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| author |   Miklos Szeredi <mszeredi@redhat.com> | 2018-02-08 15:17:38 +0100 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2018-03-20 17:11:43 +0100 |
| commit | df0e91d488276086bc07da2e389986cae0048c37 (patch) | |
| tree | b02f6993a75e9f16f10299613e6e9e7ff51869ae /fs/fuse/dir.c | |
| parent | Linux 4.16-rc6 (diff) | |
| download | linux-dev-df0e91d488276086bc07da2e389986cae0048c37.tar.xz linux-dev-df0e91d488276086bc07da2e389986cae0048c37.zip | |
fuse: atomic_o_trunc should truncate pagecache
Fuse has an "atomic_o_trunc" mode, where userspace filesystem uses the
O_TRUNC flag in the OPEN request to truncate the file atomically with the
open.
In this mode there's no need to send a SETATTR request to userspace after
the open, so fuse_do_setattr() checks this mode and returns. But this
misses the important step of truncating the pagecache.
Add the missing parts of truncation to the ATTR_OPEN branch.
Reported-by: Chad Austin <chadaustin@fb.com>
Fixes: 6ff958edbf39 ("fuse: add atomic open+truncate support")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'fs/fuse/dir.c')
| -rw-r--r-- | fs/fuse/dir.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 24967382a7b1..7a980b4462d9 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -1629,8 +1629,19 @@ int fuse_do_setattr(struct dentry *dentry, struct iattr *attr, return err; if (attr->ia_valid & ATTR_OPEN) { - if (fc->atomic_o_trunc) + /* This is coming from open(..., ... | O_TRUNC); */ + WARN_ON(!(attr->ia_valid & ATTR_SIZE)); + WARN_ON(attr->ia_size != 0); + if (fc->atomic_o_trunc) { + /* + * No need to send request to userspace, since actual + * truncation has already been done by OPEN. But still + * need to truncate page cache. + */ + i_size_write(inode, 0); + truncate_pagecache(inode, 0); return 0; + } file = NULL; } |