From: Mohan Srinivasan <srmohan@google.com>
Date: Fri, 3 Feb 2017 23:48:03 +0000 (-0800)
Subject: ANDROID: Refactor fs readpage/write tracepoints.
X-Git-Tag: release-20171130_firefly~4^2~100^2~244
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=db943372859b8acf8b99e258c0f2146238793e12;p=firefly-linux-kernel-4.4.55.git
ANDROID: Refactor fs readpage/write tracepoints.
Refactor the fs readpage/write tracepoints to move the
inode->path lookup outside the tracepoint code, and pass a pointer
to the path into the tracepoint code instead. This is necessary
because the tracepoint code runs non-preemptible. Thanks to
Trilok Soni for catching this in 4.4.
Change-Id: I7486c5947918d155a30c61d6b9cd5027cf8fbe15
Signed-off-by: Mohan Srinivasan <srmohan@google.com>
---
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
index 84da8fd0ab11..bc7c082b7913 100644
--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -503,8 +503,16 @@ int ext4_readpage_inline(struct inode *inode, struct page *page)
return -EAGAIN;
}
- trace_android_fs_dataread_start(inode, page_offset(page), PAGE_SIZE,
- current->pid, current->comm);
+ if (trace_android_fs_dataread_start_enabled()) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_dataread_start(inode, page_offset(page),
+ PAGE_SIZE, current->pid,
+ path, current->comm);
+ }
/*
* Current inline data can only exist in the 1st page,
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 3b8a0b052988..1c733321b03c 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1017,8 +1017,16 @@ static int ext4_write_begin(struct file *file, struct address_space *mapping,
pgoff_t index;
unsigned from, to;
- trace_android_fs_datawrite_start(inode, pos, len,
- current->pid, current->comm);
+ if (trace_android_fs_datawrite_start_enabled()) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_datawrite_start(inode, pos, len,
+ current->pid, path,
+ current->comm);
+ }
trace_ext4_write_begin(inode, pos, len, flags);
/*
* Reserve one block more for addition to orphan list in case
@@ -2745,8 +2753,16 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
len, flags, pagep, fsdata);
}
*fsdata = (void *)0;
- trace_android_fs_datawrite_start(inode, pos, len,
- current->pid, current->comm);
+ if (trace_android_fs_datawrite_start_enabled()) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_datawrite_start(inode, pos, len,
+ current->pid,
+ path, current->comm);
+ }
trace_ext4_da_write_begin(inode, pos, len, flags);
if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
@@ -3355,16 +3371,27 @@ static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
return 0;
if (trace_android_fs_dataread_start_enabled() &&
- (iov_iter_rw(iter) == READ))
+ (iov_iter_rw(iter) == READ)) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
trace_android_fs_dataread_start(inode, offset, count,
- current->pid,
+ current->pid, path,
current->comm);
+ }
if (trace_android_fs_datawrite_start_enabled() &&
- (iov_iter_rw(iter) == WRITE))
+ (iov_iter_rw(iter) == WRITE)) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
trace_android_fs_datawrite_start(inode, offset, count,
- current->pid,
+ current->pid, path,
current->comm);
-
+ }
trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
ret = ext4_ext_direct_IO(iocb, iter, offset);
diff --git a/fs/ext4/readpage.c b/fs/ext4/readpage.c
index 1ce24a6759a0..1c5db9fd9c8f 100644
--- a/fs/ext4/readpage.c
+++ b/fs/ext4/readpage.c
@@ -152,11 +152,17 @@ ext4_submit_bio_read(struct bio *bio)
struct page *first_page = bio->bi_io_vec[0].bv_page;
if (first_page != NULL) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ first_page->mapping->host);
trace_android_fs_dataread_start(
first_page->mapping->host,
page_offset(first_page),
bio->bi_iter.bi_size,
current->pid,
+ path,
current->comm);
}
}
diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index e692958d6e78..8936044dee4c 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1402,8 +1402,16 @@ static int f2fs_write_begin(struct file *file, struct address_space *mapping,
struct dnode_of_data dn;
int err = 0;
- trace_android_fs_datawrite_start(inode, pos, len,
- current->pid, current->comm);
