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Diffstat (limited to 'fs/btrfs/file.c')
-rw-r--r--fs/btrfs/file.c166
1 files changed, 102 insertions, 64 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 29ff749ff4ca..79437c5eeb1e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -46,32 +46,42 @@
static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
int write_bytes,
struct page **prepared_pages,
- const char __user *buf)
+ struct iov_iter *i)
{
- long page_fault = 0;
- int i;
+ size_t copied;
+ int pg = 0;
int offset = pos & (PAGE_CACHE_SIZE - 1);
- for (i = 0; i < num_pages && write_bytes > 0; i++, offset = 0) {
+ while (write_bytes > 0) {
size_t count = min_t(size_t,
PAGE_CACHE_SIZE - offset, write_bytes);
- struct page *page = prepared_pages[i];
- fault_in_pages_readable(buf, count);
+ struct page *page = prepared_pages[pg];
+again:
+ if (unlikely(iov_iter_fault_in_readable(i, count)))
+ return -EFAULT;
/* Copy data from userspace to the current page */
- kmap(page);
- page_fault = __copy_from_user(page_address(page) + offset,
- buf, count);
+ copied = iov_iter_copy_from_user(page, i, offset, count);
+
/* Flush processor's dcache for this page */
flush_dcache_page(page);
- kunmap(page);
- buf += count;
- write_bytes -= count;
+ iov_iter_advance(i, copied);
+ write_bytes -= copied;
- if (page_fault)
- break;
+ if (unlikely(copied == 0)) {
+ count = min_t(size_t, PAGE_CACHE_SIZE - offset,
+ iov_iter_single_seg_count(i));
+ goto again;
+ }
+
+ if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
+ offset += copied;
+ } else {
+ pg++;
+ offset = 0;
+ }
}
- return page_fault ? -EFAULT : 0;
+ return 0;
}
/*
@@ -126,8 +136,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
end_of_last_block = start_pos + num_bytes - 1;
err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
NULL);
- if (err)
- return err;
+ BUG_ON(err);
for (i = 0; i < num_pages; i++) {
struct page *p = pages[i];
@@ -142,7 +151,7 @@ static noinline int dirty_and_release_pages(struct btrfs_trans_handle *trans,
* at this time.
*/
}
- return err;
+ return 0;
}
/*
@@ -823,45 +832,46 @@ again:
return 0;
}
-static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
- size_t count, loff_t *ppos)
+static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
+ const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
{
- loff_t pos;
+ struct file *file = iocb->ki_filp;
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct page *pinned[2];
+ struct page **pages = NULL;
+ struct iov_iter i;
+ loff_t *ppos = &iocb->ki_pos;
loff_t start_pos;
ssize_t num_written = 0;
ssize_t err = 0;
+ size_t count;
+ size_t ocount;
int ret = 0;
- struct inode *inode = fdentry(file)->d_inode;
- struct btrfs_root *root = BTRFS_I(inode)->root;
- struct page **pages = NULL;
int nrptrs;
- struct page *pinned[2];
unsigned long first_index;
unsigned long last_index;
int will_write;
+ int buffered = 0;
will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) ||
(file->f_flags & O_DIRECT));
- nrptrs = min((count + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE,
- PAGE_CACHE_SIZE / (sizeof(struct page *)));
pinned[0] = NULL;
pinned[1] = NULL;
- pos = *ppos;
start_pos = pos;
vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
- /* do the reserve before the mutex lock in case we have to do some
- * flushing. We wouldn't deadlock, but this is more polite.
- */
- err = btrfs_reserve_metadata_for_delalloc(root, inode, 1);
- if (err)
- goto out_nolock;
-
mutex_lock(&inode->i_mutex);
+ err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
+ if (err)
+ goto out;
+ count = ocount;
+
current->backing_dev_info = inode->i_mapping->backing_dev_info;
err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
if (err)
@@ -875,15 +885,53 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
goto out;
file_update_time(file);
+ BTRFS_I(inode)->sequence++;
+
+ if (unlikely(file->f_flags & O_DIRECT)) {
+ num_written = generic_file_direct_write(iocb, iov, &nr_segs,
+ pos, ppos, count,
+ ocount);
+ /*
+ * the generic O_DIRECT will update in-memory i_size after the
+ * DIOs are done. But our endio handlers that update the on
+ * disk i_size never update past the in memory i_size. So we
+ * need one more update here to catch any additions to the
+ * file
+ */
+ if (inode->i_size != BTRFS_I(inode)->disk_i_size) {
+ btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
+ mark_inode_dirty(inode);
+ }
+ if (num_written < 0) {
+ ret = num_written;
+ num_written = 0;
+ goto out;
+ } else if (num_written == count) {
+ /* pick up pos changes done by the generic code */
+ pos = *ppos;
+ goto out;
+ }
+ /*
+ * We are going to do buffered for the rest of the range, so we
+ * need to make sure to invalidate the buffered pages when we're
+ * done.
