From 15eb42d674de8da66950f78b5c7202accabe026e Mon Sep 17 00:00:00 2001 From: Nathan Scott Date: Thu, 16 Apr 2015 12:49:35 -0700 Subject: docs: add missing and new /proc/PID/status file entries, fix typos docs: add missing and new /proc/PID/status file entries, fix typos Signed-off-by: Nathan Scott Signed-off-by: Chen Hanxiao Cc: Serge Hallyn Cc: "Eric W. Biederman" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/filesystems/proc.txt | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a07ba61662ed..6d370622fdfe 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//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 -- cgit v1.2.3 From 6c8c90319c0bb1c9e0b68e721359b89ae4f28465 Mon Sep 17 00:00:00 2001 From: Andrey Vagin Date: Thu, 16 Apr 2015 12:49:38 -0700 Subject: proc: show locks in /proc/pid/fdinfo/X Let's show locks which are associated with a file descriptor in its fdinfo file. Currently we don't have a reliable way to determine who holds a lock. We can find some information in /proc/locks, but PID which is reported there can be wrong. For example, a process takes a lock, then forks a child and dies. In this case /proc/locks contains the parent pid, which can be reused by another process. $ cat /proc/locks ... 6: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF ... $ ps -C rpcbind PID TTY TIME CMD 332 ? 00:00:00 rpcbind $ cat /proc/332/fdinfo/4 pos: 0 flags: 0100000 mnt_id: 22 lock: 1: FLOCK ADVISORY WRITE 324 00:13:13431 0 EOF $ ls -l /proc/332/fd/4 lr-x------ 1 root root 64 Mar 5 14:43 /proc/332/fd/4 -> /run/rpcbind.lock $ ls -l /proc/324/fd/ total 0 lrwx------ 1 root root 64 Feb 27 14:50 0 -> /dev/pts/0 lrwx------ 1 root root 64 Feb 27 14:50 1 -> /dev/pts/0 lrwx------ 1 root root 64 Feb 27 14:49 2 -> /dev/pts/0 You can see that the process with the 324 pid doesn't hold the lock. This information is required for proper dumping and restoring file locks. Signed-off-by: Andrey Vagin Cc: Jonathan Corbet Cc: Alexander Viro Acked-by: Jeff Layton Acked-by: "J. Bruce Fields" Acked-by: Cyrill Gorcunov Cc: Pavel Emelyanov Cc: Joe Perches Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Documentation/filesystems/proc.txt | 4 ++++ fs/locks.c | 38 ++++++++++++++++++++++++++++++++++++++ fs/proc/fd.c | 27 +++++++++++++++++---------- include/linux/fs.h | 7 +++++++ 4 files changed, 66 insertions(+), 10 deletions(-) (limited to 'Documentation/filesystems') diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index 6d370622fdfe..8e36c7e3c345 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1709,6 +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/fs/locks.c b/fs/locks.c index 52b780fb5258..653faabb07f4 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -2590,6 +2590,44 @@ static int locks_show(struct seq_file *f, void *v) return 0; } +static void __show_fd_locks(struct seq_file *f, + struct list_head *head, int *id, + struct file *filp, struct files_struct *files) +{ + struct file_lock *fl; + + list_for_each_entry(fl, head, fl_list) { + + if (filp != fl->fl_file) + continue; + if (fl->fl_owner != files && + fl->fl_owner != filp) + continue; + + (*id)++; + seq_puts(f, "lock:\t"); + lock_get_status(f, fl, *id, ""); + } +} + +void show_fd_locks(struct seq_file *f, + struct file *filp, struct files_struct *files) +{ + struct inode *inode = file_inode(filp); + struct file_lock_context *ctx; + int id = 0; + + ctx = inode->i_flctx; + if (!ctx) + return; + + spin_lock(&ctx->flc_lock); + __show_fd_locks(f, &ctx->flc_flock, &id, filp, files); + __show_fd_locks(f, &ctx->flc_posix, &id, filp, files); + __show_fd_locks(f, &ctx->flc_lease, &id, filp, files); + spin_unlock(&ctx->flc_lock); +} + static void *locks_start(struct seq_file *f, loff_t *pos) __acquires(&blocked_lock_lock) { diff --git a/fs/proc/fd.c b/fs/proc/fd.c index 8e5ad83b629a..af84ad04df77 100644 --- a/fs/proc/fd.c +++ b/fs/proc/fd.c @@ -8,6 +8,7 @@ #include #include #include +#include #include @@ -48,17 +49,23 @@ static int seq_show(struct seq_file *m, void *v) put_files_struct(files); } - if (!ret) { - seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", - (long long)file->f_pos, f_flags, - real_mount(file->f_path.mnt)->mnt_id); - if (file->f_op->show_fdinfo) - file->f_op->show_fdinfo(m, file); - ret = seq_has_overflowed(m); - fput(file); - } + if (ret) + return ret; - return ret; + seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n", + (long long)file->f_pos, f_flags, + real_mount(file->f_path.mnt)->mnt_id); + + show_fd_locks(m, file, files); + if (seq_has_overflowed(m)) + goto out; + + if (file->f_op->show_fdinfo) + file->f_op->show_fdinfo(m, file); + +out: + fput(file); + return 0; } static int seq_fdinfo_open(struct inode *inode, struct file *file) diff --git a/include/linux/fs.h b/include/linux/fs.h index 6bf7ab7c1573..c4e927358503 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1042,6 +1042,9 @@ extern void lease_get_mtime(struct inode *, struct timespec *time); extern int generic_setlease(struct file *, long, struct file_lock **, void **priv); extern int vfs_setlease(struct file *, long, struct file_lock **, void **); extern int lease_modify(struct file_lock *, int, struct list_head *); +struct files_struct; +extern void show_fd_locks(struct seq_file *f, + struct file *filp, struct files_struct *files); #else /* !CONFIG_FILE_LOCKING */ static inline int fcntl_getlk(struct file *file, unsigned int cmd, struct flock __user *user) @@ -1178,6 +1181,10 @@ static inline int lease_modify(struct file_lock *fl, int arg, { return -EINVAL; } + +struct files_struct; +static inline void show_fd_locks(struct seq_file *f, + struct file *filp, struct files_struct *files) {} #endif /* !CONFIG_FILE_LOCKING */ -- cgit v1.2.3