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authorLinus Torvalds <torvalds@linux-foundation.org>2012-01-25 15:03:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2012-01-25 15:03:04 -0800
commit3074c0350b173c9e98b62685e0a61a66d9ff8728 (patch)
tree28f2cd48f1278983b1fa7d5b4a5895882ce5ca84 /fs
parentf8275f9694b8adf9f3498e747ea4c3e8b984499b (diff)
parent58ded24f0fcb85bddb665baba75892f6ad0f4b8a (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs
Says Tyler: "Tim's logging message update will be really helpful to users when they're trying to locate a problematic file in the lower filesystem with filename encryption enabled. You'll recognize the fix from Li, as you commented on that. You should also be familiar with my setattr/truncate improvements, since you were the one that pointed them out to us (thanks again!). Andrew noted the /dev/ecryptfs write count sanitization needed to be improved, so I've got a fix in there for that along with some other less important cleanups of the /dev/ecryptfs read/write code." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tyhicks/ecryptfs: eCryptfs: Fix oops when printing debug info in extent crypto functions eCryptfs: Remove unused ecryptfs_read() eCryptfs: Check inode changes in setattr eCryptfs: Make truncate path killable eCryptfs: Infinite loop due to overflow in ecryptfs_write() eCryptfs: Replace miscdev read/write magic numbers eCryptfs: Report errors in writes to /dev/ecryptfs eCryptfs: Sanitize write counts of /dev/ecryptfs ecryptfs: Remove unnecessary variable initialization ecryptfs: Improve metadata read failure logging MAINTAINERS: Update eCryptfs maintainer address
Diffstat (limited to 'fs')
-rw-r--r--fs/ecryptfs/crypto.c54
-rw-r--r--fs/ecryptfs/ecryptfs_kernel.h5
-rw-r--r--fs/ecryptfs/inode.c48
-rw-r--r--fs/ecryptfs/keystore.c5
-rw-r--r--fs/ecryptfs/miscdev.c140
-rw-r--r--fs/ecryptfs/read_write.c96
6 files changed, 154 insertions, 194 deletions
diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 2a834255c75d..63ab24510649 100644
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -417,17 +417,6 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
(unsigned long long)(extent_base + extent_offset), rc);
goto out;
}
- if (unlikely(ecryptfs_verbosity > 0)) {
- ecryptfs_printk(KERN_DEBUG, "Encrypting extent "
- "with iv:\n");
- ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes);
- ecryptfs_printk(KERN_DEBUG, "First 8 bytes before "
- "encryption:\n");
- ecryptfs_dump_hex((char *)
- (page_address(page)
- + (extent_offset * crypt_stat->extent_size)),
- 8);
- }
rc = ecryptfs_encrypt_page_offset(crypt_stat, enc_extent_page, 0,
page, (extent_offset
* crypt_stat->extent_size),
@@ -440,14 +429,6 @@ static int ecryptfs_encrypt_extent(struct page *enc_extent_page,
goto out;
}
rc = 0;
- if (unlikely(ecryptfs_verbosity > 0)) {
- ecryptfs_printk(KERN_DEBUG, "Encrypt extent [0x%.16llx]; "
- "rc = [%d]\n",
- (unsigned long long)(extent_base + extent_offset), rc);
- ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
- "encryption:\n");
- ecryptfs_dump_hex((char *)(page_address(enc_extent_page)), 8);
- }
out:
return rc;
}
@@ -543,17 +524,6 @@ static int ecryptfs_decrypt_extent(struct page *page,
(unsigned long long)(extent_base + extent_offset), rc);
goto out;
}
- if (unlikely(ecryptfs_verbosity > 0)) {
- ecryptfs_printk(KERN_DEBUG, "Decrypting extent "
- "with iv:\n");
- ecryptfs_dump_hex(extent_iv, crypt_stat->iv_bytes);
- ecryptfs_printk(KERN_DEBUG, "First 8 bytes before "
