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-rw-r--r--fs/char_dev.c4
-rw-r--r--fs/debugfs/file.c436
-rw-r--r--fs/debugfs/inode.c108
-rw-r--r--fs/debugfs/internal.h26
-rw-r--r--fs/kernfs/dir.c8
-rw-r--r--fs/kernfs/file.c51
-rw-r--r--fs/kernfs/inode.c15
7 files changed, 532 insertions, 116 deletions
diff --git a/fs/char_dev.c b/fs/char_dev.c
index 24b142569ca9..687471dc04a0 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -91,6 +91,10 @@ __register_chrdev_region(unsigned int major, unsigned int baseminor,
break;
}
+ if (i < CHRDEV_MAJOR_DYN_END)
+ pr_warn("CHRDEV \"%s\" major number %d goes below the dynamic allocation range",
+ name, i);
+
if (i == 0) {
ret = -EBUSY;
goto out;
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c
index d2ba12e23ed9..9c1c9a01b7e5 100644
--- a/fs/debugfs/file.c
+++ b/fs/debugfs/file.c
@@ -22,6 +22,12 @@
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/device.h>
+#include <linux/srcu.h>
+#include <asm/poll.h>
+
+#include "internal.h"
+
+struct poll_table_struct;
static ssize_t default_read_file(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
@@ -35,27 +41,293 @@ static ssize_t default_write_file(struct file *file, const char __user *buf,
return count;
}
-const struct file_operations debugfs_file_operations = {
+const struct file_operations debugfs_noop_file_operations = {
.read = default_read_file,
.write = default_write_file,
.open = simple_open,
.llseek = noop_llseek,
};
-static struct dentry *debugfs_create_mode(const char *name, umode_t mode,
- struct dentry *parent, void *value,
- const struct file_operations *fops,
- const struct file_operations *fops_ro,
- const struct file_operations *fops_wo)
+/**
+ * debugfs_use_file_start - mark the beginning of file data access
+ * @dentry: the dentry object whose data is being accessed.
+ * @srcu_idx: a pointer to some memory to store a SRCU index in.
+ *
+ * Up to a matching call to debugfs_use_file_finish(), any
+ * successive call into the file removing functions debugfs_remove()
+ * and debugfs_remove_recursive() will block. Since associated private
+ * file data may only get freed after a successful return of any of
+ * the removal functions, you may safely access it after a successful
+ * call to debugfs_use_file_start() without worrying about
+ * lifetime issues.
+ *
+ * If -%EIO is returned, the file has already been removed and thus,
+ * it is not safe to access any of its data. If, on the other hand,
+ * it is allowed to access the file data, zero is returned.
+ *
+ * Regardless of the return code, any call to
+ * debugfs_use_file_start() must be followed by a matching call
+ * to debugfs_use_file_finish().
+ */
+int debugfs_use_file_start(const struct dentry *dentry, int *srcu_idx)
+ __acquires(&debugfs_srcu)
+{
+ *srcu_idx = srcu_read_lock(&debugfs_srcu);
+ barrier();
+ if (d_unlinked(dentry))
+ return -EIO;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(debugfs_use_file_start);
+
+/**
+ * debugfs_use_file_finish - mark the end of file data access
+ * @srcu_idx: the SRCU index "created" by a former call to
+ * debugfs_use_file_start().
+ *
+ * Allow any ongoing concurrent call into debugfs_remove() or
+ * debugfs_remove_recursive() blocked by a former call to
+ * debugfs_use_file_start() to proceed and return to its caller.
