From: Joe Perches <j...@perches.com>

seq_printf functions shouldn't really check the return value.
Checking seq_has_overflowed() occasionally is used instead.

Update vfs documentation.

Link: 
http://lkml.kernel.org/p/e37e6e7b76acbdcc3bb4ab2a57c8f8ca1ae11b9a.1412031505.git....@perches.com

Cc: David S. Miller <da...@davemloft.net>
Cc: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Joe Perches <j...@perches.com>
[ did a few clean ups ]
Signed-off-by: Steven Rostedt <rost...@goodmis.org>
---
 Documentation/filesystems/vfs.txt |  2 +-
 drivers/net/tun.c                 |  4 +-
 fs/eventfd.c                      |  9 ++---
 fs/eventpoll.c                    | 13 +++----
 fs/notify/fdinfo.c                | 78 ++++++++++++++++-----------------------
 fs/notify/fdinfo.h                |  4 +-
 fs/proc/fd.c                      |  3 +-
 fs/signalfd.c                     |  4 +-
 fs/timerfd.c                      | 27 +++++++-------
 include/linux/fs.h                |  2 +-
 10 files changed, 63 insertions(+), 83 deletions(-)

diff --git a/Documentation/filesystems/vfs.txt 
b/Documentation/filesystems/vfs.txt
index fceff7c00a3c..af1dbc1823bb 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -828,7 +828,7 @@ struct file_operations {
        ssize_t (*splice_read)(struct file *, struct pipe_inode_info *, size_t, 
unsigned int);
        int (*setlease)(struct file *, long arg, struct file_lock **, void **);
        long (*fallocate)(struct file *, int mode, loff_t offset, loff_t len);
-       int (*show_fdinfo)(struct seq_file *m, struct file *f);
+       void (*show_fdinfo)(struct seq_file *m, struct file *f);
 };
 
 Again, all methods are called without any locks being held, unless
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 186ce541c657..a3420e091689 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -2209,7 +2209,7 @@ static int tun_chr_close(struct inode *inode, struct file 
*file)
 }
 
 #ifdef CONFIG_PROC_FS
-static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
+static void tun_chr_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct tun_struct *tun;
        struct ifreq ifr;
@@ -2225,7 +2225,7 @@ static int tun_chr_show_fdinfo(struct seq_file *m, struct 
file *f)
        if (tun)
                tun_put(tun);
 
-       return seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
+       seq_printf(m, "iff:\t%s\n", ifr.ifr_name);
 }
 #endif
 
diff --git a/fs/eventfd.c b/fs/eventfd.c
index d6a88e7812f3..4b0a226024fa 100644
--- a/fs/eventfd.c
+++ b/fs/eventfd.c
@@ -287,17 +287,14 @@ static ssize_t eventfd_write(struct file *file, const 
char __user *buf, size_t c
 }
 
 #ifdef CONFIG_PROC_FS
-static int eventfd_show_fdinfo(struct seq_file *m, struct file *f)
+static void eventfd_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct eventfd_ctx *ctx = f->private_data;
-       int ret;
 
        spin_lock_irq(&ctx->wqh.lock);
-       ret = seq_printf(m, "eventfd-count: %16llx\n",
-                        (unsigned long long)ctx->count);
+       seq_printf(m, "eventfd-count: %16llx\n",
+                  (unsigned long long)ctx->count);
        spin_unlock_irq(&ctx->wqh.lock);
-
-       return ret;
 }
 #endif
 
diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 7bcfff900f05..d77f94491352 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -870,25 +870,22 @@ static unsigned int ep_eventpoll_poll(struct file *file, 
poll_table *wait)
 }
 
 #ifdef CONFIG_PROC_FS
-static int ep_show_fdinfo(struct seq_file *m, struct file *f)
+static void ep_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct eventpoll *ep = f->private_data;
        struct rb_node *rbp;
-       int ret = 0;
 
        mutex_lock(&ep->mtx);
        for (rbp = rb_first(&ep->rbr); rbp; rbp = rb_next(rbp)) {
                struct epitem *epi = rb_entry(rbp, struct epitem, rbn);
 
