From: Paulo Alcantara <pc@manguebit.org>
To: smfrench@gmail.com
Cc: Frank Sorenson <sorenson@redhat.com>,
"Paulo Alcantara (Red Hat)" <pc@manguebit.org>,
David Howells <dhowells@redhat.com>,
linux-cifs@vger.kernel.org
Subject: [PATCH 1/3] smb: client: fix missing timestamp updates with O_TRUNC
Date: Mon, 6 Oct 2025 13:42:18 -0300 [thread overview]
Message-ID: <20251006164220.67333-1-pc@manguebit.org> (raw)
Don't call ->set_file_info() on open handle to prevent the server from
stopping [cm]time updates automatically as per MS-FSA 2.1.4.17.
Fix this by checking for ATTR_OPEN bit earlier in cifs_setattr() to
prevent ->set_file_info() from being called when opening a file with
O_TRUNC. Do the truncation in ->open() instead.
This also saves two roundtrips when opening a file with O_TRUNC and
there are currently no open handles to be reused.
Before patch:
$ mount.cifs //srv/share /mnt -o ...
$ cd /mnt
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
old: 2025-10-03 13:26:23.151030500 -0300 2025-10-03 13:26:23.151030500 -0300
new: 2025-10-03 13:26:23.151030500 -0300 2025-10-03 13:26:23.151030500 -0300
After patch:
$ mount.cifs //srv/share /mnt -o ...
$ cd /mnt
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
$ exec 3>foo; stat -c 'old: %z %y' foo; sleep 2; echo test >&3; exec 3>&-; sleep 2; stat -c 'new: %z %y' foo
old: 2025-10-03 13:28:13.911933800 -0300 2025-10-03 13:28:13.911933800 -0300
new: 2025-10-03 13:28:26.647492700 -0300 2025-10-03 13:28:26.647492700 -0300
Reported-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
---
fs/smb/client/cifsglob.h | 5 ++
fs/smb/client/file.c | 94 +++++++++++++++++-------
fs/smb/client/inode.c | 152 ++++++++++++++++++++++-----------------
3 files changed, 159 insertions(+), 92 deletions(-)
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 3ac254e123dc..8f6f567d7474 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1566,6 +1566,11 @@ struct cifsFileInfo *cifsFileInfo_get(struct cifsFileInfo *cifs_file);
void _cifsFileInfo_put(struct cifsFileInfo *cifs_file, bool wait_oplock_hdlr,
bool offload);
void cifsFileInfo_put(struct cifsFileInfo *cifs_file);
+int cifs_file_flush(const unsigned int xid, struct inode *inode,
+ struct cifsFileInfo *cfile);
+int cifs_file_set_size(const unsigned int xid, struct dentry *dentry,
+ const char *full_path, struct cifsFileInfo *open_file,
+ loff_t size);
#define CIFS_CACHE_READ_FLG 1
#define CIFS_CACHE_HANDLE_FLG 2
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index a5ed742afa00..ecbb63e66521 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -952,6 +952,66 @@ void _cifsFileInfo_put(struct cifsFileInfo *cifs_file,
}
}
+int cifs_file_flush(const unsigned int xid, struct inode *inode,
+ struct cifsFileInfo *cfile)
+{
+ struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct cifs_tcon *tcon;
+ int rc;
+
+ if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)
+ return 0;
+
+ if (cfile && (OPEN_FMODE(cfile->f_flags) & FMODE_WRITE)) {
+ tcon = tlink_tcon(cfile->tlink);
+ return tcon->ses->server->ops->flush(xid, tcon,
+ &cfile->fid);
+ }
+ rc = cifs_get_writable_file(CIFS_I(inode), FIND_WR_ANY, &cfile);
+ if (!rc) {
+ tcon = tlink_tcon(cfile->tlink);
+ rc = tcon->ses->server->ops->flush(xid, tcon, &cfile->fid);
+ cifsFileInfo_put(cfile);
+ } else if (rc == -EBADF) {
+ rc = 0;
+ }
+ return rc;
+}
+
+static int cifs_do_truncate(const unsigned int xid, struct dentry *dentry)
+{
+ struct cifsInodeInfo *cinode = CIFS_I(d_inode(dentry));
+ struct inode *inode = d_inode(dentry);
+ struct cifsFileInfo *cfile = NULL;
+ struct TCP_Server_Info *server;
+ struct cifs_tcon *tcon;
+ int rc;
+
+ rc = filemap_write_and_wait(inode->i_mapping);
+ if (is_interrupt_error(rc))
+ return -ERESTARTSYS;
+ mapping_set_error(inode->i_mapping, rc);
+
+ cfile = find_writable_file(cinode, FIND_WR_FSUID_ONLY);
+ rc = cifs_file_flush(xid, inode, cfile);
+ if (!rc) {
+ if (cfile) {
+ tcon = tlink_tcon(cfile->tlink);
+ server = tcon->ses->server;
+ rc = server->ops->set_file_size(xid, tcon,
+ cfile, 0, false);
+ }
+ if (!rc) {
+ netfs_resize_file(&cinode->netfs, 0, true);
+ cifs_setsize(inode, 0);
+ inode->i_blocks = 0;
+ }
+ }
+ if (cfile)
+ cifsFileInfo_put(cfile);
+ return rc;
+}
+
int cifs_open(struct inode *inode, struct file *file)