+ */
+ buffered = 1;
+ pos += num_written;
+ }
+
+ iov_iter_init(&i, iov, nr_segs, count, num_written);
+ nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) /
+ PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
+ (sizeof(struct page *)));
pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
/* generic_write_checks can change our pos */
start_pos = pos;
- BTRFS_I(inode)->sequence++;
first_index = pos >> PAGE_CACHE_SHIFT;
- last_index = (pos + count) >> PAGE_CACHE_SHIFT;
+ last_index = (pos + iov_iter_count(&i)) >> PAGE_CACHE_SHIFT;
/*
* there are lots of better ways to do this, but this code
@@ -900,7 +948,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
unlock_page(pinned[0]);
}
}
- if ((pos + count) & (PAGE_CACHE_SIZE - 1)) {
+ if ((pos + iov_iter_count(&i)) & (PAGE_CACHE_SIZE - 1)) {
pinned[1] = grab_cache_page(inode->i_mapping, last_index);
if (!PageUptodate(pinned[1])) {
ret = btrfs_readpage(NULL, pinned[1]);
@@ -911,10 +959,10 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
}
}
- while (count > 0) {
+ while (iov_iter_count(&i) > 0) {
size_t offset = pos & (PAGE_CACHE_SIZE - 1);
- size_t write_bytes = min(count, nrptrs *
- (size_t)PAGE_CACHE_SIZE -
+ size_t write_bytes = min(iov_iter_count(&i),
+ nrptrs * (size_t)PAGE_CACHE_SIZE -
offset);
size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
PAGE_CACHE_SHIFT;
@@ -922,7 +970,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
WARN_ON(num_pages > nrptrs);
memset(pages, 0, sizeof(struct page *) * nrptrs);
- ret = btrfs_check_data_free_space(root, inode, write_bytes);
+ ret = btrfs_delalloc_reserve_space(inode, write_bytes);
if (ret)
goto out;
@@ -930,26 +978,20 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
pos, first_index, last_index,
write_bytes);
if (ret) {
- btrfs_free_reserved_data_space(root, inode,
- write_bytes);
+ btrfs_delalloc_release_space(inode, write_bytes);
goto out;
}
ret = btrfs_copy_from_user(pos, num_pages,
- write_bytes, pages, buf);
- if (ret) {
- btrfs_free_reserved_data_space(root, inode,
- write_bytes);
- btrfs_drop_pages(pages, num_pages);
- goto out;
+ write_bytes, pages, &i);
+ if (ret == 0) {
+ dirty_and_release_pages(NULL, root, file, pages,
+ num_pages, pos, write_bytes);
}
- ret = dirty_and_release_pages(NULL, root, file, pages,
- num_pages, pos, write_bytes);
btrfs_drop_pages(pages, num_pages);
if (ret) {
- btrfs_free_reserved_data_space(root, inode,
- write_bytes);
+ btrfs_delalloc_release_space(inode, write_bytes);
goto out;
}
@@ -965,8 +1007,6 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
btrfs_throttle(root);
}
- buf += write_bytes;
- count -= write_bytes;
pos += write_bytes;
num_written += write_bytes;
@@ -976,9 +1016,7 @@ out:
mutex_unlock(&inode->i_mutex);
if (ret)
err = ret;
- btrfs_unreserve_metadata_for_delalloc(root, inode, 1);
-out_nolock:
kfree(pages);
if (pinned[0])
page_cache_release(pinned[0]);
@@ -1008,7 +1046,7 @@ out_nolock:
num_written = err;
if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
- trans = btrfs_start_transaction(root, 1);
+ trans = btrfs_start_transaction(root, 0);
ret = btrfs_log_dentry_safe(trans, root,
file->f_dentry);
if (ret == 0) {
@@ -1023,7 +1061,7 @@ out_nolock:
btrfs_end_transaction(trans, root);
}
}
- if (file->f_flags & O_DIRECT) {
+ if (file->f_flags & O_DIRECT && buffered) {
invalidate_mapping_pages(inode->i_mapping,
start_pos >> PAGE_CACHE_SHIFT,
(start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
@@ -1104,9 +1142,9 @@ int btrfs_sync_file(struct file *file, struct dentry *dentry, int datasync)
if (file && file->private_data)
btrfs_ioctl_trans_end(file);
- trans = btrfs_start_transaction(root, 1);
- if (!trans) {
- ret = -ENOMEM;
+ trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
goto out;
}
@@ -1161,7 +1199,7 @@ const struct file_operations btrfs_file_operations = {
.read = do_sync_read,
.aio_read = generic_file_aio_read,
.splice_read = generic_file_splice_read,
- .write = btrfs_file_write,
+ .aio_write = btrfs_file_aio_write,
.mmap = btrfs_file_mmap,
.open = generic_file_open,
.release = btrfs_release_file,