Lines Matching full:write
12 device support (e.g. f2fs), zonefs does not hide the sequential write
14 write zones of the device must be written sequentially starting from the end
38 conventional zones. Any read or write access can be executed, similarly to a
41 sequentially. Each sequential zone has a write pointer maintained by the
42 device that keeps track of the mandatory start LBA position of the next write
43 to the device. As a result of this write constraint, LBAs in a sequential zone
53 to, for instance, reduce internal write amplification due to garbage collection.
73 information. File sizes come from the device zone type and write pointer
80 state to make it read-only, preventing any data write.
94 For sequential write zones, the sub-directory "seq" is used.
112 All read and write operations to zone files are not allowed beyond the file
136 the file's zone write pointer position relative to the zone start sector.
139 end, that is, write operations can only be append writes. Zonefs makes no
140 attempt at accepting random writes and will fail any write request that has a
142 write issued and still in-flight (for asynchronous I/O operations).
145 write pattern, zonefs prevents buffered writes and writeable shared mappings
147 zonefs relies on the sequential delivery of write I/O requests to the device
149 write feature for zoned block device (ELEVATOR_F_ZBD_SEQ_WRITE elevator feature)
158 zone is reset to rewind the file zone write pointer position to the start of
184 read/write access) can change the zone condition back to a normal read/write
187 would be a defective write head on an HDD (all zones under this head are
194 condition are undefined. A typical cause would be a defective read-write head
198 * Unaligned write errors: These errors result from the host issuing write
199 requests with a start sector that does not correspond to a zone write pointer
200 position when the write request is executed by the device. Even though zonefs
201 enforces sequential file write for sequential zones, unaligned write errors
204 If one of the write request within the set of sequential write requests
205 issued to the device fails, all write requests queued after it will
208 * Delayed write errors: similarly to regular block devices, if the device side
209 write cache is enabled, write errors may occur in ranges of previously
210 completed writes when the device write cache is flushed, e.g. on fsync().
211 Similarly to the previous immediate unaligned write error case, delayed write
218 vs write) and on the reason for the error (bad sector, unaligned writes or zone
223 inconsistency between the file inode size and its zone write pointer position.
226 * For write I/O errors, zonefs I/O error recovery is always executed.
235 Immediate or delayed write errors in a sequential zone file may cause the file
237 the file zone. For instance, the partial failure of a multi-BIO large write
238 operation will cause the zone write pointer to advance partially, even though
239 the entire write operation will be reported as failed to the user. In such
240 case, the file inode size must be advanced to reflect the zone write pointer
243 A file size may also be reduced to reflect a delayed write error detected on
253 (read and write) to the file are disabled.
264 | option | condition | size read write read write |
296 the device will not re-enable file write access.
330 file size set to 0. This is necessary as the write pointer of read-only zones
342 translates into a risk for applications to see write IO errors due to this
343 limit being exceeded if the zone of a file is not already active when a write
349 guaranteed that write requests can be processed. Conversely, the
377 application to not write simultaneously more than *max_wro_seq_files*
378 sequential zone files. Failure to do so can result in write errors.
430 The "seq" sub-directory grouping files for sequential write zones has in this
442 For sequential write zone files, the file size changes as data is appended at
454 write operation::