diff options
Diffstat (limited to 'fs/ceph/crypto.c')
| -rw-r--r-- | fs/ceph/crypto.c | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/fs/ceph/crypto.c b/fs/ceph/crypto.c index 5df2c52b384f..9494bf485f6a 100644 --- a/fs/ceph/crypto.c +++ b/fs/ceph/crypto.c @@ -9,6 +9,7 @@ #include <linux/ceph/ceph_debug.h> #include <linux/xattr.h> #include <linux/fscrypt.h> +#include <linux/ceph/striper.h> #include "super.h" #include "mds_client.h" @@ -365,3 +366,173 @@ int ceph_fscrypt_prepare_readdir(struct inode *dir) } return 0; } + +int ceph_fscrypt_decrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num) +{ + dout("%s: len %u offs %u blk %llu\n", __func__, len, offs, lblk_num); + return fscrypt_decrypt_block_inplace(inode, page, len, offs, lblk_num); +} + +int ceph_fscrypt_encrypt_block_inplace(const struct inode *inode, + struct page *page, unsigned int len, + unsigned int offs, u64 lblk_num, + gfp_t gfp_flags) +{ + dout("%s: len %u offs %u blk %llu\n", __func__, len, offs, lblk_num); + return fscrypt_encrypt_block_inplace(inode, page, len, offs, lblk_num, + gfp_flags); +} + +/** + * ceph_fscrypt_decrypt_pages - decrypt an array of pages + * @inode: pointer to inode associated with these pages + * @page: pointer to page array + * @off: offset into the file that the read data starts + * @len: max length to decrypt + * + * Decrypt an array of fscrypt'ed pages and return the amount of + * data decrypted. Any data in the page prior to the start of the + * first complete block in the read is ignored. Any incomplete + * crypto blocks at the end of the array are ignored (and should + * probably be zeroed by the caller). + * + * Returns the length of the decrypted data or a negative errno. + */ +int ceph_fscrypt_decrypt_pages(struct inode *inode, struct page **page, + u64 off, int len) +{ + int i, num_blocks; + u64 baseblk = off >> CEPH_FSCRYPT_BLOCK_SHIFT; + int ret = 0; + + /* + * We can't deal with partial blocks on an encrypted file, so mask off + * the last bit. + */ + num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK); + + /* Decrypt each block */ + for (i = 0; i < num_blocks; ++i) { + int blkoff = i << CEPH_FSCRYPT_BLOCK_SHIFT; + int pgidx = blkoff >> PAGE_SHIFT; + unsigned int pgoffs = offset_in_page(blkoff); + int fret; + + fret = ceph_fscrypt_decrypt_block_inplace(inode, page[pgidx], + CEPH_FSCRYPT_BLOCK_SIZE, pgoffs, + baseblk + i); + if (fret < 0) { + if (ret == 0) + ret = fret; + break; + } + ret += CEPH_FSCRYPT_BLOCK_SIZE; + } + return ret; +} + +/** + * ceph_fscrypt_decrypt_extents: decrypt received extents in given buffer + * @inode: inode associated with pages being decrypted + * @page: pointer to page array + * @off: offset into the file that the data in page[0] starts + * @map: pointer to extent array + * @ext_cnt: length of extent array + * + * Given an extent map and a page array, decrypt the received data in-place, + * skipping holes. Returns the offset into buffer of end of last decrypted + * block. + */ +int ceph_fscrypt_decrypt_extents(struct inode *inode, struct page **page, + u64 off, struct ceph_sparse_extent *map, + u32 ext_cnt) +{ + int i, ret = 0; + struct ceph_inode_info *ci = ceph_inode(inode); + u64 objno, objoff; + u32 xlen; + + /* Nothing to do for empty array */ + if (ext_cnt == 0) { + dout("%s: empty array, ret 0\n", __func__); + return 0; + } + + ceph_calc_file_object_mapping(&ci->i_layout, off, map[0].len, + &objno, &objoff, &xlen); + + for (i = 0; i < ext_cnt; ++i) { + struct ceph_sparse_extent *ext = &map[i]; + int pgsoff = ext->off - objoff; + int pgidx = pgsoff >> PAGE_SHIFT; + int fret; + + if ((ext->off | ext->len) & ~CEPH_FSCRYPT_BLOCK_MASK) { + pr_warn("%s: bad encrypted sparse extent idx %d off %llx len %llx\n", + __func__, i, ext->off, ext->len); + return -EIO; + } + fret = ceph_fscrypt_decrypt_pages(inode, &page[pgidx], + off + pgsoff, ext->len); + dout("%s: [%d] 0x%llx~0x%llx fret %d\n", __func__, i, + ext->off, ext->len, fret); + if (fret < 0) { + if (ret == 0) + ret = fret; + break; + } + ret = pgsoff + fret; + } + dout("%s: ret %d\n", __func__, ret); + return ret; +} + +/** + * ceph_fscrypt_encrypt_pages - encrypt an array of pages + * @inode: pointer to inode associated with these pages + * @page: pointer to page array + * @off: offset into the file that the data starts + * @len: max length to encrypt + * @gfp: gfp flags to use for allocation + * + * Decrypt an array of cleartext pages and return the amount of + * data encrypted. Any data in the page prior to the start of the + * first complete block in the read is ignored. Any incomplete + * crypto blocks at the end of the array are ignored. + * + * Returns the length of the encrypted data or a negative errno. + */ +int ceph_fscrypt_encrypt_pages(struct inode *inode, struct page **page, u64 off, + int len, gfp_t gfp) +{ + int i, num_blocks; + u64 baseblk = off >> CEPH_FSCRYPT_BLOCK_SHIFT; + int ret = 0; + + /* + * We can't deal with partial blocks on an encrypted file, so mask off + * the last bit. + */ + num_blocks = ceph_fscrypt_blocks(off, len & CEPH_FSCRYPT_BLOCK_MASK); + + /* Encrypt each block */ + for (i = 0; i < num_blocks; ++i) { + int blkoff = i << CEPH_FSCRYPT_BLOCK_SHIFT; + int pgidx = blkoff >> PAGE_SHIFT; + unsigned int pgoffs = offset_in_page(blkoff); + int fret; + + fret = ceph_fscrypt_encrypt_block_inplace(inode, page[pgidx], + CEPH_FSCRYPT_BLOCK_SIZE, pgoffs, + baseblk + i, gfp); + if (fret < 0) { + if (ret == 0) + ret = fret; + break; + } + ret += CEPH_FSCRYPT_BLOCK_SIZE; + } + return ret; +} |