Merge branches 'misc', 'eeepc-laptop' and 'bugzilla-14445' into release

[safe/jmp/linux-2.6] / Documentation / filesystems / ext4.txt

diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 97882df..6d94e06 100644 (file)
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -235,6 +235,10 @@ minixdf                    Make 'df' act like Minix.
 
 debug                  Extra debugging information is sent to syslog.
 
+abort                  Simulate the effects of calling ext4_abort() for
+                       debugging purposes.  This is normally used while
+                       remounting a filesystem which is already mounted.
+
 errors=remount-ro      Remount the filesystem read-only on an error.
 errors=continue                Keep going on a filesystem error.
 errors=panic           Panic and halt the machine if an error occurs.
@@ -259,10 +263,18 @@ resuid=n          The user ID which may use the reserved blocks.
 
 sb=n                   Use alternate superblock at this location.
 
-quota
-noquota
-grpquota
-usrquota
+quota                  These options are ignored by the filesystem. They
+noquota                        are used only by quota tools to recognize volumes
+grpquota               where quota should be turned on. See documentation
+usrquota               in the quota-tools package for more details
+                       (http://sourceforge.net/projects/linuxquota).
+
+jqfmt=<quota type>     These options tell filesystem details about quota
+usrjquota=<file>       so that quota information can be properly updated
+grpjquota=<file>       during journal replay. They replace the above
+                       quota options. See documentation in the quota-tools
+                       package for more details
+                       (http://sourceforge.net/projects/linuxquota).
 
 bh             (*)     ext4 associates buffer heads to data pages to
 nobh                   (a) cache disk block mapping information
@@ -276,9 +288,16 @@ stripe=n           Number of filesystem blocks that mballoc will try
                        to use for allocation size and alignment. For RAID5/6
                        systems this should be the number of data
                        disks *  RAID chunk size in file system blocks.
-delalloc       (*)     Deferring block allocation until write-out time.
-nodelalloc             Disable delayed allocation. Blocks are allocation
-                       when data is copied from user to page cache.
+
+delalloc       (*)     Defer block allocation until just before ext4
+                       writes out the block(s) in question.  This
+                       allows ext4 to better allocation decisions
+                       more efficiently.
+nodelalloc             Disable delayed allocation.  Blocks are allocated
+                       when the data is copied from userspace to the
+                       page cache, either via the write(2) system call
+                       or when an mmap'ed page which was previously
+                       unallocated is written for the first time.
 
 max_batch_time=usec    Maximum amount of time ext4 should wait for
                        additional filesystem operations to be batch
@@ -294,7 +313,7 @@ max_batch_time=usec Maximum amount of time ext4 should wait for
                        amount of time (on average) that it takes to
                        finish committing a transaction.  Call this time
                        the "commit time".  If the time that the
-                       transactoin has been running is less than the
+                       transaction has been running is less than the
                        commit time, ext4 will try sleeping for the
                        commit time to see if other operations will join
                        the transaction.   The commit time is capped by
@@ -328,7 +347,7 @@ noauto_da_alloc             replacing existing files via patterns such as
                        journal commit, in the default data=ordered
                        mode, the data blocks of the new file are forced
                        to disk before the rename() operation is
-                       commited.  This provides roughly the same level
+                       committed.  This provides roughly the same level
                        of guarantees as ext3, and avoids the
                        "zero-length" problem that can happen when a
                        system crashes before the delayed allocation
@@ -358,7 +377,7 @@ written to the journal first, and then to its final location.
 In the event of a crash, the journal can be replayed, bringing both data and
 metadata into a consistent state.  This mode is the slowest except when data
 needs to be read from and written to disk at the same time where it
-outperforms all others modes.  Curently ext4 does not have delayed
+outperforms all others modes.  Currently ext4 does not have delayed
 allocation support if this data journalling mode is selected.
 
 References