+ */
+void debugfs_use_file_finish(int srcu_idx) __releases(&debugfs_srcu)
+{
+ srcu_read_unlock(&debugfs_srcu, srcu_idx);
+}
+EXPORT_SYMBOL_GPL(debugfs_use_file_finish);
+
+#define F_DENTRY(filp) ((filp)->f_path.dentry)
+
+#define REAL_FOPS_DEREF(dentry) \
+ ((const struct file_operations *)(dentry)->d_fsdata)
+
+static int open_proxy_open(struct inode *inode, struct file *filp)
+{
+ const struct dentry *dentry = F_DENTRY(filp);
+ const struct file_operations *real_fops = NULL;
+ int srcu_idx, r;
+
+ r = debugfs_use_file_start(dentry, &srcu_idx);
+ if (r) {
+ r = -ENOENT;
+ goto out;
+ }
+
+ real_fops = REAL_FOPS_DEREF(dentry);
+ real_fops = fops_get(real_fops);
+ if (!real_fops) {
+ /* Huh? Module did not clean up after itself at exit? */
+ WARN(1, "debugfs file owner did not clean up at exit: %pd",
+ dentry);
+ r = -ENXIO;
+ goto out;
+ }
+ replace_fops(filp, real_fops);
+
+ if (real_fops->open)
+ r = real_fops->open(inode, filp);
+
+out:
+ fops_put(real_fops);
+ debugfs_use_file_finish(srcu_idx);
+ return r;
+}
+
+const struct file_operations debugfs_open_proxy_file_operations = {
+ .open = open_proxy_open,
+};
+
+#define PROTO(args...) args
+#define ARGS(args...) args
+
+#define FULL_PROXY_FUNC(name, ret_type, filp, proto, args) \
+static ret_type full_proxy_ ## name(proto) \
+{ \
+ const struct dentry *dentry = F_DENTRY(filp); \
+ const struct file_operations *real_fops = \
+ REAL_FOPS_DEREF(dentry); \
+ int srcu_idx; \
+ ret_type r; \
+ \
+ r = debugfs_use_file_start(dentry, &srcu_idx); \
+ if (likely(!r)) \
+ r = real_fops->name(args); \
+ debugfs_use_file_finish(srcu_idx); \
+ return r; \
+}
+
+FULL_PROXY_FUNC(llseek, loff_t, filp,
+ PROTO(struct file *filp, loff_t offset, int whence),
+ ARGS(filp, offset, whence));
+
+FULL_PROXY_FUNC(read, ssize_t, filp,
+ PROTO(struct file *filp, char __user *buf, size_t size,
+ loff_t *ppos),
+ ARGS(filp, buf, size, ppos));
+
+FULL_PROXY_FUNC(write, ssize_t, filp,
+ PROTO(struct file *filp, const char __user *buf, size_t size,
+ loff_t *ppos),
+ ARGS(filp, buf, size, ppos));
+
+FULL_PROXY_FUNC(unlocked_ioctl, long, filp,
+ PROTO(struct file *filp, unsigned int cmd, unsigned long arg),
+ ARGS(filp, cmd, arg));
+
+static unsigned int full_proxy_poll(struct file *filp,
+ struct poll_table_struct *wait)
+{
+ const struct dentry *dentry = F_DENTRY(filp);
+ const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
+ int srcu_idx;
+ unsigned int r = 0;
+
+ if (debugfs_use_file_start(dentry, &srcu_idx)) {
+ debugfs_use_file_finish(srcu_idx);
+ return POLLHUP;
+ }
+
+ r = real_fops->poll(filp, wait);
+ debugfs_use_file_finish(srcu_idx);
+ return r;
+}
+
+static int full_proxy_release(struct inode *inode, struct file *filp)
+{
+ const struct dentry *dentry = F_DENTRY(filp);
+ const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry);
+ const struct file_operations *proxy_fops = filp->f_op;
+ int r = 0;
+
+ /*
+ * We must not protect this against removal races here: the
+ * original releaser should be called unconditionally in order
+ * not to leak any resources. Releasers must not assume that
+ * ->i_private is still being meaningful here.