- "decryption:\n");
- ecryptfs_dump_hex((char *)
- (page_address(enc_extent_page)
- + (extent_offset * crypt_stat->extent_size)),
- 8);
- }
rc = ecryptfs_decrypt_page_offset(crypt_stat, page,
(extent_offset
* crypt_stat->extent_size),
@@ -567,16 +537,6 @@ static int ecryptfs_decrypt_extent(struct page *page,
goto out;
}
rc = 0;
- if (unlikely(ecryptfs_verbosity > 0)) {
- ecryptfs_printk(KERN_DEBUG, "Decrypt extent [0x%.16llx]; "
- "rc = [%d]\n",
- (unsigned long long)(extent_base + extent_offset), rc);
- ecryptfs_printk(KERN_DEBUG, "First 8 bytes after "
- "decryption:\n");
- ecryptfs_dump_hex((char *)(page_address(page)
- + (extent_offset
- * crypt_stat->extent_size)), 8);
- }
out:
return rc;
}
@@ -1590,8 +1550,8 @@ int ecryptfs_read_and_validate_xattr_region(struct dentry *dentry,
*/
int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
{
- int rc = 0;
- char *page_virt = NULL;
+ int rc;
+ char *page_virt;
struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
@@ -1616,11 +1576,13 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
ecryptfs_dentry,
ECRYPTFS_VALIDATE_HEADER_SIZE);
if (rc) {
+ /* metadata is not in the file header, so try xattrs */
memset(page_virt, 0, PAGE_CACHE_SIZE);
rc = ecryptfs_read_xattr_region(page_virt, ecryptfs_inode);
if (rc) {
printk(KERN_DEBUG "Valid eCryptfs headers not found in "
- "file header region or xattr region\n");
+ "file header region or xattr region, inode %lu\n",
+ ecryptfs_inode->i_ino);
rc = -EINVAL;
goto out;
}
@@ -1629,7 +1591,8 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
ECRYPTFS_DONT_VALIDATE_HEADER_SIZE);
if (rc) {
printk(KERN_DEBUG "Valid eCryptfs headers not found in "
- "file xattr region either\n");
+ "file xattr region either, inode %lu\n",
+ ecryptfs_inode->i_ino);
rc = -EINVAL;
}
if (crypt_stat->mount_crypt_stat->flags
@@ -1640,7 +1603,8 @@ int ecryptfs_read_metadata(struct dentry *ecryptfs_dentry)
"crypto metadata only in the extended attribute "
"region, but eCryptfs was mounted without "
"xattr support enabled. eCryptfs will not treat "
- "this like an encrypted file.\n");
+ "this like an encrypted file, inode %lu\n",
+ ecryptfs_inode->i_ino);
rc = -EINVAL;
}
}
diff --git a/fs/ecryptfs/ecryptfs_kernel.h b/fs/ecryptfs/ecryptfs_kernel.h
index a9f29b12fbf2..a2362df58ae8 100644
--- a/fs/ecryptfs/ecryptfs_kernel.h
+++ b/fs/ecryptfs/ecryptfs_kernel.h
@@ -151,6 +151,11 @@ ecryptfs_get_key_payload_data(struct key *key)
* dentry name */
#define ECRYPTFS_TAG_73_PACKET_TYPE 0x49 /* FEK-encrypted filename as
* metadata */
+#define ECRYPTFS_MIN_PKT_LEN_SIZE 1 /* Min size to specify packet length */
+#define ECRYPTFS_MAX_PKT_LEN_SIZE 2 /* Pass at least this many bytes to
+ * ecryptfs_parse_packet_length() and
+ * ecryptfs_write_packet_length()
+ */
/* Constraint: ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES >=
* ECRYPTFS_MAX_IV_BYTES */
#define ECRYPTFS_FILENAME_MIN_RANDOM_PREPEND_BYTES 16
diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 19a8ca4ab1dd..19892d7d2ed1 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -822,18 +822,6 @@ static int truncate_upper(struct dentry *dentry, struct iattr *ia,
size_t num_zeros = (PAGE_CACHE_SIZE
- (ia->ia_size & ~PAGE_CACHE_MASK));
-
- /*
- * XXX(truncate) this should really happen at the begginning
- * of ->setattr. But the code is too messy to that as part
- * of a larger patch. ecryptfs is also totally missing out
- * on the inode_change_ok check at the beginning of
- * ->setattr while would include this.
