From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/read_write.c | 1379 +++++++++++++++++++----------------------------------------
1 files changed, 457 insertions(+), 922 deletions(-)
diff --git a/kernel/fs/read_write.c b/kernel/fs/read_write.c
index 650fc7e..729c02a 100644
--- a/kernel/fs/read_write.c
+++ b/kernel/fs/read_write.c
@@ -301,7 +301,7 @@
}
EXPORT_SYMBOL(vfs_llseek);
-off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
+static off_t ksys_lseek(unsigned int fd, off_t offset, unsigned int whence)
{
off_t retval;
struct fd f = fdget_pos(fd);
@@ -331,7 +331,8 @@
}
#endif
-#ifdef __ARCH_WANT_SYS_LLSEEK
+#if !defined(CONFIG_64BIT) || defined(CONFIG_COMPAT) || \
+ defined(__ARCH_WANT_SYS_LLSEEK)
SYSCALL_DEFINE5(llseek, unsigned int, fd, unsigned long, offset_high,
unsigned long, offset_low, loff_t __user *, result,
unsigned int, whence)
@@ -365,29 +366,37 @@
int rw_verify_area(int read_write, struct file *file, const loff_t *ppos, size_t count)
{
struct inode *inode;
- loff_t pos;
int retval = -EINVAL;
inode = file_inode(file);
if (unlikely((ssize_t) count < 0))
return retval;
- pos = *ppos;
- if (unlikely(pos < 0)) {
- if (!unsigned_offsets(file))
- return retval;
- if (count >= -pos) /* both values are in 0..LLONG_MAX */
- return -EOVERFLOW;
- } else if (unlikely((loff_t) (pos + count) < 0)) {
- if (!unsigned_offsets(file))
- return retval;
+
+ /*
+ * ranged mandatory locking does not apply to streams - it makes sense
+ * only for files where position has a meaning.
+ */
+ if (ppos) {
+ loff_t pos = *ppos;
+
+ if (unlikely(pos < 0)) {
+ if (!unsigned_offsets(file))
+ return retval;
+ if (count >= -pos) /* both values are in 0..LLONG_MAX */
+ return -EOVERFLOW;
+ } else if (unlikely((loff_t) (pos + count) < 0)) {
+ if (!unsigned_offsets(file))
+ return retval;
+ }
+
+ if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
+ retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
+ read_write == READ ? F_RDLCK : F_WRLCK);
+ if (retval < 0)
+ return retval;
+ }
}
- if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
- retval = locks_mandatory_area(inode, file, pos, pos + count - 1,
- read_write == READ ? F_RDLCK : F_WRLCK);
- if (retval < 0)
- return retval;
- }
return security_file_permission(file,
read_write == READ ? MAY_READ : MAY_WRITE);
}
@@ -400,39 +409,69 @@
ssize_t ret;
init_sync_kiocb(&kiocb, filp);
- kiocb.ki_pos = *ppos;
+ kiocb.ki_pos = (ppos ? *ppos : 0);
iov_iter_init(&iter, READ, &iov, 1, len);
ret = call_read_iter(filp, &kiocb, &iter);
BUG_ON(ret == -EIOCBQUEUED);
- *ppos = kiocb.ki_pos;
+ if (ppos)
+ *ppos = kiocb.ki_pos;
return ret;
}
-ssize_t __vfs_read(struct file *file, char __user *buf, size_t count,
- loff_t *pos)
+static int warn_unsupported(struct file *file, const char *op)
{
- if (file->f_op->read)
- return file->f_op->read(file, buf, count, pos);
- else if (file->f_op->read_iter)
- return new_sync_read(file, buf, count, pos);
- else
+ pr_warn_ratelimited(
+ "kernel %s not supported for file %pD4 (pid: %d comm: %.20s)\n",
+ op, file, current->pid, current->comm);
+ return -EINVAL;
+}
+
+ssize_t __kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
+{
+ struct kvec iov = {
+ .iov_base = buf,
+ .iov_len = min_t(size_t, count, MAX_RW_COUNT),
+ };
+ struct kiocb kiocb;
+ struct iov_iter iter;
+ ssize_t ret;
+
+ if (WARN_ON_ONCE(!(file->f_mode & FMODE_READ)))
return -EINVAL;
+ if (!(file->f_mode & FMODE_CAN_READ))
+ return -EINVAL;
+ /*
+ * Also fail if ->read_iter and ->read are both wired up as that
+ * implies very convoluted semantics.
+ */
+ if (unlikely(!file->f_op->read_iter || file->f_op->read))
+ return warn_unsupported(file, "read");
+
+ init_sync_kiocb(&kiocb, file);
+ kiocb.ki_pos = pos ? *pos : 0;
+ iov_iter_kvec(&iter, READ, &iov, 1, iov.iov_len);
+ ret = file->f_op->read_iter(&kiocb, &iter);
+ if (ret > 0) {
+ if (pos)
+ *pos = kiocb.ki_pos;
+ fsnotify_access(file);
+ add_rchar(current, ret);
+ }
+ inc_syscr(current);
+ return ret;
}
ssize_t kernel_read(struct file *file, void *buf, size_t count, loff_t *pos)
{
- mm_segment_t old_fs;
- ssize_t result;
+ ssize_t ret;
- old_fs = get_fs();
- set_fs(get_ds());
- /* The cast to a user pointer is valid due to the set_fs() */
- result = vfs_read(file, (void __user *)buf, count, pos);
- set_fs(old_fs);
- return result;
+ ret = rw_verify_area(READ, file, pos, count);
+ if (ret)
+ return ret;
+ return __kernel_read(file, buf, count, pos);
}
-EXPORT_SYMBOL(kernel_read);
+EXPORT_SYMBOL_NS(kernel_read, ANDROID_GKI_VFS_EXPORT_ONLY);
ssize_t vfs_read(struct file *file, char __user *buf, size_t count, loff_t *pos)
{
@@ -442,24 +481,28 @@
return -EBADF;
if (!(file->f_mode & FMODE_CAN_READ))
return -EINVAL;
- if (unlikely(!access_ok(VERIFY_WRITE, buf, count)))
+ if (unlikely(!access_ok(buf, count)))
return -EFAULT;
ret = rw_verify_area(READ, file, pos, count);
- if (!ret) {
- if (count > MAX_RW_COUNT)
- count = MAX_RW_COUNT;
- ret = __vfs_read(file, buf, count, pos);
- if (ret > 0) {
- fsnotify_access(file);
- add_rchar(current, ret);
- }
- inc_syscr(current);
- }
+ if (ret)
+ return ret;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ if (file->f_op->read)
+ ret = file->f_op->read(file, buf, count, pos);
+ else if (file->f_op->read_iter)
+ ret = new_sync_read(file, buf, count, pos);
+ else
+ ret = -EINVAL;
+ if (ret > 0) {
+ fsnotify_access(file);
+ add_rchar(current, ret);
+ }
+ inc_syscr(current);
return ret;
}
-EXPORT_SYMBOL_GPL(vfs_read);
static ssize_t new_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos)
{
@@ -469,67 +512,75 @@
ssize_t ret;
init_sync_kiocb(&kiocb, filp);
- kiocb.ki_pos = *ppos;
+ kiocb.ki_pos = (ppos ? *ppos : 0);
iov_iter_init(&iter, WRITE, &iov, 1, len);
ret = call_write_iter(filp, &kiocb, &iter);
BUG_ON(ret == -EIOCBQUEUED);
- if (ret > 0)
+ if (ret > 0 && ppos)
*ppos = kiocb.ki_pos;
return ret;
}
-ssize_t __vfs_write(struct file *file, const char __user *p, size_t count,
- loff_t *pos)
-{
- if (file->f_op->write)
- return file->f_op->write(file, p, count, pos);
- else if (file->f_op->write_iter)
- return new_sync_write(file, p, count, pos);
- else
- return -EINVAL;
-}
-
+/* caller is responsible for file_start_write/file_end_write */
ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t *pos)
{
- mm_segment_t old_fs;
- const char __user *p;
+ struct kvec iov = {
+ .iov_base = (void *)buf,
+ .iov_len = min_t(size_t, count, MAX_RW_COUNT),
+ };
+ struct kiocb kiocb;
+ struct iov_iter iter;
ssize_t ret;
+ if (WARN_ON_ONCE(!(file->f_mode & FMODE_WRITE)))
+ return -EBADF;
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
+ /*
+ * Also fail if ->write_iter and ->write are both wired up as that
+ * implies very convoluted semantics.