+ */
+ if (real_fops->release)
+ r = real_fops->release(inode, filp);
+
+ replace_fops(filp, d_inode(dentry)->i_fop);
+ kfree((void *)proxy_fops);
+ fops_put(real_fops);
+ return 0;
+}
+
+static void __full_proxy_fops_init(struct file_operations *proxy_fops,
+ const struct file_operations *real_fops)
+{
+ proxy_fops->release = full_proxy_release;
+ if (real_fops->llseek)
+ proxy_fops->llseek = full_proxy_llseek;
+ if (real_fops->read)
+ proxy_fops->read = full_proxy_read;
+ if (real_fops->write)
+ proxy_fops->write = full_proxy_write;
+ if (real_fops->poll)
+ proxy_fops->poll = full_proxy_poll;
+ if (real_fops->unlocked_ioctl)
+ proxy_fops->unlocked_ioctl = full_proxy_unlocked_ioctl;
+}
+
+static int full_proxy_open(struct inode *inode, struct file *filp)
+{
+ const struct dentry *dentry = F_DENTRY(filp);
+ const struct file_operations *real_fops = NULL;
+ struct file_operations *proxy_fops = NULL;
+ int srcu_idx, r;
+
+ r = debugfs_use_file_start(dentry, &srcu_idx);
+ if (r) {
+ r = -ENOENT;
+ goto out;
+ }
+
+ real_fops = REAL_FOPS_DEREF(dentry);
+ real_fops = fops_get(real_fops);
+ if (!real_fops) {
+ /* Huh? Module did not cleanup after itself at exit? */
+ WARN(1, "debugfs file owner did not clean up at exit: %pd",
+ dentry);
+ r = -ENXIO;
+ goto out;
+ }
+
+ proxy_fops = kzalloc(sizeof(*proxy_fops), GFP_KERNEL);
+ if (!proxy_fops) {
+ r = -ENOMEM;
+ goto free_proxy;
+ }
+ __full_proxy_fops_init(proxy_fops, real_fops);
+ replace_fops(filp, proxy_fops);
+
+ if (real_fops->open) {
+ r = real_fops->open(inode, filp);
+
+ if (filp->f_op != proxy_fops) {
+ /* No protection against file removal anymore. */
+ WARN(1, "debugfs file owner replaced proxy fops: %pd",
+ dentry);
+ goto free_proxy;
+ }
+ }
+
+ goto out;
+free_proxy:
+ kfree(proxy_fops);
+ fops_put(real_fops);
+out:
+ debugfs_use_file_finish(srcu_idx);
+ return r;
+}
+
+const struct file_operations debugfs_full_proxy_file_operations = {
+ .open = full_proxy_open,
+};
+
+ssize_t debugfs_attr_read(struct file *file, char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ ssize_t ret;
+ int srcu_idx;
+
+ ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
+ if (likely(!ret))
+ ret = simple_attr_read(file, buf, len, ppos);
+ debugfs_use_file_finish(srcu_idx);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(debugfs_attr_read);
+
+ssize_t debugfs_attr_write(struct file *file, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ ssize_t ret;
+ int srcu_idx;
+
+ ret = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
+ if (likely(!ret))
+ ret = simple_attr_write(file, buf, len, ppos);
+ debugfs_use_file_finish(srcu_idx);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(debugfs_attr_write);
+
+static struct dentry *debugfs_create_mode_unsafe(const char *name, umode_t mode,
+ struct dentry *parent, void *value,
+ const struct file_operations *fops,
+ const struct file_operations *fops_ro,
+ const struct file_operations *fops_wo)
{
/* if there are no write bits set, make read only */
if (!(mode & S_IWUGO))
- return debugfs_create_file(name, mode, parent, value, fops_ro);
+ return debugfs_create_file_unsafe(name, mode, parent, value,
+ fops_ro);
/* if there are no read bits set, make write only */
if (!(mode & S_IRUGO))
- return debugfs_create_file(name, mode, parent, value, fops_wo);
+ return debugfs_create_file_unsafe(name, mode, parent, value,
+ fops_wo);
- return debugfs_create_file(name, mode, parent, value, fops);
+ return debugfs_create_file_unsafe(name, mode, parent, value, fops);
}
static int debugfs_u8_set(void *data, u64 val)
@@ -68,9 +340,9 @@ static int debugfs_u8_get(void *data, u64 *val)
*val = *(u8 *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
/**
* debugfs_create_u8 - create a debugfs file that is used to read and write an unsigned 8-bit value
@@ -99,7 +371,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%llu\n");
struct dentry *debugfs_create_u8(const char *name, umode_t mode,
struct dentry *parent, u8 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_u8,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
&fops_u8_ro, &fops_u8_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_u8);
@@ -114,9 +386,9 @@ static int debugfs_u16_get(void *data, u64 *val)
*val = *(u16 *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u16, debugfs_u16_get, debugfs_u16_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_ro, debugfs_u16_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
