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Diffstat (limited to 'Documentation/filesystems/ubifs.txt')
| -rw-r--r-- | Documentation/filesystems/ubifs.txt | 71 |
1 files changed, 13 insertions, 58 deletions
diff --git a/Documentation/filesystems/ubifs.txt b/Documentation/filesystems/ubifs.txt index 540e9e7f59c..a0a61d2f389 100644 --- a/Documentation/filesystems/ubifs.txt +++ b/Documentation/filesystems/ubifs.txt @@ -57,7 +57,7 @@ Similarly to JFFS2, UBIFS supports on-the-flight compression which makes it possible to fit quite a lot of data to the flash. Similarly to JFFS2, UBIFS is tolerant of unclean reboots and power-cuts. -It does not need stuff like ckfs.ext2. UBIFS automatically replays its +It does not need stuff like fsck.ext2. UBIFS automatically replays its journal and recovers from crashes, ensuring that the on-flash data structures are consistent. @@ -79,13 +79,18 @@ Mount options (*) == default. -norm_unmount (*) commit on unmount; the journal is committed - when the file-system is unmounted so that the - next mount does not have to replay the journal - and it becomes very fast; -fast_unmount do not commit on unmount; this option makes - unmount faster, but the next mount slower - because of the need to replay the journal. +bulk_read read more in one go to take advantage of flash + media that read faster sequentially +no_bulk_read (*) do not bulk-read +no_chk_data_crc (*) skip checking of CRCs on data nodes in order to + improve read performance. Use this option only + if the flash media is highly reliable. The effect + of this option is that corruption of the contents + of a file can go unnoticed. +chk_data_crc do not skip checking CRCs on data nodes +compr=none override default compressor and set it to "none" +compr=lzo override default compressor and set it to "lzo" +compr=zlib override default compressor and set it to "zlib" Quick usage instructions @@ -106,56 +111,6 @@ The following is an example of the kernel boot arguments to attach mtd0 to UBI and mount volume "rootfs": ubi.mtd=0 root=ubi0:rootfs rootfstype=ubifs - -Module Parameters for Debugging -=============================== - -When UBIFS has been compiled with debugging enabled, there are 3 module -parameters that are available to control aspects of testing and debugging. -The parameters are unsigned integers where each bit controls an option. -The parameters are: - -debug_msgs Selects which debug messages to display, as follows: - - Message Type Flag value - - General messages 1 - Journal messages 2 - Mount messages 4 - Commit messages 8 - LEB search messages 16 - Budgeting messages 32 - Garbage collection messages 64 - Tree Node Cache (TNC) messages 128 - LEB properties (lprops) messages 256 - Input/output messages 512 - Log messages 1024 - Scan messages 2048 - Recovery messages 4096 - -debug_chks Selects extra checks that UBIFS can do while running: - - Check Flag value - - General checks 1 - Check Tree Node Cache (TNC) 2 - Check indexing tree size 4 - Check orphan area 8 - Check old indexing tree 16 - Check LEB properties (lprops) 32 - Check leaf nodes and inodes 64 - -debug_tsts Selects a mode of testing, as follows: - - Test mode Flag value - - Force in-the-gaps method 2 - Failure mode for recovery testing 4 - -For example, set debug_msgs to 5 to display General messages and Mount -messages. - - References ========== |