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Message-ID: <20251223124119.1383159-1-s.piyush1024@gmail.com>
Date: Tue, 23 Dec 2025 18:11:19 +0530
From: Piyush Sachdeva <s.piyush1024@...il.com>
To: sfrench@...ba.org,
linux-cifs@...r.kernel.org,
linux-kernel@...r.kernel.org
Cc: sprasad@...rosoft.com,
bharathsm@...rosoft.com,
msetiya@...rosoft.com,
rajasimandal@...rosoft.com,
psachdeva@...rosoft.com,
Piyush Sachdeva <s.piyush1024@...il.com>
Subject: [PATCH] smb: client: close all files marked for deferred close immediately
From: Piyush Sachdeva <psachdeva@...rosoft.com>
SMB client has a feature to delay the close of a file on the server,
expecting if an open call comes for the same file, the file doesn't
need to be re-opened. The time duration of the deferred close is set
by the mount option `closetimeo`.
This patch lets a user list all handles marked for deferred close, by
cat /proc/fs/cifs/close_deferred_closes.
It also allow for force close of all files marked for deferred close,
across all session by writing a non-zero value to the same procfs file.
Signed-off-by: Piyush Sachdeva <psachdeva@...rosoft.com>
Signed-off-by: Piyush Sachdeva <s.piyush1024@...il.com>
---
fs/smb/client/cifs_debug.c | 137 +++++++++++++++++++++++++++++++++++++
fs/smb/client/cifsglob.h | 5 ++
2 files changed, 142 insertions(+)
diff --git a/fs/smb/client/cifs_debug.c b/fs/smb/client/cifs_debug.c
index 7fdcaf9feb16..e149a403b16e 100644
--- a/fs/smb/client/cifs_debug.c
+++ b/fs/smb/client/cifs_debug.c
@@ -952,6 +952,7 @@ static const struct proc_ops traceSMB_proc_ops;
static const struct proc_ops cifs_security_flags_proc_ops;
static const struct proc_ops cifs_linux_ext_proc_ops;
static const struct proc_ops cifs_mount_params_proc_ops;
+static const struct proc_ops close_all_deferred_close_ops;
void
cifs_proc_init(void)
@@ -981,6 +982,8 @@ cifs_proc_init(void)
proc_create("mount_params", 0444, proc_fs_cifs, &cifs_mount_params_proc_ops);
+ proc_create("close_deferred_closes", 0644, proc_fs_cifs, &close_all_deferred_close_ops);
+
#ifdef CONFIG_CIFS_DFS_UPCALL
proc_create("dfscache", 0644, proc_fs_cifs, &dfscache_proc_ops);
#endif
@@ -1021,6 +1024,7 @@ cifs_proc_clean(void)
remove_proc_entry("LinuxExtensionsEnabled", proc_fs_cifs);
remove_proc_entry("LookupCacheEnabled", proc_fs_cifs);
remove_proc_entry("mount_params", proc_fs_cifs);
+ remove_proc_entry("close_deferred_closes", proc_fs_cifs);
#ifdef CONFIG_CIFS_DFS_UPCALL
remove_proc_entry("dfscache", proc_fs_cifs);
@@ -1317,6 +1321,139 @@ static const struct proc_ops cifs_mount_params_proc_ops = {
/* .proc_write = cifs_mount_params_proc_write, */
};
+static struct list_head *get_all_tcons(void)
+{
+ struct TCP_Server_Info *server;
+ struct cifs_ses *ses;
+ struct cifs_tcon *tcon;
+ struct global_tcon_list *tree_con_list, *tmp_tree_con_list;
+ struct list_head *tcon_head;
+
+ tcon_head = kmalloc(sizeof(struct list_head), GFP_KERNEL);
+ if (tcon_head == NULL)
+ return NULL;
+
+ INIT_LIST_HEAD(tcon_head);
+ spin_lock(&cifs_tcp_ses_lock);
+ list_for_each_entry(server, &cifs_tcp_ses_list, tcp_ses_list) {
+ list_for_each_entry(ses, &server->smb_ses_list, smb_ses_list) {
+ if (cifs_ses_exiting(ses))
+ continue;