+ */
+ if (unlikely(!file->f_op->write_iter || file->f_op->write))
+ return warn_unsupported(file, "write");
- old_fs = get_fs();
- set_fs(get_ds());
- p = (__force const char __user *)buf;
- if (count > MAX_RW_COUNT)
- count = MAX_RW_COUNT;
- ret = __vfs_write(file, p, count, pos);
- set_fs(old_fs);
+ init_sync_kiocb(&kiocb, file);
+ kiocb.ki_pos = pos ? *pos : 0;
+ iov_iter_kvec(&iter, WRITE, &iov, 1, iov.iov_len);
+ ret = file->f_op->write_iter(&kiocb, &iter);
if (ret > 0) {
+ if (pos)
+ *pos = kiocb.ki_pos;
fsnotify_modify(file);
add_wchar(current, ret);
}
inc_syscw(current);
return ret;
}
-EXPORT_SYMBOL(__kernel_write);
+/*
+ * This "EXPORT_SYMBOL_GPL()" is more of a "EXPORT_SYMBOL_DONTUSE()",
+ * but autofs is one of the few internal kernel users that actually
+ * wants this _and_ can be built as a module. So we need to export
+ * this symbol for autofs, even though it really isn't appropriate
+ * for any other kernel modules.
+ */
+EXPORT_SYMBOL_GPL(__kernel_write);
ssize_t kernel_write(struct file *file, const void *buf, size_t count,
loff_t *pos)
{
- mm_segment_t old_fs;
- ssize_t res;
+ ssize_t ret;
- old_fs = get_fs();
- set_fs(get_ds());
- /* The cast to a user pointer is valid due to the set_fs() */
- res = vfs_write(file, (__force const char __user *)buf, count, pos);
- set_fs(old_fs);
+ ret = rw_verify_area(WRITE, file, pos, count);
+ if (ret)
+ return ret;
- return res;
+ file_start_write(file);
+ ret = __kernel_write(file, buf, count, pos);
+ file_end_write(file);
+ return ret;
}
-EXPORT_SYMBOL(kernel_write);
+EXPORT_SYMBOL_NS(kernel_write, ANDROID_GKI_VFS_EXPORT_ONLY);
ssize_t vfs_write(struct file *file, const char __user *buf, size_t count, loff_t *pos)
{
@@ -539,36 +590,34 @@
return -EBADF;
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
- if (unlikely(!access_ok(VERIFY_READ, buf, count)))
+ if (unlikely(!access_ok(buf, count)))
return -EFAULT;
ret = rw_verify_area(WRITE, file, pos, count);
- if (!ret) {
- if (count > MAX_RW_COUNT)
- count = MAX_RW_COUNT;
- file_start_write(file);
- ret = __vfs_write(file, buf, count, pos);
- if (ret > 0) {
- fsnotify_modify(file);
- add_wchar(current, ret);
- }
- inc_syscw(current);
- file_end_write(file);
+ if (ret)
+ return ret;
+ if (count > MAX_RW_COUNT)
+ count = MAX_RW_COUNT;
+ file_start_write(file);
+ if (file->f_op->write)
+ ret = file->f_op->write(file, buf, count, pos);
+ else if (file->f_op->write_iter)
+ ret = new_sync_write(file, buf, count, pos);
+ else
+ ret = -EINVAL;
+ if (ret > 0) {
+ fsnotify_modify(file);
+ add_wchar(current, ret);
}
-
+ inc_syscw(current);
+ file_end_write(file);
return ret;
}
-EXPORT_SYMBOL_GPL(vfs_write);
-static inline loff_t file_pos_read(struct file *file)
+/* file_ppos returns &file->f_pos or NULL if file is stream */
+static inline loff_t *file_ppos(struct file *file)
{
- return file->f_mode & FMODE_STREAM ? 0 : file->f_pos;
-}
-
-static inline void file_pos_write(struct file *file, loff_t pos)
-{
- if ((file->f_mode & FMODE_STREAM) == 0)
- file->f_pos = pos;
+ return file->f_mode & FMODE_STREAM ? NULL : &file->f_pos;
}
ssize_t ksys_read(unsigned int fd, char __user *buf, size_t count)
@@ -577,10 +626,14 @@
ssize_t ret = -EBADF;
if (f.file) {
- loff_t pos = file_pos_read(f.file);
- ret = vfs_read(f.file, buf, count, &pos);
- if (ret >= 0)
- file_pos_write(f.file, pos);
+ loff_t pos, *ppos = file_ppos(f.file);
+ if (ppos) {
+ pos = *ppos;
+ ppos = &pos;
+ }
+ ret = vfs_read(f.file, buf, count, ppos);
+ if (ret >= 0 && ppos)
+ f.file->f_pos = pos;
fdput_pos(f);
}
return ret;
@@ -597,10 +650,14 @@
ssize_t ret = -EBADF;
if (f.file) {
- loff_t pos = file_pos_read(f.file);
- ret = vfs_write(f.file, buf, count, &pos);
- if (ret >= 0)
- file_pos_write(f.file, pos);
+ loff_t pos, *ppos = file_ppos(f.file);
+ if (ppos) {
+ pos = *ppos;
+ ppos = &pos;
+ }
+ ret = vfs_write(f.file, buf, count, ppos);
+ if (ret >= 0 && ppos)
+ f.file->f_pos = pos;
fdput_pos(f);
}
@@ -675,14 +732,15 @@
ret = kiocb_set_rw_flags(&kiocb, flags);
if (ret)
return ret;
- kiocb.ki_pos = *ppos;
+ kiocb.ki_pos = (ppos ? *ppos : 0);
if (type == READ)
ret = call_read_iter(filp, &kiocb, iter);
else
ret = call_write_iter(filp, &kiocb, iter);
BUG_ON(ret == -EIOCBQUEUED);
- *ppos = kiocb.ki_pos;
+ if (ppos)
+ *ppos = kiocb.ki_pos;
return ret;
}
@@ -721,188 +779,6 @@
return ret;
}
-/* A write operation does a read from user space and vice versa */
-#define vrfy_dir(type) ((type) == READ ? VERIFY_WRITE : VERIFY_READ)
-
-/**
- * rw_copy_check_uvector() - Copy an array of &struct iovec from userspace
- * into the kernel and check that it is valid.
