diff options
author | Anton Blanchard <anton@samba.org> | 2011-06-13 22:31:12 +0100 |
---|---|---|
committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-06-16 11:44:46 -0400 |
commit | 5e7f23373bf9a853e9256e81e86724cdd0a33c29 (patch) | |
tree | 4e49311429c995889853d0ec0f43a3023869c227 | |
parent | 8aef18845266f5c05904c610088f2d1ed58f6be3 (diff) | |
download | kernel_samsung_smdk4412-5e7f23373bf9a853e9256e81e86724cdd0a33c29.tar.gz kernel_samsung_smdk4412-5e7f23373bf9a853e9256e81e86724cdd0a33c29.tar.bz2 kernel_samsung_smdk4412-5e7f23373bf9a853e9256e81e86724cdd0a33c29.zip |
afs: afs_fill_page reads too much, or wrong data
afs_fill_page should read the page that is about to be written but
the current implementation has a number of issues. If we aren't
extending the file we always read PAGE_CACHE_SIZE at offset 0. If we
are extending the file we try to read the entire file.
Change afs_fill_page to read PAGE_CACHE_SIZE at the right offset,
clamped to i_size.
While here, avoid calling afs_fill_page when we are doing a
PAGE_CACHE_SIZE write.
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-rw-r--r-- | fs/afs/write.c | 21 |
1 files changed, 9 insertions, 12 deletions
diff --git a/fs/afs/write.c b/fs/afs/write.c index 789b3afb342..b806285ff85 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -84,23 +84,21 @@ void afs_put_writeback(struct afs_writeback *wb) * partly or wholly fill a page that's under preparation for writing */ static int afs_fill_page(struct afs_vnode *vnode, struct key *key, - loff_t pos, unsigned len, struct page *page) + loff_t pos, struct page *page) { loff_t i_size; - unsigned eof; int ret; + int len; - _enter(",,%llu,%u", (unsigned long long)pos, len); - - ASSERTCMP(len, <=, PAGE_CACHE_SIZE); + _enter(",,%llu", (unsigned long long)pos); i_size = i_size_read(&vnode->vfs_inode); - if (pos + len > i_size) - eof = i_size; + if (pos + PAGE_CACHE_SIZE > i_size) + len = i_size - pos; else - eof = PAGE_CACHE_SIZE; + len = PAGE_CACHE_SIZE; - ret = afs_vnode_fetch_data(vnode, key, 0, eof, page); + ret = afs_vnode_fetch_data(vnode, key, pos, len, page); if (ret < 0) { if (ret == -ENOENT) { _debug("got NOENT from server" @@ -153,9 +151,8 @@ int afs_write_begin(struct file *file, struct address_space *mapping, *pagep = page; /* page won't leak in error case: it eventually gets cleaned off LRU */ - if (!PageUptodate(page)) { - _debug("not up to date"); - ret = afs_fill_page(vnode, key, pos, len, page); + if (!PageUptodate(page) && len != PAGE_CACHE_SIZE) { + ret = afs_fill_page(vnode, key, index << PAGE_CACHE_SHIFT, page); if (ret < 0) { kfree(candidate); _leave(" = %d [prep]", ret); |