linux_old1/fs
Miao Xie 6d07bcec96 btrfs: fix wrong free space information of btrfs
When we store data by raid profile in btrfs with two or more different size
disks, df command shows there is some free space in the filesystem, but the
user can not write any data in fact, df command shows the wrong free space
information of btrfs.

 # mkfs.btrfs -d raid1 /dev/sda9 /dev/sda10
 # btrfs-show
 Label: none  uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
 	Total devices 2 FS bytes used 28.00KB
 	devid    1 size 5.01GB used 2.03GB path /dev/sda9
 	devid    2 size 10.00GB used 2.01GB path /dev/sda10
 # btrfs device scan /dev/sda9 /dev/sda10
 # mount /dev/sda9 /mnt
 # dd if=/dev/zero of=tmpfile0 bs=4K count=9999999999
   (fill the filesystem)
 # sync
 # df -TH
 Filesystem	Type	Size	Used	Avail	Use%	Mounted on
 /dev/sda9	btrfs	17G	8.6G	5.4G	62%	/mnt
 # btrfs-show
 Label: none  uuid: a95cd49e-6e33-45b8-8741-a36153ce4b64
 	Total devices 2 FS bytes used 3.99GB
 	devid    1 size 5.01GB used 5.01GB path /dev/sda9
 	devid    2 size 10.00GB used 4.99GB path /dev/sda10

It is because btrfs cannot allocate chunks when one of the pairing disks has
no space, the free space on the other disks can not be used for ever, and should
be subtracted from the total space, but btrfs doesn't subtract this space from
the total. It is strange to the user.

This patch fixes it by calcing the free space that can be used to allocate
chunks.

Implementation:
1. get all the devices free space, and align them by stripe length.
2. sort the devices by the free space.
3. check the free space of the devices,
   3.1. if it is not zero, and then check the number of the devices that has
        more free space than this device,
        if the number of the devices is beyond the min stripe number, the free
        space can be used, and add into total free space.
        if the number of the devices is below the min stripe number, we can not
        use the free space, the check ends.
   3.2. if the free space is zero, check the next devices, goto 3.1

This implementation is just likely fake chunk allocation.

After appling this patch, df can show correct space information:
 # df -TH
 Filesystem	Type	Size	Used	Avail	Use%	Mounted on
 /dev/sda9	btrfs	17G	8.6G	0	100%	/mnt

