diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-04 11:15:50 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2021-09-04 11:15:50 -0700 |
commit | f7464060f7ab9a2424428008f0ee9f1e267e410f (patch) | |
tree | ebed9542b3efeafe3ba6a3b8df107e644a9933de /fs/ntfs3/bitfunc.c | |
parent | Merge tag 'f2fs-for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs (diff) | |
parent | fs/ntfs3: Change how module init/info messages are displayed (diff) | |
download | linux-dev-f7464060f7ab9a2424428008f0ee9f1e267e410f.tar.xz linux-dev-f7464060f7ab9a2424428008f0ee9f1e267e410f.zip |
Merge git://github.com/Paragon-Software-Group/linux-ntfs3
Merge NTFSv3 filesystem from Konstantin Komarov:
"This patch adds NTFS Read-Write driver to fs/ntfs3.
Having decades of expertise in commercial file systems development and
huge test coverage, we at Paragon Software GmbH want to make our
contribution to the Open Source Community by providing implementation
of NTFS Read-Write driver for the Linux Kernel.
This is fully functional NTFS Read-Write driver. Current version works
with NTFS (including v3.1) and normal/compressed/sparse files and
supports journal replaying.
We plan to support this version after the codebase once merged, and
add new features and fix bugs. For example, full journaling support
over JBD will be added in later updates"
Link: https://lore.kernel.org/lkml/20210729134943.778917-1-almaz.alexandrovich@paragon-software.com/
Link: https://lore.kernel.org/lkml/aa4aa155-b9b2-9099-b7a2-349d8d9d8fbd@paragon-software.com/
* git://github.com/Paragon-Software-Group/linux-ntfs3: (35 commits)
fs/ntfs3: Change how module init/info messages are displayed
fs/ntfs3: Remove GPL boilerplates from decompress lib files
fs/ntfs3: Remove unnecessary condition checking from ntfs_file_read_iter
fs/ntfs3: Fix integer overflow in ni_fiemap with fiemap_prep()
fs/ntfs3: Restyle comments to better align with kernel-doc
fs/ntfs3: Rework file operations
fs/ntfs3: Remove fat ioctl's from ntfs3 driver for now
fs/ntfs3: Restyle comments to better align with kernel-doc
fs/ntfs3: Fix error handling in indx_insert_into_root()
fs/ntfs3: Potential NULL dereference in hdr_find_split()
fs/ntfs3: Fix error code in indx_add_allocate()
fs/ntfs3: fix an error code in ntfs_get_acl_ex()
fs/ntfs3: add checks for allocation failure
fs/ntfs3: Use kcalloc/kmalloc_array over kzalloc/kmalloc
fs/ntfs3: Do not use driver own alloc wrappers
fs/ntfs3: Use kernel ALIGN macros over driver specific
fs/ntfs3: Restyle comment block in ni_parse_reparse()
fs/ntfs3: Remove unused including <linux/version.h>
fs/ntfs3: Fix fall-through warnings for Clang
fs/ntfs3: Fix one none utf8 char in source file
...
Diffstat (limited to 'fs/ntfs3/bitfunc.c')
-rw-r--r-- | fs/ntfs3/bitfunc.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/fs/ntfs3/bitfunc.c b/fs/ntfs3/bitfunc.c new file mode 100644 index 000000000000..ce304d40b5e1 --- /dev/null +++ b/fs/ntfs3/bitfunc.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * + * Copyright (C) 2019-2021 Paragon Software GmbH, All rights reserved. + * + */ + +#include <linux/blkdev.h> +#include <linux/buffer_head.h> +#include <linux/fs.h> +#include <linux/nls.h> + +#include "debug.h" +#include "ntfs.h" +#include "ntfs_fs.h" + +#define BITS_IN_SIZE_T (sizeof(size_t) * 8) + +/* + * fill_mask[i] - first i bits are '1' , i = 0,1,2,3,4,5,6,7,8 + * fill_mask[i] = 0xFF >> (8-i) + */ +static const u8 fill_mask[] = { 0x00, 0x01, 0x03, 0x07, 0x0F, + 0x1F, 0x3F, 0x7F, 0xFF }; + +/* + * zero_mask[i] - first i bits are '0' , i = 0,1,2,3,4,5,6,7,8 + * zero_mask[i] = 0xFF << i + */ +static const u8 zero_mask[] = { 0xFF, 0xFE, 0xFC, 0xF8, 0xF0, + 0xE0, 0xC0, 0x80, 0x00 }; + +/* + * are_bits_clear + * + * Return: True if all bits [bit, bit+nbits) are zeros "0". + */ +bool are_bits_clear(const ulong *lmap, size_t bit, size_t nbits) +{ + size_t pos = bit & 7; + const u8 *map = (u8 *)lmap + (bit >> 3); + + if (pos) { + if (8 - pos >= nbits) + return !nbits || !(*map & fill_mask[pos + nbits] & + zero_mask[pos]); + + if (*map++ & zero_mask[pos]) + return false; + nbits -= 8 - pos; + } + + pos = ((size_t)map) & (sizeof(size_t) - 1); + if (pos) { + pos = sizeof(size_t) - pos; + if (nbits >= pos * 8) { + for (nbits -= pos * 8; pos; pos--, map++) { + if (*map) + return false; + } + } + } + + for (pos = nbits / BITS_IN_SIZE_T; pos; pos--, map += sizeof(size_t)) { + if (*((size_t *)map)) + return false; + } + + for (pos = (nbits % BITS_IN_SIZE_T) >> 3; pos; pos--, map++) { + if (*map) + return false; + } + + pos = nbits & 7; + if (pos && (*map & fill_mask[pos])) + return false; + + return true; +} + +/* + * are_bits_set + * + * Return: True if all bits [bit, bit+nbits) are ones "1". + */ +bool are_bits_set(const ulong *lmap, size_t bit, size_t nbits) +{ + u8 mask; + size_t pos = bit & 7; + const u8 *map = (u8 *)lmap + (bit >> 3); + + if (pos) { + if (8 - pos >= nbits) { + mask = fill_mask[pos + nbits] & zero_mask[pos]; + return !nbits || (*map & mask) == mask; + } + + mask = zero_mask[pos]; + if ((*map++ & mask) != mask) + return false; + nbits -= 8 - pos; + } + + pos = ((size_t)map) & (sizeof(size_t) - 1); + if (pos) { + pos = sizeof(size_t) - pos; + if (nbits >= pos * 8) { + for (nbits -= pos * 8; pos; pos--, map++) { + if (*map != 0xFF) + return false; + } + } + } + + for (pos = nbits / BITS_IN_SIZE_T; pos; pos--, map += sizeof(size_t)) { + if (*((size_t *)map) != MINUS_ONE_T) + return false; + } + + for (pos = (nbits % BITS_IN_SIZE_T) >> 3; pos; pos--, map++) { + if (*map != 0xFF) + return false; + } + + pos = nbits & 7; + if (pos) { + u8 mask = fill_mask[pos]; + + if ((*map & mask) != mask) + return false; + } + + return true; +} |