+ if (trace_android_fs_datawrite_start_enabled()) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_datawrite_start(inode, pos, len,
+ current->pid, path,
+ current->comm);
+ }
trace_f2fs_write_begin(inode, pos, len, flags);
f2fs_balance_fs(sbi);
@@ -1587,15 +1595,27 @@ static ssize_t f2fs_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
trace_f2fs_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
if (trace_android_fs_dataread_start_enabled() &&
- (iov_iter_rw(iter) == READ))
+ (iov_iter_rw(iter) == READ)) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
trace_android_fs_dataread_start(inode, offset,
- count, current->pid,
+ count, current->pid, path,
current->comm);
+ }
if (trace_android_fs_datawrite_start_enabled() &&
- (iov_iter_rw(iter) == WRITE))
- trace_android_fs_datawrite_start(inode, offset, count,
- current->pid, current->comm);
+ (iov_iter_rw(iter) == WRITE)) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_datawrite_start(inode, offset, count,
+ current->pid, path,
+ current->comm);
+ }
if (iov_iter_rw(iter) == WRITE) {
__allocate_data_blocks(inode, offset, count);
if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index d2c5d69ba0b1..dbb2cc4df603 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -85,9 +85,16 @@ int f2fs_read_inline_data(struct inode *inode, struct page *page)
{
struct page *ipage;
- trace_android_fs_dataread_start(inode, page_offset(page),
- PAGE_SIZE, current->pid,
- current->comm);
+ if (trace_android_fs_dataread_start_enabled()) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ inode);
+ trace_android_fs_dataread_start(inode, page_offset(page),
+ PAGE_SIZE, current->pid,
+ path, current->comm);
+ }
ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
if (IS_ERR(ipage)) {
diff --git a/fs/mpage.c b/fs/mpage.c
index 5c65d8942692..0fd48fdcc1b1 100644
--- a/fs/mpage.c
+++ b/fs/mpage.c
@@ -79,11 +79,17 @@ static struct bio *mpage_bio_submit(int rw, struct bio *bio)
struct page *first_page = bio->bi_io_vec[0].bv_page;
if (first_page != NULL) {
+ char *path, pathbuf[MAX_TRACE_PATHBUF_LEN];
+
+ path = android_fstrace_get_pathname(pathbuf,
+ MAX_TRACE_PATHBUF_LEN,
+ first_page->mapping->host);
trace_android_fs_dataread_start(
first_page->mapping->host,
page_offset(first_page),
bio->bi_iter.bi_size,
current->pid,
+ path,
current->comm);
}
}
diff --git a/include/trace/events/android_fs.h b/include/trace/events/android_fs.h
index 531da433a7bc..49509533d3fa 100644
--- a/include/trace/events/android_fs.h
+++ b/include/trace/events/android_fs.h
@@ -9,8 +9,8 @@
DEFINE_EVENT(android_fs_data_start_template, android_fs_dataread_start,
TP_PROTO(struct inode *inode, loff_t offset, int bytes,
- pid_t pid, char *command),
- TP_ARGS(inode, offset, bytes, pid, command));
+ pid_t pid, char *pathname, char *command),
+ TP_ARGS(inode, offset, bytes, pid, pathname, command));
DEFINE_EVENT(android_fs_data_end_template, android_fs_dataread_end,
TP_PROTO(struct inode *inode, loff_t offset, int bytes),
@@ -18,14 +18,48 @@ DEFINE_EVENT(android_fs_data_end_template, android_fs_dataread_end,
DEFINE_EVENT(android_fs_data_start_template, android_fs_datawrite_start,
TP_PROTO(struct inode *inode, loff_t offset, int bytes,
- pid_t pid, char *command),
- TP_ARGS(inode, offset, bytes, pid, command));
+ pid_t pid, char *pathname, char *command),
+ TP_ARGS(inode, offset, bytes, pid, pathname, command));
DEFINE_EVENT(android_fs_data_end_template, android_fs_datawrite_end,
TP_PROTO(struct inode *inode, loff_t offset, int bytes),
- TP_ARGS(inode, offset, bytes));
+ TP_ARGS(inode, offset, bytes));
#endif /* _TRACE_ANDROID_FS_H */
/* This part must be outside protection */
#include <trace/define_trace.h>
+
+#ifndef ANDROID_FSTRACE_GET_PATHNAME
+#define ANDROID_FSTRACE_GET_PATHNAME
+
+/* Sizes an on-stack array, so careful if sizing this up ! */
+#define MAX_TRACE_PATHBUF_LEN 256
+
+static inline char *
+android_fstrace_get_pathname(char *buf, int buflen, struct inode *inode)
+{
+ char *path;
+ struct dentry *d;
+
+ /*
+ * d_obtain_alias() will either iput() if it locates an existing
+ * dentry or transfer the reference to the new dentry created.
