*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
#include <linux/fs_context.h>
#include <linux/fs_parser.h>
#include <linux/fs.h>
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
#include <net/net_namespace.h>
+#include <asm/sections.h>
#include "mount.h"
#include "internal.h"
fc->cred = get_current_cred();
fc->net_ns = get_net(current->nsproxy->net_ns);
+ mutex_init(&fc->uapi_mutex);
+
switch (purpose) {
case FS_CONTEXT_FOR_MOUNT:
fc->user_ns = get_user_ns(fc->cred->user_ns);
if (!fc)
return ERR_PTR(-ENOMEM);
+ mutex_init(&fc->uapi_mutex);
+
fc->fs_private = NULL;
fc->s_fs_info = NULL;
fc->source = NULL;
get_net(fc->net_ns);
get_user_ns(fc->user_ns);
get_cred(fc->cred);
+ if (fc->log)
+ refcount_inc(&fc->log->usage);
/* Can't call put until we've called ->dup */
ret = fc->ops->dup(fc, src_fc);
}
EXPORT_SYMBOL(vfs_dup_fs_context);
-#ifdef CONFIG_PRINTK
/**
* logfc - Log a message to a filesystem context
* @fc: The filesystem context to log to.
*/
void logfc(struct fs_context *fc, const char *fmt, ...)
{
+ static const char store_failure[] = "OOM: Can't store error string";
+ struct fc_log *log = fc ? fc->log : NULL;
+ const char *p;
va_list va;
+ char *q;
+ u8 freeable;
va_start(va, fmt);
-
- switch (fmt[0]) {
- case 'w':
- vprintk_emit(0, LOGLEVEL_WARNING, NULL, 0, fmt, va);
- break;
- case 'e':
- vprintk_emit(0, LOGLEVEL_ERR, NULL, 0, fmt, va);
- break;
- default:
- vprintk_emit(0, LOGLEVEL_NOTICE, NULL, 0, fmt, va);
- break;
+ if (!strchr(fmt, '%')) {
+ p = fmt;
+ goto unformatted_string;
+ }
+ if (strcmp(fmt, "%s") == 0) {
+ p = va_arg(va, const char *);
+ goto unformatted_string;
}
- pr_cont("\n");
+ q = kvasprintf(GFP_KERNEL, fmt, va);
+copied_string:
+ if (!q)
+ goto store_failure;
+ freeable = 1;
+ goto store_string;
+
+unformatted_string:
+ if ((unsigned long)p >= (unsigned long)__start_rodata &&
+ (unsigned long)p < (unsigned long)__end_rodata)
+ goto const_string;
+ if (log && within_module_core((unsigned long)p, log->owner))
+ goto const_string;
+ q = kstrdup(p, GFP_KERNEL);
+ goto copied_string;
+
+store_failure:
+ p = store_failure;
+const_string:
+ q = (char *)p;
+ freeable = 0;
+store_string:
+ if (!log) {
+ switch (fmt[0]) {
+ case 'w':
+ printk(KERN_WARNING "%s\n", q + 2);
+ break;
+ case 'e':
+ printk(KERN_ERR "%s\n", q + 2);
+ break;
+ default:
+ printk(KERN_NOTICE "%s\n", q + 2);
+ break;
+ }
+ if (freeable)
+ kfree(q);
+ } else {
+ unsigned int logsize = ARRAY_SIZE(log->buffer);
+ u8 index;
+
+ index = log->head & (logsize - 1);
+ BUILD_BUG_ON(sizeof(log->head) != sizeof(u8) ||
+ sizeof(log->tail) != sizeof(u8));
+ if ((u8)(log->head - log->tail) == logsize) {
+ /* The buffer is full, discard the oldest message */
+ if (log->need_free & (1 << index))
+ kfree(log->buffer[index]);
+ log->tail++;
+ }
+
+ log->buffer[index] = q;
+ log->need_free &= ~(1 << index);
+ log->need_free |= freeable << index;
+ log->head++;
+ }
va_end(va);
}
EXPORT_SYMBOL(logfc);
-#endif
+
+/*
+ * Free a logging structure.
+ */
+static void put_fc_log(struct fs_context *fc)
+{
+ struct fc_log *log = fc->log;
+ int i;
+
+ if (log) {
+ if (refcount_dec_and_test(&log->usage)) {
+ fc->log = NULL;
+ for (i = 0; i <= 7; i++)
+ if (log->need_free & (1 << i))
+ kfree(log->buffer[i]);
+ kfree(log);
+ }
+ }
+}
/**
* put_fs_context - Dispose of a superblock configuration context.
put_user_ns(fc->user_ns);
put_cred(fc->cred);
kfree(fc->subtype);
+ put_fc_log(fc);
put_filesystem(fc->fs_type);
kfree(fc->source);
kfree(fc);
return monolithic_mount_data(fc, data);
}
+
+/*
+ * Clean up a context after performing an action on it and put it into a state
+ * from where it can be used to reconfigure a superblock.
+ *
+ * Note that here we do only the parts that can't fail; the rest is in
+ * finish_clean_context() below and in between those fs_context is marked
+ * FS_CONTEXT_AWAITING_RECONF. The reason for splitup is that after
+ * successful mount or remount we need to report success to userland.
+ * Trying to do full reinit (for the sake of possible subsequent remount)
+ * and failing to allocate memory would've put us into a nasty situation.
+ * So here we only discard the old state and reinitialization is left
+ * until we actually try to reconfigure.
+ */
+void vfs_clean_context(struct fs_context *fc)
+{
+ if (fc->need_free && fc->ops && fc->ops->free)
+ fc->ops->free(fc);
+ fc->need_free = false;
+ fc->fs_private = NULL;
+ fc->s_fs_info = NULL;
+ fc->sb_flags = 0;
+ security_free_mnt_opts(&fc->security);
+ kfree(fc->subtype);
+ fc->subtype = NULL;
+ kfree(fc->source);
+ fc->source = NULL;
+
+ fc->purpose = FS_CONTEXT_FOR_RECONFIGURE;
+ fc->phase = FS_CONTEXT_AWAITING_RECONF;
+}
+
+int finish_clean_context(struct fs_context *fc)
+{
+ int error;
+
+ if (fc->phase != FS_CONTEXT_AWAITING_RECONF)
+ return 0;
+
+ if (fc->fs_type->init_fs_context)
+ error = fc->fs_type->init_fs_context(fc);
+ else
+ error = legacy_init_fs_context(fc);
+ if (unlikely(error)) {
+ fc->phase = FS_CONTEXT_FAILED;
+ return error;
+ }
+ fc->need_free = true;
+ fc->phase = FS_CONTEXT_RECONF_PARAMS;
+ return 0;
+}
git.samba.org / sfrench / cifs-2.6.git / blobdiff