- */
- rc = inode_newsize_ok(inode, ia->ia_size);
- if (rc)
- goto out;
-
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
truncate_setsize(inode, ia->ia_size);
lower_ia->ia_size = ia->ia_size;
@@ -883,6 +871,28 @@ out:
return rc;
}
+static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
+{
+ struct ecryptfs_crypt_stat *crypt_stat;
+ loff_t lower_oldsize, lower_newsize;
+
+ crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
+ lower_oldsize = upper_size_to_lower_size(crypt_stat,
+ i_size_read(inode));
+ lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
+ if (lower_newsize > lower_oldsize) {
+ /*
+ * The eCryptfs inode and the new *lower* size are mixed here
+ * because we may not have the lower i_mutex held and/or it may
+ * not be appropriate to call inode_newsize_ok() with inodes
+ * from other filesystems.
+ */
+ return inode_newsize_ok(inode, lower_newsize);
+ }
+
+ return 0;
+}
+
/**
* ecryptfs_truncate
* @dentry: The ecryptfs layer dentry
@@ -899,6 +909,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
struct iattr lower_ia = { .ia_valid = 0 };
int rc;
+ rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
+ if (rc)
+ return rc;
+
rc = truncate_upper(dentry, &ia, &lower_ia);
if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
@@ -978,6 +992,16 @@ static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
}
}
mutex_unlock(&crypt_stat->cs_mutex);
+
+ rc = inode_change_ok(inode, ia);
+ if (rc)
+ goto out;
+ if (ia->ia_valid & ATTR_SIZE) {
+ rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
+ if (rc)
+ goto out;
+ }
+
if (S_ISREG(inode->i_mode)) {
rc = filemap_write_and_wait(inode->i_mapping);
if (rc)
diff --git a/fs/ecryptfs/keystore.c b/fs/ecryptfs/keystore.c
index ac1ad48c2376..8e3b943e330f 100644
--- a/fs/ecryptfs/keystore.c
+++ b/fs/ecryptfs/keystore.c
@@ -109,7 +109,7 @@ int ecryptfs_parse_packet_length(unsigned char *data, size_t *size,
(*size) += ((unsigned char)(data[1]) + 192);
(*length_size) = 2;
} else if (data[0] == 255) {
- /* Five-byte length; we're not supposed to see this */
+ /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
ecryptfs_printk(KERN_ERR, "Five-byte packet length not "
"supported\n");
rc = -EINVAL;
@@ -126,7 +126,7 @@ out:
/**
* ecryptfs_write_packet_length
* @dest: The byte array target into which to write the length. Must
- * have at least 5 bytes allocated.
+ * have at least ECRYPTFS_MAX_PKT_LEN_SIZE bytes allocated.
* @size: The length to write.
* @packet_size_length: The number of bytes used to encode the packet
* length is written to this address.
@@ -146,6 +146,7 @@ int ecryptfs_write_packet_length(char *dest, size_t size,
dest[1] = ((size - 192) % 256);
(*packet_size_length) = 2;
} else {
+ /* If support is added, adjust ECRYPTFS_MAX_PKT_LEN_SIZE */
rc = -EINVAL;
ecryptfs_printk(KERN_WARNING,
"Unsupported packet size: [%zd]\n", size);
diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 940a82e63dc3..349209dc6a91 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -218,6 +218,29 @@ out_unlock:
return rc;
}
+/*
+ * miscdevfs packet format:
+ * Octet 0: Type
+ * Octets 1-4: network byte order msg_ctx->counter
+ * Octets 5-N0: Size of struct ecryptfs_message to follow
+ * Octets N0-N1: struct ecryptfs_message (including data)
+ *
+ * Octets 5-N1 not written if the packet type does not include a message
+ */
+#define PKT_TYPE_SIZE 1
+#define PKT_CTR_SIZE 4