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-01-16 11:30:19 -05:00
..
9p fs/9p: Don't use dotl version of mknod for dotu inode operations 2010-09-13 08:13:03 -05:00
adfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
affs AFFS: wait for sb synchronization when needed 2010-08-09 16:48:51 -04:00
afs Merge git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6 2010-08-13 10:37:30 -07:00
autofs autofs/autofs4: Move compat_ioctl handling into fs 2010-08-09 00:13:34 +02:00
autofs4 autofs4: remove unneeded null check in try_to_fill_dentry() 2010-08-11 08:59:06 -07:00
befs fix typos concerning "initiali[zs]e" 2010-06-16 18:05:05 +02:00
bfs BFS: clean up the superblock usage 2010-08-09 16:48:53 -04:00
btrfs btrfs: fix wrong free space information of btrfs 2011-01-16 11:30:19 -05:00
cachefiles Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
ceph ceph: update issue_seq on cap grant 2010-10-07 08:01:50 -07:00
cifs cifs: prevent infinite recursion in cifs_reconnect_tcon 2010-10-01 17:50:08 +00:00
coda Coda: mount hangs because of missed REQ_WRITE rename 2010-09-19 11:03:09 -07:00
configfs fix setattr error handling in sysfs, configfs 2010-06-04 17:16:29 -04:00
cramfs cramfs: only unlock new inodes 2010-08-18 01:01:33 -04:00
debugfs Add x64 support to debugfs 2010-05-19 22:41:57 -04:00
devpts Simplify devpts_get_sb() failure exits 2010-05-21 18:31:12 -04:00
dlm fs/dlm: Drop unnecessary null test 2010-08-05 14:23:45 -05:00
ecryptfs eCryptfs: Fix encrypted file name lookup regression 2010-08-27 10:50:53 -05:00
efs
exofs exofs: Fix double page_unlock BUG in write_begin/end 2010-10-08 11:26:54 -04:00
exportfs
ext2 mbcache: Remove unused features 2010-08-09 16:48:45 -04:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ext4 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fat remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
freevxfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
fscache Add a dummy printk function for the maintenance of unused printks 2010-08-12 09:51:35 -07:00
fuse fuse: Initialize total_len in fuse_retrieve() 2010-10-04 10:45:32 +02:00
gfs2 GFS2: gfs2_logd should be using interruptible waits 2010-09-17 14:00:10 +01:00
hfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hfsplus convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
hostfs hostfs ->follow_link() braino 2010-08-18 06:21:10 -04:00
hpfs switch hpfs to ->evict_inode() 2010-08-09 16:48:17 -04:00
hppfs switch hppfs to ->evict_inode() 2010-08-09 16:48:16 -04:00
hugetlbfs new helper: end_writeback() 2010-08-09 16:47:49 -04:00
isofs isofs: Fix lseek() to position beyond 4 GB 2010-08-11 00:29:47 -04:00
jbd remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jbd2 remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
jffs2 Merge git://git.infradead.org/mtd-2.6 2010-08-10 11:49:21 -07:00
jfs jfs: don't allow os2 xattr namespace overlap with others 2010-08-10 15:33:09 -07:00
lockd include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
logfs logfs: kill BKL 2010-08-14 00:24:24 +02:00
minix minix: fix regression in minix_mkdir() 2010-09-09 18:57:25 -07:00
ncpfs Merge branch 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing 2010-08-10 13:58:28 -07:00
nfs SUNRPC: Fix the NFSv4 and RPCSEC_GSS Kconfig dependencies 2010-09-12 19:57:50 -04:00
nfs_common include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
nfsd nfsd: fix BUG at fs/nfsd/nfsfh.h:199 on unlink 2010-10-13 15:48:55 -04:00
nilfs2 nilfs2: fix leak of shadow dat inode in error path of load_nilfs 2010-08-30 10:18:03 +09:00
nls
notify fanotify: disable fanotify syscalls 2010-10-11 18:15:28 -07:00
ntfs convert remaining ->clear_inode() to ->evict_inode() 2010-08-09 16:48:37 -04:00
ocfs2 ocfs2: Don't walk off the end of fast symlinks. 2010-09-29 17:33:05 -07:00
omfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/bcopeland/omfs 2010-08-10 11:47:36 -07:00
openpromfs
partitions [S390] partitions: fix build error in ibm partition detection code 2010-08-13 10:06:55 +02:00
proc proc: make /proc/pid/limits world readable 2010-10-01 10:50:59 -07:00
qnx4 get rid of cont_write_begin_newtrunc 2010-08-09 16:47:31 -04:00
quota Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ramfs check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
reiserfs reiserfs: fix unwanted reiserfs lock recursion 2010-10-01 10:50:59 -07:00
romfs
smbfs switch smbfs to evict_inode() 2010-08-09 16:48:00 -04:00
squashfs Squashfs: fix checkpatch.pl warnings 2010-08-08 22:29:33 +00:00
sysfs sysfs: checking for NULL instead of ERR_PTR 2010-09-03 17:26:28 -07:00
sysv fs/sysv/super.c: add support for non-PDP11 v7 filesystems 2010-08-11 08:59:23 -07:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
udf Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 2010-08-10 11:26:52 -07:00
ufs remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
xfs xfs: properly account for reclaimed inodes 2010-10-06 22:35:48 -05:00
