): in this case, the amount of data effectively written in the zone may
be less than originally indicated by the file inode size. After such I/O be less than originally indicated by the file inode size. After such I/O
error, zonefs always fixes a file inode size to reflect the amount of data error, zonefs always fixes the file inode size to reflect the amount of data
persistently stored in the file zone. persistently stored in the file zone.
* Access permission changes: * Access permission changes:
...@@ -281,11 +281,11 @@ Further notes: ...@@ -281,11 +281,11 @@ Further notes:
permissions to read-only applies to all files. The file system is remounted permissions to read-only applies to all files. The file system is remounted
read-only. read-only.
* Access permission and file size changes due to the device transitioning zones * Access permission and file size changes due to the device transitioning zones
to the offline condition are permanent. Remounting or reformating the device to the offline condition are permanent. Remounting or reformatting the device
with mkfs.zonefs (mkzonefs) will not change back offline zone files to a good with mkfs.zonefs (mkzonefs) will not change back offline zone files to a good
state. state.
* File access permission changes to read-only due to the device transitioning * File access permission changes to read-only due to the device transitioning
zones to the read-only condition are permanent. Remounting or reformating zones to the read-only condition are permanent. Remounting or reformatting
the device will not re-enable file write access. the device will not re-enable file write access.
* File access permission changes implied by the remount-ro, zone-ro and * File access permission changes implied by the remount-ro, zone-ro and
zone-offline mount options are temporary for zones in a good condition. zone-offline mount options are temporary for zones in a good condition.
...@@ -301,13 +301,13 @@ Mount options ...@@ -301,13 +301,13 @@ Mount options
zonefs define the "errors=<behavior>" mount option to allow the user to specify zonefs define the "errors=<behavior>" mount option to allow the user to specify
zonefs behavior in response to I/O errors, inode size inconsistencies or zone zonefs behavior in response to I/O errors, inode size inconsistencies or zone
condition chages. The defined behaviors are as follow: condition changes. The defined behaviors are as follow:
* remount-ro (default) * remount-ro (default)
* zone-ro * zone-ro
* zone-offline * zone-offline
* repair * repair
The I/O error actions defined for each behavior is detailed in the previous The I/O error actions defined for each behavior are detailed in the previous
section. section.
Zonefs User Space Tools Zonefs User Space Tools
......
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