+#define MIN_NON_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE)
+#define MIN_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \
+ + ECRYPTFS_MIN_PKT_LEN_SIZE)
+/* 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES comes from tag 65 packet format */
+#define MAX_MSG_PKT_SIZE (PKT_TYPE_SIZE + PKT_CTR_SIZE \
+ + ECRYPTFS_MAX_PKT_LEN_SIZE \
+ + sizeof(struct ecryptfs_message) \
+ + 4 + ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES)
+#define PKT_TYPE_OFFSET 0
+#define PKT_CTR_OFFSET PKT_TYPE_SIZE
+#define PKT_LEN_OFFSET (PKT_TYPE_SIZE + PKT_CTR_SIZE)
+
/**
* ecryptfs_miscdev_read - format and send message from queue
* @file: fs/ecryptfs/euid miscdevfs handle (ignored)
@@ -237,7 +260,7 @@ ecryptfs_miscdev_read(struct file *file, char __user *buf, size_t count,
struct ecryptfs_daemon *daemon;
struct ecryptfs_msg_ctx *msg_ctx;
size_t packet_length_size;
- char packet_length[3];
+ char packet_length[ECRYPTFS_MAX_PKT_LEN_SIZE];
size_t i;
size_t total_length;
uid_t euid = current_euid();
@@ -305,15 +328,8 @@ check_list:
packet_length_size = 0;
msg_ctx->msg_size = 0;
}
- /* miscdevfs packet format:
- * Octet 0: Type
- * Octets 1-4: network byte order msg_ctx->counter
- * Octets 5-N0: Size of struct ecryptfs_message to follow
- * Octets N0-N1: struct ecryptfs_message (including data)
- *
- * Octets 5-N1 not written if the packet type does not
- * include a message */
- total_length = (1 + 4 + packet_length_size + msg_ctx->msg_size);
+ total_length = (PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_length_size
+ + msg_ctx->msg_size);
if (count < total_length) {
rc = 0;
printk(KERN_WARNING "%s: Only given user buffer of "
@@ -324,9 +340,10 @@ check_list:
rc = -EFAULT;
if (put_user(msg_ctx->type, buf))
goto out_unlock_msg_ctx;
- if (put_user(cpu_to_be32(msg_ctx->counter), (__be32 __user *)(buf + 1)))
+ if (put_user(cpu_to_be32(msg_ctx->counter),
+ (__be32 __user *)(&buf[PKT_CTR_OFFSET])))
goto out_unlock_msg_ctx;
- i = 5;
+ i = PKT_TYPE_SIZE + PKT_CTR_SIZE;
if (msg_ctx->msg) {
if (copy_to_user(&buf[i], packet_length, packet_length_size))
goto out_unlock_msg_ctx;
@@ -391,12 +408,6 @@ out:
* @count: Amount of data in @buf
* @ppos: Pointer to offset in file (ignored)
*
- * miscdevfs packet format:
- * Octet 0: Type
- * Octets 1-4: network byte order msg_ctx->counter (0's for non-response)
- * Octets 5-N0: Size of struct ecryptfs_message to follow
- * Octets N0-N1: struct ecryptfs_message (including data)
- *
* Returns the number of bytes read from @buf
*/
static ssize_t
@@ -405,60 +416,78 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
{
__be32 counter_nbo;
u32 seq;
- size_t packet_size, packet_size_length, i;
- ssize_t sz = 0;
+ size_t packet_size, packet_size_length;
char *data;
uid_t euid = current_euid();
- int rc;
+ unsigned char packet_size_peek[ECRYPTFS_MAX_PKT_LEN_SIZE];
+ ssize_t rc;
- if (count == 0)
- goto out;
+ if (count == 0) {
+ return 0;
+ } else if (count == MIN_NON_MSG_PKT_SIZE) {
+ /* Likely a harmless MSG_HELO or MSG_QUIT - no packet length */
+ goto memdup;
+ } else if (count < MIN_MSG_PKT_SIZE || count > MAX_MSG_PKT_SIZE) {
+ printk(KERN_WARNING "%s: Acceptable packet size range is "
+ "[%d-%lu], but amount of data written is [%zu].",
+ __func__, MIN_MSG_PKT_SIZE, MAX_MSG_PKT_SIZE, count);
+ return -EINVAL;
+ }
+
+ if (copy_from_user(packet_size_peek, &buf[PKT_LEN_OFFSET],
+ sizeof(packet_size_peek))) {
+ printk(KERN_WARNING "%s: Error while inspecting packet size\n",
