From cc9bf5d246fc23267e14cc328728f146aee142e2 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Mon, 18 Feb 2008 14:59:45 -0500 Subject: [PATCH] Add read/only support for extents to ext2fs_bmap() Signed-off-by: "Theodore Ts'o" --- lib/ext2fs/bmap.c | 75 ++++++++++++++++++++++++++++++++++++++++----- lib/ext2fs/ext2fs.h | 10 +++++- 2 files changed, 76 insertions(+), 9 deletions(-) diff --git a/lib/ext2fs/bmap.c b/lib/ext2fs/bmap.c index 76cac3f0..24f05fd2 100644 --- a/lib/ext2fs/bmap.c +++ b/lib/ext2fs/bmap.c @@ -14,6 +14,7 @@ #if HAVE_UNISTD_H #include #endif +#include #include "ext2_fs.h" #include "ext2fs.h" @@ -128,13 +129,14 @@ static _BMAP_INLINE_ errcode_t block_tind_bmap(ext2_filsys fs, int flags, return retval; } -errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, - char *block_buf, int bmap_flags, blk_t block, - blk_t *phys_blk) +errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, + char *block_buf, int bmap_flags, blk64_t block, + int *ret_flags, blk64_t *phys_blk) { struct ext2_inode inode_buf; + ext2_extent_handle_t handle = 0; blk_t addr_per_block; - blk_t b; + blk_t b, blk32; char *buf = 0; errcode_t retval = 0; int blocks_alloc = 0, inode_dirty = 0; @@ -142,6 +144,9 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, if (!(bmap_flags & BMAP_SET)) *phys_blk = 0; + if (ret_flags) + *ret_flags = 0; + /* Read inode structure if necessary */ if (!inode) { retval = ext2fs_read_inode(fs, ino, &inode_buf); @@ -151,6 +156,37 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, } addr_per_block = (blk_t) fs->blocksize >> 2; + if (inode->i_flags & EXT4_EXTENTS_FL) { + struct ext2fs_extent extent; + int offset; + + if (bmap_flags & BMAP_SET) { + retval = EXT2_ET_EXTENT_NOT_SUPPORTED; + goto done; + } + retval = ext2fs_extent_open(fs, ino, &handle); + if (retval) + goto done; + retval = ext2fs_extent_goto(handle, block); + if (retval) { + /* If the extent is not found, return phys_blk = 0 */ + if (retval == EXT2_ET_EXTENT_NOT_FOUND) + retval = 0; + goto done; + } + retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent); + if (retval) + goto done; + offset = block - extent.e_lblk; + if (block >= extent.e_lblk && (offset <= extent.e_len)) { + *phys_blk = extent.e_pblk + offset; + if (ret_flags && extent.e_flags & EXT2_EXTENT_FLAGS_UNINIT) + *ret_flags |= BMAP_RET_UNINIT; + } + retval = 0; + goto done; + } + if (!block_buf) { retval = ext2fs_get_array(2, fs->blocksize, &buf); if (retval) @@ -185,6 +221,7 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, /* Indirect block */ block -= EXT2_NDIR_BLOCKS; + blk32 = *phys_blk; if (block < addr_per_block) { b = inode_bmap(inode, EXT2_IND_BLOCK); if (!b) { @@ -202,7 +239,9 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, blocks_alloc++; } retval = block_ind_bmap(fs, bmap_flags, b, block_buf, - &blocks_alloc, block, phys_blk); + &blocks_alloc, block, &blk32); + if (retval == 0) + *phys_blk = blk32; goto done; } @@ -225,7 +264,9 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, blocks_alloc++; } retval = block_dind_bmap(fs, bmap_flags, b, block_buf, - &blocks_alloc, block, phys_blk); + &blocks_alloc, block, &blk32); + if (retval == 0) + *phys_blk = blk32; goto done; } @@ -247,10 +288,14 @@ errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, blocks_alloc++; } retval = block_tind_bmap(fs, bmap_flags, b, block_buf, - &blocks_alloc, block, phys_blk); + &blocks_alloc, block, &blk32); + if (retval == 0) + *phys_blk = blk32; done: if (buf) ext2fs_free_mem(&buf); + if (handle) + ext2fs_extent_free(handle); if ((retval == 0) && (blocks_alloc || inode_dirty)) { inode->i_blocks += (blocks_alloc * fs->blocksize) / 512; retval = ext2fs_write_inode(fs, ino, inode); @@ -258,5 +303,19 @@ done: return retval; } +errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, + char *block_buf, int bmap_flags, blk_t block, + blk_t *phys_blk) +{ + errcode_t ret; + blk64_t ret_blk; - + ret = ext2fs_bmap2(fs, ino, inode, block_buf, bmap_flags, block, + 0, &ret_blk); + if (ret) + return ret; + if (ret_blk >= ((long long) 1 << 32)) + return EOVERFLOW; + *phys_blk = ret_blk; + return 0; +} diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h index 563ec308..02d2b420 100644 --- a/lib/ext2fs/ext2fs.h +++ b/lib/ext2fs/ext2fs.h @@ -453,6 +453,11 @@ typedef struct ext2_icount *ext2_icount_t; #define BMAP_ALLOC 0x0001 #define BMAP_SET 0x0002 +/* + * Returned flags from ext2fs_bmap + */ +#define BMAP_RET_UNINIT 0x0001 + /* * Flags for imager.c functions */ @@ -668,7 +673,10 @@ extern errcode_t ext2fs_bmap(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, char *block_buf, int bmap_flags, blk_t block, blk_t *phys_blk); - +extern errcode_t ext2fs_bmap2(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode, + char *block_buf, int bmap_flags, blk64_t block, + int *ret_flags, blk64_t *phys_blk); #if 0 /* bmove.c */