/* * linux/fs/ext2/inode.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/inode.c * * Copyright (C) 1991, 1992 Linus Torvalds * * Goal-directed block allocation by Stephen Tweedie * (sct@dcs.ed.ac.uk), 1993, 1998 * Big-endian to little-endian byte-swapping/bitmaps by * David S. Miller (davem@caip.rutgers.edu), 1995 * 64-bit file support on 64-bit platforms by Jakub Jelinek * (jj@sunsite.ms.mff.cuni.cz) * * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 */ #include <linux/smp_lock.h> #include <linux/time.h> #include <linux/highuid.h> #include <linux/pagemap.h> #include <linux/quotaops.h> #include <linux/module.h> #include <linux/writeback.h> #include <linux/buffer_head.h> #include <linux/mpage.h> #include "ext2.h" #include "acl.h" #include "xip.h" MODULE_AUTHOR("Remy Card and others"); MODULE_DESCRIPTION("Second Extended Filesystem"); MODULE_LICENSE("GPL"); static int ext2_update_inode(struct inode * inode, int do_sync); /* * Test whether an inode is a fast symlink. */ static inline int ext2_inode_is_fast_symlink(struct inode *inode) { int ea_blocks = EXT2_I(inode)->i_file_acl ? (inode->i_sb->s_blocksize >> 9) : 0; return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); } /* * Called at each iput(). * * The inode may be "bad" if ext2_read_inode() saw an error from * ext2_get_inode(), so we need to check that to avoid freeing random disk * blocks. */ void ext2_put_inode(struct inode *inode) { if (!is_bad_inode(inode)) ext2_discard_prealloc(inode); } /* * Called at the last iput() if i_nlink is zero. */ void ext2_delete_inode (struct inode * inode) { truncate_inode_pages(&inode->i_data, 0); if (is_bad_inode(inode)) goto no_delete; EXT2_I(inode)->i_dtime = get_seconds(); mark_inode_dirty(inode); ext2_update_inode(inode, inode_needs_sync(inode)); inode->i_size = 0; if (inode->i_blocks) ext2_truncate (inode); ext2_free_inode (inode); return; no_delete: clear_inode(inode); /* We must guarantee clearing of inode... */ } void ext2_discard_prealloc (struct inode * inode) { #ifdef EXT2_PREALLOCATE struct ext2_inode_info *ei = EXT2_I(inode); write_lock(&ei->i_meta_lock); if (ei->i_prealloc_count) { unsigned short total = ei->i_prealloc_count; unsigned long block = ei->i_prealloc_block; ei->i_prealloc_count = 0; ei->i_prealloc_block = 0; write_unlock(&ei->i_meta_lock); ext2_free_blocks (inode, block, total); return; } else write_unlock(&ei->i_meta_lock); #endif } static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err) { #ifdef EXT2FS_DEBUG static unsigned long alloc_hits, alloc_attempts; #endif unsigned long result; #ifdef EXT2_PREALLOCATE struct ext2_inode_info *ei = EXT2_I(inode); write_lock(&ei->i_meta_lock); if (ei->i_prealloc_count && (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block)) { result = ei->i_prealloc_block++; ei->i_prealloc_count--; write_unlock(&ei->i_meta_lock); ext2_debug ("preallocation hit (%lu/%lu).\n", ++alloc_hits, ++alloc_attempts); } else { write_unlock(&ei->i_meta_lock); ext2_discard_prealloc (inode); ext2_debug ("preallocation miss (%lu/%lu).\n", alloc_hits, ++alloc_attempts); if (S_ISREG(inode->i_mode)) result = ext2_new_block (inode, goal, &ei->i_prealloc_count, &ei->i_prealloc_block, err); else result = ext2_new_block(inode, goal, NULL, NULL, err); } #else result = ext2_new_block (inode, goal, 0, 0, err); #endif return result; } typedef struct { __le32 *p; __le32 key; struct buffer_head *bh; } Indirect; static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) { p->key = *(p->p = v); p->bh = bh; } static inline int verify_chain(Indirect *from, Indirect *to) { while (from <= to && from->key == *from->p) from++; return (from > to); } /** * ext2_block_to_path - parse the block number into array of offsets * @inode: inode in question (we are only interested in its superblock) * @i_block: block number to be parsed * @offsets: array to store the offsets in * @boundary: set this non-zero if the referred-to block is likely to be * followed (on disk) by an indirect block. * To store the locations of file's data ext2 uses a data structure common * for UNIX filesystems - tree