"people just forget to add inotify hooks to their I/O routines as a rule"?
Guess what I did, fully knowing that some are missing in this file :)
==> te.c <==
#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
int main() {
ssize_t rd, acc = 0;
while ((rd = tee(0, 1, 128 * 1024 * 1024, 0)) > 0)
acc += rd;
fprintf(stderr, "te=%zd: %m\n", acc);
}
==> vm.c <==
#define _GNU_SOURCE
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
static char sb[1024 * 1024];
int main() {
memcpy(sb, "żupan", sizeof("żupan"));
ssize_t rd =
vmsplice(1, &(struct iovec){.iov_base = sb, .iov_len = sizeof(sb)}, 1,
SPLICE_F_GIFT);
fprintf(stderr, "vm=%zd: %m\n", rd);
}
echo zupa | ./te > fifo tees a few times and then blocks when the pipe
fills, at which point we get into the broken state.
Similarly, ./vm > fifo (with the default 64k F_GETPIPE_SZ) enters that
same state instantly.
With 2/3 and 3/3, they instead do
1: mask=2, cook=0, len=0, name=
rd=80
1: mask=2, cook=0, len=0, name=
rd=80
...
in a loop, as-expected, and
# ./vm > fifo
vm=65200: Success
1: mask=2, cook=0, len=0, name=
rd=65200
I took the liberty of marking 2/3 and 3/3 as Fixes: of the original
fanotify-in-splice commit as well, I think they fit the bill.
Ahelenia Ziemiańska (3):
splice: always fsnotify_access(in), fsnotify_modify(out) on success
splice: fsnotify_modify(fd) in vmsplice
splice: fsnotify_access(in), fsnotify_modify(out) on success in tee
fs/splice.c | 29 ++++++++++++++++++++---------
1 file changed, 20 insertions(+), 9 deletions(-)
--
2.39.2
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