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author | Christoph Hellwig <hch@lst.de> | 2010-06-07 09:29:20 +0200 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2010-08-09 16:47:40 -0400 |
commit | 1e2317350971c8b01e6adddc798a00e9bcc1a440 (patch) | |
tree | 651dd728ac563504c510356bddcc8ae879c2d3fe /Documentation/filesystems/porting | |
parent | 2c27c65ed0696f0b5df2dad2cf6462d72164d547 (diff) | |
download | linux-1e2317350971c8b01e6adddc798a00e9bcc1a440.tar.bz2 |
update documentation for the new truncate sequence
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation/filesystems/porting')
-rw-r--r-- | Documentation/filesystems/porting | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index a7e9746ee7ea..f9547a5c187b 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -273,3 +273,21 @@ it's safe to remove it. If you don't need it, remove it. deliberate; as soon as struct block_device * is propagated in a reasonable way by that code fixing will become trivial; until then nothing can be done. + +[mandatory] + + block truncatation on error exit from ->write_begin, and ->direct_IO +moved from generic methods (block_write_begin, cont_write_begin, +nobh_write_begin, blockdev_direct_IO*) to callers. Take a look at +ext2_write_failed and callers for an example. + +[mandatory] + + ->truncate is going away. The whole truncate sequence needs to be +implemented in ->setattr, which is now mandatory for filesystems +implementing on-disk size changes. Start with a copy of the old inode_setattr +and vmtruncate, and the reorder the vmtruncate + foofs_vmtruncate sequence to +be in order of zeroing blocks using block_truncate_page or similar helpers, +size update and on finally on-disk truncation which should not fail. +inode_change_ok now includes the size checks for ATTR_SIZE and must be called +in the beginning of ->setattr unconditionally. |