-               ret = seq_printf(m, "tfd: %8d events: %8x data: %16llx\n",
-                                epi->ffd.fd, epi->event.events,
-                                (long long)epi->event.data);
-               if (ret)
+               seq_printf(m, "tfd: %8d events: %8x data: %16llx\n",
+                          epi->ffd.fd, epi->event.events,
+                          (long long)epi->event.data);
+               if (seq_has_overflowed(m))
                        break;
        }
        mutex_unlock(&ep->mtx);
-
-       return ret;
 }
 #endif
 
diff --git a/fs/notify/fdinfo.c b/fs/notify/fdinfo.c
index 9d7e2b9659cb..6ffd220eb14d 100644
--- a/fs/notify/fdinfo.c
+++ b/fs/notify/fdinfo.c
@@ -20,25 +20,24 @@
 
 #if defined(CONFIG_INOTIFY_USER) || defined(CONFIG_FANOTIFY)
 
-static int show_fdinfo(struct seq_file *m, struct file *f,
-                      int (*show)(struct seq_file *m, struct fsnotify_mark 
*mark))
+static void show_fdinfo(struct seq_file *m, struct file *f,
+                       void (*show)(struct seq_file *m,
+                                    struct fsnotify_mark *mark))
 {
        struct fsnotify_group *group = f->private_data;
        struct fsnotify_mark *mark;
-       int ret = 0;
 
        mutex_lock(&group->mark_mutex);
        list_for_each_entry(mark, &group->marks_list, g_list) {
-               ret = show(m, mark);
-               if (ret)
+               show(m, mark);
+               if (seq_has_overflowed(m))
                        break;
        }
        mutex_unlock(&group->mark_mutex);
-       return ret;
 }
 
 #if defined(CONFIG_EXPORTFS)
-static int show_mark_fhandle(struct seq_file *m, struct inode *inode)
+static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
 {
        struct {
                struct file_handle handle;
@@ -52,71 +51,62 @@ static int show_mark_fhandle(struct seq_file *m, struct 
inode *inode)
        ret = exportfs_encode_inode_fh(inode, (struct fid *)f.handle.f_handle, 
&size, 0);
        if ((ret == FILEID_INVALID) || (ret < 0)) {
                WARN_ONCE(1, "Can't encode file handler for inotify: %d\n", 
ret);
-               return 0;
+               return;
        }
 
        f.handle.handle_type = ret;
        f.handle.handle_bytes = size * sizeof(u32);
 
-       ret = seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
-                        f.handle.handle_bytes, f.handle.handle_type);
+       seq_printf(m, "fhandle-bytes:%x fhandle-type:%x f_handle:",
+                  f.handle.handle_bytes, f.handle.handle_type);
 
        for (i = 0; i < f.handle.handle_bytes; i++)
-               ret |= seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
-
-       return ret;
+               seq_printf(m, "%02x", (int)f.handle.f_handle[i]);
 }
 #else
-static int show_mark_fhandle(struct seq_file *m, struct inode *inode)
+static void show_mark_fhandle(struct seq_file *m, struct inode *inode)
 {
-       return 0;
 }
 #endif
 
 #ifdef CONFIG_INOTIFY_USER
 
-static int inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
+static void inotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 {
        struct inotify_inode_mark *inode_mark;
        struct inode *inode;
-       int ret = 0;
 
        if (!(mark->flags & (FSNOTIFY_MARK_FLAG_ALIVE | 
FSNOTIFY_MARK_FLAG_INODE)))
-               return 0;
+               return;
 
        inode_mark = container_of(mark, struct inotify_inode_mark, fsn_mark);
        inode = igrab(mark->i.inode);
        if (inode) {
-               ret = seq_printf(m, "inotify wd:%x ino:%lx sdev:%x "
-                                "mask:%x ignored_mask:%x ",
-                                inode_mark->wd, inode->i_ino,
-                                inode->i_sb->s_dev,
-                                mark->mask, mark->ignored_mask);
-               ret |= show_mark_fhandle(m, inode);
-               ret |= seq_putc(m, '\n');
+               seq_printf(m, "inotify wd:%x ino:%lx sdev:%x mask:%x 
ignored_mask:%x ",
+                          inode_mark->wd, inode->i_ino, inode->i_sb->s_dev,
+                          mark->mask, mark->ignored_mask);
+               show_mark_fhandle(m, inode);
+               seq_putc(m, '\n');
                iput(inode);
        }
-
-       return ret;
 }
 