Kconfig fs/Kconfig: Fix typo Userpace -> Userspace 2010-07-20 17:30:22 +02:00
Kconfig.binfmt
Makefile Take statfs variants to fs/statfs.c 2010-05-21 18:31:17 -04:00
aio.c aio: do not return ERESTARTSYS as a result of AIO 2010-09-22 17:22:39 -07:00
anon_inodes.c Revert "anon_inode: set S_IFREG on the anon_inode" 2010-05-27 22:03:05 -04:00
attr.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
bad_inode.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
binfmt_aout.c Don't dump task struct in a.out core-dumps 2010-10-14 10:57:40 -07:00
binfmt_elf.c coredump: pass mm->flags as a coredump parameter for consistency 2010-03-06 11:26:46 -08:00
binfmt_elf_fdpic.c binfmt_elf_fdpic: Fix clear_user() error handling 2010-06-01 08:11:06 -07:00
binfmt_em86.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
binfmt_flat.c flat: tweak default stack alignment 2010-06-29 15:29:31 -07:00
binfmt_misc.c binfmt_misc: fix binfmt_misc priority 2010-09-09 18:57:24 -07:00
binfmt_script.c Make do_execve() take a const filename pointer 2010-08-17 18:07:43 -07:00
binfmt_som.c
bio-integrity.c fs/bio-integrity.c: return -ENOMEM on kmalloc failure 2010-08-23 13:36:59 +02:00
bio.c block: unify flags for struct bio and struct request 2010-08-07 18:20:39 +02:00
block_dev.c blkdev: cgroup whitelist permission fix 2010-08-11 08:59:18 -07:00
buffer.c remove SWRITE* I/O types 2010-08-18 01:09:01 -04:00
char_dev.c char: Mark /dev/zero and /dev/kmem as not capable of writeback 2010-09-22 09:48:47 +02:00
compat.c Prevent freeing uninitialized pointer in compat_do_readv_writev 2010-09-22 17:22:38 -07:00
compat_binfmt_elf.c elf coredump: replace ELF_CORE_EXTRA_* macros by functions 2010-03-06 11:26:45 -08:00
compat_ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
dcache.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
dcookies.c
direct-io.c O_DIRECT: fix the splitting up of contiguous I/O 2010-09-09 18:57:22 -07:00
drop_caches.c simplify checks for I_CLEAR/I_FREEING 2010-08-09 16:47:44 -04:00
eventfd.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
eventpoll.c sched, wait: Use wrapper functions 2010-05-11 17:43:58 +02:00
exec.c Export dump_{write,seek} to binary loader modules 2010-10-14 19:15:28 -07:00
fcntl.c vfs: take O_NONBLOCK out of the O_* uniqueness test 2010-09-09 18:57:25 -07:00
fifo.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
file.c vfs: use kmalloc() to allocate fdmem if possible 2010-08-11 08:59:02 -07:00
file_table.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
filesystems.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
fs-writeback.c Add new functions for triggering inode writeback 2010-10-29 11:25:29 -04:00
fs_struct.c fs: fs_struct rwlock to spinlock 2010-08-18 08:35:46 -04:00
generic_acl.c vfs: update ctime when changing the file's permission by setfacl 2010-08-18 01:04:22 -04:00
inode.c Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify 2010-08-10 11:39:13 -07:00
internal.h fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
ioctl.c bkl: Remove locked .ioctl file operation 2010-08-14 00:24:24 +02:00
ioprio.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
libfs.c check ATTR_SIZE contraints in inode_change_ok 2010-08-09 16:47:39 -04:00
locks.c Merge branch 'for-next' into for-linus 2010-03-08 16:55:37 +01:00
mbcache.c mbcache: Limit the maximum number of cache entries 2010-08-18 06:24:41 -04:00
mpage.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
namei.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
namespace.c VFS: Sanity check mount flags passed to change_mnt_propagation() 2010-09-07 13:46:20 -07:00
nfsctl.c
no-block.c
open.c fs: cleanup files_lock locking 2010-08-18 08:35:47 -04:00
pipe.c pipe: fix check in "set size" fcntl 2010-06-10 19:08:34 +02:00
pnode.c fs: brlock vfsmount_lock 2010-08-18 08:35:48 -04:00
pnode.h
posix_acl.c
read_write.c fsnotify: pass a file instead of an inode to open, read, and write 2010-07-28 09:58:32 -04:00
read_write.h
readdir.c vfs: fix warning: 'dirent' is used uninitialized in this function 2010-08-09 20:45:05 -07:00
select.c Add generic sys_old_select() 2010-03-12 15:52:32 -08:00
seq_file.c seq_file: fix new kernel-doc warnings 2010-03-07 15:48:26 -08:00
signalfd.c signalfd: fill in ssi_int for posix timers and message queues 2010-08-11 08:59:20 -07:00
splice.c splice: fix misuse of SPLICE_F_NONBLOCK 2010-08-07 18:52:56 +02:00
stack.c
stat.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
statfs.c add f_flags to struct statfs(64) 2010-08-09 16:48:44 -04:00
super.c fs: scale files_lock 2010-08-18 08:35:48 -04:00
sync.c get rid of file_fsync() 2010-08-09 16:47:43 -04:00
timerfd.c fs/timerfd.c: make use of wait_event_interruptible_locked_irq() 2010-05-20 13:21:42 -07:00
utimes.c Mark arguments to certain syscalls as being const 2010-08-13 16:53:13 -07:00
xattr.c fs: xattr_handler table should be const 2010-05-21 18:31:18 -04:00
xattr_acl.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00