of pointers anchored in the inode, with * data blocks at leaves and indirect blocks in intermediate nodes. * This function translates the block number into path in that tree - * return value is the path length and @offsets[n] is the offset of * pointer to (n+1)th node in the nth one. If @block is out of range * (negative or too large) warning is printed and zero returned. * * Note: function doesn't find node addresses, so no IO is needed. All * we need to know is the capacity of indirect blocks (taken from the * inode->i_sb). */ /* * Portability note: the last comparison (check that we fit into triple * indirect block) is spelled differently, because otherwise on an * architecture with 32-bit longs and 8Kb pages we might get into trouble * if our filesystem had 8Kb blocks. We might use long long, but that would * kill us on x86. Oh, well, at least the sign propagation does not matter - * i_block would have to be negative in the very beginning, so we would not * get there at all. */ static int ext2_block_to_path(struct inode *inode, long i_block, int offsets[4], int *boundary) { int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); const long direct_blocks = EXT2_NDIR_BLOCKS, indirect_blocks = ptrs, double_blocks = (1 << (ptrs_bits * 2)); int n = 0; int final = 0; if (i_block < 0) { ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); } else if (i_block < direct_blocks) { offsets[n++] = i_block; final = direct_blocks; } else if ( (i_block -= direct_blocks) < indirect_blocks) { offsets[n++] = EXT2_IND_BLOCK; offsets[n++] = i_block; final = ptrs; } else if ((i_block -= indirect_blocks) < double_blocks) { offsets[n++] = EXT2_DIND_BLOCK; offsets[n++] = i_block >> ptrs_bits; offsets[n++] = i_block & (ptrs - 1); final = ptrs; } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { offsets[n++] = EXT2_TIND_BLOCK; offsets[n++] = i_block >> (ptrs_bits * 2); offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); offsets[n++] = i_block & (ptrs - 1); final = ptrs; } else { ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); } if (boundary) *boundary = (i_block & (ptrs - 1)) == (final - 1); return n; } /** * ext2_get_branch - read the chain of indirect blocks leading to data * @inode: inode in question * @depth: depth of the chain (1 - direct pointer, etc.) * @offsets: offsets of pointers in inode/indirect blocks * @chain: place to store the result * @err: here we store the error value * * Function fills the array of triples <key, p, bh> and returns %NULL * if everything went OK or the pointer to the last filled triple * (incomplete one) otherwise. Upon the return chain[i].key contains * the number of (i+1)-th block in the chain (as it is stored in memory, * i.e. little-endian 32-bit), chain[i].p contains the address of that * number (it points into struct inode for i==0 and into the bh->b_data * for i>0) and chain[i].bh points to the buffer_head of i-th indirect * block for i>0 and NULL for i==0. In other words, it holds the block * numbers of the chain, addresses they were taken from (and where we can * verify that chain did not change) and buffer_heads hosting these * numbers. * * Function stops when it stumbles upon zero pointer (absent block) * (pointer to last triple returned, *@err == 0) * or when it gets an IO error reading an indirect block * (ditto, *@err == -EIO) * or when it notices that chain had been changed while it was reading * (ditto, *@err == -EAGAIN) * or when it reads all @depth-1 indirect blocks successfully and finds * the whole chain, all way to the data (returns %NULL, *err == 0). */ static Indirect *ext2_get_branch(struct inode *inode, int depth, int *offsets, Indirect chain[4], int *err) { struct super_block *sb = inode->i_sb; Indirect *p = chain; struct buffer_head *bh; *err = 0; /* i_data is not going away, no lock needed */ add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); if (!p->key) goto no_block; while (--depth) { bh = sb_bread(sb, le32_to_cpu(p->key)); if (!bh) goto failure; read_lock(&EXT2_I(inode)->i_meta_lock); if (!verify_chain(chain, p)) goto