diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 12 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 12 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 21 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 8 |
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 |