/**
* debugfs_create_u16 - create a debugfs file that is used to read and write an unsigned 16-bit value
@@ -145,7 +417,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u16_wo, NULL, debugfs_u16_set, "%llu\n");
struct dentry *debugfs_create_u16(const char *name, umode_t mode,
struct dentry *parent, u16 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_u16,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u16,
&fops_u16_ro, &fops_u16_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_u16);
@@ -160,9 +432,9 @@ static int debugfs_u32_get(void *data, u64 *val)
*val = *(u32 *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u32, debugfs_u32_get, debugfs_u32_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_ro, debugfs_u32_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
/**
* debugfs_create_u32 - create a debugfs file that is used to read and write an unsigned 32-bit value
@@ -191,7 +463,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u32_wo, NULL, debugfs_u32_set, "%llu\n");
struct dentry *debugfs_create_u32(const char *name, umode_t mode,
struct dentry *parent, u32 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_u32,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u32,
&fops_u32_ro, &fops_u32_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32);
@@ -207,9 +479,9 @@ static int debugfs_u64_get(void *data, u64 *val)
*val = *(u64 *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u64, debugfs_u64_get, debugfs_u64_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_ro, debugfs_u64_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
/**
* debugfs_create_u64 - create a debugfs file that is used to read and write an unsigned 64-bit value
@@ -238,7 +510,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_u64_wo, NULL, debugfs_u64_set, "%llu\n");
struct dentry *debugfs_create_u64(const char *name, umode_t mode,
struct dentry *parent, u64 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_u64,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u64,
&fops_u64_ro, &fops_u64_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_u64);
@@ -254,9 +526,10 @@ static int debugfs_ulong_get(void *data, u64 *val)
*val = *(unsigned long *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set,
+ "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
/**
* debugfs_create_ulong - create a debugfs file that is used to read and write
@@ -286,26 +559,30 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
struct dentry *parent, unsigned long *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_ulong,
- &fops_ulong_ro, &fops_ulong_wo);
+ return debugfs_create_mode_unsafe(name, mode, parent, value,
+ &fops_ulong, &fops_ulong_ro,
+ &fops_ulong_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_ulong);
-DEFINE_SIMPLE_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x8, debugfs_u8_get, debugfs_u8_set, "0x%02llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_ro, debugfs_u8_get, NULL, "0x%02llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x8_wo, NULL, debugfs_u8_set, "0x%02llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set, "0x%04llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x16, debugfs_u16_get, debugfs_u16_set,
+ "0x%04llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_ro, debugfs_u16_get, NULL, "0x%04llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x16_wo, NULL, debugfs_u16_set, "0x%04llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set, "0x%08llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x32, debugfs_u32_get, debugfs_u32_set,
+ "0x%08llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_ro, debugfs_u32_get, NULL, "0x%08llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x32_wo, NULL, debugfs_u32_set, "0x%08llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set, "0x%016llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x64, debugfs_u64_get, debugfs_u64_set,
+ "0x%016llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_ro, debugfs_u64_get, NULL, "0x%016llx\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
/*
* debugfs_create_x{8,16,32,64} - create a debugfs file that is used to read and write an unsigned {8,16,32,64}-bit value
@@ -328,7 +605,7 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_x64_wo, NULL, debugfs_u64_set, "0x%016llx\n");
struct dentry *debugfs_create_x8(const char *name, umode_t mode,