-int inotify_show_fdinfo(struct seq_file *m, struct file *f)
+void inotify_show_fdinfo(struct seq_file *m, struct file *f)
 {
-       return show_fdinfo(m, f, inotify_fdinfo);
+       show_fdinfo(m, f, inotify_fdinfo);
 }
 
 #endif /* CONFIG_INOTIFY_USER */
 
 #ifdef CONFIG_FANOTIFY
 
-static int fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
+static void fanotify_fdinfo(struct seq_file *m, struct fsnotify_mark *mark)
 {
        unsigned int mflags = 0;
        struct inode *inode;
-       int ret = 0;
 
        if (!(mark->flags & FSNOTIFY_MARK_FLAG_ALIVE))
-               return 0;
+               return;
 
        if (mark->flags & FSNOTIFY_MARK_FLAG_IGNORED_SURV_MODIFY)
                mflags |= FAN_MARK_IGNORED_SURV_MODIFY;
@@ -124,26 +114,22 @@ static int fanotify_fdinfo(struct seq_file *m, struct 
fsnotify_mark *mark)
        if (mark->flags & FSNOTIFY_MARK_FLAG_INODE) {
                inode = igrab(mark->i.inode);
                if (!inode)
-                       goto out;
-               ret = seq_printf(m, "fanotify ino:%lx sdev:%x "
-                                "mflags:%x mask:%x ignored_mask:%x ",
-                                inode->i_ino, inode->i_sb->s_dev,
-                                mflags, mark->mask, mark->ignored_mask);
-               ret |= show_mark_fhandle(m, inode);
-               ret |= seq_putc(m, '\n');
+                       return;
+               seq_printf(m, "fanotify ino:%lx sdev:%x mflags:%x mask:%x 
ignored_mask:%x ",
+                          inode->i_ino, inode->i_sb->s_dev,
+                          mflags, mark->mask, mark->ignored_mask);
+               show_mark_fhandle(m, inode);
+               seq_putc(m, '\n');
                iput(inode);
        } else if (mark->flags & FSNOTIFY_MARK_FLAG_VFSMOUNT) {
                struct mount *mnt = real_mount(mark->m.mnt);
 
-               ret = seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x "
-                                "ignored_mask:%x\n", mnt->mnt_id, mflags,
-                                mark->mask, mark->ignored_mask);
+               seq_printf(m, "fanotify mnt_id:%x mflags:%x mask:%x 
ignored_mask:%x\n",
+                          mnt->mnt_id, mflags, mark->mask, mark->ignored_mask);
        }
-out:
-       return ret;
 }
 
-int fanotify_show_fdinfo(struct seq_file *m, struct file *f)
+void fanotify_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct fsnotify_group *group = f->private_data;
        unsigned int flags = 0;
@@ -169,7 +155,7 @@ int fanotify_show_fdinfo(struct seq_file *m, struct file *f)
        seq_printf(m, "fanotify flags:%x event-flags:%x\n",
                   flags, group->fanotify_data.f_flags);
 
-       return show_fdinfo(m, f, fanotify_fdinfo);
+       show_fdinfo(m, f, fanotify_fdinfo);
 }
 
 #endif /* CONFIG_FANOTIFY */
diff --git a/fs/notify/fdinfo.h b/fs/notify/fdinfo.h
index 556afda990e9..9664c4904d6b 100644
--- a/fs/notify/fdinfo.h
+++ b/fs/notify/fdinfo.h
@@ -10,11 +10,11 @@ struct file;
 #ifdef CONFIG_PROC_FS
 
 #ifdef CONFIG_INOTIFY_USER
-extern int inotify_show_fdinfo(struct seq_file *m, struct file *f);
+void inotify_show_fdinfo(struct seq_file *m, struct file *f);
 #endif
 
 #ifdef CONFIG_FANOTIFY
-extern int fanotify_show_fdinfo(struct seq_file *m, struct file *f);
+void fanotify_show_fdinfo(struct seq_file *m, struct file *f);
 #endif
 