+ __func__);
+ return -EFAULT;
+ }
+ rc = ecryptfs_parse_packet_length(packet_size_peek, &packet_size,
+ &packet_size_length);
+ if (rc) {
+ printk(KERN_WARNING "%s: Error parsing packet length; "
+ "rc = [%zd]\n", __func__, rc);
+ return rc;
+ }
+
+ if ((PKT_TYPE_SIZE + PKT_CTR_SIZE + packet_size_length + packet_size)
+ != count) {
+ printk(KERN_WARNING "%s: Invalid packet size [%zu]\n", __func__,
+ packet_size);
+ return -EINVAL;
+ }
+
+memdup:
data = memdup_user(buf, count);
if (IS_ERR(data)) {
printk(KERN_ERR "%s: memdup_user returned error [%ld]\n",
__func__, PTR_ERR(data));
- goto out;
+ return PTR_ERR(data);
}
- sz = count;
- i = 0;
- switch (data[i++]) {
+ switch (data[PKT_TYPE_OFFSET]) {
case ECRYPTFS_MSG_RESPONSE:
- if (count < (1 + 4 + 1 + sizeof(struct ecryptfs_message))) {
+ if (count < (MIN_MSG_PKT_SIZE
+ + sizeof(struct ecryptfs_message))) {
printk(KERN_WARNING "%s: Minimum acceptable packet "
"size is [%zd], but amount of data written is "
"only [%zd]. Discarding response packet.\n",
__func__,
- (1 + 4 + 1 + sizeof(struct ecryptfs_message)),
- count);
+ (MIN_MSG_PKT_SIZE
+ + sizeof(struct ecryptfs_message)), count);
+ rc = -EINVAL;
goto out_free;
}
- memcpy(&counter_nbo, &data[i], 4);
+ memcpy(&counter_nbo, &data[PKT_CTR_OFFSET], PKT_CTR_SIZE);
seq = be32_to_cpu(counter_nbo);
- i += 4;
- rc = ecryptfs_parse_packet_length(&data[i], &packet_size,
- &packet_size_length);
+ rc = ecryptfs_miscdev_response(
+ &data[PKT_LEN_OFFSET + packet_size_length],
+ packet_size, euid, current_user_ns(),
+ task_pid(current), seq);
if (rc) {
- printk(KERN_WARNING "%s: Error parsing packet length; "
- "rc = [%d]\n", __func__, rc);
- goto out_free;
- }
- i += packet_size_length;
- if ((1 + 4 + packet_size_length + packet_size) != count) {
- printk(KERN_WARNING "%s: (1 + packet_size_length([%zd])"
- " + packet_size([%zd]))([%zd]) != "
- "count([%zd]). Invalid packet format.\n",
- __func__, packet_size_length, packet_size,
- (1 + packet_size_length + packet_size), count);
- goto out_free;
- }
- rc = ecryptfs_miscdev_response(&data[i], packet_size,
- euid, current_user_ns(),
- task_pid(current), seq);
- if (rc)
printk(KERN_WARNING "%s: Failed to deliver miscdev "
- "response to requesting operation; rc = [%d]\n",
+ "response to requesting operation; rc = [%zd]\n",
__func__, rc);
+ goto out_free;
+ }
break;
case ECRYPTFS_MSG_HELO:
case ECRYPTFS_MSG_QUIT:
@@ -467,12 +496,13 @@ ecryptfs_miscdev_write(struct file *file, const char __user *buf,
ecryptfs_printk(KERN_WARNING, "Dropping miscdev "
"message of unrecognized type [%d]\n",
data[0]);
- break;
+ rc = -EINVAL;
+ goto out_free;
}
+ rc = count;
out_free:
kfree(data);
-out:
- return sz;
+ return rc;
}
diff --git a/fs/ecryptfs/read_write.c b/fs/ecryptfs/read_write.c
index 3745f7c2b9c2..5c0106f75775 100644
--- a/fs/ecryptfs/read_write.c
+++ b/fs/ecryptfs/read_write.c
@@ -130,13 +130,18 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT);
size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK);
size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page);
- size_t total_remaining_bytes = ((offset + size) - pos);
+ loff_t total_remaining_bytes = ((offset + size) - pos);
+
+ if (fatal_signal_pending(current)) {
+ rc = -EINTR;
+ break;
+ }
if (num_bytes > total_remaining_bytes)
num_bytes = total_remaining_bytes;
if (pos < offset) {
/* remaining zeros to write, up to destination offset */
- size_t total_remaining_zeros = (offset - pos);