- *
- * @type: One of %CHECK_IOVEC_ONLY, %READ, or %WRITE.
- * @uvector: Pointer to the userspace array.
- * @nr_segs: Number of elements in userspace array.
- * @fast_segs: Number of elements in @fast_pointer.
- * @fast_pointer: Pointer to (usually small on-stack) kernel array.
- * @ret_pointer: (output parameter) Pointer to a variable that will point to
- * either @fast_pointer, a newly allocated kernel array, or NULL,
- * depending on which array was used.
- *
- * This function copies an array of &struct iovec of @nr_segs from
- * userspace into the kernel and checks that each element is valid (e.g.
- * it does not point to a kernel address or cause overflow by being too
- * large, etc.).
- *
- * As an optimization, the caller may provide a pointer to a small
- * on-stack array in @fast_pointer, typically %UIO_FASTIOV elements long
- * (the size of this array, or 0 if unused, should be given in @fast_segs).
- *
- * @ret_pointer will always point to the array that was used, so the
- * caller must take care not to call kfree() on it e.g. in case the
- * @fast_pointer array was used and it was allocated on the stack.
- *
- * Return: The total number of bytes covered by the iovec array on success
- * or a negative error code on error.
- */
-ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
- unsigned long nr_segs, unsigned long fast_segs,
- struct iovec *fast_pointer,
- struct iovec **ret_pointer)
-{
- unsigned long seg;
- ssize_t ret;
- struct iovec *iov = fast_pointer;
-
- /*
- * SuS says "The readv() function *may* fail if the iovcnt argument
- * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
- * traditionally returned zero for zero segments, so...
- */
- if (nr_segs == 0) {
- ret = 0;
- goto out;
- }
-
- /*
- * First get the "struct iovec" from user memory and
- * verify all the pointers
- */
- if (nr_segs > UIO_MAXIOV) {
- ret = -EINVAL;
- goto out;
- }
- if (nr_segs > fast_segs) {
- iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
- if (iov == NULL) {
- ret = -ENOMEM;
- goto out;
- }
- }
- if (copy_from_user(iov, uvector, nr_segs*sizeof(*uvector))) {
- ret = -EFAULT;
- goto out;
- }
-
- /*
- * According to the Single Unix Specification we should return EINVAL
- * if an element length is < 0 when cast to ssize_t or if the
- * total length would overflow the ssize_t return value of the
- * system call.
- *
- * Linux caps all read/write calls to MAX_RW_COUNT, and avoids the
- * overflow case.
- */
- ret = 0;
- for (seg = 0; seg < nr_segs; seg++) {
- void __user *buf = iov[seg].iov_base;
- ssize_t len = (ssize_t)iov[seg].iov_len;
-
- /* see if we we're about to use an invalid len or if
- * it's about to overflow ssize_t */
- if (len < 0) {
- ret = -EINVAL;
- goto out;
- }
- if (type >= 0
- && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
- ret = -EFAULT;
- goto out;
- }
- if (len > MAX_RW_COUNT - ret) {
- len = MAX_RW_COUNT - ret;
- iov[seg].iov_len = len;
- }
- ret += len;
- }
-out:
- *ret_pointer = iov;
- return ret;
-}
-
-#ifdef CONFIG_COMPAT
-ssize_t compat_rw_copy_check_uvector(int type,
- const struct compat_iovec __user *uvector, unsigned long nr_segs,
- unsigned long fast_segs, struct iovec *fast_pointer,
- struct iovec **ret_pointer)
-{
- compat_ssize_t tot_len;
- struct iovec *iov = *ret_pointer = fast_pointer;
- ssize_t ret = 0;
- int seg;
-
- /*
- * SuS says "The readv() function *may* fail if the iovcnt argument
- * was less than or equal to 0, or greater than {IOV_MAX}. Linux has
- * traditionally returned zero for zero segments, so...
- */
- if (nr_segs == 0)
- goto out;
-
- ret = -EINVAL;
- if (nr_segs > UIO_MAXIOV)
- goto out;
- if (nr_segs > fast_segs) {
- ret = -ENOMEM;
- iov = kmalloc_array(nr_segs, sizeof(struct iovec), GFP_KERNEL);
- if (iov == NULL)
- goto out;
- }
- *ret_pointer = iov;
-
- ret = -EFAULT;
- if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector)))
- goto out;
-
- /*
- * Single unix specification:
- * We should -EINVAL if an element length is not >= 0 and fitting an
- * ssize_t.
- *
- * In Linux, the total length is limited to MAX_RW_COUNT, there is
- * no overflow possibility.