{
@@ -1004,6 +1064,12 @@ int cifs_open(struct inode *inode, struct file *file)
file->f_op = &cifs_file_direct_ops;
}
+ if (file->f_flags & O_TRUNC) {
+ rc = cifs_do_truncate(xid, file_dentry(file));
+ if (rc)
+ goto out;
+ }
+
/* Get the cached handle as SMB2 close is deferred */
if (OPEN_FMODE(file->f_flags) & FMODE_WRITE) {
rc = cifs_get_writable_path(tcon, full_path,
@@ -2685,13 +2751,10 @@ cifs_get_readable_path(struct cifs_tcon *tcon, const char *name,
int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
int datasync)
{
- unsigned int xid;
- int rc = 0;
- struct cifs_tcon *tcon;
- struct TCP_Server_Info *server;
struct cifsFileInfo *smbfile = file->private_data;
struct inode *inode = file_inode(file);
- struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ unsigned int xid;
+ int rc = 0;
rc = file_write_and_wait_range(file, start, end);
if (rc) {
@@ -2712,26 +2775,7 @@ int cifs_strict_fsync(struct file *file, loff_t start, loff_t end,
}
}
- tcon = tlink_tcon(smbfile->tlink);
- if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
- server = tcon->ses->server;
- if (server->ops->flush == NULL) {
- rc = -ENOSYS;
- goto strict_fsync_exit;
- }
-
- if ((OPEN_FMODE(smbfile->f_flags) & FMODE_WRITE) == 0) {
- smbfile = find_writable_file(CIFS_I(inode), FIND_WR_ANY);
- if (smbfile) {
- rc = server->ops->flush(xid, tcon, &smbfile->fid);
- cifsFileInfo_put(smbfile);
- } else
- cifs_dbg(FYI, "ignore fsync for file not open for write\n");
- } else
- rc = server->ops->flush(xid, tcon, &smbfile->fid);
- }
-
-strict_fsync_exit:
+ rc = cifs_file_flush(xid, inode, smbfile);
free_xid(xid);
return rc;
}
diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
index 8bb544be401e..17d3fa9f88fc 100644
--- a/fs/smb/client/inode.c
+++ b/fs/smb/client/inode.c
@@ -3007,28 +3007,24 @@ int cifs_fiemap(struct inode *inode, struct fiemap_extent_info *fei, u64 start,
void cifs_setsize(struct inode *inode, loff_t offset)
{
- struct cifsInodeInfo *cifs_i = CIFS_I(inode);
-
spin_lock(&inode->i_lock);
i_size_write(inode, offset);
spin_unlock(&inode->i_lock);
-
- /* Cached inode must be refreshed on truncate */
- cifs_i->time = 0;
+ inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
truncate_pagecache(inode, offset);
}
-static int
-cifs_set_file_size(struct inode *inode, struct iattr *attrs,
- unsigned int xid, const char *full_path, struct dentry *dentry)
+int cifs_file_set_size(const unsigned int xid, struct dentry *dentry,
+ const char *full_path, struct cifsFileInfo *open_file,
+ loff_t size)
{
- int rc;
- struct cifsFileInfo *open_file;
- struct cifsInodeInfo *cifsInode = CIFS_I(inode);
+ struct inode *inode = d_inode(dentry);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
+ struct cifsInodeInfo *cifsInode = CIFS_I(inode);
struct tcon_link *tlink = NULL;
struct cifs_tcon *tcon = NULL;
struct TCP_Server_Info *server;
+ int rc = -EINVAL;
/*
* To avoid spurious oplock breaks from server, in the case of
@@ -3039,19 +3035,25 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
* writebehind data than the SMB timeout for the SetPathInfo
* request would allow
*/
- open_file = find_writable_file(cifsInode, FIND_WR_FSUID_ONLY);
- if (open_file) {
+ if (open_file && (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE)) {
tcon = tlink_tcon(open_file->tlink);
server = tcon->ses->server;
- if (server->ops->set_file_size)
- rc = server->ops->set_file_size(xid, tcon, open_file,
- attrs->ia_size, false);
- else
- rc = -ENOSYS;
- cifsFileInfo_put(open_file);
- cifs_dbg(FYI, "SetFSize for attrs rc = %d\n", rc);
- } else
- rc = -EINVAL;
+ rc = server->ops->set_file_size(xid, tcon,
+ open_file,
+ size, false);
+ cifs_dbg(FYI, "%s: set_file_size: rc = %d\n", __func__, rc);
+ } else {
+ open_file = find_writable_file(cifsInode, FIND_WR_FSUID_ONLY);
+ if (open_file) {
+ tcon = tlink_tcon(open_file->tlink);
+ server = tcon->ses->server;
+ rc = server->ops->set_file_size(xid, tcon,
+ open_file,
+ size, false);
+ cifs_dbg(FYI, "%s: set_file_size: rc = %d\n", __func__, rc);
+ cifsFileInfo_put(open_file);
+ }
+ }
if (!rc)
goto set_size_out;
@@ -3069,20 +3071,15 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
* valid, writeable file handle for it was found or because there was
* an error setting it by handle.
