[PATCH 5.10 103/167] cifs: only write 64kb at a time when fallocating a small region of a file
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Date: 2021-07-26 16:23:28
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Ronnie Sahlberg <redacted>
[ Upstream commit 2485bd7557a7edb4520b4072af464f0a08c8efe0 ]
We only allow sending single credit writes through the SMB2_write() synchronous
api so split this into smaller chunks.
Fixes: 966a3cb7c7db ("cifs: improve fallocate emulation")
Signed-off-by: Ronnie Sahlberg <redacted>
Reported-by: Namjae Jeon <redacted>
Signed-off-by: Steve French <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/cifs/smb2ops.c | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index f6ceb79a995d..442bf422aa01 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c@@ -3466,7 +3466,7 @@ static int smb3_simple_fallocate_write_range(unsigned int xid, char *buf) { struct cifs_io_parms io_parms = {0}; - int nbytes; + int rc, nbytes; struct kvec iov[2]; io_parms.netfid = cfile->fid.netfid;
@@ -3474,13 +3474,25 @@ static int smb3_simple_fallocate_write_range(unsigned int xid, io_parms.tcon = tcon; io_parms.persistent_fid = cfile->fid.persistent_fid; io_parms.volatile_fid = cfile->fid.volatile_fid; - io_parms.offset = off; - io_parms.length = len; - /* iov[0] is reserved for smb header */ - iov[1].iov_base = buf; - iov[1].iov_len = io_parms.length; - return SMB2_write(xid, &io_parms, &nbytes, iov, 1); + while (len) { + io_parms.offset = off; + io_parms.length = len; + if (io_parms.length > SMB2_MAX_BUFFER_SIZE) + io_parms.length = SMB2_MAX_BUFFER_SIZE; + /* iov[0] is reserved for smb header */ + iov[1].iov_base = buf; + iov[1].iov_len = io_parms.length; + rc = SMB2_write(xid, &io_parms, &nbytes, iov, 1); + if (rc) + break; + if (nbytes > len) + return -EINVAL; + buf += nbytes; + off += nbytes; + len -= nbytes; + } + return rc; } static int smb3_simple_fallocate_range(unsigned int xid,
--
2.30.2