+ list_for_each_entry(tcon, &ses->tcon_list, tcon_list) {
+ tree_con_list =
+ kmalloc(sizeof(struct global_tcon_list),
+ GFP_ATOMIC);
+ if (tree_con_list == NULL)
+ goto tcon_alloc_fail;
+ tree_con_list->tcon = tcon;
+ list_add_tail(&tree_con_list->list, tcon_head);
+ }
+ }
+ }
+ spin_unlock(&cifs_tcp_ses_lock);
+ return tcon_head;
+
+tcon_alloc_fail:
+ spin_unlock(&cifs_tcp_ses_lock);
+ list_for_each_entry_safe(tree_con_list, tmp_tree_con_list, tcon_head,
+ list) {
+ list_del(&tree_con_list->list);
+ kfree(tree_con_list);
+ }
+ kfree(tcon_head);
+ return NULL;
+}
+
+static ssize_t close_all_deferred_close_files(struct file *file,
+ const char __user *buffer,
+ size_t count, loff_t *ppos)
+{
+ char c;
+ int rc;
+ struct global_tcon_list *tmp_list, *tmp_next_list;
+ struct list_head *tcon_head;
+
+ rc = get_user(c, buffer);
+ if (rc)
+ return rc;
+ if (c == '0')
+ return -EINVAL;
+
+ tcon_head = get_all_tcons();
+ if (tcon_head == NULL)
+ return count;
+
+ list_for_each_entry_safe(tmp_list, tmp_next_list, tcon_head, list) {
+ cifs_close_all_deferred_files(tmp_list->tcon);
+ list_del(&tmp_list->list);
+ kfree(tmp_list);
+ }
+
+ kfree(tcon_head);
+ return count;
+}
+
+static int show_all_deferred_close_files(struct seq_file *m, void *v)
+{
+ struct global_tcon_list *tmp_list, *tmp_next_list;
+ struct list_head *tcon_head;
+ struct cifs_tcon *tcon;
+ struct cifsFileInfo *cfile;
+
+ seq_puts(m, "# Version:1\n");
+ seq_puts(m, "# Format:\n");
+ seq_puts(m, "# <tree id> <ses id> <persistent fid> <flags> <count> <pid> <uid>");
+#ifdef CONFIG_CIFS_DEBUG2
+ seq_puts(m, " <filename> <mid>\n");
+#else
+ seq_puts(m, " <filename>\n");
+#endif /* CIFS_DEBUG2 */
+
+ tcon_head = get_all_tcons();
+ if (tcon_head == NULL)
+ return 0;
+
+ list_for_each_entry_safe(tmp_list, tmp_next_list, tcon_head, list) {
+ tcon = tmp_list->tcon;
+ spin_lock(&tcon->open_file_lock);
+ list_for_each_entry(cfile, &tcon->openFileList, tlist) {
+ if (delayed_work_pending(&cfile->deferred)) {
+ seq_printf(
+ m,
+ "0x%x 0x%llx 0x%llx 0x%x %d %d %d %pd",
+ tcon->tid, tcon->ses->Suid,
+ cfile->fid.persistent_fid,
+ cfile->f_flags, cfile->count,
+ cfile->pid,
+ from_kuid(&init_user_ns, cfile->uid),
+ cfile->dentry);
+ }
+ }
+ spin_unlock(&tcon->open_file_lock);
+ list_del(&tmp_list->list);
+ kfree(tmp_list);
+ }
+
+ kfree(tcon_head);
+ seq_putc(m, '\n');
+
+ return 0;
+}
+
+static int show_all_deferred_close_proc_open(struct inode *inode,
+ struct file *file)
+{
+ return single_open(file, show_all_deferred_close_files, NULL);
+}
+
+static const struct proc_ops close_all_deferred_close_ops = {
+ .proc_open = show_all_deferred_close_proc_open,
+ .proc_read = seq_read,
+ .proc_lseek = seq_lseek,
+ .proc_release = single_release,
+ .proc_write = close_all_deferred_close_files,
+};
+
#else
inline void cifs_proc_init(void)
{
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 203e2aaa3c25..56c987258c4b 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1806,6 +1806,11 @@ struct dfs_info3_param {
int ttl;
};
+struct global_tcon_list {
+ struct list_head list;
+ struct cifs_tcon *tcon;
+};
+
struct file_list {
struct list_head list;
struct cifsFileInfo *cfile;
--
2.52.0
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