 #else /* CONFIG_PROC_FS */
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index e11d7c590bb0..8e5ad83b629a 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -53,7 +53,8 @@ static int seq_show(struct seq_file *m, void *v)
                           (long long)file->f_pos, f_flags,
                           real_mount(file->f_path.mnt)->mnt_id);
                if (file->f_op->show_fdinfo)
-                       ret = file->f_op->show_fdinfo(m, file);
+                       file->f_op->show_fdinfo(m, file);
+               ret = seq_has_overflowed(m);
                fput(file);
        }
 
diff --git a/fs/signalfd.c b/fs/signalfd.c
index 424b7b65321f..7e412ad74836 100644
--- a/fs/signalfd.c
+++ b/fs/signalfd.c
@@ -230,7 +230,7 @@ static ssize_t signalfd_read(struct file *file, char __user 
*buf, size_t count,
 }
 
 #ifdef CONFIG_PROC_FS
-static int signalfd_show_fdinfo(struct seq_file *m, struct file *f)
+static void signalfd_show_fdinfo(struct seq_file *m, struct file *f)
 {
        struct signalfd_ctx *ctx = f->private_data;
        sigset_t sigmask;
@@ -238,8 +238,6 @@ static int signalfd_show_fdinfo(struct seq_file *m, struct 
file *f)
        sigmask = ctx->sigmask;
        signotset(&sigmask);
        render_sigset_t(m, "sigmask:\t", &sigmask);
-
-       return 0;
 }
 #endif
 
diff --git a/fs/timerfd.c b/fs/timerfd.c
index b46ffa94372a..b94fa6c3c6eb 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -288,7 +288,7 @@ static ssize_t timerfd_read(struct file *file, char __user 
*buf, size_t count,
 }
 
 #ifdef CONFIG_PROC_FS
-static int timerfd_show(struct seq_file *m, struct file *file)
+static void timerfd_show(struct seq_file *m, struct file *file)
 {
        struct timerfd_ctx *ctx = file->private_data;
        struct itimerspec t;
@@ -298,18 +298,19 @@ static int timerfd_show(struct seq_file *m, struct file 
*file)
        t.it_interval = ktime_to_timespec(ctx->tintv);
        spin_unlock_irq(&ctx->wqh.lock);
 
-       return seq_printf(m,
-                         "clockid: %d\n"
-                         "ticks: %llu\n"
-                         "settime flags: 0%o\n"
-                         "it_value: (%llu, %llu)\n"
-                         "it_interval: (%llu, %llu)\n",
-                         ctx->clockid, (unsigned long long)ctx->ticks,
-                         ctx->settime_flags,
-                         (unsigned long long)t.it_value.tv_sec,
-                         (unsigned long long)t.it_value.tv_nsec,
-                         (unsigned long long)t.it_interval.tv_sec,
-                         (unsigned long long)t.it_interval.tv_nsec);
+       seq_printf(m,
+                  "clockid: %d\n"
+                  "ticks: %llu\n"
+                  "settime flags: 0%o\n"
+                  "it_value: (%llu, %llu)\n"
+                  "it_interval: (%llu, %llu)\n",
+                  ctx->clockid,
+                  (unsigned long long)ctx->ticks,
+                  ctx->settime_flags,
+                  (unsigned long long)t.it_value.tv_sec,
+                  (unsigned long long)t.it_value.tv_nsec,
+                  (unsigned long long)t.it_interval.tv_sec,
+                  (unsigned long long)t.it_interval.tv_nsec);
 }
 #else
 #define timerfd_show NULL
diff --git a/include/linux/fs.h b/include/linux/fs.h
index a957d4366c24..01dd9052a142 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1491,7 +1491,7 @@ struct file_operations {
        int (*setlease)(struct file *, long, struct file_lock **, void **);
        long (*fallocate)(struct file *file, int mode, loff_t offset,
                          loff_t len);
-       int (*show_fdinfo)(struct seq_file *m, struct file *f);
+       void (*show_fdinfo)(struct seq_file *m, struct file *f);
 };
 
 struct inode_operations {
-- 
2.1.1


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