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-rw-r--r--Documentation/filesystems/Locking12
-rw-r--r--Documentation/filesystems/porting12
-rw-r--r--Documentation/filesystems/proc.txt21
-rw-r--r--Documentation/filesystems/vfs.txt8
4 files changed, 37 insertions, 16 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index f91926f2f482..0a926e2ba3ab 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -196,7 +196,7 @@ prototypes:
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
- int (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
+ int (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
int (*migratepage)(struct address_space *, struct page *, struct page *);
int (*launder_page)(struct page *);
int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long);
@@ -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/proc.txt b/Documentation/filesystems/proc.txt
index a07ba61662ed..c3b6b301d8b0 100644
--- a/Documentation/filesystems/proc.txt
+++ b/Documentation/filesystems/proc.txt
@@ -200,12 +200,12 @@ contains details information about the process itself. Its fields are
explained in Table 1-4.
(for SMP CONFIG users)
-For making accounting scalable, RSS related information are handled in
-asynchronous manner and the vaule may not be very precise. To see a precise
+For making accounting scalable, RSS related information are handled in an
+asynchronous manner and the value may not be very precise. To see a precise
snapshot of a moment, you can see /proc/<pid>/smaps file and scan page table.
It's slow but very precise.
-Table 1-2: Contents of the status files (as of 2.6.30-rc7)
+Table 1-2: Contents of the status files (as of 3.20.0)
..............................................................................
Field Content
Name filename of the executable
@@ -213,6 +213,7 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
in an uninterruptible wait, Z is zombie,
T is traced or stopped)
Tgid thread group ID
+ Ngid NUMA group ID (0 if none)
Pid process id
PPid process id of the parent process
TracerPid PID of process tracing this process (0 if not)
@@ -220,6 +221,10 @@ Table 1-2: Contents of the status files (as of 2.6.30-rc7)
Gid Real, effective, saved set, and file system GIDs
FDSize number of file descriptor slots currently allocated
Groups supplementary group list
+ NStgid descendant namespace thread group ID hierarchy
+ NSpid descendant namespace process ID hierarchy
+ NSpgid descendant namespace process group ID hierarchy
+ NSsid descendant namespace session ID hierarchy
VmPeak peak virtual memory size
VmSize total program size
VmLck locked memory size
@@ -1255,9 +1260,9 @@ Various pieces of information about kernel activity are available in the
since the system first booted. For a quick look, simply cat the file:
> cat /proc/stat
- cpu 2255 34 2290 22625563 6290 127 456 0 0
- cpu0 1132 34 1441 11311718 3675 127 438 0 0
- cpu1 1123 0 849 11313845 2614 0 18 0 0
+ cpu 2255 34 2290 22625563 6290 127 456 0 0 0
+ cpu0 1132 34 1441 11311718 3675 127 438 0 0 0
+ cpu1 1123 0 849 11313845 2614 0 18 0 0 0
intr 114930548 113199788 3 0 5 263 0 4 [... lots more numbers ...]
ctxt 1990473
btime 1062191376
@@ -1704,6 +1709,10 @@ A typical output is
flags: 0100002
mnt_id: 19
+All locks associated with a file descriptor are shown in its fdinfo too.
+
+lock: 1: FLOCK ADVISORY WRITE 359 00:13:11691 0 EOF
+
The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags
pair provide additional information particular to the objects they represent.
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 966b22829f3b..5d833b32bbcd 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -590,7 +590,7 @@ struct address_space_operations {
void (*invalidatepage) (struct page *, unsigned int, unsigned int);
int (*releasepage) (struct page *, int);
void (*freepage)(struct page *);
- ssize_t (*direct_IO)(int, struct kiocb *, struct iov_iter *iter, loff_t offset);
+ ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter, loff_t offset);
/* migrate the contents of a page to the specified target */
int (*migratepage) (struct page *, struct page *);
int (*launder_page) (struct page *);
@@ -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