Historically hostfs did not open directories on the host filesystem for performance and memory reasons. But it turned out that this optimization has a drawback. Calling fsync() on a hostfs directory returns immediately with -EINVAL as fsync is not implemented. While this is behavior is strictly speaking correct common userspace like dpkg(1) stumbles over that and makes it impossible to use hostfs as root filesystem. The fix is easy, wire up the existing host open/fsync functions to the directory file operations.
Reported-by: Daniel Gröber <d...@darkboxed.org> Signed-off-by: Richard Weinberger <rich...@nod.at> --- fs/hostfs/hostfs_kern.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 112ba5a..92b008f 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -295,7 +295,7 @@ static int hostfs_readdir(struct file *file, struct dir_context *ctx) return 0; } -static int hostfs_file_open(struct inode *ino, struct file *file) +static int hostfs_open(struct inode *ino, struct file *file) { char *name; fmode_t mode = 0; @@ -386,7 +386,7 @@ static const struct file_operations hostfs_file_fops = { .write_iter = generic_file_write_iter, .write = new_sync_write, .mmap = generic_file_mmap, - .open = hostfs_file_open, + .open = hostfs_open, .release = hostfs_file_release, .fsync = hostfs_fsync, }; @@ -395,6 +395,8 @@ static const struct file_operations hostfs_dir_fops = { .llseek = generic_file_llseek, .iterate = hostfs_readdir, .read = generic_read_dir, + .open = hostfs_open, + .fsync = hostfs_fsync, }; static int hostfs_writepage(struct page *page, struct writeback_control *wbc) -- 2.3.2 ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel