summaryrefslogtreecommitdiff
path: root/fs/fuse/file.c
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:22:09 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-12-12 20:22:09 -0800
commit043930b1c8895d626d340decfe9e418f7233edb8 (patch)
treea13edba88cfd63bce2f5c68f8e39182283a4a8b0 /fs/fuse/file.c
parent6df7cc2268745e91d090830c58689aa7fcbde6f9 (diff)
parentb138777786f780b9d5ce1989032608acbede0493 (diff)
Merge tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse update from Miklos Szeredi: - Allow some write requests to proceed in parallel - Fix a performance problem with allow_sys_admin_access - Add a special kind of invalidation that doesn't immediately purge submounts - On revalidation treat the target of rename(RENAME_NOREPLACE) the same as open(O_EXCL) - Use type safe helpers for some mnt_userns transformations * tag 'fuse-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: Rearrange fuse_allow_current_process checks fuse: allow non-extending parallel direct writes on the same file fuse: remove the unneeded result variable fuse: port to vfs{g,u}id_t and associated helpers fuse: Remove user_ns check for FUSE_DEV_IOC_CLONE fuse: always revalidate rename target dentry fuse: add "expire only" mode to FUSE_NOTIFY_INVAL_ENTRY fs/fuse: Replace kmap() with kmap_local_page()
Diffstat (limited to 'fs/fuse/file.c')
-rw-r--r--fs/fuse/file.c43
1 files changed, 40 insertions, 3 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index c996c0ef8c63..875314ee6f59 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -1563,14 +1563,47 @@ static ssize_t fuse_direct_read_iter(struct kiocb *iocb, struct iov_iter *to)
return res;
}
+static bool fuse_direct_write_extending_i_size(struct kiocb *iocb,
+ struct iov_iter *iter)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+
+ return iocb->ki_pos + iov_iter_count(iter) > i_size_read(inode);
+}
+
static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct inode *inode = file_inode(iocb->ki_filp);
+ struct file *file = iocb->ki_filp;
+ struct fuse_file *ff = file->private_data;
struct fuse_io_priv io = FUSE_IO_PRIV_SYNC(iocb);
ssize_t res;
+ bool exclusive_lock =
+ !(ff->open_flags & FOPEN_PARALLEL_DIRECT_WRITES) ||
+ iocb->ki_flags & IOCB_APPEND ||
+ fuse_direct_write_extending_i_size(iocb, from);
+
+ /*
+ * Take exclusive lock if
+ * - Parallel direct writes are disabled - a user space decision
+ * - Parallel direct writes are enabled and i_size is being extended.
+ * This might not be needed at all, but needs further investigation.
+ */
+ if (exclusive_lock)
+ inode_lock(inode);
+ else {
+ inode_lock_shared(inode);
+
+ /* A race with truncate might have come up as the decision for
+ * the lock type was done without holding the lock, check again.
+ */
+ if (fuse_direct_write_extending_i_size(iocb, from)) {
+ inode_unlock_shared(inode);
+ inode_lock(inode);
+ exclusive_lock = true;
+ }
+ }
- /* Don't allow parallel writes to the same file */
- inode_lock(inode);
res = generic_write_checks(iocb, from);
if (res > 0) {
if (!is_sync_kiocb(iocb) && iocb->ki_flags & IOCB_DIRECT) {
@@ -1581,7 +1614,10 @@ static ssize_t fuse_direct_write_iter(struct kiocb *iocb, struct iov_iter *from)
fuse_write_update_attr(inode, iocb->ki_pos, res);
}
}
- inode_unlock(inode);
+ if (exclusive_lock)
+ inode_unlock(inode);
+ else
+ inode_unlock_shared(inode);
return res;
}
@@ -2931,6 +2967,7 @@ fuse_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
if (iov_iter_rw(iter) == WRITE) {
fuse_write_update_attr(inode, pos, ret);
+ /* For extending writes we already hold exclusive lock */
if (ret < 0 && offset + count > i_size)
fuse_do_truncate(file);
}