d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Update copy_file_range(2) to be Linux5 compatible.

Browse Source 
The current linux man page and testing done on a fairly recent linux5.n
kernel have identified two changes to the semantics of the linux
copy_file_range system call.
Since the copy_file_range(2) system call is intended to be linux compatible
and is only currently in head/current and not used by any commands,
it seems appropriate to update the system call to be compatible with
the current linux one.
The first of these semantic changes was changed to be compatible with
linux5.n by r354564.
For the second semantic change, the old linux man page stated that, if
infd and outfd referred to the same file, EBADF should be returned.
Now, the semantics is to allow infd and outfd to refer to the same file
so long as the byte ranges defined by the input file offset, output file offset
and len does not overlap. If the byte ranges do overlap, EINVAL should be
returned.
This patch modifies copy_file_range(2) to be linux5.n compatible for this
semantic change.
This commit is contained in:
Rick Macklem 2019-11-10 01:08:14 +00:00
parent 306e46eb1e
commit 48e4857859
2 changed files with 12 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
sys/kern/vfs_syscalls.c
View File

@ -4838,7 +4838,7 @@ kern_copy_file_range(struct thread *td, int infd, off_t *inoffp, int outfd,
outvp = outfp->f_vnode;
/* Sanity check the f_flag bits. */
if ((outfp->f_flag & (FWRITE | FAPPEND)) != FWRITE ||
(infp->f_flag & FREAD) == 0 || invp == outvp) {
(infp->f_flag & FREAD) == 0) {
error = EBADF;
goto out;
}
@ -4847,6 +4847,17 @@ kern_copy_file_range(struct thread *td, int infd, off_t *inoffp, int outfd,
if (len == 0)
goto out;
/*
* If infp and outfp refer to the same file, the byte ranges cannot
* overlap.
*/
if (invp == outvp && ((savinoff <= savoutoff && savinoff + len >
savoutoff) || (savinoff > savoutoff && savoutoff + len >
savinoff))) {
error = EINVAL;
goto out;
}
/* Range lock the byte ranges for both invp and outvp. */
for (;;) {
rl_wcookie = vn_rangelock_wlock(outvp, *outoffp, *outoffp +

2
sys/kern/vfs_vnops.c
View File

@ -2699,8 +2699,6 @@ vn_copy_file_range(struct vnode *invp, off_t *inoffp, struct vnode *outvp,
uvalout < (uint64_t)*outoffp || invp->v_type != VREG ||
outvp->v_type != VREG)
error = EINVAL;
else if (invp == outvp)
error = EBADF;
if (error != 0)
goto out;