- */
- tot_len = 0;
- ret = -EINVAL;
- for (seg = 0; seg < nr_segs; seg++) {
- compat_uptr_t buf;
- compat_ssize_t len;
-
- if (__get_user(len, &uvector->iov_len) ||
- __get_user(buf, &uvector->iov_base)) {
- ret = -EFAULT;
- goto out;
- }
- if (len < 0) /* size_t not fitting in compat_ssize_t .. */
- goto out;
- if (type >= 0 &&
- !access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
- ret = -EFAULT;
- goto out;
- }
- if (len > MAX_RW_COUNT - tot_len)
- len = MAX_RW_COUNT - tot_len;
- tot_len += len;
- iov->iov_base = compat_ptr(buf);
- iov->iov_len = (compat_size_t) len;
- uvector++;
- iov++;
- }
- ret = tot_len;
-
-out:
- return ret;
-}
-#endif
-
static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
loff_t *pos, rwf_t flags)
{
@@ -930,6 +806,34 @@
fsnotify_access(file);
return ret;
}
+
+ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
+ struct iov_iter *iter)
+{
+ size_t tot_len;
+ ssize_t ret = 0;
+
+ if (!file->f_op->read_iter)
+ return -EINVAL;
+ if (!(file->f_mode & FMODE_READ))
+ return -EBADF;
+ if (!(file->f_mode & FMODE_CAN_READ))
+ return -EINVAL;
+
+ tot_len = iov_iter_count(iter);
+ if (!tot_len)
+ goto out;
+ ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);
+ if (ret < 0)
+ return ret;
+
+ ret = call_read_iter(file, iocb, iter);
+out:
+ if (ret >= 0)
+ fsnotify_access(file);
+ return ret;
+}
+EXPORT_SYMBOL(vfs_iocb_iter_read);
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags)
@@ -967,6 +871,34 @@
return ret;
}
+ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
+ struct iov_iter *iter)
+{
+ size_t tot_len;
+ ssize_t ret = 0;
+
+ if (!file->f_op->write_iter)
+ return -EINVAL;
+ if (!(file->f_mode & FMODE_WRITE))
+ return -EBADF;
+ if (!(file->f_mode & FMODE_CAN_WRITE))
+ return -EINVAL;
+
+ tot_len = iov_iter_count(iter);
+ if (!tot_len)
+ return 0;
+ ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
+ if (ret < 0)
+ return ret;
+
+ ret = call_write_iter(file, iocb, iter);
+ if (ret > 0)
+ fsnotify_modify(file);
+
+ return ret;
+}
+EXPORT_SYMBOL(vfs_iocb_iter_write);
+
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags)
{
@@ -976,7 +908,7 @@
}
EXPORT_SYMBOL(vfs_iter_write);
-ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
+static ssize_t vfs_readv(struct file *file, const struct iovec __user *vec,
unsigned long vlen, loff_t *pos, rwf_t flags)
{
struct iovec iovstack[UIO_FASTIOV];
@@ -1018,10 +950,14 @@
ssize_t ret = -EBADF;
if (f.file) {
- loff_t pos = file_pos_read(f.file);
- ret = vfs_readv(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- file_pos_write(f.file, pos);
+ loff_t pos, *ppos = file_ppos(f.file);
+ if (ppos) {
+ pos = *ppos;
+ ppos = &pos;
+ }
+ ret = vfs_readv(f.file, vec, vlen, ppos, flags);
+ if (ret >= 0 && ppos)
+ f.file->f_pos = pos;
fdput_pos(f);
}
@@ -1038,10 +974,14 @@
ssize_t ret = -EBADF;
if (f.file) {
- loff_t pos = file_pos_read(f.file);
- ret = vfs_writev(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- file_pos_write(f.file, pos);
+ loff_t pos, *ppos = file_ppos(f.file);
+ if (ppos) {
+ pos = *ppos;
+ ppos = &pos;
+ }
+ ret = vfs_writev(f.file, vec, vlen, ppos, flags);
+ if (ret >= 0 && ppos)
+ f.file->f_pos = pos;
fdput_pos(f);
}
@@ -1155,224 +1095,93 @@
return do_pwritev(fd, vec, vlen, pos, flags);
}
+/*
+ * Various compat syscalls. Note that they all pretend to take a native
+ * iovec - import_iovec will properly treat those as compat_iovecs based on
+ * in_compat_syscall().
+ */
#ifdef CONFIG_COMPAT
-static size_t compat_readv(struct file *file,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t *pos, rwf_t flags)
-{
- struct iovec iovstack[UIO_FASTIOV];
- struct iovec *iov = iovstack;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
- if (ret >= 0) {
- ret = do_iter_read(file, &iter, pos, flags);
- kfree(iov);
- }
- if (ret > 0)
- add_rchar(current, ret);
- inc_syscr(current);
- return ret;
-}
-
-static size_t do_compat_readv(compat_ulong_t fd,
- const struct compat_iovec __user *vec,
- compat_ulong_t vlen, rwf_t flags)
-{
- struct fd f = fdget_pos(fd);
- ssize_t ret;
- loff_t pos;
-
- if (!f.file)
- return -EBADF;
- pos = f.file->f_pos;
- ret = compat_readv(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- f.file->f_pos = pos;
- fdput_pos(f);
- return ret;
-
-}
-
-COMPAT_SYSCALL_DEFINE3(readv, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
- compat_ulong_t, vlen)
-{
- return do_compat_readv(fd, vec, vlen, 0);
-}
-
-static long do_compat_preadv64(unsigned long fd,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t pos, rwf_t flags)
-{
- struct fd f;
- ssize_t ret;
-
- if (pos < 0)
- return -EINVAL;
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
- ret = -ESPIPE;
- if (f.file->f_mode & FMODE_PREAD)
- ret = compat_readv(f.file, vec, vlen, &pos, flags);
- fdput(f);
- return ret;
-}
-
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64
COMPAT_SYSCALL_DEFINE4(preadv64, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos)
{
- return do_compat_preadv64(fd, vec, vlen, pos, 0);
+ return do_preadv(fd, vec, vlen, pos, 0);
}
#endif
COMPAT_SYSCALL_DEFINE5(preadv, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
- return do_compat_preadv64(fd, vec, vlen, pos, 0);
+ return do_preadv(fd, vec, vlen, pos, 0);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PREADV64V2
COMPAT_SYSCALL_DEFINE5(preadv64v2, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
if (pos == -1)
- return do_compat_readv(fd, vec, vlen, flags);
-
- return do_compat_preadv64(fd, vec, vlen, pos, flags);
+ return do_readv(fd, vec, vlen, flags);
+ return do_preadv(fd, vec, vlen, pos, flags);
}
#endif
