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Diffstat (limited to 'fs/ecryptfs/mmap.c')
-rw-r--r--fs/ecryptfs/mmap.c94
1 files changed, 54 insertions, 40 deletions
diff --git a/fs/ecryptfs/mmap.c b/fs/ecryptfs/mmap.c
index b1d82756544..6a44148c5fb 100644
--- a/fs/ecryptfs/mmap.c
+++ b/fs/ecryptfs/mmap.c
@@ -62,16 +62,28 @@ static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
{
int rc;
+ /*
+ * Refuse to write the page out if we are called from reclaim context
+ * since our writepage() path may potentially allocate memory when
+ * calling into the lower fs vfs_write() which may in turn invoke
+ * us again.
+ */
+ if (current->flags & PF_MEMALLOC) {
+ redirty_page_for_writepage(wbc, page);
+ rc = 0;
+ goto out;
+ }
+
rc = ecryptfs_encrypt_page(page);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error encrypting "
- "page (upper index [0x%.16x])\n", page->index);
+ "page (upper index [0x%.16lx])\n", page->index);
ClearPageUptodate(page);
goto out;
}
SetPageUptodate(page);
- unlock_page(page);
out:
+ unlock_page(page);
return rc;
}
@@ -193,11 +205,7 @@ static int ecryptfs_readpage(struct file *file, struct page *page)
&ecryptfs_inode_to_private(page->mapping->host)->crypt_stat;
int rc = 0;
- if (!crypt_stat
- || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
- || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
- ecryptfs_printk(KERN_DEBUG,
- "Passing through unencrypted page\n");
+ if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(page, page->index, 0,
PAGE_CACHE_SIZE,
page->mapping->host);
@@ -237,7 +245,7 @@ out:
ClearPageUptodate(page);
else
SetPageUptodate(page);
- ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
+ ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n",
page->index);
unlock_page(page);
return rc;
@@ -290,12 +298,12 @@ static int ecryptfs_write_begin(struct file *file,
return -ENOMEM;
*pagep = page;
+ prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
if (!PageUptodate(page)) {
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(mapping->host)->crypt_stat;
- if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
- || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
+ if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_read_lower_page_segment(
page, index, 0, PAGE_CACHE_SIZE, mapping->host);
if (rc) {
@@ -335,18 +343,23 @@ static int ecryptfs_write_begin(struct file *file,
SetPageUptodate(page);
}
} else {
- rc = ecryptfs_decrypt_page(page);
- if (rc) {
- printk(KERN_ERR "%s: Error decrypting page "
- "at index [%ld]; rc = [%d]\n",
- __func__, page->index, rc);
- ClearPageUptodate(page);
- goto out;
+ if (prev_page_end_size
+ >= i_size_read(page->mapping->host)) {
+ zero_user(page, 0, PAGE_CACHE_SIZE);
+ } else {
+ rc = ecryptfs_decrypt_page(page);
+ if (rc) {
+ printk(KERN_ERR "%s: Error decrypting "
+ "page at index [%ld]; "
+ "rc = [%d]\n",
+ __func__, page->index, rc);
+ ClearPageUptodate(page);
+ goto out;
+ }
}
SetPageUptodate(page);
}
}
- prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT);
/* If creating a page or more of holes, zero them out via truncate.
* Note, this will increase i_size. */
if (index != 0) {
@@ -368,6 +381,11 @@ static int ecryptfs_write_begin(struct file *file,
&& (pos != 0))
zero_user(page, 0, PAGE_CACHE_SIZE);
out:
+ if (unlikely(rc)) {
+ unlock_page(page);
+ page_cache_release(page);
+ *pagep = NULL;
+ }
return rc;
}
@@ -480,15 +498,10 @@ static int ecryptfs_write_end(struct file *file,
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
int rc;
+ int need_unlock_page = 1;
- if (crypt_stat->flags & ECRYPTFS_NEW_FILE) {
- ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in "
- "crypt_stat at memory location [%p]\n", crypt_stat);
- crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE);
- } else
- ecryptfs_printk(KERN_DEBUG, "Not a new file\n");
ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
- "(page w/ index = [0x%.16x], to = [%d])\n", index, to);
+ "(page w/ index = [0x%.16lx], to = [%d])\n", index, to);
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0,
to);
@@ -503,28 +516,29 @@ static int ecryptfs_write_end(struct file *file,
rc = fill_zeros_to_end_of_page(page, to);
if (rc) {
ecryptfs_printk(KERN_WARNING, "Error attempting to fill "
- "zeros in page with index = [0x%.16x]\n", index);
- goto out;
- }
- rc = ecryptfs_encrypt_page(page);
- if (rc) {
- ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
- "index [0x%.16x])\n", index);
+ "zeros in page with index = [0x%.16lx]\n", index);
goto out;
}
+ set_page_dirty(page);
+ unlock_page(page);
+ need_unlock_page = 0;
if (pos + copied > i_size_read(ecryptfs_inode)) {
i_size_write(ecryptfs_inode, pos + copied);
ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
- "[0x%.16x]\n", i_size_read(ecryptfs_inode));
+ "[0x%.16llx]\n",
+ (unsigned long long)i_size_read(ecryptfs_inode));
+ balance_dirty_pages_ratelimited(mapping);
+ rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
+ if (rc) {
+ printk(KERN_ERR "Error writing inode size to metadata; "
+ "rc = [%d]\n", rc);
+ goto out;
+ }
}
- rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
- if (rc)
- printk(KERN_ERR "Error writing inode size to metadata; "
- "rc = [%d]\n", rc);
- else
- rc = copied;
+ rc = copied;
out:
- unlock_page(page);
+ if (need_unlock_page)
+ unlock_page(page);
page_cache_release(page);
return rc;
}
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-04-03 23:11:20 +0000