*/
- if (server->ops->set_path_size)
- rc = server->ops->set_path_size(xid, tcon, full_path,
- attrs->ia_size, cifs_sb, false, dentry);
- else
- rc = -ENOSYS;
- cifs_dbg(FYI, "SetEOF by path (setattrs) rc = %d\n", rc);
-
- if (tlink)
- cifs_put_tlink(tlink);
+ rc = server->ops->set_path_size(xid, tcon, full_path, size,
+ cifs_sb, false, dentry);
+ cifs_dbg(FYI, "%s: SetEOF by path (setattrs) rc = %d\n", __func__, rc);
+ cifs_put_tlink(tlink);
set_size_out:
if (rc == 0) {
- netfs_resize_file(&cifsInode->netfs, attrs->ia_size, true);
- cifs_setsize(inode, attrs->ia_size);
+ netfs_resize_file(&cifsInode->netfs, size, true);
+ cifs_setsize(inode, size);
/*
* i_blocks is not related to (i_size / i_blksize), but instead
* 512 byte (2**9) size is required for calculating num blocks.
@@ -3090,15 +3087,7 @@ cifs_set_file_size(struct inode *inode, struct iattr *attrs,
* this is best estimate we have for blocks allocated for a file
* Number of blocks must be rounded up so size 1 is not 0 blocks
*/
- inode->i_blocks = (512 - 1 + attrs->ia_size) >> 9;
-
- /*
- * The man page of truncate says if the size changed,
- * then the st_ctime and st_mtime fields for the file
- * are updated.
- */
- attrs->ia_ctime = attrs->ia_mtime = current_time(inode);
- attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME;
+ inode->i_blocks = DIV_ROUND_UP(size, 512);
}
return rc;
@@ -3118,7 +3107,7 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
struct tcon_link *tlink;
struct cifs_tcon *pTcon;
struct cifs_unix_set_info_args *args = NULL;
- struct cifsFileInfo *open_file;
+ struct cifsFileInfo *open_file = NULL;
cifs_dbg(FYI, "setattr_unix on file %pd attrs->ia_valid=0x%x\n",
direntry, attrs->ia_valid);
@@ -3132,6 +3121,9 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
if (rc < 0)
goto out;
+ if (attrs->ia_valid & ATTR_FILE)
+ open_file = attrs->ia_file->private_data;
+
full_path = build_path_from_dentry(direntry, page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
@@ -3159,9 +3151,17 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
rc = 0;
if (attrs->ia_valid & ATTR_SIZE) {
- rc = cifs_set_file_size(inode, attrs, xid, full_path, direntry);
+ rc = cifs_file_set_size(xid, direntry, full_path,
+ open_file, attrs->ia_size);
if (rc != 0)
goto out;
+ /*
+ * The man page of truncate says if the size changed,
+ * then the st_ctime and st_mtime fields for the file
+ * are updated.