COMPAT_SYSCALL_DEFINE6(preadv2, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high,
rwf_t, flags)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
if (pos == -1)
- return do_compat_readv(fd, vec, vlen, flags);
-
- return do_compat_preadv64(fd, vec, vlen, pos, flags);
-}
-
-static size_t compat_writev(struct file *file,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t *pos, rwf_t flags)
-{
- struct iovec iovstack[UIO_FASTIOV];
- struct iovec *iov = iovstack;
- struct iov_iter iter;
- ssize_t ret;
-
- ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
- if (ret >= 0) {
- file_start_write(file);
- ret = do_iter_write(file, &iter, pos, flags);
- file_end_write(file);
- kfree(iov);
- }
- if (ret > 0)
- add_wchar(current, ret);
- inc_syscw(current);
- return ret;
-}
-
-static size_t do_compat_writev(compat_ulong_t fd,
- const struct compat_iovec __user* vec,
- compat_ulong_t vlen, rwf_t flags)
-{
- struct fd f = fdget_pos(fd);
- ssize_t ret;
- loff_t pos;
-
- if (!f.file)
- return -EBADF;
- pos = f.file->f_pos;
- ret = compat_writev(f.file, vec, vlen, &pos, flags);
- if (ret >= 0)
- f.file->f_pos = pos;
- fdput_pos(f);
- return ret;
-}
-
-COMPAT_SYSCALL_DEFINE3(writev, compat_ulong_t, fd,
- const struct compat_iovec __user *, vec,
- compat_ulong_t, vlen)
-{
- return do_compat_writev(fd, vec, vlen, 0);
-}
-
-static long do_compat_pwritev64(unsigned long fd,
- const struct compat_iovec __user *vec,
- unsigned long vlen, loff_t pos, rwf_t flags)
-{
- struct fd f;
- ssize_t ret;
-
- if (pos < 0)
- return -EINVAL;
- f = fdget(fd);
- if (!f.file)
- return -EBADF;
- ret = -ESPIPE;
- if (f.file->f_mode & FMODE_PWRITE)
- ret = compat_writev(f.file, vec, vlen, &pos, flags);
- fdput(f);
- return ret;
+ return do_readv(fd, vec, vlen, flags);
+ return do_preadv(fd, vec, vlen, pos, flags);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64
COMPAT_SYSCALL_DEFINE4(pwritev64, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos)
{
- return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+ return do_pwritev(fd, vec, vlen, pos, 0);
}
#endif
COMPAT_SYSCALL_DEFINE5(pwritev, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
- return do_compat_pwritev64(fd, vec, vlen, pos, 0);
+ return do_pwritev(fd, vec, vlen, pos, 0);
}
#ifdef __ARCH_WANT_COMPAT_SYS_PWRITEV64V2
COMPAT_SYSCALL_DEFINE5(pwritev64v2, unsigned long, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *, vec,
unsigned long, vlen, loff_t, pos, rwf_t, flags)
{
if (pos == -1)
- return do_compat_writev(fd, vec, vlen, flags);
-
- return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+ return do_writev(fd, vec, vlen, flags);
+ return do_pwritev(fd, vec, vlen, pos, flags);
}
#endif
COMPAT_SYSCALL_DEFINE6(pwritev2, compat_ulong_t, fd,
- const struct compat_iovec __user *,vec,
+ const struct iovec __user *,vec,
compat_ulong_t, vlen, u32, pos_low, u32, pos_high, rwf_t, flags)
{
loff_t pos = ((loff_t)pos_high << 32) | pos_low;
if (pos == -1)
- return do_compat_writev(fd, vec, vlen, flags);
-
- return do_compat_pwritev64(fd, vec, vlen, pos, flags);
+ return do_writev(fd, vec, vlen, flags);
+ return do_pwritev(fd, vec, vlen, pos, flags);
}
-
-#endif
+#endif /* CONFIG_COMPAT */
static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
size_t count, loff_t max)
@@ -1416,7 +1225,6 @@
goto fput_in;
if (!(out.file->f_mode & FMODE_WRITE))
goto fput_out;
- retval = -EINVAL;
in_inode = file_inode(in.file);
out_inode = file_inode(out.file);
out_pos = out.file->f_pos;
@@ -1550,6 +1358,109 @@
}
#endif
+/**
+ * generic_copy_file_range - copy data between two files
+ * @file_in: file structure to read from
+ * @pos_in: file offset to read from
+ * @file_out: file structure to write data to
+ * @pos_out: file offset to write data to
+ * @len: amount of data to copy
+ * @flags: copy flags
+ *
+ * This is a generic filesystem helper to copy data from one file to another.
+ * It has no constraints on the source or destination file owners - the files
+ * can belong to different superblocks and different filesystem types. Short
+ * copies are allowed.
+ *
+ * This should be called from the @file_out filesystem, as per the
+ * ->copy_file_range() method.
+ *
+ * Returns the number of bytes copied or a negative error indicating the
+ * failure.
+ */
+
+ssize_t generic_copy_file_range(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ size_t len, unsigned int flags)
+{
+ return do_splice_direct(file_in, &pos_in, file_out, &pos_out,
+ len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+}
+EXPORT_SYMBOL(generic_copy_file_range);
+
+/*
+ * Performs necessary checks before doing a file copy
+ *
+ * Can adjust amount of bytes to copy via @req_count argument.
+ * Returns appropriate error code that caller should return or
+ * zero in case the copy should be allowed.
+ */
+static int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
+ struct file *file_out, loff_t pos_out,
+ size_t *req_count, unsigned int flags)
+{
+ struct inode *inode_in = file_inode(file_in);
+ struct inode *inode_out = file_inode(file_out);
+ uint64_t count = *req_count;
+ loff_t size_in;
+ int ret;
+
+ ret = generic_file_rw_checks(file_in, file_out);
+ if (ret)
+ return ret;
+
+ /*
+ * We allow some filesystems to handle cross sb copy, but passing
+ * a file of the wrong filesystem type to filesystem driver can result
+ * in an attempt to dereference the wrong type of ->private_data, so
+ * avoid doing that until we really have a good reason.
+ *
+ * nfs and cifs define several different file_system_type structures
+ * and several different sets of file_operations, but they all end up
+ * using the same ->copy_file_range() function pointer.