+ * So get an extra reference here.
+ */
+ ihold(inode);
+ d = d_obtain_alias(inode);
+ if (likely(!IS_ERR(d))) {
+ path = dentry_path_raw(d, buf, buflen);
+ if (unlikely(IS_ERR(path))) {
+ strcpy(buf, "ERROR");
+ path = buf;
+ }
+ dput(d);
+ } else {
+ strcpy(buf, "ERROR");
+ path = buf;
+ }
+ return path;
+}
+#endif
diff --git a/include/trace/events/android_fs_template.h b/include/trace/events/android_fs_template.h
index 618988b047c1..4e61ffe7a814 100644
--- a/include/trace/events/android_fs_template.h
+++ b/include/trace/events/android_fs_template.h
@@ -5,11 +5,10 @@
DECLARE_EVENT_CLASS(android_fs_data_start_template,
TP_PROTO(struct inode *inode, loff_t offset, int bytes,
- pid_t pid, char *command),
- TP_ARGS(inode, offset, bytes, pid, command),
+ pid_t pid, char *pathname, char *command),
+ TP_ARGS(inode, offset, bytes, pid, pathname, command),
TP_STRUCT__entry(
- __array(char, path, MAX_FILTER_STR_VAL);
- __field(char *, pathname);
+ __string(pathbuf, pathname);
__field(loff_t, offset);
__field(int, bytes);
__field(loff_t, i_size);
@@ -19,27 +18,7 @@ DECLARE_EVENT_CLASS(android_fs_data_start_template,
),
TP_fast_assign(
{
- struct dentry *d;
-
- /*
- * Grab a reference to the inode here because
- * d_obtain_alias() will either drop the inode
- * reference if it locates an existing dentry
- * or transfer the reference to the new dentry
- * created. In our case, the file is still open,
- * so the dentry is guaranteed to exist (connected),
- * so d_obtain_alias() drops the reference we
- * grabbed here.
- */
- ihold(inode);
- d = d_obtain_alias(inode);
- if (!IS_ERR(d)) {
- __entry->pathname = dentry_path(d,
- __entry->path,
- MAX_FILTER_STR_VAL);
- dput(d);
- } else
- __entry->pathname = ERR_PTR(-EINVAL);
+ __assign_str(pathbuf, pathname);
__entry->offset = offset;
__entry->bytes = bytes;
__entry->i_size = i_size_read(inode);
@@ -50,9 +29,8 @@ DECLARE_EVENT_CLASS(android_fs_data_start_template,
),
TP_printk("entry_name %s, offset %llu, bytes %d, cmdline %s,"
" pid %d, i_size %llu, ino %lu",
- (IS_ERR(__entry->pathname) ? "ERROR" : __entry->pathname),
- __entry->offset, __entry->bytes, __get_str(cmdline),
- __entry->pid, __entry->i_size,
+ __get_str(pathbuf), __entry->offset, __entry->bytes,
+ __get_str(cmdline), __entry->pid, __entry->i_size,
(unsigned long) __entry->ino)
);