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author | David Woodhouse <David.Woodhouse@intel.com> | 2010-10-30 13:35:11 +0200 |
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committer | David Woodhouse <David.Woodhouse@intel.com> | 2010-10-30 13:35:11 +0200 |
commit | 67577927e8d7a1f4b09b4992df640eadc6aacb36 (patch) | |
tree | 2e9efe6b5745965faf0dcc084d4613d9356263f9 /fs/libfs.c | |
parent | MTD: Fix wrong check register_blkdev return value (diff) | |
parent | Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6 (diff) | |
download | linux-67577927e8d7a1f4b09b4992df640eadc6aacb36.tar.xz linux-67577927e8d7a1f4b09b4992df640eadc6aacb36.zip |
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Conflicts:
drivers/mtd/mtd_blkdevs.c
Merge Grant's device-tree bits so that we can apply the subsequent fixes.
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Diffstat (limited to 'fs/libfs.c')
-rw-r--r-- | fs/libfs.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 0a9da95317f7..62baa0387d6e 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -913,6 +913,35 @@ int generic_file_fsync(struct file *file, int datasync) } EXPORT_SYMBOL(generic_file_fsync); +/** + * generic_check_addressable - Check addressability of file system + * @blocksize_bits: log of file system block size + * @num_blocks: number of blocks in file system + * + * Determine whether a file system with @num_blocks blocks (and a + * block size of 2**@blocksize_bits) is addressable by the sector_t + * and page cache of the system. Return 0 if so and -EFBIG otherwise. + */ +int generic_check_addressable(unsigned blocksize_bits, u64 num_blocks) +{ + u64 last_fs_block = num_blocks - 1; + u64 last_fs_page = + last_fs_block >> (PAGE_CACHE_SHIFT - blocksize_bits); + + if (unlikely(num_blocks == 0)) + return 0; + + if ((blocksize_bits < 9) || (blocksize_bits > PAGE_CACHE_SHIFT)) + return -EINVAL; + + if ((last_fs_block > (sector_t)(~0ULL) >> (blocksize_bits - 9)) || + (last_fs_page > (pgoff_t)(~0ULL))) { + return -EFBIG; + } + return 0; +} +EXPORT_SYMBOL(generic_check_addressable); + /* * No-op implementation of ->fsync for in-memory filesystems. */ |