diff options
| author | Amir Goldstein <amir73il@gmail.com> | 2023-11-30 16:16:23 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2023-12-01 11:39:50 +0100 |
| commit | da40448ce4eb4de18eb7b0db61dddece32677939 (patch) | |
| tree | 8e9b7d76b71343504a594db874ad0b7192718f0f /fs/read_write.c | |
| parent | 488e8f685207e0758398963d6834f81e5e61c162 (diff) | |
fs: move file_start_write() into direct_splice_actor()
The callers of do_splice_direct() hold file_start_write() on the output
file.
This may cause file permission hooks to be called indirectly on an
overlayfs lower layer, which is on the same filesystem of the output
file and could lead to deadlock with fanotify permission events.
To fix this potential deadlock, move file_start_write() from the callers
into the direct_splice_actor(), so file_start_write() will not be held
while splicing from the input file.
Suggested-by: Josef Bacik <josef@toxicpanda.com>
Link: https://lore.kernel.org/r/20231128214258.GA2398475@perftesting/
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20231130141624.3338942-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/read_write.c')
| -rw-r--r-- | fs/read_write.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/fs/read_write.c b/fs/read_write.c index 642c7ce1ced1..0bc99f38e623 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1286,10 +1286,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, retval = rw_verify_area(WRITE, out.file, &out_pos, count); if (retval < 0) goto fput_out; - file_start_write(out.file); retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); - file_end_write(out.file); } else { if (out.file->f_flags & O_NONBLOCK) fl |= SPLICE_F_NONBLOCK; |