[PATCH RFC 09/13] mm/filemap: simplify the printing with '%pD' specifier

[PATCH RFC 09/13] mm/filemap: simplify the printing with '%pD' specifier

[Jia He]

After the behavior of '%pD' is changed to print the full path of file,
the log printing in dio_warn_stale_pagecache() can be simplified.

Given that the error case is well handled in d_path_unsafe(), the error
string would be copied in '%pD' buffer, no need to additionally handle
IS_ERR().

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jia He <justin.he@arm.com>
---
 mm/filemap.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index d1458ecf2f51..477288017765 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -3497,16 +3497,11 @@ EXPORT_SYMBOL(pagecache_write_end);
 void dio_warn_stale_pagecache(struct file *filp)
 {
 	static DEFINE_RATELIMIT_STATE(_rs, 86400 * HZ, DEFAULT_RATELIMIT_BURST);
-	char pathname[128];
-	char *path;
 
 	errseq_set(&filp->f_mapping->wb_err, -EIO);
 	if (__ratelimit(&_rs)) {
-		path = file_path(filp, pathname, sizeof(pathname));
-		if (IS_ERR(path))
-			path = "(unknown)";
 		pr_crit("Page cache invalidation failure on direct I/O.  Possible data corruption due to collision with buffered I/O!\n");
-		pr_crit("File: %s PID: %d Comm: %.20s\n", path, current->pid,
+		pr_crit("File: %pD PID: %d Comm: %.20s\n", filp, current->pid,
 			current->comm);
 	}
 }
-- 
2.17.1

[PATCH RFC 12/13] mm: simplify the printing with '%pd' specifier

[Jia He]

Use '%pd' to simplify the printing since kbasename(file_path()) is to
get the last dentry of the full path.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jia He <justin.he@arm.com>
---
 mm/memory.c | 16 ++++++----------
 1 file changed, 6 insertions(+), 10 deletions(-)

diff --git a/mm/memory.c b/mm/memory.c
index 747a01d495f2..350692ada6f7 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -5217,18 +5217,14 @@ void print_vma_addr(char *prefix, unsigned long ip)
 	vma = find_vma(mm, ip);
 	if (vma && vma->vm_file) {
 		struct file *f = vma->vm_file;
-		char *buf = (char *)__get_free_page(GFP_NOWAIT);
-		if (buf) {
-			char *p;
-
-			p = file_path(f, buf, PAGE_SIZE);
-			if (IS_ERR(p))
-				p = "?";
-			printk("%s%s[%lx+%lx]", prefix, kbasename(p),
+
+		if (f)
+			printk("%s%pd[%lx+%lx]", prefix, f->f_path.dentry,
 					vma->vm_start,
 					vma->vm_end - vma->vm_start);
-			free_page((unsigned long)buf);
-		}
+		else
+			printk("%s?[%lx+%lx]", prefix, vma->vm_start,
+					vma->vm_end - vma->vm_start);
 	}
 	mmap_read_unlock(mm);
 }
-- 
2.17.1