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Diffstat (limited to 'fs/btrfs/file.c')
-rw-r--r--fs/btrfs/file.c144
1 files changed, 44 insertions, 100 deletions
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index fde125616687..b0d2c976587e 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1533,7 +1533,7 @@ lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
}
static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
- size_t *write_bytes)
+ size_t *write_bytes, bool nowait)
{
struct btrfs_fs_info *fs_info = inode->root->fs_info;
struct btrfs_root *root = inode->root;
@@ -1541,27 +1541,43 @@ static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
u64 num_bytes;
int ret;
- if (!btrfs_drew_try_write_lock(&root->snapshot_lock))
+ if (!nowait && !btrfs_drew_try_write_lock(&root->snapshot_lock))
return -EAGAIN;
lockstart = round_down(pos, fs_info->sectorsize);
lockend = round_up(pos + *write_bytes,
fs_info->sectorsize) - 1;
+ num_bytes = lockend - lockstart + 1;
- btrfs_lock_and_flush_ordered_range(inode, lockstart,
- lockend, NULL);
+ if (nowait) {
+ struct btrfs_ordered_extent *ordered;
+
+ if (!try_lock_extent(&inode->io_tree, lockstart, lockend))
+ return -EAGAIN;
+
+ ordered = btrfs_lookup_ordered_range(inode, lockstart,
+ num_bytes);
+ if (ordered) {
+ btrfs_put_ordered_extent(ordered);
+ ret = -EAGAIN;
+ goto out_unlock;
+ }
+ } else {
+ btrfs_lock_and_flush_ordered_range(inode, lockstart,
+ lockend, NULL);
+ }
- num_bytes = lockend - lockstart + 1;
ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
NULL, NULL, NULL);
if (ret <= 0) {
ret = 0;
- btrfs_drew_write_unlock(&root->snapshot_lock);
+ if (!nowait)
+ btrfs_drew_write_unlock(&root->snapshot_lock);
} else {
*write_bytes = min_t(size_t, *write_bytes ,
num_bytes - pos + lockstart);
}
-
+out_unlock:
unlock_extent(&inode->io_tree, lockstart, lockend);
return ret;
@@ -1633,7 +1649,7 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
BTRFS_INODE_PREALLOC)) &&
check_can_nocow(BTRFS_I(inode), pos,
- &write_bytes) > 0) {
+ &write_bytes, false) > 0) {
/*
* For nodata cow case, no need to reserve
* data space.
@@ -1809,61 +1825,21 @@ again:
return num_written ? num_written : ret;
}
-static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
- const struct iov_iter *iter, loff_t offset)
-{
- const unsigned int blocksize_mask = fs_info->sectorsize - 1;
-
- if (offset & blocksize_mask)
- return -EINVAL;
-
- if (iov_iter_alignment(iter) & blocksize_mask)
- return -EINVAL;
-
- return 0;
-}
-
-static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
- struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
- loff_t pos = iocb->ki_pos;
- ssize_t written = 0;
+ loff_t pos;
+ ssize_t written;
ssize_t written_buffered;
loff_t endbyte;
int err;
- size_t count = 0;
- bool relock = false;
-
- if (check_direct_IO(fs_info, from, pos))
- goto buffered;
-
- count = iov_iter_count(from);
- /*
- * If the write DIO is beyond the EOF, we need update the isize, but it
- * is protected by i_mutex. So we can not unlock the i_mutex at this
- * case.
- */
- if (pos + count <= inode->i_size) {
- inode_unlock(inode);
- relock = true;
- } else if (iocb->ki_flags & IOCB_NOWAIT) {
- return -EAGAIN;
- }
-
- down_read(&BTRFS_I(inode)->dio_sem);
- written = iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dops,
- is_sync_kiocb(iocb));
- up_read(&BTRFS_I(inode)->dio_sem);
- if (relock)
- inode_lock(inode);
+ written = generic_file_direct_write(iocb, from);
if (written < 0 || !iov_iter_count(from))
return written;
-buffered:
pos = iocb->ki_pos;
written_buffered = btrfs_buffered_write(iocb, from);
if (written_buffered < 0) {
@@ -1944,13 +1920,25 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
pos = iocb->ki_pos;
count = iov_iter_count(from);
if (iocb->ki_flags & IOCB_NOWAIT) {
+ size_t nocow_bytes = count;
+
/*
* We will allocate space in case nodatacow is not set,
* so bail
*/
if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
BTRFS_INODE_PREALLOC)) ||
- check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
+ check_can_nocow(BTRFS_I(inode), pos, &nocow_bytes,
+ true) <= 0) {
+ inode_unlock(inode);
+ return -EAGAIN;
+ }
+ /*
+ * There are holes in the range or parts of the range that must
+ * be COWed (shared extents, RO block groups, etc), so just bail
+ * out.
+ */
+ if (nocow_bytes < count) {
inode_unlock(inode);
return -EAGAIN;
}
@@ -2002,7 +1990,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
atomic_inc(&BTRFS_I(inode)->sync_writers);
if (iocb->ki_flags & IOCB_DIRECT) {
- num_written = btrfs_direct_write(iocb, from);
+ num_written = __btrfs_direct_write(iocb, from);
} else {
num_written = btrfs_buffered_write(iocb, from);
if (num_written > 0)
@@ -3516,56 +3504,12 @@ static int btrfs_file_open(struct inode *inode, struct file *filp)
return generic_file_open(inode, filp);
}
-static int check_direct_read(struct btrfs_fs_info *fs_info,
- const struct iov_iter *iter, loff_t offset)
-{
- int ret;
- int i, seg;
-
- ret = check_direct_IO(fs_info, iter, offset);
- if (ret < 0)
- return ret;
-
- for (seg = 0; seg < iter->nr_segs; seg++)
- for (i = seg + 1; i < iter->nr_segs; i++)
- if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
- return -EINVAL;
- return 0;
-}
-
-static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to)
-{
- struct inode *inode = file_inode(iocb->ki_filp);
- ssize_t ret;
-
- if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
- return 0;
-
- inode_lock_shared(inode);
- ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dops,
- is_sync_kiocb(iocb));
- inode_unlock_shared(inode);
- return ret;
-}
-
-static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
-{
- ssize_t ret = 0;
-
- if (iocb->ki_flags & IOCB_DIRECT) {
- ret = btrfs_direct_read(iocb, to);
- if (ret < 0)
- return ret;
- }
-
- return generic_file_buffered_read(iocb, to, ret);
-}
-
const struct file_operations btrfs_file_operations = {
.llseek = btrfs_file_llseek,
- .read_iter = btrfs_file_read_iter,
+ .read_iter = generic_file_read_iter,
.splice_read = generic_file_splice_read,
.write_iter = btrfs_file_write_iter,
+ .splice_write = iter_file_splice_write,
.mmap = btrfs_file_mmap,
.open = btrfs_file_open,
.release = btrfs_release_file,
generated by cgit v1.2.3 (git 2.51.0) at 2025-09-26 04:26:20 +0000