| Enumerator |
|---|
| PA_NONE | Page not spanned by io vector.
|
| PA_READ | Page needs to be read.
|
| PA_FULLPAGE_MODIFY | Page is completely spanned by incoming io vector, which is why file data can be modified while read IO is going on. Such pages need not be read from server. Mutually exclusive with PA_READ and PA_PARTPAGE_MODIFY.
|
| PA_PARTPAGE_MODIFY | Page is partially spanned by incoming io vector, which is why it has to wait till the whole page (superset) is read first and then it can be modified as per user request. Used only in case of read-modify-write. Mutually exclusive with PA_FULLPAGE_MODIFY.
|
| PA_WRITE | Page needs to be written.
|
| PA_DATA | Page contains file data.
|
| PA_PARITY | Page contains parity.
|
| PA_COPY_FRMUSR_DONE | Data has been copied from user-space into page. Flag used only when copy_direction == CD_COPY_FROM_USER. This flag is needed since in case of read-old approach, even if page/s are fully modified, they have to be read in order to generate correct parity. Hence for read-modify-write requests, fully modified pages from parity groups which have adopted read-old approach can not be copied before read state finishes.
|
| PA_READ_FAILED | Read IO failed for given page.
|
| PA_DGMODE_READ | Page needs to be read in degraded mode read IO state.
|
| PA_DGMODE_WRITE | Page needs to be written in degraded mode write IO state.
|
| PA_NR | |
| PA_NONE | Page not spanned by io vector.
|
| PA_READ | Page needs to be read.
|
| PA_FULLPAGE_MODIFY | Page is completely spanned by incoming io vector, which is why file data can be modified while read IO is going on. Such pages need not be read from server. Mutually exclusive with PA_READ and PA_PARTPAGE_MODIFY.
|
| PA_PARTPAGE_MODIFY | Page is partially spanned by incoming io vector, which is why it has to wait till the whole page (superset) is read first and then it can be modified as per user request. Used only in case of read-modify-write. Mutually exclusive with PA_FULLPAGE_MODIFY.
|
| PA_WRITE | Page needs to be written.
|
| PA_DATA | Page contains file data.
|
| PA_PARITY | Page contains parity.
|
| PA_COPY_FRMUSR_DONE | Data has been copied from user-space into page. Flag used only when copy_direction == CD_COPY_FROM_USER. This flag is needed since in case of read-old approach, even if page/s are fully modified, they have to be read in order to generate correct parity. Hence for read-modify-write requests, fully modified pages from parity groups which have adopted read-old approach can not be copied before read state finishes.
|
| PA_READ_FAILED | Read IO failed for given page.
|
| PA_DGMODE_READ | Page needs to be read in degraded mode read IO state.
|
| PA_DGMODE_WRITE | Page needs to be written in degraded mode write IO state.
|
| PA_APP_MEMORY | The application provided this memory, don't try to free it
|
| PA_TRUNC | This page will be truncated, so don't do RW operation.
|
| PA_NR | |
