The branch stable/13 has been updated by rmacklem:
URL:
https://cgit.FreeBSD.org/src/commit/?id=322412b83bef927afb6c807636a37a95d415422e
commit 322412b83bef927afb6c807636a37a95d415422e
Author: Rick Macklem <rmack...@freebsd.org>
AuthorDate: 2024-03-15 00:35:32 +0000
Commit: Rick Macklem <rmack...@freebsd.org>
CommitDate: 2024-03-30 20:56:17 +0000
vfs_vnops.c: Use va_bytes >= va_size hint to avoid SEEK_DATA/SEEKHOLE
vn_generic_copy_file_range() tries to maintain holes
in file ranges being copied, using SEEK_DATA/SEEK_HOLE
where possible.
Unfortunately SEEK_DATA/SEEK_HOLE operations can take
a long time under certain circumstances.
Although it is not currently possible to know if a file has
unallocated data regions, the case where va_bytes >= va_size
is a strong hint that there are no unallocated data regions.
This hint does not work well for file systems doing compression,
but since it is only a hint, it is still useful.
For the case of va_bytes >= va_size, avoid doing SEEK_DATA/SEEK_HOLE.
(cherry picked from commit 89f1dcb3eb468e4cbaebd1ccde9a643d85f1282e)
---
sys/kern/vfs_vnops.c | 21 +++++++++++++++++++--
1 file changed, 19 insertions(+), 2 deletions(-)
diff --git a/sys/kern/vfs_vnops.c b/sys/kern/vfs_vnops.c
index e095fb9df13b..6591b543ddea 100644
--- a/sys/kern/vfs_vnops.c
+++ b/sys/kern/vfs_vnops.c
@@ -3296,7 +3296,7 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
off_t startoff, endoff, xfer, xfer2;
u_long blksize;
int error, interrupted;
- bool cantseek, readzeros, eof, lastblock, holetoeof;
+ bool cantseek, readzeros, eof, lastblock, holetoeof, sparse;
ssize_t aresid, r = 0;
size_t copylen, len, savlen;
char *dat;
@@ -3315,10 +3315,25 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
if (VOP_PATHCONF(invp, _PC_MIN_HOLE_SIZE, &holein) != 0)
holein = 0;
error = VOP_GETATTR(invp, &inva, incred);
+ if (error == 0 && inva.va_size > OFF_MAX)
+ error = EFBIG;
VOP_UNLOCK(invp);
if (error != 0)
goto out;
+ /*
+ * Use va_bytes >= va_size as a hint that the file does not have
+ * sufficient holes to justify the overhead of doing FIOSEEKHOLE.
+ * This hint does not work well for file systems doing compression
+ * and may fail when allocations for extended attributes increases
+ * the value of va_bytes to >= va_size.
+ */
+ sparse = true;
+ if (holein != 0 && inva.va_bytes >= inva.va_size) {
+ holein = 0;
+ sparse = false;
+ }
+
mp = NULL;
error = vn_start_write(outvp, &mp, V_WAIT);
if (error == 0)
@@ -3372,7 +3387,7 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
if (error != 0)
goto out;
- if (holein == 0 && holeout > 0) {
+ if (sparse && holein == 0 && holeout > 0) {
/*
* For this special case, the input data will be scanned
* for blocks of all 0 bytes. For these blocks, the
@@ -3506,6 +3521,8 @@ vn_generic_copy_file_range(struct vnode *invp, off_t
*inoffp,
cantseek = false;
} else {
cantseek = true;
+ if (!sparse)
+ cantseek = false;
startoff = *inoffp;
copylen = len;
error = 0;
