linux.git/fs/f2fs/extent_cache.c, branch v4.19

f2fs: clean up symbol namespace

2018-05-31T18:31:53+00:00

As Ted reported:

"Hi, I was looking at f2fs's sources recently, and I noticed that there
is a very large number of non-static symbols which don't have a f2fs
prefix.  There's well over a hundred (see attached below).

As one example, in fs/f2fs/dir.c there is:

unsigned char get_de_type(struct f2fs_dir_entry *de)

This function is clearly only useful for f2fs, but it has a generic
name.  This means that if any other file system tries to have the same
symbol name, there will be a symbol conflict and the kernel would not
successfully build.  It also means that when someone is looking f2fs
sources, it's not at all obvious whether a function such as
read_data_page(), invalidate_blocks(), is a generic kernel function
found in the fs, mm, or block layers, or a f2fs specific function.

You might want to fix this at some point.  Hopefully Kent's bcachefs
isn't similarly using genericly named functions, since that might
cause conflicts with f2fs's functions --- but just as this would be a
problem that we would rightly insist that Kent fix, this is something
that we should have rightly insisted that f2fs should have fixed
before it was integrated into the mainline kernel.

acquire_orphan_inode
add_ino_entry
add_orphan_inode
allocate_data_block
allocate_new_segments
alloc_nid
alloc_nid_done
alloc_nid_failed
available_free_memory
...."

This patch adds "f2fs_" prefix for all non-static symbols in order to:
a) avoid conflict with other kernel generic symbols;
b) to indicate the function is f2fs specific one instead of generic
one;

Reported-by: Theodore Ts'o 
Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: remove redundant initialization of pointer 'p'

2018-03-12T23:05:45+00:00

Pointer p is initialized with a value that is never read and is later
re-assigned a new value, hence the initialization is redundant and can
be removed.

Cleans up clang warning:
fs/f2fs/extent_cache.c:463:19: warning: Value stored to 'p' during
its initialization is never read

Signed-off-by: Colin Ian King 
Reviewed-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix to check extent cache in f2fs_drop_extent_tree

2018-03-12T23:05:32+00:00

If noextent_cache mount option is on, we will never initialize extent tree
in inode, but still we're going to access it in f2fs_drop_extent_tree,
result in kernel panic as below:

 BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
 IP: _raw_write_lock+0xc/0x30
 Call Trace:
  ? f2fs_drop_extent_tree+0x41/0x70 [f2fs]
  f2fs_fallocate+0x5a0/0xdd0 [f2fs]
  ? common_file_perm+0x47/0xc0
  ? apparmor_file_permission+0x1a/0x20
  vfs_fallocate+0x15b/0x290
  SyS_fallocate+0x44/0x70
  do_syscall_64+0x6e/0x160
  entry_SYSCALL64_slow_path+0x25/0x25

This patch fixes to check extent cache status before using in
f2fs_drop_extent_tree.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: fix a bug caused by NULL extent tree

2017-05-24T04:07:18+00:00

Thread A:					Thread B:

-f2fs_remount
    -sbi->mount_opt.opt = 0;
						<--- -f2fs_iget
						         -do_read_inode
							     -f2fs_init_extent_tree
							         -F2FS_I(inode)->extent_tree is NULL
        -default_options && parse_options
	    -remount return
						<---  -f2fs_map_blocks
						          -f2fs_lookup_extent_tree
                                                              -f2fs_bug_on(sbi, !et);

The same problem with f2fs_new_inode.

Signed-off-by: Yunlei He 
Signed-off-by: Jaegeuk Kim

f2fs: introduce __check_rb_tree_consistence

2017-04-19T18:00:44+00:00

Introduce __check_rb_tree_consistence to check consistence of rb-tree
based discard cache in runtime.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: use rb-tree to track pending discard commands

2017-04-19T18:00:40+00:00

Introduce rb-tree based discard cache infrastructure to speed up lookup and
merge operation of discard entry.

Signed-off-by: Chao Yu 
[Jaegeuk Kim: initialize dc to avoid build warning]
Signed-off-by: Jaegeuk Kim

f2fs: extract rb-tree operation infrastructure

2017-04-11T22:13:52+00:00

rb-tree lookup/update functions are deeply coupled into extent cache
codes, it's very hard to reuse these basic functions, this patch
extracts common rb-tree operation infrastructure for latter reusing.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: kill __is_extent_same

2017-02-27T18:07:43+00:00

Since commit ee6d182f2a19 ("f2fs: remove syncing inode page in all the
cases") delayed inode element updating from inode cache to node page
cache, so once largest cached extent is updated, we can make inode dirty
immediately instead of checking and updating it in the end of extent
cache update.

The above commit didn't clean up unneeded codes in extent_cache.c, let's
finish the job in this patch.

Signed-off-by: Chao Yu 
Signed-off-by: Jaegeuk Kim

f2fs: replace rw semaphore extent_tree_lock with mutex lock

2017-02-27T17:59:53+00:00

This patch replace rw semaphore extent_tree_lock with mutex lock
for no read cases with this lock.

Signed-off-by: Yunlei He 
Signed-off-by: Jaegeuk Kim

f2fs: use rb_entry_safe

2017-01-29T03:46:01+00:00

Use rb_entry_safe() instead of open-coding it.

Signed-off-by: Geliang Tang 
Signed-off-by: Jaegeuk Kim