[PATCH v2 15/16] gfs2: add pre-content fsnotify hook to fault

Josef Bacik
2024-08-08T19:28:36Z

gfs2 takes the glock before calling into filemap fault, so add the
fsnotify hook for ->fault before we take the glock in order to avoid any
possible deadlock with the HSM.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/gfs2/file.c | 13 +++++++++++++
1 file changed, 13 insertions(+)

diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c
index 08982937b5df..b841b1720b5c 100644
--- a/fs/gfs2/file.c
+++ b/fs/gfs2/file.c
@@ -553,9 +553,22 @@ static vm_fault_t gfs2_fault(struct vm_fault *vmf)
struct inode *inode = file_inode(vmf->vma->vm_file);
struct gfs2_inode *ip = GFS2_I(inode);
struct gfs2_holder gh;
+ struct file *fpin = NULL;
vm_fault_t ret;
int err;

+ ret = filemap_maybe_emit_fsnotify_event(vmf, &fpin);
+ if (unlikely(ret)) {
+ if (fpin) {
+ fput(fpin);
+ ret |= VM_FAULT_RETRY;
+ }
+ return ret;
+ } else if (fpin) {
+ fput(fpin);
+ return VM_FAULT_RETRY;
+ }
+
gfs2_holder_init(ip->i_gl, LM_ST_SHARED, 0, &gh);
err = gfs2_glock_nq(&gh);
if (err) {
--
2.43.0