struct dentry *parent, u8 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_x8,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x8,
&fops_x8_ro, &fops_x8_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_x8);
@@ -346,7 +623,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x8);
struct dentry *debugfs_create_x16(const char *name, umode_t mode,
struct dentry *parent, u16 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_x16,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x16,
&fops_x16_ro, &fops_x16_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_x16);
@@ -364,7 +641,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x16);
struct dentry *debugfs_create_x32(const char *name, umode_t mode,
struct dentry *parent, u32 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_x32,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x32,
&fops_x32_ro, &fops_x32_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_x32);
@@ -382,7 +659,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_x32);
struct dentry *debugfs_create_x64(const char *name, umode_t mode,
struct dentry *parent, u64 *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_x64,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_x64,
&fops_x64_ro, &fops_x64_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_x64);
@@ -398,10 +675,10 @@ static int debugfs_size_t_get(void *data, u64 *val)
*val = *(size_t *)data;
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
- "%llu\n"); /* %llu and %zu are more or less the same */
-DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t, debugfs_size_t_get, debugfs_size_t_set,
+ "%llu\n"); /* %llu and %zu are more or less the same */
+DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_ro, debugfs_size_t_get, NULL, "%llu\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
/**
* debugfs_create_size_t - create a debugfs file that is used to read and write an size_t value
@@ -416,8 +693,9 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_size_t_wo, NULL, debugfs_size_t_set, "%llu\n");
struct dentry *debugfs_create_size_t(const char *name, umode_t mode,
struct dentry *parent, size_t *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_size_t,
- &fops_size_t_ro, &fops_size_t_wo);
+ return debugfs_create_mode_unsafe(name, mode, parent, value,
+ &fops_size_t, &fops_size_t_ro,
+ &fops_size_t_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_size_t);
@@ -431,10 +709,12 @@ static int debugfs_atomic_t_get(void *data, u64 *val)
*val = atomic_read((atomic_t *)data);
return 0;
}
-DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
+DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t, debugfs_atomic_t_get,
debugfs_atomic_t_set, "%lld\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL, "%lld\n");
-DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_ro, debugfs_atomic_t_get, NULL,
+ "%lld\n");
+DEFINE_DEBUGFS_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set,
+ "%lld\n");
/**
* debugfs_create_atomic_t - create a debugfs file that is used to read and
@@ -450,8 +730,9 @@ DEFINE_SIMPLE_ATTRIBUTE(fops_atomic_t_wo, NULL, debugfs_atomic_t_set, "%lld\n");
struct dentry *debugfs_create_atomic_t(const char *name, umode_t mode,
struct dentry *parent, atomic_t *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_atomic_t,
- &fops_atomic_t_ro, &fops_atomic_t_wo);
+ return debugfs_create_mode_unsafe(name, mode, parent, value,
+ &fops_atomic_t, &fops_atomic_t_ro,
+ &fops_atomic_t_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_atomic_t);
@@ -459,9 +740,17 @@ ssize_t debugfs_read_file_bool(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
char buf[3];
- bool *val = file->private_data;
+ bool val;
+ int r, srcu_idx;
- if (*val)
+ r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
+ if (likely(!r))
+ val = *(bool *)file->private_data;
+ debugfs_use_file_finish(srcu_idx);
+ if (r)
+ return r;
+
+ if (val)
buf[0] = 'Y';
else
buf[0] = 'N';
@@ -477,6 +766,7 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
char buf[32];
size_t buf_size;
bool bv;
+ int r, srcu_idx;
bool *val = file->private_data;
buf_size = min(count, (sizeof(buf)-1));
@@ -484,8 +774,14 @@ ssize_t debugfs_write_file_bool(struct file *file, const char __user *user_buf,
return -EFAULT;
buf[buf_size] = '\0';
- if (strtobool(buf, &bv) == 0)
- *val = bv;
+ if (strtobool(buf, &bv) == 0) {
+ r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
+ if (likely(!r))
