UBIFS fast path in write_begin may mark a page up to date
and then discover that there may not be enough space to do
the write, and so fall back to a slow path. The slow path
tries harder, but may still find no space - leaving the page
marked up to date, when it is not. This patch ensures that
the page is marked not up to date in that case.
The bug that this patch fixes becomes evident when the write
is into a hole (sparse file) or is at the end of the file
and a subsequent read is off the end of the file. In both
cases, the file system should return zeros but was instead
returning the page that had not been written because the
file system was out of space.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
We observe space corrupted accounting when re-mounting. So add some
debbugging checks to catch problems like this.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
With the write_begin/write_end aops, page_symlink was broken because it
could no longer pass a GFP_NOFS type mask into the point where the
allocations happened. They are done in write_begin, which would always
assume that the filesystem can be entered from reclaim. This bug could
cause filesystem deadlocks.
The funny thing with having a gfp_t mask there is that it doesn't really
allow the caller to arbitrarily tinker with the context in which it can be
called. It couldn't ever be GFP_ATOMIC, for example, because it needs to
take the page lock. The only thing any callers care about is __GFP_FS
anyway, so turn that into a single flag.
Add a new flag for write_begin, AOP_FLAG_NOFS. Filesystems can now act on
this flag in their write_begin function. Change __grab_cache_page to
accept a nofs argument as well, to honour that flag (while we're there,
change the name to grab_cache_page_write_begin which is more instructive
and does away with random leading underscores).
This is really a more flexible way to go in the end anyway -- if a
filesystem happens to want any extra allocations aside from the pagecache
ones in ints write_begin function, it may now use GFP_KERNEL (rather than
GFP_NOFS) for common case allocations (eg. ocfs2_alloc_write_ctxt, for a
random example).
[kosaki.motohiro@jp.fujitsu.com: fix ubifs]
[kosaki.motohiro@jp.fujitsu.com: fix fuse]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: <stable@kernel.org> [2.6.28.x]
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Cleaned up the calling convention: just pass in the AOP flags
untouched to the grab_cache_page_write_begin() function. That
just simplifies everybody, and may even allow future expansion of the
logic. - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are mostly long lines and wrong indentation warning
fixes. But also there are two volatile variables and
checkpatch.pl complains about them:
WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
+ volatile int gc_seq;
WARNING: Use of volatile is usually wrong: see Documentation/volatile-considered-harmful.txt
+ volatile int gced_lnum;
Well, we anyway use smp_wmb() for c->gc_seq and c->gced_lnum, so
these 'volatile' modifiers can be just dropped.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
To avoid memory allocation failure during bulk-read, pre-allocate
a bulk-read buffer, so that if there is only one bulk-reader at
a time, it would just use the pre-allocated buffer and would not
do any memory allocation. However, if there are more than 1 bulk-
reader, then only one reader would use the pre-allocated buffer,
while the other reader would allocate the buffer for itself.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Bulk-read allocates 128KiB or more using kmalloc. The allocation
starts failing often when the memory gets fragmented. UBIFS still
works fine in this case, because it falls-back to standard
(non-optimized) read method, though. This patch teaches bulk-read
to allocate exactly the amount of memory it needs, instead of
allocating 128KiB every time.
This patch is also a preparation to the further fix where we'll
have a pre-allocated bulk-read buffer as well. For example, now
the @bu object is prepared in 'ubifs_bulk_read()', so we could
path either pre-allocated or allocated information to
'ubifs_do_bulk_read()' later. Or teaching 'ubifs_do_bulk_read()'
not to allocate 'bu->buf' if it is already there.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Bulk-read allocates a lot of memory with 'kmalloc()', and when it
is/gets fragmented 'kmalloc()' fails with a scarry warning. But
because bulk-read is just an optimization, UBIFS keeps working fine.
Supress the warning by passing __GFP_NOWARN option to 'kmalloc()'.
This patch also introduces a macro for the magic 128KiB constant.
This is just neater.
Note, this is not really fixes the problem we had, but just hides
the warnings. The further patches fix the problem.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Noticed by sparse:
fs/ubifs/file.c:75:2: warning: restricted __le64 degrades to integer
fs/ubifs/file.c:629:4: warning: restricted __le64 degrades to integer
fs/ubifs/dir.c:431:3: warning: restricted __le64 degrades to integer
This should be checked to ensure the ubifs_assert is working as
intended, I've done the suggested annotation in this patch.
fs/ubifs/sb.c:298:6: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:298:6: expected int [signed] [assigned] tmp
fs/ubifs/sb.c:298:6: got restricted __le64 [usertype] <noident>
fs/ubifs/sb.c:299:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:299:19: expected restricted __le64 [usertype] atime_sec
fs/ubifs/sb.c:299:19: got int [signed] [assigned] tmp
fs/ubifs/sb.c:300:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:300:19: expected restricted __le64 [usertype] ctime_sec
fs/ubifs/sb.c:300:19: got int [signed] [assigned] tmp
fs/ubifs/sb.c:301:19: warning: incorrect type in assignment (different base types)
fs/ubifs/sb.c:301:19: expected restricted __le64 [usertype] mtime_sec
fs/ubifs/sb.c:301:19: got int [signed] [assigned] tmp
This looks like a bugfix as your tmp was a u32 so there was truncation in
the atime, mtime, ctime value, probably not intentional, add a tmp_le64
and use it here.
fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:348:9: warning: cast to restricted __le32
fs/ubifs/key.h:419:9: warning: cast to restricted __le32
Read from the annotated union member instead.
fs/ubifs/recovery.c:175:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:175:13: expected unsigned int [unsigned] [usertype] save_flags
fs/ubifs/recovery.c:175:13: got restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13: warning: incorrect type in assignment (different base types)
fs/ubifs/recovery.c:186:13: expected restricted __le32 [usertype] flags
fs/ubifs/recovery.c:186:13: got unsigned int [unsigned] [usertype] save_flags
Do byteshifting at compile time of the flag value. Annotate the saved_flags
as le32.
fs/ubifs/debug.c:368:10: warning: cast to restricted __le32
fs/ubifs/debug.c:368:10: warning: cast from restricted __le64
Should be checked if the truncation was intentional, I've changed the
printk to print the full width.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Bulk-read skips uptodate pages but this was putting its
array index out and causing it to treat subsequent pages
as holes.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Some flash media are capable of reading sequentially at faster rates.
UBIFS bulk-read facility is designed to take advantage of that, by
reading in one go consecutive data nodes that are also located
consecutively in the same LEB.
Read speed on Arm platform with OneNAND goes from 17 MiB/s to
19 MiB/s.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Always allow truncations to zero, even if budgeting thinks there
is no space. UBIFS reserves some space for deletions anyway.
Otherwise, the following happans:
1. create a file, and write as much as possible there, until ENOSPC
2. truncate the file, which fails with ENOSPC, which is not good.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
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: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all.
Several places in the tree needed direct include.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This is a new flash file system. See
http://www.linux-mtd.infradead.org/doc/ubifs.html
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: Adrian Hunter <ext-adrian.hunter@nokia.com>
Adrian Hunter