diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 12 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 6 |
3 files changed, 20 insertions, 8 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index f91926f2f482..7c3f187d48bf 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -429,8 +429,6 @@ prototypes: loff_t (*llseek) (struct file *, loff_t, int); ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); - ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); - ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); int (*iterate) (struct file *, struct dir_context *); @@ -525,6 +523,7 @@ prototypes: void (*close)(struct vm_area_struct*); int (*fault)(struct vm_area_struct*, struct vm_fault *); int (*page_mkwrite)(struct vm_area_struct *, struct vm_fault *); + int (*pfn_mkwrite)(struct vm_area_struct *, struct vm_fault *); int (*access)(struct vm_area_struct *, unsigned long, void*, int, int); locking rules: @@ -534,6 +533,7 @@ close: yes fault: yes can return with page locked map_pages: yes page_mkwrite: yes can return with page locked +pfn_mkwrite: yes access: yes ->fault() is called when a previously not present pte is about @@ -560,6 +560,12 @@ the page has been truncated, the filesystem should not look up a new page like the ->fault() handler, but simply return with VM_FAULT_NOPAGE, which will cause the VM to retry the fault. + ->pfn_mkwrite() is the same as page_mkwrite but when the pte is +VM_PFNMAP or VM_MIXEDMAP with a page-less entry. Expected return is +VM_FAULT_NOPAGE. Or one of the VM_FAULT_ERROR types. The default behavior +after this call is to make the pte read-write, unless pfn_mkwrite returns +an error. + ->access() is called when get_user_pages() fails in access_process_vm(), typically used to debug a process through /proc/pid/mem or ptrace. This function is needed only for diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index fa2db081505e..e69274de8d0c 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -471,3 +471,15 @@ in your dentry operations instead. [mandatory] f_dentry is gone; use f_path.dentry, or, better yet, see if you can avoid it entirely. +-- +[mandatory] + never call ->read() and ->write() directly; use __vfs_{read,write} or + wrappers; instead of checking for ->write or ->read being NULL, look for + FMODE_CAN_{WRITE,READ} in file->f_mode. +-- +[mandatory] + do _not_ use new_sync_{read,write} for ->read/->write; leave it NULL + instead. +-- +[mandatory] + ->aio_read/->aio_write are gone. Use ->read_iter/->write_iter. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 966b22829f3b..207cdca68bed 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -804,8 +804,6 @@ struct file_operations { loff_t (*llseek) (struct file *, loff_t, int); ssize_t (*read) (struct file *, char __user *, size_t, loff_t *); ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *); - ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); - ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); ssize_t (*read_iter) (struct kiocb *, struct iov_iter *); ssize_t (*write_iter) (struct kiocb *, struct iov_iter *); int (*iterate) (struct file *, struct dir_context *); @@ -838,14 +836,10 @@ otherwise noted. read: called by read(2) and related system calls - aio_read: vectored, possibly asynchronous read - read_iter: possibly asynchronous read with iov_iter as destination write: called by write(2) and related system calls - aio_write: vectored, possibly asynchronous write - write_iter: possibly asynchronous write with iov_iter as source iterate: called when the VFS needs to read the directory contents |