+ *val = bv;
+ debugfs_use_file_finish(srcu_idx);
+ if (r)
+ return r;
+ }
return count;
}
@@ -537,7 +833,7 @@ static const struct file_operations fops_bool_wo = {
struct dentry *debugfs_create_bool(const char *name, umode_t mode,
struct dentry *parent, bool *value)
{
- return debugfs_create_mode(name, mode, parent, value, &fops_bool,
+ return debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
&fops_bool_ro, &fops_bool_wo);
}
EXPORT_SYMBOL_GPL(debugfs_create_bool);
@@ -546,8 +842,15 @@ static ssize_t read_file_blob(struct file *file, char __user *user_buf,
size_t count, loff_t *ppos)
{
struct debugfs_blob_wrapper *blob = file->private_data;
- return simple_read_from_buffer(user_buf, count, ppos, blob->data,
- blob->size);
+ ssize_t r;
+ int srcu_idx;
+
+ r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx);
+ if (likely(!r))
+ r = simple_read_from_buffer(user_buf, count, ppos, blob->data,
+ blob->size);
+ debugfs_use_file_finish(srcu_idx);
+ return r;
}
static const struct file_operations fops_blob = {
@@ -584,7 +887,7 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob)
{
- return debugfs_create_file(name, mode, parent, blob, &fops_blob);
+ return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob);
}
EXPORT_SYMBOL_GPL(debugfs_create_blob);
@@ -689,7 +992,8 @@ struct dentry *debugfs_create_u32_array(const char *name, umode_t mode,
data->array = array;
data->elements = elements;
- return debugfs_create_file(name, mode, parent, data, &u32_array_fops);
+ return debugfs_create_file_unsafe(name, mode, parent, data,
+ &u32_array_fops);
}
EXPORT_SYMBOL_GPL(debugfs_create_u32_array);
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 8580831ed237..4bc1f68243c1 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -27,9 +27,14 @@
#include <linux/parser.h>
#include <linux/magic.h>
#include <linux/slab.h>
+#include <linux/srcu.h>
+
+#include "internal.h"
#define DEBUGFS_DEFAULT_MODE 0700
+DEFINE_SRCU(debugfs_srcu);
+
static struct vfsmount *debugfs_mount;
static int debugfs_mount_count;
static bool debugfs_registered;
@@ -39,7 +44,8 @@ static struct inode *debugfs_get_inode(struct super_block *sb)
struct inode *inode = new_inode(sb);
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_atime = inode->i_mtime =
+ inode->i_ctime = current_fs_time(sb);
}
return inode;
}
@@ -294,6 +300,37 @@ static struct dentry *end_creating(struct dentry *dentry)
return dentry;
}
+static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *proxy_fops,
+ const struct file_operations *real_fops)
+{
+ struct dentry *dentry;
+ struct inode *inode;
+
+ if (!(mode & S_IFMT))
+ mode |= S_IFREG;
+ BUG_ON(!S_ISREG(mode));
+ dentry = start_creating(name, parent);
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = mode;
+ inode->i_private = data;
+
+ inode->i_fop = proxy_fops;
+ dentry->d_fsdata = (void *)real_fops;
+
+ d_instantiate(dentry, inode);
+ fsnotify_create(d_inode(dentry->d_parent), dentry);
+ return end_creating(dentry);
+}
+
/**
* debugfs_create_file - create a file in the debugfs filesystem
* @name: a pointer to a string containing the name of the file to create.
@@ -324,29 +361,52 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
- struct dentry *dentry;
- struct inode *inode;
- if (!(mode & S_IFMT))
- mode |= S_IFREG;
- BUG_ON(!S_ISREG(mode));
- dentry = start_creating(name, parent);
-
- if (IS_ERR(dentry))
- return NULL;
+ return __debugfs_create_file(name, mode, parent, data,
+ fops ? &debugfs_full_proxy_file_operations :
+ &debugfs_noop_file_operations,
+ fops);
+}
+EXPORT_SYMBOL_GPL(debugfs_create_file);
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode))
- return failed_creating(dentry);
+/**
+ * debugfs_create_file_unsafe - create a file in the debugfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the debugfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ *
+ * debugfs_create_file_unsafe() is completely analogous to
+ * debugfs_create_file(), the only difference being that the fops
+ * handed it will not get protected against file removals by the
+ * debugfs core.
+ *
+ * It is your responsibility to protect your struct file_operation
+ * methods against file removals by means of debugfs_use_file_start()
+ * and debugfs_use_file_finish(). ->open() is still protected by
+ * debugfs though.
+ *
+ * Any struct file_operations defined by means of
+ * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and
+ * thus, may be used here.