changed; add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); read_unlock(&EXT2_I(inode)->i_meta_lock); if (!p->key) goto no_block; } return NULL; changed: read_unlock(&EXT2_I(inode)->i_meta_lock); brelse(bh); *err = -EAGAIN; goto no_block; failure: *err = -EIO; no_block: return p; } /** * ext2_find_near - find a place for allocation with sufficient locality * @inode: owner * @ind: descriptor of indirect block. * * This function returns the prefered place for block allocation. * It is used when heuristic for sequential allocation fails. * Rules are: * + if there is a block to the left of our position - allocate near it. * + if pointer will live in indirect block - allocate near that block. * + if pointer will live in inode - allocate in the same cylinder group. * * In the latter case we colour the starting block by the callers PID to * prevent it from clashing with concurrent allocations for a different inode * in the same block group. The PID is used here so that functionally related * files will be close-by on-disk. * * Caller must make sure that @ind is valid and will stay that way. */ static unsigned long ext2_find_near(struct inode *inode, Indirect *ind) { struct ext2_inode_info *ei = EXT2_I(inode); __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; __le32 *p; unsigned long bg_start; unsigned long colour; /* Try to find previous block */ for (p = ind->p - 1; p >= start; p--) if (*p) return le32_to_cpu(*p); /* No such thing, so let's try location of indirect block */ if (ind->bh) return ind->bh->b_blocknr; /* * It is going to be refered from inode itself? OK, just put it into * the same cylinder group then. */ bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) + le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block); colour = (current->pid % 16) * (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); return bg_start + colour; } /** * ext2_find_goal - find a prefered place for allocation. * @inode: owner * @block: block we want * @chain: chain of indirect blocks * @partial: pointer to the last triple within a chain * @goal: place to store the result. * * Normally this function find the prefered place for block allocation, * stores it in *@goal and returns zero. If the branch had been changed * under us we return -EAGAIN. */ static inline int ext2_find_goal(struct inode *inode, long block, Indirect chain[4], Indirect *partial, unsigned long *goal) { struct ext2_inode_info *ei = EXT2_I(inode); write_lock(&ei->i_meta_lock); if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) { ei->i_next_alloc_block++; ei->i_next_alloc_goal++; } if (verify_chain(chain, partial)) { /* * try the heuristic for sequential allocation, * failing that at least try to get decent locality. */ if (block == ei->i_next_alloc_block) *goal = ei->i_next_alloc_goal; if (!*goal) *goal = ext2_find_near(inode, partial); write_unlock(&ei->i_meta_lock); return 0; } write_unlock(&ei->i_meta_lock); return -EAGAIN; } /** * ext2_alloc_branch - allocate and set up a chain of blocks. * @inode: owner * @num: depth of the chain (number of blocks to allocate) * @offsets: offsets (in the blocks) to store the pointers to next. * @branch: place to store the chain in. * * This function allocates @num blocks, zeroes out all but the last one, * links them into chain and (if we are synchronous) writes them to disk. * In other words, it prepares a branch that can be spliced onto the * inode. It stores the information about that chain in the branch[], in * the same format as ext2_get_branch() would do. We are calling it after * we had read the existing part of chain and partial points to the last * triple of that (one with zero ->key). Upon the exit we have the same * picture as after the successful ext2_get_block(), excpet that in one * place chain is disconnected - *branch->p is still zero (we did not * set the last link), but branch->key contains the number that should * be placed into *branch->p to fill that gap. * * If allocation fails we free all blocks we've allocated (and forget * their buffer_heads) and return the error value the from failed * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain * as described above and return 0. */ static int ext2_alloc_branch(struct inode *inode, int num, unsigned long goal, int *offsets, Indirect *branch) { int blocksize = inode->i_sb->s_blocksize; int n = 0; int err; int i; int parent = ext2_alloc_block(inode, goal, &err); branch[0].key = cpu_to_le32(parent); if (parent) for (n = 1; n < num; n++) { struct buffer_head *bh; /* Allocate the next block */ int nr = ext2_alloc_block(inode, parent, &err); if (!nr) break; branch[n].key = cpu_to_le32(nr); /* * Get buffer_head for parent block, zero it out and set * the pointer to new one, then send parent to disk. */ bh = sb_getblk(inode->i_sb, parent); if (!bh) { err = -EIO; break; } lock_buffer(bh); memset(bh->b_data, 0, blocksize); branch[n].bh = bh; branch[n].p = (__le32 *) bh->b_data + offsets[n]; *branch[n].p = branch[n].key; set_buffer_uptodate(bh); unlock_buffer(bh); mark_buffer_dirty_inode(bh, inode); /* We used to sync bh here if IS_SYNC(inode). * But we now rely upon generic_osync_inode() * and b_inode_buffers. But not for directories. */ if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) sync_dirty_buffer(bh); parent = nr; } if (n == num) return 0; /* Allocation failed, free what we already allocated */ for (i = 1; i < n; i++) bforget(branch[i].bh); for (i = 0; i < n; i++) ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1); return err; } /** * ext2_splice_branch - splice the allocated branch onto inode. * @inode: owner * @block: (logical) number of block we are adding * @chain: chain of indirect blocks (with a missing link - see * ext2_alloc_branch) * @where: location of missing link * @num: number of blocks we are adding * * This function verifies that chain (up to the missing link) had not * changed, fills the missing link and does all housekeeping needed in * inode (->i_blocks, etc.). In case of success we end up with the full * chain to new block and return 0. Otherwise (== chain had been changed) * we free the new blocks (forgetting their buffer_heads, indeed) and * return -EAGAIN. */ static inline int ext2_splice_branch(struct inode *inode, long block, Indirect chain[4], Indirect *where, int num) { struct ext2_inode_info *ei = EXT2_I(inode); int i; /* Verify that place we are splicing to is still there and vacant */ write_lock(&ei->i_meta_lock); if (!verify_chain(chain, where-1) || *where->p) goto changed; /* That's it */ *where->p = where->key; ei->i_next_alloc_block = block; ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key); write_unlock(&ei->i_meta_lock); /* We are done with atomic stuff, now do the rest of housekeeping */ inode->i_ctime = CURRENT_TIME_SEC; /* had we spliced it onto indirect block? */ if (where->bh) mark_buffer_dirty_inode(where->bh, inode); mark_inode_dirty(inode); return 0; changed: write_unlock(&ei->i_meta_lock); for (i = 1; i < num; i++) bforget(where[i].bh); for (i = 0; i < num; i++) ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1); return -EAGAIN; } /* * Allocation strategy is simple: if we have to allocate something, we will * have to go the whole way to leaf. So let's do it before attaching anything * to tree, set linkage between the newborn blocks, write them if sync is * required, recheck the path, free and repeat if check fails, otherwise * set the last missing link (that will protect us from any truncate-generated * removals - all blocks on the path are immune now) and possibly force the * write on the parent block. * That has a nice additional property: no special recovery from the failed * allocations is needed - we simply release blocks and do not touch anything * reachable from inode. */ int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) { int err = -EIO; int offsets[4]; Indirect chain[4]; Indirect *partial; unsigned long goal; int left; int boundary = 0; int depth = ext2_block_to_path(inode, iblock, offsets, &boundary); if (depth == 0) goto out; reread: partial = ext2_get_branch(inode, depth, offsets, chain, &err); /* Simplest case - block found, no allocation needed */ if (!partial) { got_it: