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authorMiklos Szeredi <mszeredi@redhat.com>2021-08-17 21:05:16 +0200
committerMiklos Szeredi <mszeredi@redhat.com>2021-08-17 21:05:16 +0200
commit76224355db7570cbe6b6f75c8929a1558828dd55 (patch)
tree5fe1da76e6516a442bfb45907eb4e5dbbf43d03f /fs/fuse
parent5d5b74aa9c766f0dd37d5cc1a2a7a94586130501 (diff)
downloadlinux-76224355db7570cbe6b6f75c8929a1558828dd55.tar.bz2
fuse: truncate pagecache on atomic_o_trunc
fuse_finish_open() will be called with FUSE_NOWRITE in case of atomic O_TRUNC. This can deadlock with fuse_wait_on_page_writeback() in fuse_launder_page() triggered by invalidate_inode_pages2(). Fix by replacing invalidate_inode_pages2() in fuse_finish_open() with a truncate_pagecache() call. This makes sense regardless of FOPEN_KEEP_CACHE or fc->writeback cache, so do it unconditionally. Reported-by: Xie Yongji <xieyongji@bytedance.com> Reported-and-tested-by: syzbot+bea44a5189836d956894@syzkaller.appspotmail.com Fixes: e4648309b85a ("fuse: truncate pending writes on O_TRUNC") Cc: <stable@vger.kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/fuse')
-rw-r--r--fs/fuse/file.c7
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 97f860cfc195..5e5efb66c7d7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -198,12 +198,11 @@ void fuse_finish_open(struct inode *inode, struct file *file)
struct fuse_file *ff = file->private_data;
struct fuse_conn *fc = get_fuse_conn(inode);
- if (!(ff->open_flags & FOPEN_KEEP_CACHE))
- invalidate_inode_pages2(inode->i_mapping);
if (ff->open_flags & FOPEN_STREAM)
stream_open(inode, file);
else if (ff->open_flags & FOPEN_NONSEEKABLE)
nonseekable_open(inode, file);
+
if (fc->atomic_o_trunc && (file->f_flags & O_TRUNC)) {
struct fuse_inode *fi = get_fuse_inode(inode);
@@ -211,10 +210,14 @@ void fuse_finish_open(struct inode *inode, struct file *file)
fi->attr_version = atomic64_inc_return(&fc->attr_version);
i_size_write(inode, 0);
spin_unlock(&fi->lock);
+ truncate_pagecache(inode, 0);
fuse_invalidate_attr(inode);
if (fc->writeback_cache)
file_update_time(file);
+ } else if (!(ff->open_flags & FOPEN_KEEP_CACHE)) {
+ invalidate_inode_pages2(inode->i_mapping);
}
+
if ((file->f_mode & FMODE_WRITE) && fc->writeback_cache)
fuse_link_write_file(file);
}