+ */
+ attrs->ia_ctime = attrs->ia_mtime = current_time(inode);
+ attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME;
}
/* skip mode change if it's just for clearing setuid/setgid */
@@ -3206,14 +3206,24 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
args->ctime = NO_CHANGE_64;
args->device = 0;
- open_file = find_writable_file(cifsInode, FIND_WR_FSUID_ONLY);
- if (open_file) {
- u16 nfid = open_file->fid.netfid;
- u32 npid = open_file->pid;
+ rc = -EINVAL;
+ if (open_file && (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE)) {
pTcon = tlink_tcon(open_file->tlink);
- rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args, nfid, npid);
- cifsFileInfo_put(open_file);
+ rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args,
+ open_file->fid.netfid,
+ open_file->pid);
} else {
+ open_file = find_writable_file(cifsInode, FIND_WR_FSUID_ONLY);
+ if (open_file) {
+ pTcon = tlink_tcon(open_file->tlink);
+ rc = CIFSSMBUnixSetFileInfo(xid, pTcon, args,
+ open_file->fid.netfid,
+ open_file->pid);
+ cifsFileInfo_put(open_file);
+ }
+ }
+
+ if (rc) {
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink)) {
rc = PTR_ERR(tlink);
@@ -3221,8 +3231,8 @@ cifs_setattr_unix(struct dentry *direntry, struct iattr *attrs)
}
pTcon = tlink_tcon(tlink);
rc = CIFSSMBUnixSetPathInfo(xid, pTcon, full_path, args,
- cifs_sb->local_nls,
- cifs_remap(cifs_sb));
+ cifs_sb->local_nls,
+ cifs_remap(cifs_sb));
cifs_put_tlink(tlink);
}
@@ -3264,8 +3274,7 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
struct inode *inode = d_inode(direntry);
struct cifs_sb_info *cifs_sb = CIFS_SB(inode->i_sb);
struct cifsInodeInfo *cifsInode = CIFS_I(inode);
- struct cifsFileInfo *wfile;
- struct cifs_tcon *tcon;
+ struct cifsFileInfo *cfile = NULL;
const char *full_path;
void *page = alloc_dentry_path();
int rc = -EACCES;
@@ -3285,6 +3294,9 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
if (rc < 0)
goto cifs_setattr_exit;
+ if (attrs->ia_valid & ATTR_FILE)
+ cfile = attrs->ia_file->private_data;
+
full_path = build_path_from_dentry(direntry, page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
@@ -3311,25 +3323,24 @@ cifs_setattr_nounix(struct dentry *direntry, struct iattr *attrs)
rc = 0;
- if ((attrs->ia_valid & ATTR_MTIME) &&
- !(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOSSYNC)) {
- rc = cifs_get_writable_file(cifsInode, FIND_WR_ANY, &wfile);
- if (!rc) {
- tcon = tlink_tcon(wfile->tlink);
- rc = tcon->ses->server->ops->flush(xid, tcon, &wfile->fid);
- cifsFileInfo_put(wfile);
- if (rc)
- goto cifs_setattr_exit;
- } else if (rc != -EBADF)
+ if (attrs->ia_valid & ATTR_MTIME) {
+ rc = cifs_file_flush(xid, inode, cfile);
+ if (rc)
goto cifs_setattr_exit;
- else
- rc = 0;
}
if (attrs->ia_valid & ATTR_SIZE) {
- rc = cifs_set_file_size(inode, attrs, xid, full_path, direntry);
+ rc = cifs_file_set_size(xid, direntry, full_path,
+ cfile, attrs->ia_size);
if (rc != 0)
goto cifs_setattr_exit;
+ /*
+ * The man page of truncate says if the size changed,
+ * then the st_ctime and st_mtime fields for the file
+ * are updated.
+ */
+ attrs->ia_ctime = attrs->ia_mtime = current_time(inode);
+ attrs->ia_valid |= ATTR_CTIME | ATTR_MTIME;
}
if (attrs->ia_valid & ATTR_UID)
@@ -3459,6 +3470,13 @@ cifs_setattr(struct mnt_idmap *idmap, struct dentry *direntry,
if (unlikely(cifs_forced_shutdown(cifs_sb)))
return -EIO;
+ /*
+ * Avoid setting [cm]time with O_TRUNC to prevent the server from
+ * disabling automatic timestamp updates as specified in
+ * MS-FSA 2.1.4.17.
+ */
+ if (attrs->ia_valid & ATTR_OPEN)
+ return 0;
do {
#ifdef CONFIG_CIFS_ALLOW_INSECURE_LEGACY
--
2.51.0
next reply other threads:[~2025-10-06 16:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-06 16:42 Paulo Alcantara [this message]
2025-10-06 16:42 ` [PATCH 2/3] smb: client: fix missing timestamp updates after ftruncate(2) Paulo Alcantara
2025-10-06 16:42 ` [PATCH 3/3] smb: client: fix missing timestamp updates after utime(2) Paulo Alcantara
2025-10-06 17:02 ` [PATCH 1/3] smb: client: fix missing timestamp updates with O_TRUNC Ralph Boehme
2025-10-06 17:05 ` Paulo Alcantara
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