map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); if (boundary) set_buffer_boundary(bh_result); /* Clean up and exit */ partial = chain+depth-1; /* the whole chain */ goto cleanup; } /* Next simple case - plain lookup or failed read of indirect block */ if (!create || err == -EIO) { cleanup: while (partial > chain) { brelse(partial->bh); partial--; } out: return err; } /* * Indirect block might be removed by truncate while we were * reading it. Handling of that case (forget what we've got and * reread) is taken out of the main path. */ if (err == -EAGAIN) goto changed; goal = 0; if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0) goto changed; left = (chain + depth) - partial; err = ext2_alloc_branch(inode, left, goal, offsets+(partial-chain), partial); if (err) goto cleanup; if (ext2_use_xip(inode->i_sb)) { /* * we need to clear the block */ err = ext2_clear_xip_target (inode, le32_to_cpu(chain[depth-1].key)); if (err) goto cleanup; } if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0) goto changed; set_buffer_new(bh_result); goto got_it; changed: while (partial > chain) { brelse(partial->bh); partial--; } goto reread; } static int ext2_writepage(struct page *page, struct writeback_control *wbc) { return block_write_full_page(page, ext2_get_block, wbc); } static int ext2_readpage(struct file *file, struct page *page) { return mpage_readpage(page, ext2_get_block); } static int ext2_readpages(struct file *file, struct address_space *mapping, struct list_head *pages, unsigned nr_pages) { return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); } static int ext2_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { return block_prepare_write(page,from,to,ext2_get_block); } static int ext2_nobh_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { return nobh_prepare_write(page,from,to,ext2_get_block); } static int ext2_nobh_writepage(struct page *page, struct writeback_control *wbc) { return nobh_writepage(page, ext2_get_block, wbc); } static sector_t ext2_bmap(struct address_space *mapping, sector_t block) { return generic_block_bmap(mapping,block,ext2_get_block); } static int ext2_get_blocks(struct inode *inode, sector_t iblock, unsigned long max_blocks, struct buffer_head *bh_result, int create) { int ret; ret = ext2_get_block(inode, iblock, bh_result, create); if (ret == 0) bh_result->b_size = (1 << inode->i_blkbits); return ret; } static ssize_t ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, loff_t offset, unsigned long nr_segs) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, offset, nr_segs, ext2_get_blocks, NULL); } static int ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) { return mpage_writepages(mapping, wbc, ext2_get_block); } struct address_space_operations ext2_aops = { .readpage = ext2_readpage, .readpages = ext2_readpages, .writepage = ext2_writepage, .sync_page = block_sync_page, .prepare_write = ext2_prepare_write, .commit_write = generic_commit_write, .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, .migratepage = buffer_migrate_page, }; struct address_space_operations ext2_aops_xip = { .bmap = ext2_bmap, .get_xip_page = ext2_get_xip_page, }; struct address_space_operations ext2_nobh_aops = { .readpage = ext2_readpage, .readpages = ext2_readpages, .writepage = ext2_nobh_writepage, .sync_page = block_sync_page, .prepare_write = ext2_nobh_prepare_write, .commit_write = nobh_commit_write, .bmap = ext2_bmap, .direct_IO = ext2_direct_IO, .writepages = ext2_writepages, .migratepage = buffer_migrate_page, }; /* * Probably it should be a library function... search for first non-zero word * or memcmp with zero_page, whatever is better for particular architecture. * Linus? */ static inline int all_zeroes(__le32 *p, __le32 *q) { while (p < q) if (*p++) return 0; return 1; } /** * ext2_find_shared - find the indirect blocks for partial truncation. * @inode: inode in question * @depth: depth of the affected branch * @offsets: offsets of pointers in that branch (see ext2_block_to_path) * @chain: place to store the pointers to partial indirect blocks * @top: place to the (detached) top