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-rw-r--r--mm/filemap.c158
1 files changed, 42 insertions, 116 deletions
diff --git a/mm/filemap.c b/mm/filemap.c
index 7fadf1c62838..dafb06f70a09 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -1665,96 +1665,42 @@ out:
return written ? written : error;
}
-/*
- * Performs necessary checks before doing a write
- * @iov: io vector request
- * @nr_segs: number of segments in the iovec
- * @count: number of bytes to write
- * @access_flags: type of access: %VERIFY_READ or %VERIFY_WRITE
- *
- * Adjust number of segments and amount of bytes to write (nr_segs should be
- * properly initialized first). Returns appropriate error code that caller
- * should return or zero in case that write should be allowed.
- */
-int generic_segment_checks(const struct iovec *iov,
- unsigned long *nr_segs, size_t *count, int access_flags)
-{
- unsigned long seg;
- size_t cnt = 0;
- for (seg = 0; seg < *nr_segs; seg++) {
- const struct iovec *iv = &iov[seg];
-
- /*
- * If any segment has a negative length, or the cumulative
- * length ever wraps negative then return -EINVAL.
- */
- cnt += iv->iov_len;
- if (unlikely((ssize_t)(cnt|iv->iov_len) < 0))
- return -EINVAL;
- if (access_ok(access_flags, iv->iov_base, iv->iov_len))
- continue;
- if (seg == 0)
- return -EFAULT;
- *nr_segs = seg;
- cnt -= iv->iov_len; /* This segment is no good */
- break;
- }
- *count = cnt;
- return 0;
-}
-EXPORT_SYMBOL(generic_segment_checks);
-
/**
- * generic_file_aio_read - generic filesystem read routine
+ * generic_file_read_iter - generic filesystem read routine
* @iocb: kernel I/O control block
- * @iov: io vector request
- * @nr_segs: number of segments in the iovec
- * @pos: current file position
+ * @iter: destination for the data read
*
- * This is the "read()" routine for all filesystems
+ * This is the "read_iter()" routine for all filesystems
* that can use the page cache directly.
*/
ssize_t
-generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
- struct file *filp = iocb->ki_filp;
- ssize_t retval;
- size_t count;
+ struct file *file = iocb->ki_filp;
+ ssize_t retval = 0;
loff_t *ppos = &iocb->ki_pos;
- struct iov_iter i;
-
- count = 0;
- retval = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
- if (retval)
- return retval;
- iov_iter_init(&i, iov, nr_segs, count, 0);
+ loff_t pos = *ppos;
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
- if (filp->f_flags & O_DIRECT) {
+ if (file->f_flags & O_DIRECT) {
+ struct address_space *mapping = file->f_mapping;
+ struct inode *inode = mapping->host;
+ size_t count = iov_iter_count(iter);
loff_t size;
- struct address_space *mapping;
- struct inode *inode;
- mapping = filp->f_mapping;
- inode = mapping->host;
if (!count)
goto out; /* skip atime */
size = i_size_read(inode);
retval = filemap_write_and_wait_range(mapping, pos,
- pos + iov_length(iov, nr_segs) - 1);
+ pos + count - 1);
if (!retval) {
- retval = mapping->a_ops->direct_IO(READ, iocb,
- iov, pos, nr_segs);
+ struct iov_iter data = *iter;
+ retval = mapping->a_ops->direct_IO(READ, iocb, &data, pos);
}
+
if (retval > 0) {
*ppos = pos + retval;
- count -= retval;
- /*
- * If we did a short DIO read we need to skip the
- * section of the iov that we've already read data into.
- */
- iov_iter_advance(&i, retval);
+ iov_iter_advance(iter, retval);
}
/*
@@ -1765,17 +1711,17 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
* and return. Otherwise fallthrough to buffered io for
* the rest of the read.