+ */
+ if (flags & COPY_FILE_SPLICE) {
+ /* cross sb splice is allowed */
+ } else if (file_out->f_op->copy_file_range) {
+ if (file_in->f_op->copy_file_range !=
+ file_out->f_op->copy_file_range)
+ return -EXDEV;
+ } else if (file_inode(file_in)->i_sb != file_inode(file_out)->i_sb) {
+ return -EXDEV;
+ }
+
+ /* Don't touch certain kinds of inodes */
+ if (IS_IMMUTABLE(inode_out))
+ return -EPERM;
+
+ if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
+ return -ETXTBSY;
+
+ /* Ensure offsets don't wrap. */
+ if (pos_in + count < pos_in || pos_out + count < pos_out)
+ return -EOVERFLOW;
+
+ /* Shorten the copy to EOF */
+ size_in = i_size_read(inode_in);
+ if (pos_in >= size_in)
+ count = 0;
+ else
+ count = min(count, size_in - (uint64_t)pos_in);
+
+ ret = generic_write_check_limits(file_out, pos_out, &count);
+ if (ret)
+ return ret;
+
+ /* Don't allow overlapped copying within the same file. */
+ if (inode_in == inode_out &&
+ pos_out + count > pos_in &&
+ pos_out < pos_in + count)
+ return -EINVAL;
+
+ *req_count = count;
+ return 0;
+}
+
/*
* copy_file_range() differs from regular file read and write in that it
* specifically allows return partial success. When it does so is up to
@@ -1559,17 +1470,16 @@
struct file *file_out, loff_t pos_out,
size_t len, unsigned int flags)
{
- struct inode *inode_in = file_inode(file_in);
- struct inode *inode_out = file_inode(file_out);
ssize_t ret;
+ bool splice = flags & COPY_FILE_SPLICE;
- if (flags != 0)
+ if (flags & ~COPY_FILE_SPLICE)
return -EINVAL;
- if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
- return -EISDIR;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
- return -EINVAL;
+ ret = generic_copy_file_checks(file_in, pos_in, file_out, pos_out, &len,
+ flags);
+ if (unlikely(ret))
+ return ret;
ret = rw_verify_area(READ, file_in, &pos_in, len);
if (unlikely(ret))
@@ -1579,42 +1489,48 @@
if (unlikely(ret))
return ret;
- if (!(file_in->f_mode & FMODE_READ) ||
- !(file_out->f_mode & FMODE_WRITE) ||
- (file_out->f_flags & O_APPEND))
- return -EBADF;
-
- /* this could be relaxed once a method supports cross-fs copies */
- if (inode_in->i_sb != inode_out->i_sb)
- return -EXDEV;
-
if (len == 0)
return 0;
file_start_write(file_out);
/*
- * Try cloning first, this is supported by more file systems, and
- * more efficient if both clone and copy are supported (e.g. NFS).
+ * Cloning is supported by more file systems, so we implement copy on
+ * same sb using clone, but for filesystems where both clone and copy
+ * are supported (e.g. nfs,cifs), we only call the copy method.
*/
- if (file_in->f_op->clone_file_range) {
- ret = file_in->f_op->clone_file_range(file_in, pos_in,
- file_out, pos_out, len);
- if (ret == 0) {
- ret = len;
- goto done;
- }
+ if (!splice && file_out->f_op->copy_file_range) {
+ ret = file_out->f_op->copy_file_range(file_in, pos_in,
+ file_out, pos_out,
+ len, flags);
+ goto done;
}
- if (file_out->f_op->copy_file_range) {
- ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out,
- pos_out, len, flags);
- if (ret != -EOPNOTSUPP)
+ if (!splice && file_in->f_op->remap_file_range &&
+ file_inode(file_in)->i_sb == file_inode(file_out)->i_sb) {
+ ret = file_in->f_op->remap_file_range(file_in, pos_in,
+ file_out, pos_out,
+ min_t(loff_t, MAX_RW_COUNT, len),
+ REMAP_FILE_CAN_SHORTEN);
+ if (ret > 0)
goto done;
}
- ret = do_splice_direct(file_in, &pos_in, file_out, &pos_out,
- len > MAX_RW_COUNT ? MAX_RW_COUNT : len, 0);
+ /*
+ * We can get here for same sb copy of filesystems that do not implement
+ * ->copy_file_range() in case filesystem does not support clone or in
+ * case filesystem supports clone but rejected the clone request (e.g.
+ * because it was not block aligned).
+ *
+ * In both cases, fall back to kernel copy so we are able to maintain a
+ * consistent story about which filesystems support copy_file_range()
+ * and which filesystems do not, that will allow userspace tools to
+ * make consistent desicions w.r.t using copy_file_range().
+ *
+ * We also get here if caller (e.g. nfsd) requested COPY_FILE_SPLICE.
+ */
+ ret = generic_copy_file_range(file_in, pos_in, file_out, pos_out, len,
+ flags);
done:
if (ret > 0) {
@@ -1666,6 +1582,10 @@
pos_out = f_out.file->f_pos;
}
+ ret = -EINVAL;
+ if (flags != 0)
+ goto out;
+
ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len,
flags);
if (ret > 0) {
@@ -1695,477 +1615,92 @@
return ret;
}
-static int clone_verify_area(struct file *file, loff_t pos, u64 len, bool write)
+/*
+ * Don't operate on ranges the page cache doesn't support, and don't exceed the
+ * LFS limits. If pos is under the limit it becomes a short access. If it
+ * exceeds the limit we return -EFBIG.
+ */
+int generic_write_check_limits(struct file *file, loff_t pos, loff_t *count)
{
- struct inode *inode = file_inode(file);
+ struct inode *inode = file->f_mapping->host;
+ loff_t max_size = inode->i_sb->s_maxbytes;
+ loff_t limit = rlimit(RLIMIT_FSIZE);
- if (unlikely(pos < 0))
- return -EINVAL;
-
- if (unlikely((loff_t) (pos + len) < 0))
- return -EINVAL;
-
- if (unlikely(inode->i_flctx && mandatory_lock(inode))) {
- loff_t end = len ? pos + len - 1 : OFFSET_MAX;
- int retval;
-
- retval = locks_mandatory_area(inode, file, pos, end,
- write ? F_WRLCK : F_RDLCK);
- if (retval < 0)
- return retval;
+ if (limit != RLIM_INFINITY) {
+ if (pos >= limit) {
+ send_sig(SIGXFSZ, current, 0);
+ return -EFBIG;
+ }
+ *count = min(*count, limit - pos);
}
- return security_file_permission(file, write ? MAY_WRITE : MAY_READ);
-}
-/*
- * Ensure that we don't remap a partial EOF block in the middle of something
- * else. Assume that the offsets have already been checked for block
- * alignment.
- *
- * For deduplication we always scale down to the previous block because we
- * can't meaningfully compare post-EOF contents.
- *
- * For clone we only link a partial EOF block above the destination file's EOF.
- */
-static int generic_remap_check_len(struct inode *inode_in,
- struct inode *inode_out,
- loff_t pos_out,
- u64 *len,
- bool is_dedupe)
-{
- u64 blkmask = i_blocksize(inode_in) - 1;
+ if (!(file->f_flags & O_LARGEFILE))
+ max_size = MAX_NON_LFS;
- if ((*len & blkmask) == 0)
- return 0;
+ if (unlikely(pos >= max_size))
+ return -EFBIG;
- if (is_dedupe)
- *len &= ~blkmask;
- else if (pos_out + *len < i_size_read(inode_out))
- return -EINVAL;
+ *count = min(*count, max_size - pos);
return 0;
}
/*
- * Check that the two inodes are eligible for cloning, the ranges make
- * sense, and then flush all dirty data. Caller must ensure that the
- * inodes have been locked against any other modifications.