of branch * * This is a helper function used by ext2_truncate(). * * When we do truncate() we may have to clean the ends of several indirect * blocks but leave the blocks themselves alive. Block is partially * truncated if some data below the new i_size is refered from it (and * it is on the path to the first completely truncated data block, indeed). * We have to free the top of that path along with everything to the right * of the path. Since no allocation past the truncation point is possible * until ext2_truncate() finishes, we may safely do the latter, but top * of branch may require special attention - pageout below the truncation * point might try to populate it. * * We atomically detach the top of branch from the tree, store the block * number of its root in *@top, pointers to buffer_heads of partially * truncated blocks - in @chain[].bh and pointers to their last elements * that should not be removed - in @chain[].p. Return value is the pointer * to last filled element of @chain. * * The work left to caller to do the actual freeing of subtrees: * a) free the subtree starting from *@top * b) free the subtrees whose roots are stored in * (@chain[i].p+1 .. end of @chain[i].bh->b_data) * c) free the subtrees growing from the inode past the @chain[0].p * (no partially truncated stuff there). */ static Indirect *ext2_find_shared(struct inode *inode, int depth, int offsets[4], Indirect chain[4], __le32 *top) { Indirect *partial, *p; int k, err; *top = 0; for (k = depth; k > 1 && !offsets[k-1]; k--) ; partial = ext2_get_branch(inode, k, offsets, chain, &err); if (!partial) partial = chain + k-1; /* * If the branch acquired continuation since we've looked at it - * fine, it should all survive and (new) top doesn't belong to us. */ write_lock(&EXT2_I(inode)->i_meta_lock); if (!partial->key && *partial->p) { write_unlock(&EXT2_I(inode)->i_meta_lock); goto no_top; } for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) ; /* * OK, we've found the last block that must survive. The rest of our * branch should be detached before unlocking. However, if that rest * of branch is all ours and does not grow immediately from the inode * it's easier to cheat and just decrement partial->p. */ if (p == chain + k - 1 && p > chain) { p->p--; } else { *top = *p->p; *p->p = 0; } write_unlock(&EXT2_I(inode)->i_meta_lock); while(partial > p) { brelse(partial->bh); partial--; } no_top: return partial; } /** * ext2_free_data - free a list of data blocks * @inode: inode we are dealing with * @p: array of block numbers * @q: points immediately past the end of array * * We are freeing all blocks refered from that array (numbers are * stored as little-endian 32-bit) and updating @inode->i_blocks * appropriately. */ static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) { unsigned long block_to_free = 0, count = 0; unsigned long nr; for ( ; p < q ; p++) { nr = le32_to_cpu(*p); if (nr) { *p = 0; /* accumulate blocks to free if they're contiguous */ if (count == 0) goto free_this; else if (block_to_free == nr - count) count++; else { mark_inode_dirty(inode); ext2_free_blocks (inode, block_to_free, count); free_this: block_to_free = nr; count = 1; } } } if (count > 0) { mark_inode_dirty(inode); ext2_free_blocks (inode, block_to_free, count); } } /** * ext2_free_branches - free an array of branches * @inode: inode we are dealing with * @p: array of block numbers * @q: pointer immediately past the end of array * @depth: depth of the branches to free * * We are freeing all blocks refered from these branches (numbers are * stored as little-endian 32-bit) and updating @inode->i_blocks * appropriately. */ static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) { struct buffer_head * bh; unsigned long nr; if (depth--) { int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); for ( ; p < q ; p++) { nr = le32_to_cpu(*p); if (!nr) continue; *p = 0; bh = sb_bread(inode->i_sb, nr); /* * A read failure? Report error and clear slot * (should be rare). */ if (!bh) { ext2_error(inode->i_sb, "ext2_free_branches", "Read