From 2e3b37a7e48f8a52fb708cdbeec9d8af0a5af0c1 Mon Sep 17 00:00:00 2001 From: Lorenzo Stoakes Date: Mon, 16 Jun 2025 20:33:29 +0100 Subject: fs: replace mmap hook with .mmap_prepare for simple mappings Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file callback"), the f_op->mmap() hook has been deprecated in favour of f_op->mmap_prepare(). This callback is invoked in the mmap() logic far earlier, so error handling can be performed more safely without complicated and bug-prone state unwinding required should an error arise. This hook also avoids passing a pointer to a not-yet-correctly-established VMA avoiding any issues with referencing this data structure. It rather provides a pointer to the new struct vm_area_desc descriptor type which contains all required state and allows easy setting of required parameters without any consideration needing to be paid to locking or reference counts. Note that nested filesystems like overlayfs are compatible with an .mmap_prepare() callback since commit bb666b7c2707 ("mm: add mmap_prepare() compatibility layer for nested file systems"). In this patch we apply this change to file systems with relatively simple mmap() hook logic - exfat, ceph, f2fs, bcachefs, zonefs, btrfs, ocfs2, orangefs, nilfs2, romfs, ramfs and aio. Signed-off-by: Lorenzo Stoakes Link: https://lore.kernel.org/f528ac4f35b9378931bd800920fee53fc0c5c74d.1750099179.git.lorenzo.stoakes@oracle.com Acked-by: Damien Le Moal Reviewed-by: Jan Kara Reviewed-by: Viacheslav Dubeyko Signed-off-by: Christian Brauner --- fs/ocfs2/file.c | 4 ++-- fs/ocfs2/mmap.c | 5 +++-- fs/ocfs2/mmap.h | 2 +- 3 files changed, 6 insertions(+), 5 deletions(-) (limited to 'fs/ocfs2') diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 2056cf08ac1e..21d797ccccd0 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2800,7 +2800,7 @@ const struct inode_operations ocfs2_special_file_iops = { */ const struct file_operations ocfs2_fops = { .llseek = ocfs2_file_llseek, - .mmap = ocfs2_mmap, + .mmap_prepare = ocfs2_mmap_prepare, .fsync = ocfs2_sync_file, .release = ocfs2_file_release, .open = ocfs2_file_open, @@ -2850,7 +2850,7 @@ const struct file_operations ocfs2_dops = { */ const struct file_operations ocfs2_fops_no_plocks = { .llseek = ocfs2_file_llseek, - .mmap = ocfs2_mmap, + .mmap_prepare = ocfs2_mmap_prepare, .fsync = ocfs2_sync_file, .release = ocfs2_file_release, .open = ocfs2_file_open, diff --git a/fs/ocfs2/mmap.c b/fs/ocfs2/mmap.c index 6a314e9f2b49..50e2faf64c19 100644 --- a/fs/ocfs2/mmap.c +++ b/fs/ocfs2/mmap.c @@ -159,8 +159,9 @@ static const struct vm_operations_struct ocfs2_file_vm_ops = { .page_mkwrite = ocfs2_page_mkwrite, }; -int ocfs2_mmap(struct file *file, struct vm_area_struct *vma) +int ocfs2_mmap_prepare(struct vm_area_desc *desc) { + struct file *file = desc->file; int ret = 0, lock_level = 0; ret = ocfs2_inode_lock_atime(file_inode(file), @@ -171,7 +172,7 @@ int ocfs2_mmap(struct file *file, struct vm_area_struct *vma) } ocfs2_inode_unlock(file_inode(file), lock_level); out: - vma->vm_ops = &ocfs2_file_vm_ops; + desc->vm_ops = &ocfs2_file_vm_ops; return 0; } diff --git a/fs/ocfs2/mmap.h b/fs/ocfs2/mmap.h index 1051507cc684..d21c30de6b8c 100644 --- a/fs/ocfs2/mmap.h +++ b/fs/ocfs2/mmap.h @@ -2,6 +2,6 @@ #ifndef OCFS2_MMAP_H #define OCFS2_MMAP_H -int ocfs2_mmap(struct file *file, struct vm_area_struct *vma); +int ocfs2_mmap_prepare(struct vm_area_desc *desc); #endif /* OCFS2_MMAP_H */ -- cgit v1.2.3