+ * Performs necessary checks before doing a write
*
- * Returns: 0 for "nothing to clone", 1 for "something to clone", or
- * the usual negative error code.
+ * Can adjust writing position or amount of bytes to write.
+ * Returns appropriate error code that caller should return or
+ * zero in case that write should be allowed.
*/
-int vfs_clone_file_prep_inodes(struct inode *inode_in, loff_t pos_in,
- struct inode *inode_out, loff_t pos_out,
- u64 *len, bool is_dedupe)
+ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
{
- loff_t bs = inode_out->i_sb->s_blocksize;
- loff_t blen;
- loff_t isize;
- bool same_inode = (inode_in == inode_out);
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ loff_t count;
int ret;
- /* Don't touch certain kinds of inodes */
- if (IS_IMMUTABLE(inode_out))
- return -EPERM;
-
- if (IS_SWAPFILE(inode_in) || IS_SWAPFILE(inode_out))
+ if (IS_SWAPFILE(inode))
return -ETXTBSY;
- /* Don't reflink dirs, pipes, sockets... */
- if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
- return -EISDIR;
- if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
- return -EINVAL;
-
- /* Are we going all the way to the end? */
- isize = i_size_read(inode_in);
- if (isize == 0)
+ if (!iov_iter_count(from))
return 0;
- /* Zero length dedupe exits immediately; reflink goes to EOF. */
- if (*len == 0) {
- if (is_dedupe || pos_in == isize)
- return 0;
- if (pos_in > isize)
- return -EINVAL;
- *len = isize - pos_in;
- }
+ /* FIXME: this is for backwards compatibility with 2.4 */
+ if (iocb->ki_flags & IOCB_APPEND)
+ iocb->ki_pos = i_size_read(inode);
- /* Ensure offsets don't wrap and the input is inside i_size */
- if (pos_in + *len < pos_in || pos_out + *len < pos_out ||
- pos_in + *len > isize)
+ if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
return -EINVAL;
- /* Don't allow dedupe past EOF in the dest file */
- if (is_dedupe) {
- loff_t disize;
-
- disize = i_size_read(inode_out);
- if (pos_out >= disize || pos_out + *len > disize)
- return -EINVAL;
- }
-
- /* If we're linking to EOF, continue to the block boundary. */
- if (pos_in + *len == isize)
- blen = ALIGN(isize, bs) - pos_in;
- else
- blen = *len;
-
- /* Only reflink if we're aligned to block boundaries */
- if (!IS_ALIGNED(pos_in, bs) || !IS_ALIGNED(pos_in + blen, bs) ||
- !IS_ALIGNED(pos_out, bs) || !IS_ALIGNED(pos_out + blen, bs))
- return -EINVAL;
-
- /* Don't allow overlapped reflink within the same file */
- if (same_inode) {
- if (pos_out + blen > pos_in && pos_out < pos_in + blen)
- return -EINVAL;
- }
-
- /* Wait for the completion of any pending IOs on both files */
- inode_dio_wait(inode_in);
- if (!same_inode)
- inode_dio_wait(inode_out);
-
- ret = filemap_write_and_wait_range(inode_in->i_mapping,
- pos_in, pos_in + *len - 1);
+ count = iov_iter_count(from);
+ ret = generic_write_check_limits(file, iocb->ki_pos, &count);
if (ret)
return ret;
- ret = filemap_write_and_wait_range(inode_out->i_mapping,
- pos_out, pos_out + *len - 1);
- if (ret)
- return ret;
-
- /*
- * Check that the extents are the same.
- */
- if (is_dedupe) {
- bool is_same = false;
-
- ret = vfs_dedupe_file_range_compare(inode_in, pos_in,
- inode_out, pos_out, *len, &is_same);
- if (ret)
- return ret;
- if (!is_same)
- return -EBADE;
- }
-
- ret = generic_remap_check_len(inode_in, inode_out, pos_out, len,
- is_dedupe);
- if (ret)
- return ret;
-
- return 1;
+ iov_iter_truncate(from, count);
+ return iov_iter_count(from);
}
-EXPORT_SYMBOL(vfs_clone_file_prep_inodes);
+EXPORT_SYMBOL(generic_write_checks);
-int do_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len)
+/*
+ * Performs common checks before doing a file copy/clone
+ * from @file_in to @file_out.
+ */
+int generic_file_rw_checks(struct file *file_in, struct file *file_out)
{
struct inode *inode_in = file_inode(file_in);
struct inode *inode_out = file_inode(file_out);
- int ret;
+ /* Don't copy dirs, pipes, sockets... */
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
return -EISDIR;
if (!S_ISREG(inode_in->i_mode) || !S_ISREG(inode_out->i_mode))
return -EINVAL;
-
- /*
- * FICLONE/FICLONERANGE ioctls enforce that src and dest files are on
- * the same mount. Practically, they only need to be on the same file
- * system.
- */
- if (inode_in->i_sb != inode_out->i_sb)
- return -EXDEV;
if (!(file_in->f_mode & FMODE_READ) ||
!(file_out->f_mode & FMODE_WRITE) ||
(file_out->f_flags & O_APPEND))
return -EBADF;
- if (!file_in->f_op->clone_file_range)
- return -EOPNOTSUPP;
-
- ret = clone_verify_area(file_in, pos_in, len, false);
- if (ret)
- return ret;
-
- ret = clone_verify_area(file_out, pos_out, len, true);
- if (ret)
- return ret;
-
- if (pos_in + len > i_size_read(inode_in))
- return -EINVAL;
-
- ret = file_in->f_op->clone_file_range(file_in, pos_in,
- file_out, pos_out, len);
- if (!ret) {
- fsnotify_access(file_in);
- fsnotify_modify(file_out);
- }
-
- return ret;
-}
-EXPORT_SYMBOL(do_clone_file_range);
-
-int vfs_clone_file_range(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out, u64 len)
-{
- int ret;
-
- file_start_write(file_out);
- ret = do_clone_file_range(file_in, pos_in, file_out, pos_out, len);
- file_end_write(file_out);
-
- return ret;
-}
-EXPORT_SYMBOL(vfs_clone_file_range);
-
-/* Read a page's worth of file data into the page cache. */
-static struct page *vfs_dedupe_get_page(struct inode *inode, loff_t offset)
-{
- struct address_space *mapping;
- struct page *page;
- pgoff_t n;
-
- n = offset >> PAGE_SHIFT;
- mapping = inode->i_mapping;
- page = read_mapping_page(mapping, n, NULL);
- if (IS_ERR(page))
- return page;
- if (!PageUptodate(page)) {
- put_page(page);
- return ERR_PTR(-EIO);
- }
- return page;
-}
-
-/*
- * Lock two pages, ensuring that we lock in offset order if the pages are from
- * the same file.
