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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-10 14:26:52 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-08-10 14:26:52 -0400 |
commit | 5f248c9c251c60af3403902b26e08de43964ea0b (patch) | |
tree | 6d3328e72a7e4015a64017eb30be18095c6a3c64 /Documentation/filesystems/porting | |
parent | f6cec0ae58c17522a7bc4e2f39dae19f199ab534 (diff) | |
parent | dca332528bc69e05f67161e1ed59929633d5e63d (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits)
no need for list_for_each_entry_safe()/resetting with superblock list
Fix sget() race with failing mount
vfs: don't hold s_umount over close_bdev_exclusive() call
sysv: do not mark superblock dirty on remount
sysv: do not mark superblock dirty on mount
btrfs: remove junk sb_dirt change
BFS: clean up the superblock usage
AFFS: wait for sb synchronization when needed
AFFS: clean up dirty flag usage
cifs: truncate fallout
mbcache: fix shrinker function return value
mbcache: Remove unused features
add f_flags to struct statfs(64)
pass a struct path to vfs_statfs
update VFS documentation for method changes.
All filesystems that need invalidate_inode_buffers() are doing that explicitly
convert remaining ->clear_inode() to ->evict_inode()
Make ->drop_inode() just return whether inode needs to be dropped
fs/inode.c:clear_inode() is gone
fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
...
Fix up trivial conflicts in fs/nilfs2/super.c
Diffstat (limited to 'Documentation/filesystems/porting')
-rw-r--r-- | Documentation/filesystems/porting | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index a7e9746ee7ea..b12c89538680 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting | |||
@@ -273,3 +273,48 @@ it's safe to remove it. If you don't need it, remove it. | |||
273 | deliberate; as soon as struct block_device * is propagated in a reasonable | 273 | deliberate; as soon as struct block_device * is propagated in a reasonable |
274 | way by that code fixing will become trivial; until then nothing can be | 274 | way by that code fixing will become trivial; until then nothing can be |
275 | done. | 275 | done. |
276 | |||
277 | [mandatory] | ||
278 | |||
279 | block truncatation on error exit from ->write_begin, and ->direct_IO | ||
280 | moved from generic methods (block_write_begin, cont_write_begin, | ||
281 | nobh_write_begin, blockdev_direct_IO*) to callers. Take a look at | ||
282 | ext2_write_failed and callers for an example. | ||
283 | |||
284 | [mandatory] | ||
285 | |||
286 | ->truncate is going away. The whole truncate sequence needs to be | ||
287 | implemented in ->setattr, which is now mandatory for filesystems | ||
288 | implementing on-disk size changes. Start with a copy of the old inode_setattr | ||
289 | and vmtruncate, and the reorder the vmtruncate + foofs_vmtruncate sequence to | ||
290 | be in order of zeroing blocks using block_truncate_page or similar helpers, | ||
291 | size update and on finally on-disk truncation which should not fail. | ||
292 | inode_change_ok now includes the size checks for ATTR_SIZE and must be called | ||
293 | in the beginning of ->setattr unconditionally. | ||
294 | |||
295 | [mandatory] | ||
296 | |||
297 | ->clear_inode() and ->delete_inode() are gone; ->evict_inode() should | ||
298 | be used instead. It gets called whenever the inode is evicted, whether it has | ||
299 | remaining links or not. Caller does *not* evict the pagecache or inode-associated | ||
300 | metadata buffers; getting rid of those is responsibility of method, as it had | ||
301 | been for ->delete_inode(). | ||
302 | ->drop_inode() returns int now; it's called on final iput() with inode_lock | ||
303 | held and it returns true if filesystems wants the inode to be dropped. As before, | ||
304 | generic_drop_inode() is still the default and it's been updated appropriately. | ||
305 | generic_delete_inode() is also alive and it consists simply of return 1. Note that | ||
306 | all actual eviction work is done by caller after ->drop_inode() returns. | ||
307 | clear_inode() is gone; use end_writeback() instead. As before, it must | ||
308 | be called exactly once on each call of ->evict_inode() (as it used to be for | ||
309 | each call of ->delete_inode()). Unlike before, if you are using inode-associated | ||
310 | metadata buffers (i.e. mark_buffer_dirty_inode()), it's your responsibility to | ||
311 | call invalidate_inode_buffers() before end_writeback(). | ||
312 | No async writeback (and thus no calls of ->write_inode()) will happen | ||
313 | after end_writeback() returns, so actions that should not overlap with ->write_inode() | ||
314 | (e.g. freeing on-disk inode if i_nlink is 0) ought to be done after that call. | ||
315 | |||
316 | NOTE: checking i_nlink in the beginning of ->write_inode() and bailing out | ||
317 | if it's zero is not *and* *never* *had* *been* enough. Final unlink() and iput() | ||
318 | may happen while the inode is in the middle of ->write_inode(); e.g. if you blindly | ||
319 | free the on-disk inode, you may end up doing that while ->write_inode() is writing | ||
320 | to it. | ||