UBIFS aligns node lengths to 8, so budgeting has to do the
same. Well, direntry, inode, and page budgets are already
aligned, but not inode data budget (e.g., data in special
devices or symlinks). Do this for inode data as well.
Also, add corresponding debugging checks.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Budgeting is a crucial UBIFS subsystem - add more assertions
to improve requests checking. This is not compiled in when
UBIFS debugging is disabled.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

The values in these two fields need to be preserved independently
and so a union cannot be used.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>

Every time anything is deleted, UBIFS writes the deletion inode
node twice - once in 'ubifs_jnl_update()' and the second time in
'ubifs_jnl_write_inode()'. However, the second write is not needed
if no commit happened after 'ubifs_jnl_update()'. This patch
checks that condition and avoids writing the deletion inode for
the second time.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Increment the commit number at the beginnig of the commit, instead
of doing this after the commit. This is needed for further
optimizations.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

Simplify 'ubifs_jnl_write_inode()' by removing the 'deletion'
parameter which is not really needed because we may test
inode->i_nlink and check whether this is a deletion or not.
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

We use ubifs_ro_mode() quite a lot, and not in fast-path, so
there is no reason to blow the code up by having it inlined.
Also, we usually want R/O mode change to be seen to other
CPUs as soon as possible, so when we make this a function
call, we will automatically have a memory barrier.
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>

This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.htmlSigned-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NAdrian Hunter <ext-adrian.hunter@nokia.com>