+ */
+struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops)
+{
- inode->i_mode = mode;
- inode->i_fop = fops ? fops : &debugfs_file_operations;
- inode->i_private = data;
- d_instantiate(dentry, inode);
- fsnotify_create(d_inode(dentry->d_parent), dentry);
- return end_creating(dentry);
+ return __debugfs_create_file(name, mode, parent, data,
+ fops ? &debugfs_open_proxy_file_operations :
+ &debugfs_noop_file_operations,
+ fops);
}
-EXPORT_SYMBOL_GPL(debugfs_create_file);
+EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe);
/**
* debugfs_create_file_size - create a file in the debugfs filesystem
@@ -461,7 +521,11 @@ struct dentry *debugfs_create_automount(const char *name,
inode->i_flags |= S_AUTOMOUNT;
inode->i_private = data;
dentry->d_fsdata = (void *)f;
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
d_instantiate(dentry, inode);
+ inc_nlink(d_inode(dentry->d_parent));
+ fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
return end_creating(dentry);
}
EXPORT_SYMBOL(debugfs_create_automount);
@@ -565,6 +629,8 @@ void debugfs_remove(struct dentry *dentry)
inode_unlock(d_inode(parent));
if (!ret)
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+
+ synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove);
@@ -642,6 +708,8 @@ void debugfs_remove_recursive(struct dentry *dentry)
if (!__debugfs_remove(child, parent))
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
inode_unlock(d_inode(parent));
+
+ synchronize_srcu(&debugfs_srcu);
}
EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
diff --git a/fs/debugfs/internal.h b/fs/debugfs/internal.h
new file mode 100644
index 000000000000..bba52634b995
--- /dev/null
+++ b/fs/debugfs/internal.h
@@ -0,0 +1,26 @@
+/*
+ * internal.h - declarations internal to debugfs
+ *
+ * Copyright (C) 2016 Nicolai Stange <nicstange@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 as published by the Free Software Foundation.
+ *
+ */
+
+#ifndef _DEBUGFS_INTERNAL_H_
+#define _DEBUGFS_INTERNAL_H_
+
+struct file_operations;
+
+/* declared over in file.c */
+extern const struct file_operations debugfs_noop_file_operations;
+extern const struct file_operations debugfs_open_proxy_file_operations;
+extern const struct file_operations debugfs_full_proxy_file_operations;
+
+struct dentry *debugfs_create_file_unsafe(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops);
+
+#endif /* _DEBUGFS_INTERNAL_H_ */
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c
index 68a44315d949..8a652404eef6 100644
--- a/fs/kernfs/dir.c
+++ b/fs/kernfs/dir.c
@@ -753,7 +753,8 @@ int kernfs_add_one(struct kernfs_node *kn)
ps_iattr = parent->iattr;
if (ps_iattr) {
struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
- ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
+ ktime_get_real_ts(&ps_iattrs->ia_ctime);
+ ps_iattrs->ia_mtime = ps_iattrs->ia_ctime;
}
mutex_unlock(&kernfs_mutex);
@@ -1279,8 +1280,9 @@ static void __kernfs_remove(struct kernfs_node *kn)
/* update timestamps on the parent */
if (ps_iattr) {
- ps_iattr->ia_iattr.ia_ctime = CURRENT_TIME;
- ps_iattr->ia_iattr.ia_mtime = CURRENT_TIME;
+ ktime_get_real_ts(&ps_iattr->ia_iattr.ia_ctime);
+ ps_iattr->ia_iattr.ia_mtime =
+ ps_iattr->ia_iattr.ia_ctime;
}
kernfs_put(pos);
diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c
index 7247252ee9b1..e1574008adc9 100644
--- a/fs/kernfs/file.c
+++ b/fs/kernfs/file.c
@@ -190,15 +190,16 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
char *buf;
buf = of->prealloc_buf;
- if (!buf)
+ if (buf)
+ mutex_lock(&of->prealloc_mutex);
+ else
buf = kmalloc(len, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/*
* @of->mutex nests outside active ref and is used both to ensure that
- * the ops aren't called concurrently for the same open file, and
- * to provide exclusive access to ->prealloc_buf (when that exists).