*/
- if (retval < 0 || !count || *ppos >= size) {
- file_accessed(filp);
+ if (retval < 0 || !iov_iter_count(iter) || *ppos >= size) {
+ file_accessed(file);
goto out;
}
}
- retval = do_generic_file_read(filp, ppos, &i, retval);
+ retval = do_generic_file_read(file, ppos, iter, retval);
out:
return retval;
}
-EXPORT_SYMBOL(generic_file_aio_read);
+EXPORT_SYMBOL(generic_file_read_iter);
#ifdef CONFIG_MMU
/**
@@ -2386,9 +2332,7 @@ int pagecache_write_end(struct file *file, struct address_space *mapping,
EXPORT_SYMBOL(pagecache_write_end);
ssize_t
-generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long *nr_segs, loff_t pos,
- size_t count, size_t ocount)
+generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
@@ -2396,11 +2340,9 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
ssize_t written;
size_t write_len;
pgoff_t end;
+ struct iov_iter data;
- if (count != ocount)
- *nr_segs = iov_shorten((struct iovec *)iov, *nr_segs, count);
-
- write_len = iov_length(iov, *nr_segs);
+ write_len = iov_iter_count(from);
end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT;
written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1);
@@ -2427,7 +2369,8 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
}
}
- written = mapping->a_ops->direct_IO(WRITE, iocb, iov, pos, *nr_segs);
+ data = *from;
+ written = mapping->a_ops->direct_IO(WRITE, iocb, &data, pos);
/*
* Finally, try again to invalidate clean pages which might have been
@@ -2444,6 +2387,7 @@ generic_file_direct_write(struct kiocb *iocb, const struct iovec *iov,
if (written > 0) {
pos += written;
+ iov_iter_advance(from, written);
if (pos > i_size_read(inode) && !S_ISBLK(inode->i_mode)) {
i_size_write(inode, pos);
mark_inode_dirty(inode);
@@ -2568,10 +2512,9 @@ again:
EXPORT_SYMBOL(generic_perform_write);
/**
- * __generic_file_aio_write - write data to a file
+ * __generic_file_write_iter - write data to a file
* @iocb: IO state structure (file, offset, etc.)
- * @iov: vector with data to write
- * @nr_segs: number of segments in the vector
+ * @from: iov_iter with data to write
*
* This function does all the work needed for actually writing data to a
* file. It does all basic checks, removes SUID from the file, updates
@@ -2585,26 +2528,16 @@ EXPORT_SYMBOL(generic_perform_write);
* A caller has to handle it. This is mainly due to the fact that we want to
* avoid syncing under i_mutex.
*/
-ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs)
+ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct address_space * mapping = file->f_mapping;
- size_t ocount; /* original count */
- size_t count; /* after file limit checks */
struct inode *inode = mapping->host;
loff_t pos = iocb->ki_pos;
ssize_t written = 0;
ssize_t err;
ssize_t status;
- struct iov_iter from;
-
- ocount = 0;
- err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
- if (err)
- return err;
-
- count = ocount;
+ size_t count = iov_iter_count(from);
/* We can write back this queue in page reclaim */
current->backing_dev_info = mapping->backing_dev_info;
@@ -2615,6 +2548,8 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
if (count == 0)
goto out;
+ iov_iter_truncate(from, count);
+
err = file_remove_suid(file);
if (err)
goto out;
@@ -2623,17 +2558,13 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
if (err)
goto out;
- iov_iter_init(&from, iov, nr_segs, count, 0);
-
/* coalesce the iovecs and go direct-to-BIO for O_DIRECT */
if (unlikely(file->f_flags & O_DIRECT)) {
loff_t endbyte;
- written = generic_file_direct_write(iocb, iov, &from.nr_segs, pos,
- count, ocount);
+ written = generic_file_direct_write(iocb, from, pos);
if (written < 0 || written == count)
goto out;
- iov_iter_advance(&from, written);
/*
* direct-io write to a hole: fall through to buffered I/O
@@ -2642,7 +2573,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
pos += written;
count -= written;
- status = generic_perform_write(file, &from, pos);
+ status = generic_perform_write(file, from, pos);
/*
* If generic_perform_write() returned a synchronous error
* then we want to return the number of bytes which were
@@ -2674,7 +2605,7 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
*/
}
} else {
- written = generic_perform_write(file, &from, pos);
+ written = generic_perform_write(file, from, pos);
if (likely(written >= 0))
iocb->ki_pos = pos + written;
}
@@ -2682,30 +2613,25 @@ out:
current->backing_dev_info = NULL;
return written ? written : err;
}
-EXPORT_SYMBOL(__generic_file_aio_write);
+EXPORT_SYMBOL(__generic_file_write_iter);
/**
- * generic_file_aio_write - write data to a file
+ * generic_file_write_iter - write data to a file
* @iocb: IO state structure
- * @iov: vector with data to write
- * @nr_segs: number of segments in the vector
- * @pos: position in file where to write
+ * @from: iov_iter with data to write
*
- * This is a wrapper around __generic_file_aio_write() to be used by most
+ * This is a wrapper around __generic_file_write_iter() to be used by most
* filesystems. It takes care of syncing the file in case of O_SYNC file
* and acquires i_mutex as needed.
*/
-ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
- unsigned long nr_segs, loff_t pos)
+ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
ssize_t ret;
- BUG_ON(iocb->ki_pos != pos);
-
mutex_lock(&inode->i_mutex);
- ret = __generic_file_aio_write(iocb, iov, nr_segs);
+ ret = __generic_file_write_iter(iocb, from);
mutex_unlock(&inode->i_mutex);
if (ret > 0) {
@@ -2717,7 +2643,7 @@ ssize_t generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
}
return ret;
}
-EXPORT_SYMBOL(generic_file_aio_write);
+EXPORT_SYMBOL(generic_file_write_iter);
/**
* try_to_release_page() - release old fs-specific metadata on a page