- */
-static void vfs_lock_two_pages(struct page *page1, struct page *page2)
-{
- /* Always lock in order of increasing index. */
- if (page1->index > page2->index)
- swap(page1, page2);
-
- lock_page(page1);
- if (page1 != page2)
- lock_page(page2);
-}
-
-/* Unlock two pages, being careful not to unlock the same page twice. */
-static void vfs_unlock_two_pages(struct page *page1, struct page *page2)
-{
- unlock_page(page1);
- if (page1 != page2)
- unlock_page(page2);
-}
-
-/*
- * Compare extents of two files to see if they are the same.
- * Caller must have locked both inodes to prevent write races.
- */
-int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff,
- struct inode *dest, loff_t destoff,
- loff_t len, bool *is_same)
-{
- loff_t src_poff;
- loff_t dest_poff;
- void *src_addr;
- void *dest_addr;
- struct page *src_page;
- struct page *dest_page;
- loff_t cmp_len;
- bool same;
- int error;
-
- error = -EINVAL;
- same = true;
- while (len) {
- src_poff = srcoff & (PAGE_SIZE - 1);
- dest_poff = destoff & (PAGE_SIZE - 1);
- cmp_len = min(PAGE_SIZE - src_poff,
- PAGE_SIZE - dest_poff);
- cmp_len = min(cmp_len, len);
- if (cmp_len <= 0)
- goto out_error;
-
- src_page = vfs_dedupe_get_page(src, srcoff);
- if (IS_ERR(src_page)) {
- error = PTR_ERR(src_page);
- goto out_error;
- }
- dest_page = vfs_dedupe_get_page(dest, destoff);
- if (IS_ERR(dest_page)) {
- error = PTR_ERR(dest_page);
- put_page(src_page);
- goto out_error;
- }
-
- vfs_lock_two_pages(src_page, dest_page);
-
- /*
- * Now that we've locked both pages, make sure they're still
- * mapped to the file data we're interested in. If not,
- * someone is invalidating pages on us and we lose.
- */
- if (!PageUptodate(src_page) || !PageUptodate(dest_page) ||
- src_page->mapping != src->i_mapping ||
- dest_page->mapping != dest->i_mapping) {
- same = false;
- goto unlock;
- }
-
- src_addr = kmap_atomic(src_page);
- dest_addr = kmap_atomic(dest_page);
-
- flush_dcache_page(src_page);
- flush_dcache_page(dest_page);
-
- if (memcmp(src_addr + src_poff, dest_addr + dest_poff, cmp_len))
- same = false;
-
- kunmap_atomic(dest_addr);
- kunmap_atomic(src_addr);
-unlock:
- vfs_unlock_two_pages(src_page, dest_page);
- put_page(dest_page);
- put_page(src_page);
-
- if (!same)
- break;
-
- srcoff += cmp_len;
- destoff += cmp_len;
- len -= cmp_len;
- }
-
- *is_same = same;
return 0;
-
-out_error:
- return error;
}
-EXPORT_SYMBOL(vfs_dedupe_file_range_compare);
-
-int vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,
- struct file *dst_file, loff_t dst_pos, u64 len)
-{
- s64 ret;
-
- ret = mnt_want_write_file(dst_file);
- if (ret)
- return ret;
-
- ret = clone_verify_area(dst_file, dst_pos, len, true);
- if (ret < 0)
- goto out_drop_write;
-
- ret = -EINVAL;
- if (!(capable(CAP_SYS_ADMIN) || (dst_file->f_mode & FMODE_WRITE)))
- goto out_drop_write;
-
- ret = -EXDEV;
- if (src_file->f_path.mnt != dst_file->f_path.mnt)
- goto out_drop_write;
-
- ret = -EISDIR;
- if (S_ISDIR(file_inode(dst_file)->i_mode))
- goto out_drop_write;
-
- ret = -EINVAL;
- if (!dst_file->f_op->dedupe_file_range)
- goto out_drop_write;
-
- ret = dst_file->f_op->dedupe_file_range(src_file, src_pos,
- dst_file, dst_pos, len);
-out_drop_write:
- mnt_drop_write_file(dst_file);
-
- return ret;
-}
-EXPORT_SYMBOL(vfs_dedupe_file_range_one);
-
-int vfs_dedupe_file_range(struct file *file, struct file_dedupe_range *same)
-{
- struct file_dedupe_range_info *info;
- struct inode *src = file_inode(file);
- u64 off;
- u64 len;
- int i;
- int ret;
- u16 count = same->dest_count;
- int deduped;
-
- if (!(file->f_mode & FMODE_READ))
- return -EINVAL;
-
- if (same->reserved1 || same->reserved2)
- return -EINVAL;
-
- off = same->src_offset;
- len = same->src_length;
-
- ret = -EISDIR;
- if (S_ISDIR(src->i_mode))
- goto out;
-
- ret = -EINVAL;
- if (!S_ISREG(src->i_mode))
- goto out;
-
- ret = clone_verify_area(file, off, len, false);
- if (ret < 0)
- goto out;
- ret = 0;
-
- if (off + len > i_size_read(src))
- return -EINVAL;
-
- /* Arbitrary 1G limit on a single dedupe request, can be raised. */
- len = min_t(u64, len, 1 << 30);
-
- /* pre-format output fields to sane values */
- for (i = 0; i < count; i++) {
- same->info[i].bytes_deduped = 0ULL;
- same->info[i].status = FILE_DEDUPE_RANGE_SAME;
- }
-
- for (i = 0, info = same->info; i < count; i++, info++) {
- struct fd dst_fd = fdget(info->dest_fd);
- struct file *dst_file = dst_fd.file;
-
- if (!dst_file) {
- info->status = -EBADF;
- goto next_loop;
- }
-
- if (info->reserved) {
- info->status = -EINVAL;
- goto next_fdput;
- }
-
- deduped = vfs_dedupe_file_range_one(file, off, dst_file,
- info->dest_offset, len);
- if (deduped == -EBADE)
- info->status = FILE_DEDUPE_RANGE_DIFFERS;
- else if (deduped < 0)
- info->status = deduped;
- else
- info->bytes_deduped = len;
-
-next_fdput:
- fdput(dst_fd);
-next_loop:
- if (fatal_signal_pending(current))
- goto out;
- }
-
-out:
- return ret;
-}
-EXPORT_SYMBOL(vfs_dedupe_file_range);
--
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