+ * the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn)) {
@@ -214,21 +215,23 @@ static ssize_t kernfs_file_direct_read(struct kernfs_open_file *of,
else
len = -EINVAL;
+ kernfs_put_active(of->kn);
+ mutex_unlock(&of->mutex);
+
if (len < 0)
- goto out_unlock;
+ goto out_free;
if (copy_to_user(user_buf, buf, len)) {
len = -EFAULT;
- goto out_unlock;
+ goto out_free;
}
*ppos += len;
- out_unlock:
- kernfs_put_active(of->kn);
- mutex_unlock(&of->mutex);
out_free:
- if (buf != of->prealloc_buf)
+ if (buf == of->prealloc_buf)
+ mutex_unlock(&of->prealloc_mutex);
+ else
kfree(buf);
return len;
}
@@ -284,15 +287,22 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf,
}
buf = of->prealloc_buf;
- if (!buf)
+ if (buf)
+ mutex_lock(&of->prealloc_mutex);
+ else
buf = kmalloc(len + 1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
+ if (copy_from_user(buf, user_buf, len)) {
+ len = -EFAULT;
+ goto out_free;
+ }
+ buf[len] = '\0'; /* guarantee string termination */
+
/*
* @of->mutex nests outside active ref and is used both to ensure that
- * the ops aren't called concurrently for the same open file, and
- * to provide exclusive access to ->prealloc_buf (when that exists).
+ * the ops aren't called concurrently for the same open file.
*/
mutex_lock(&of->mutex);
if (!kernfs_get_active(of->kn)) {
@@ -301,26 +311,22 @@ static ssize_t kernfs_fop_write(struct file *file, const char __user *user_buf,
goto out_free;
}
- if (copy_from_user(buf, user_buf, len)) {
- len = -EFAULT;
- goto out_unlock;
- }
- buf[len] = '\0'; /* guarantee string termination */
-
ops = kernfs_ops(of->kn);
if (ops->write)
len = ops->write(of, buf, len, *ppos);
else
len = -EINVAL;
+ kernfs_put_active(of->kn);
+ mutex_unlock(&of->mutex);
+
if (len > 0)
*ppos += len;
-out_unlock:
- kernfs_put_active(of->kn);
- mutex_unlock(&of->mutex);
out_free:
- if (buf != of->prealloc_buf)
+ if (buf == of->prealloc_buf)
+ mutex_unlock(&of->prealloc_mutex);
+ else
kfree(buf);
return len;
}
@@ -687,6 +693,7 @@ static int kernfs_fop_open(struct inode *inode, struct file *file)
error = -ENOMEM;
if (!of->prealloc_buf)
goto err_free;
+ mutex_init(&of->prealloc_mutex);
}
/*
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index b5247226732b..1719649d7ad7 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -54,7 +54,10 @@ static struct kernfs_iattrs *kernfs_iattrs(struct kernfs_node *kn)
iattrs->ia_mode = kn->mode;
iattrs->ia_uid = GLOBAL_ROOT_UID;
iattrs->ia_gid = GLOBAL_ROOT_GID;
- iattrs->ia_atime = iattrs->ia_mtime = iattrs->ia_ctime = CURRENT_TIME;
+
+ ktime_get_real_ts(&iattrs->ia_atime);
+ iattrs->ia_mtime = iattrs->ia_atime;
+ iattrs->ia_ctime = iattrs->ia_atime;
simple_xattrs_init(&kn->iattr->xattrs);
out_unlock:
@@ -236,16 +239,18 @@ ssize_t kernfs_iop_listxattr(struct dentry *dentry, char *buf, size_t size)
static inline void set_default_inode_attr(struct inode *inode, umode_t mode)
{
inode->i_mode = mode;
- inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
+ inode->i_atime = inode->i_mtime =
+ inode->i_ctime = current_fs_time(inode->i_sb);
}
static inline void set_inode_attr(struct inode *inode, struct iattr *iattr)
{
+ struct super_block *sb = inode->i_sb;
inode->i_uid = iattr->ia_uid;
inode->i_gid = iattr->ia_gid;
- inode->i_atime = iattr->ia_atime;
- inode->i_mtime = iattr->ia_mtime;
- inode->i_ctime = iattr->ia_ctime;
+ inode->i_atime = timespec_trunc(iattr->ia_atime, sb->s_time_gran);
+ inode->i_mtime = timespec_trunc(iattr->ia_mtime, sb->s_time_gran);
+ inode->i_ctime = timespec_trunc(iattr->ia_ctime, sb->s_time_gran);
}
static void kernfs_refresh_inode(struct kernfs_node *kn, struct inode *inode)
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-29 17:46:08 +0000