failure, inode=%ld, block=%ld", inode->i_ino, nr); continue; } ext2_free_branches(inode, (__le32*)bh->b_data, (__le32*)bh->b_data + addr_per_block, depth); bforget(bh); ext2_free_blocks(inode, nr, 1); mark_inode_dirty(inode); } } else ext2_free_data(inode, p, q); } void ext2_truncate (struct inode * inode) { __le32 *i_data = EXT2_I(inode)->i_data; int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); int offsets[4]; Indirect chain[4]; Indirect *partial; __le32 nr = 0; int n; long iblock; unsigned blocksize; if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))) return; if (ext2_inode_is_fast_symlink(inode)) return; if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return; ext2_discard_prealloc(inode); blocksize = inode->i_sb->s_blocksize; iblock = (inode->i_size + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); if (mapping_is_xip(inode->i_mapping)) xip_truncate_page(inode->i_mapping, inode->i_size); else if (test_opt(inode->i_sb, NOBH)) nobh_truncate_page(inode->i_mapping, inode->i_size); else block_truncate_page(inode->i_mapping, inode->i_size, ext2_get_block); n = ext2_block_to_path(inode, iblock, offsets, NULL); if (n == 0) return; if (n == 1) { ext2_free_data(inode, i_data+offsets[0], i_data + EXT2_NDIR_BLOCKS); goto do_indirects; } partial = ext2_find_shared(inode, n, offsets, chain, &nr); /* Kill the top of shared branch (already detached) */ if (nr) { if (partial == chain) mark_inode_dirty(inode); else mark_buffer_dirty_inode(partial->bh, inode); ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); } /* Clear the ends of indirect blocks on the shared branch */ while (partial > chain) { ext2_free_branches(inode, partial->p + 1, (__le32*)partial->bh->b_data+addr_per_block, (chain+n-1) - partial); mark_buffer_dirty_inode(partial->bh, inode); brelse (partial->bh); partial--; } do_indirects: /* Kill the remaining (whole) subtrees */ switch (offsets[0]) { default: nr = i_data[EXT2_IND_BLOCK]; if (nr) { i_data[EXT2_IND_BLOCK] = 0; mark_inode_dirty(inode); ext2_free_branches(inode, &nr, &nr+1, 1); } case EXT2_IND_BLOCK: nr = i_data[EXT2_DIND_BLOCK]; if (nr) { i_data[EXT2_DIND_BLOCK] = 0; mark_inode_dirty(inode); ext2_free_branches(inode, &nr, &nr+1, 2); } case EXT2_DIND_BLOCK: nr = i_data[EXT2_TIND_BLOCK]; if (nr) { i_data[EXT2_TIND_BLOCK] = 0; mark_inode_dirty(inode); ext2_free_branches(inode, &nr, &nr+1, 3); } case EXT2_TIND_BLOCK: ; } inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; if (inode_needs_sync(inode)) { sync_mapping_buffers(inode->i_mapping); ext2_sync_inode (inode); } else { mark_inode_dirty(inode); } } static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, struct buffer_head **p) { struct buffer_head * bh; unsigned long block_group; unsigned long block; unsigned long offset; struct ext2_group_desc * gdp; *p = NULL; if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) goto Einval; block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); gdp = ext2_get_group_desc(sb, block_group, &bh); if (!gdp) goto Egdp; /* * Figure out the offset within the block group inode table */ offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); block = le32_to_cpu(gdp->bg_inode_table) + (offset >> EXT2_BLOCK_SIZE_BITS(sb)); if (!(bh = sb_bread(sb, block))) goto Eio; *p = bh; offset &= (EXT2_BLOCK_SIZE(sb) - 1); return (struct ext2_inode *) (bh->b_data + offset); Einval: ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", (unsigned long) ino); return ERR_PTR(-EINVAL); Eio: ext2_error(sb, "ext2_get_inode", "unable to read inode block - inode=%lu, block=%lu", (unsigned long) ino, block); Egdp: return ERR_PTR(-EIO); } void ext2_set_inode_flags(struct inode *inode) { unsigned int flags = EXT2_I(inode)->i_flags; inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); if (flags & EXT2_SYNC_FL) inode->i_flags |= S_SYNC; if (flags & EXT2_APPEND_FL) inode->i_flags |= S_APPEND; if (flags & EXT2_IMMUTABLE_FL) inode->i_flags |= S_IMMUTABLE; if (flags & EXT2_NOATIME_FL) inode->i_flags |= S_NOATIME; if (flags & EXT2_DIRSYNC_FL) inode->i_flags |= S_DIRSYNC; } void ext2_read_inode (struct inode * inode) { struct ext2_inode_info *ei = EXT2_I(inode); ino_t ino = inode->i_ino; struct buffer_head * bh; struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); int n; #ifdef CONFIG_EXT2_FS_POSIX_ACL ei->i_acl = EXT2_ACL_NOT_CACHED; ei->i_default_acl = EXT2_ACL_NOT_CACHED; #endif if (IS_ERR(raw_inode)) goto bad_inode; inode->i_mode = le16_to_cpu(raw_inode->i_mode); inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); if (!