From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
The generic write check helpers also don't have much to do with the page
cache, so move them to the vfs.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
fs/read_write.c | 143 ++++++++++++++++++++++++++++++++++++++++++++++++++++
include/linux/fs.h | 3 -
mm/filemap.c | 143 ----------------------------------------------------
3 files changed, 143 insertions(+), 146 deletions(-)
diff --git a/fs/read_write.c b/fs/read_write.c
index f0877f1c0c49..016444255d3e 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1701,6 +1701,59 @@ static ssize_t do_copy_file_range(struct file *file_in, loff_t pos_in,
flags);
}
+/*
+ * 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;
+
+ /* 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
@@ -1832,3 +1885,93 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in,
out2:
return ret;
}
+
+/*
+ * 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->f_mapping->host;
+ loff_t max_size = inode->i_sb->s_maxbytes;
+ loff_t limit = rlimit(RLIMIT_FSIZE);
+
+ if (limit != RLIM_INFINITY) {
+ if (pos >= limit) {
+ send_sig(SIGXFSZ, current, 0);
+ return -EFBIG;
+ }
+ *count = min(*count, limit - pos);
+ }
+
+ if (!(file->f_flags & O_LARGEFILE))
+ max_size = MAX_NON_LFS;
+
+ if (unlikely(pos >= max_size))
+ return -EFBIG;
+
+ *count = min(*count, max_size - pos);
+
+ return 0;
+}
+
+/*
+ * Performs necessary checks before doing a write
+ *
+ * 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.
+ */
+ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
+{
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = file->f_mapping->host;
+ loff_t count;
+ int ret;
+
+ if (IS_SWAPFILE(inode))
+ return -ETXTBSY;
+
+ if (!iov_iter_count(from))
+ return 0;
+
+ /* FIXME: this is for backwards compatibility with 2.4 */
+ if (iocb->ki_flags & IOCB_APPEND)
+ iocb->ki_pos = i_size_read(inode);
+
+ if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
+ return -EINVAL;
+
+ count = iov_iter_count(from);
+ ret = generic_write_check_limits(file, iocb->ki_pos, &count);
+ if (ret)
+ return ret;
+
+ iov_iter_truncate(from, count);
+ return iov_iter_count(from);
+}
+EXPORT_SYMBOL(generic_write_checks);
+
+/*
+ * 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);
+
+ /* 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;
+
+ if (!(file_in->f_mode & FMODE_READ) ||
+ !(file_out->f_mode & FMODE_WRITE) ||
+ (file_out->f_flags & O_APPEND))
+ return -EBADF;
+
+ return 0;
+}
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 073da53b59b0..8fb063ab7d50 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3012,9 +3012,6 @@ extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *);
extern int generic_write_check_limits(struct file *file, loff_t pos,
loff_t *count);
extern int generic_file_rw_checks(struct file *file_in, struct file *file_out);
-extern int generic_copy_file_checks(struct file *file_in, loff_t pos_in,
- struct file *file_out, loff_t pos_out,
- size_t *count, unsigned int flags);
extern ssize_t generic_file_buffered_read(struct kiocb *iocb,
struct iov_iter *to, ssize_t already_read);
extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
diff --git a/mm/filemap.c b/mm/filemap.c
index cf20e5aeb11b..9962fd682f20 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3093,149 +3093,6 @@ struct page *read_cache_page_gfp(struct address_space *mapping,
}
EXPORT_SYMBOL(read_cache_page_gfp);
-/*
- * 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->f_mapping->host;
- loff_t max_size = inode->i_sb->s_maxbytes;
- loff_t limit = rlimit(RLIMIT_FSIZE);
-
- if (limit != RLIM_INFINITY) {
- if (pos >= limit) {
- send_sig(SIGXFSZ, current, 0);
- return -EFBIG;
- }
- *count = min(*count, limit - pos);
- }
-
- if (!(file->f_flags & O_LARGEFILE))
- max_size = MAX_NON_LFS;
-
- if (unlikely(pos >= max_size))
- return -EFBIG;
-
- *count = min(*count, max_size - pos);
-
- return 0;
-}
-
-/*
- * Performs necessary checks before doing a write
- *
- * 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.
- */
-inline ssize_t generic_write_checks(struct kiocb *iocb, struct iov_iter *from)
-{
- struct file *file = iocb->ki_filp;
- struct inode *inode = file->f_mapping->host;
- loff_t count;
- int ret;
-
- if (IS_SWAPFILE(inode))
- return -ETXTBSY;
-
- if (!iov_iter_count(from))
- return 0;
-
- /* FIXME: this is for backwards compatibility with 2.4 */
- if (iocb->ki_flags & IOCB_APPEND)
- iocb->ki_pos = i_size_read(inode);
-
- if ((iocb->ki_flags & IOCB_NOWAIT) && !(iocb->ki_flags & IOCB_DIRECT))
- return -EINVAL;
-
- count = iov_iter_count(from);
- ret = generic_write_check_limits(file, iocb->ki_pos, &count);
- if (ret)
- return ret;
-
- iov_iter_truncate(from, count);
- return iov_iter_count(from);
-}
-EXPORT_SYMBOL(generic_write_checks);
-
-/*
- * 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);
-
- /* 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;
-
- if (!(file_in->f_mode & FMODE_READ) ||
- !(file_out->f_mode & FMODE_WRITE) ||
- (file_out->f_flags & O_APPEND))
- return -EBADF;
-
- return 0;
-}
-
-/*
- * 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.
- */
-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;
-
- /* 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;
-}
-
int pagecache_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
