Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
ntfs: use page allocation for resident attribute inline data
The current kmemdup() based allocation for IOMAP_INLINE can result in
inline_data pointer having a non-zero page offset. This causes
iomap_inline_data_valid() to fail the check:
iomap->length <= PAGE_SIZE - offset_in_page(iomap->inline_data)
and triggers the kernel BUG at fs/iomap/buffered-io.c:1061.
This particularly affects workloads with frequent small file access
(e.g. Firefox Nightly profile on NTFS with bind mount) when using the
new ntfs. This fix this by allocating a full page with alloc_page() so that
page_address() always returns a page-aligned address.
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
+19
-7
+19
-7
fs/ntfs/iomap.c
+19
-7
fs/ntfs/iomap.c
···
89
89
u32 attr_len;
90
90
int err = 0;
91
91
char *kattr;
92
+
struct page *ipage;
92
93
93
94
if (NInoAttr(ni))
94
95
base_ni = ni->ext.base_ntfs_ino;
···
130
129
131
130
kattr = (u8 *)ctx->attr + le16_to_cpu(ctx->attr->data.resident.value_offset);
132
131
133
-
iomap->inline_data = kmemdup(kattr, attr_len, GFP_KERNEL);
134
-
if (!iomap->inline_data) {
132
+
ipage = alloc_page(GFP_NOFS | __GFP_ZERO);
133
+
if (!ipage) {
135
134
err = -ENOMEM;
136
135
goto out;
137
136
}
138
137
138
+
memcpy(page_address(ipage), kattr, attr_len);
139
139
iomap->type = IOMAP_INLINE;
140
+
iomap->inline_data = page_address(ipage);
140
141
iomap->offset = 0;
141
142
iomap->length = attr_len;
143
+
iomap->private = ipage;
142
144
143
145
out:
144
146
if (ctx)
···
289
285
static int ntfs_read_iomap_end(struct inode *inode, loff_t pos, loff_t length,
290
286
ssize_t written, unsigned int flags, struct iomap *iomap)
291
287
{
292
-
if (iomap->type == IOMAP_INLINE)
293
-
kfree(iomap->inline_data);
288
+
if (iomap->type == IOMAP_INLINE) {
289
+
struct page *ipage = iomap->private;
290
+
291
+
put_page(ipage);
292
+
}
294
293
295
294
return written;
296
295
}
···
659
652
u32 attr_len;
660
653
int err = 0;
661
654
char *kattr;
655
+
struct page *ipage;
662
656
663
657
ctx = ntfs_attr_get_search_ctx(ni, NULL);
664
658
if (!ctx) {
···
680
672
attr_len = le32_to_cpu(a->data.resident.value_length);
681
673
kattr = (u8 *)a + le16_to_cpu(a->data.resident.value_offset);
682
674
683
-
iomap->inline_data = kmemdup(kattr, attr_len, GFP_KERNEL);
684
-
if (!iomap->inline_data) {
675
+
ipage = alloc_page(GFP_NOFS | __GFP_ZERO);
676
+
if (!ipage) {
685
677
err = -ENOMEM;
686
678
goto out;
687
679
}
688
680
681
+
memcpy(page_address(ipage), kattr, attr_len);
689
682
iomap->type = IOMAP_INLINE;
683
+
iomap->inline_data = page_address(ipage);
690
684
iomap->offset = 0;
691
685
/* iomap requires there is only one INLINE_DATA extent */
692
686
iomap->length = attr_len;
687
+
iomap->private = ipage;
693
688
694
689
out:
695
690
if (ctx)
···
782
771
u32 attr_len;
783
772
int err;
784
773
char *kattr;
774
+
struct page *ipage = iomap->private;
785
775
786
776
mutex_lock(&ni->mrec_lock);
787
777
ctx = ntfs_attr_get_search_ctx(ni, NULL);
···
811
799
mark_mft_record_dirty(ctx->ntfs_ino);
812
800
err_out:
813
801
ntfs_attr_put_search_ctx(ctx);
814
-
kfree(iomap->inline_data);
802
+
put_page(ipage);
815
803
mutex_unlock(&ni->mrec_lock);
816
804
return written;
817
805