+ loff_t total_remaining_zeros = (offset - pos);
if (num_bytes > total_remaining_zeros)
num_bytes = total_remaining_zeros;
@@ -193,15 +198,19 @@ int ecryptfs_write(struct inode *ecryptfs_inode, char *data, loff_t offset,
}
pos += num_bytes;
}
- if ((offset + size) > ecryptfs_file_size) {
- i_size_write(ecryptfs_inode, (offset + size));
+ if (pos > ecryptfs_file_size) {
+ i_size_write(ecryptfs_inode, pos);
if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) {
- rc = ecryptfs_write_inode_size_to_metadata(
+ int rc2;
+
+ rc2 = ecryptfs_write_inode_size_to_metadata(
ecryptfs_inode);
- if (rc) {
+ if (rc2) {
printk(KERN_ERR "Problem with "
"ecryptfs_write_inode_size_to_metadata; "
- "rc = [%d]\n", rc);
+ "rc = [%d]\n", rc2);
+ if (!rc)
+ rc = rc2;
goto out;
}
}
@@ -273,76 +282,3 @@ int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs,
flush_dcache_page(page_for_ecryptfs);
return rc;
}
-
-#if 0
-/**
- * ecryptfs_read
- * @data: The virtual address into which to write the data read (and
- * possibly decrypted) from the lower file
- * @offset: The offset in the decrypted view of the file from which to
- * read into @data
- * @size: The number of bytes to read into @data
- * @ecryptfs_file: The eCryptfs file from which to read
- *
- * Read an arbitrary amount of data from an arbitrary location in the
- * eCryptfs page cache. This is done on an extent-by-extent basis;
- * individual extents are decrypted and read from the lower page
- * cache (via VFS reads). This function takes care of all the
- * address translation to locations in the lower filesystem.
- *
- * Returns zero on success; non-zero otherwise
- */
-int ecryptfs_read(char *data, loff_t offset, size_t size,
- struct file *ecryptfs_file)
-{
- struct inode *ecryptfs_inode = ecryptfs_file->f_dentry->d_inode;
- struct page *ecryptfs_page;
- char *ecryptfs_page_virt;
- loff_t ecryptfs_file_size = i_size_read(ecryptfs_inode);
- loff_t data_offset = 0;
- loff_t pos;
- int rc = 0;
-
- if ((offset + size) > ecryptfs_file_size) {
- rc = -EINVAL;
- printk(KERN_ERR "%s: Attempt to read data past the end of the "
- "file; offset = [%lld]; size = [%td]; "
- "ecryptfs_file_size = [%lld]\n",
- __func__, offset, size, ecryptfs_file_size);
- goto out;
- }
- pos = offset;
- while (pos < (offset + size)) {
- pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT);
- size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK);
- size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page);
- size_t total_remaining_bytes = ((offset + size) - pos);
-
- if (num_bytes > total_remaining_bytes)
- num_bytes = total_remaining_bytes;
- ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_inode,
- ecryptfs_page_idx);
- if (IS_ERR(ecryptfs_page)) {
- rc = PTR_ERR(ecryptfs_page);
- printk(KERN_ERR "%s: Error getting page at "
- "index [%ld] from eCryptfs inode "
- "mapping; rc = [%d]\n", __func__,
- ecryptfs_page_idx, rc);
- goto out;
- }
- ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0);
- memcpy((data + data_offset),
- ((char *)ecryptfs_page_virt + start_offset_in_page),
- num_bytes);
- kunmap_atomic(ecryptfs_page_virt, KM_USER0);
- flush_dcache_page(ecryptfs_page);
- SetPageUptodate(ecryptfs_page);
- unlock_page(ecryptfs_page);
- page_cache_release(ecryptfs_page);
- pos += num_bytes;
- data_offset += num_bytes;
- }
-out:
- return rc;
-}
-#endif /* 0 */

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