f2fs: add key functions for f2fs_io_tracer
This patch adds two key functions to trace process ids and IOs.
The basic idea is to
1. remain process ids, pids, in page->private.
2. show pids in IO traces.
So, later we can retrieve process information according to IO traces.
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
diff --git a/fs/f2fs/trace.c b/fs/f2fs/trace.c
index 4e4a069..19f5216 100644
--- a/fs/f2fs/trace.c
+++ b/fs/f2fs/trace.c
@@ -15,10 +15,96 @@
#include "f2fs.h"
#include "trace.h"
+RADIX_TREE(pids, GFP_NOIO);
+struct last_io_info last_io;
+
+static inline void __print_last_io(void)
+{
+ if (!last_io.len)
+ return;
+
+ trace_printk("%3x:%3x %4x %-16s %2x %5x %12x %4x\n",
+ last_io.major, last_io.minor,
+ last_io.pid, "----------------",
+ last_io.type,
+ last_io.fio.rw, last_io.fio.blk_addr,
+ last_io.len);
+ memset(&last_io, 0, sizeof(last_io));
+}
+
+static int __file_type(struct inode *inode, pid_t pid)
+{
+ if (f2fs_is_atomic_file(inode))
+ return __ATOMIC_FILE;
+ else if (f2fs_is_volatile_file(inode))
+ return __VOLATILE_FILE;
+ else if (S_ISDIR(inode->i_mode))
+ return __DIR_FILE;
+ else if (inode->i_ino == F2FS_NODE_INO(F2FS_I_SB(inode)))
+ return __NODE_FILE;
+ else if (inode->i_ino == F2FS_META_INO(F2FS_I_SB(inode)))
+ return __META_FILE;
+ else if (pid)
+ return __NORMAL_FILE;
+ else
+ return __MISC_FILE;
+}
+
void f2fs_trace_pid(struct page *page)
{
+ struct inode *inode = page->mapping->host;
+ pid_t pid = task_pid_nr(current);
+ void *p;
+
+ page->private = pid;
+
+ p = radix_tree_lookup(&pids, pid);
+ if (p == current)
+ return;
+ if (p)
+ radix_tree_delete(&pids, pid);
+
+ f2fs_radix_tree_insert(&pids, pid, current);
+
+ trace_printk("%3x:%3x %4x %-16s\n",
+ MAJOR(inode->i_sb->s_dev), MINOR(inode->i_sb->s_dev),
+ pid, current->comm);
+
}
void f2fs_trace_ios(struct page *page, struct f2fs_io_info *fio, int flush)
{
+ struct inode *inode;
+ pid_t pid;
+ int major, minor;
+
+ if (flush) {
+ __print_last_io();
+ return;
+ }
+
+ inode = page->mapping->host;
+ pid = page_private(page);
+
+ major = MAJOR(inode->i_sb->s_dev);
+ minor = MINOR(inode->i_sb->s_dev);
+
+ if (last_io.major == major && last_io.minor == minor &&
+ last_io.pid == pid &&
+ last_io.type == __file_type(inode, pid) &&
+ last_io.fio.rw == fio->rw &&
+ last_io.fio.blk_addr + last_io.len == fio->blk_addr) {
+ last_io.len++;
+ return;
+ }
+
+ __print_last_io();
+
+ last_io.major = major;
+ last_io.minor = minor;
+ last_io.pid = pid;
+ last_io.type = __file_type(inode, pid);
+ last_io.fio = *fio;
+ last_io.len = 1;
+ return;
}