Commit bd39597c authored by Eric Sandeen's avatar Eric Sandeen Committed by Linus Torvalds
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ext2: avoid printk floods in the face of directory corruption



A very large directory with many read failures (either due to storage
problems, or due to invalid size & blocks from corruption) will generate a
printk storm as the filesystem continues to try to read all the blocks.
This flood of messages can tie up the box until it is complete - which may
be a very long time, especially for very large corrupted values.

This is fixed by only reporting the corruption once each time we try to
read the directory.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarEric Sandeen <sandeen@redhat.com>
Signed-off-by: default avatar"Theodore Ts'o" <tytso@mit.edu>
Cc: Eugene Teo <eugeneteo@kernel.sg>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent d707d31c
......@@ -103,7 +103,7 @@ static int ext2_commit_chunk(struct page *page, loff_t pos, unsigned len)
return err;
}
static void ext2_check_page(struct page *page)
static void ext2_check_page(struct page *page, int quiet)
{
struct inode *dir = page->mapping->host;
struct super_block *sb = dir->i_sb;
......@@ -146,10 +146,10 @@ out:
/* Too bad, we had an error */
Ebadsize:
ext2_error(sb, "ext2_check_page",
"size of directory #%lu is not a multiple of chunk size",
dir->i_ino
);
if (!quiet)
ext2_error(sb, __func__,
"size of directory #%lu is not a multiple "
"of chunk size", dir->i_ino);
goto fail;
Eshort:
error = "rec_len is smaller than minimal";
......@@ -166,32 +166,36 @@ Espan:
Einumber:
error = "inode out of bounds";
bad_entry:
ext2_error (sb, "ext2_check_page", "bad entry in directory #%lu: %s - "
"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
(unsigned long) le32_to_cpu(p->inode),
rec_len, p->name_len);
if (!quiet)
ext2_error(sb, __func__, "bad entry in directory #%lu: : %s - "
"offset=%lu, inode=%lu, rec_len=%d, name_len=%d",
dir->i_ino, error, (page->index<<PAGE_CACHE_SHIFT)+offs,
(unsigned long) le32_to_cpu(p->inode),
rec_len, p->name_len);
goto fail;
Eend:
p = (ext2_dirent *)(kaddr + offs);
ext2_error (sb, "ext2_check_page",
"entry in directory #%lu spans the page boundary"
"offset=%lu, inode=%lu",
dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
(unsigned long) le32_to_cpu(p->inode));
if (!quiet) {
p = (ext2_dirent *)(kaddr + offs);
ext2_error(sb, "ext2_check_page",
"entry in directory #%lu spans the page boundary"
"offset=%lu, inode=%lu",
dir->i_ino, (page->index<<PAGE_CACHE_SHIFT)+offs,
(unsigned long) le32_to_cpu(p->inode));
}
fail:
SetPageChecked(page);
SetPageError(page);
}
static struct page * ext2_get_page(struct inode *dir, unsigned long n)
static struct page * ext2_get_page(struct inode *dir, unsigned long n,
int quiet)
{
struct address_space *mapping = dir->i_mapping;
struct page *page = read_mapping_page(mapping, n, NULL);
if (!IS_ERR(page)) {
kmap(page);
if (!PageChecked(page))
ext2_check_page(page);
ext2_check_page(page, quiet);
if (PageError(page))
goto fail;
}
......@@ -292,7 +296,7 @@ ext2_readdir (struct file * filp, void * dirent, filldir_t filldir)
for ( ; n < npages; n++, offset = 0) {
char *kaddr, *limit;
ext2_dirent *de;
struct page *page = ext2_get_page(inode, n);
struct page *page = ext2_get_page(inode, n, 0);
if (IS_ERR(page)) {
ext2_error(sb, __func__,
......@@ -361,6 +365,7 @@ struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir,
struct page *page = NULL;
struct ext2_inode_info *ei = EXT2_I(dir);
ext2_dirent * de;
int dir_has_error = 0;
if (npages == 0)
goto out;
......@@ -374,7 +379,7 @@ struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir,
n = start;
do {
char *kaddr;
page = ext2_get_page(dir, n);
page = ext2_get_page(dir, n, dir_has_error);
if (!IS_ERR(page)) {
kaddr = page_address(page);
de = (ext2_dirent *) kaddr;
......@@ -391,7 +396,9 @@ struct ext2_dir_entry_2 * ext2_find_entry (struct inode * dir,
de = ext2_next_entry(de);
}
ext2_put_page(page);
}
} else
dir_has_error = 1;
if (++n >= npages)
n = 0;
/* next page is past the blocks we've got */
......@@ -414,7 +421,7 @@ found:
struct ext2_dir_entry_2 * ext2_dotdot (struct inode *dir, struct page **p)
{
struct page *page = ext2_get_page(dir, 0);
struct page *page = ext2_get_page(dir, 0, 0);
ext2_dirent *de = NULL;
if (!IS_ERR(page)) {
......@@ -487,7 +494,7 @@ int ext2_add_link (struct dentry *dentry, struct inode *inode)
for (n = 0; n <= npages; n++) {
char *dir_end;
page = ext2_get_page(dir, n);
page = ext2_get_page(dir, n, 0);
err = PTR_ERR(page);
if (IS_ERR(page))
goto out;
......@@ -655,14 +662,17 @@ int ext2_empty_dir (struct inode * inode)
{
struct page *page = NULL;
unsigned long i, npages = dir_pages(inode);
int dir_has_error = 0;
for (i = 0; i < npages; i++) {
char *kaddr;
ext2_dirent * de;
page = ext2_get_page(inode, i);
page = ext2_get_page(inode, i, dir_has_error);
if (IS_ERR(page))
if (IS_ERR(page)) {
dir_has_error = 1;
continue;
}
kaddr = page_address(page);
de = (ext2_dirent *)kaddr;
......
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