(test_opt (inode->i_sb, NO_UID32))) { inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; } inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); inode->i_size = le32_to_cpu(raw_inode->i_size); inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime); inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime); inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime); inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); /* We now have enough fields to check if the inode was active or not. * This is needed because nfsd might try to access dead inodes * the test is that same one that e2fsck uses * NeilBrown 1999oct15 */ if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { /* this inode is deleted */ brelse (bh); goto bad_inode; } inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size (for stat), not the fs block size */ inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); ei->i_flags = le32_to_cpu(raw_inode->i_flags); ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); ei->i_frag_no = raw_inode->i_frag; ei->i_frag_size = raw_inode->i_fsize; ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); ei->i_dir_acl = 0; if (S_ISREG(inode->i_mode)) inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; else ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); ei->i_dtime = 0; inode->i_generation = le32_to_cpu(raw_inode->i_generation); ei->i_state = 0; ei->i_next_alloc_block = 0; ei->i_next_alloc_goal = 0; ei->i_prealloc_count = 0; ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); ei->i_dir_start_lookup = 0; /* * NOTE! The in-memory inode i_data array is in little-endian order * even on big-endian machines: we do NOT byteswap the block numbers! */ for (n = 0; n < EXT2_N_BLOCKS; n++) ei->i_data[n] = raw_inode->i_block[n]; if (S_ISREG(inode->i_mode)) { inode->i_op = &ext2_file_inode_operations; if (ext2_use_xip(inode->i_sb)) { inode->i_mapping->a_ops = &ext2_aops_xip; inode->i_fop = &ext2_xip_file_operations; } else if (test_opt(inode->i_sb, NOBH)) { inode->i_mapping->a_ops = &ext2_nobh_aops; inode->i_fop = &ext2_file_operations; } else { inode->i_mapping->a_ops = &ext2_aops; inode->i_fop = &ext2_file_operations; } } else if (S_ISDIR(inode->i_mode)) { inode->i_op = &ext2_dir_inode_operations; inode->i_fop = &ext2_dir_operations; if (test_opt(inode->i_sb, NOBH)) inode->i_mapping->a_ops = &ext2_nobh_aops; else inode->i_mapping->a_ops = &ext2_aops; } else if (S_ISLNK(inode->i_mode)) { if (ext2_inode_is_fast_symlink(inode)) inode->i_op = &ext2_fast_symlink_inode_operations; else { inode->i_op = &ext2_symlink_inode_operations; if (test_opt(inode->i_sb, NOBH)) inode->i_mapping->a_ops = &ext2_nobh_aops; else inode->i_mapping->a_ops = &ext2_aops; } } else { inode->i_op = &ext2_special_inode_operations; if (raw_inode->i_block[0]) init_special_inode(inode, inode->i_mode, old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); else init_special_inode(inode, inode->i_mode, new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); } brelse (bh); ext2_set_inode_flags(inode); return; bad_inode: make_bad_inode(inode); return; } static int ext2_update_inode(struct inode * inode, int do_sync) { struct ext2_inode_info *ei = EXT2_I(inode); struct super_block *sb = inode->i_sb; ino_t ino = inode->i_ino; uid_t uid = inode->i_uid; gid_t gid = inode->i_gid; struct buffer_head * bh; struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); int n; int err = 0; if (IS_ERR(raw_inode)) return -EIO; /* For fields not not tracking in the in-memory inode, * initialise them to zero for new inodes. */ if (ei->i_state & EXT2_STATE_NEW) memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); raw_inode->i_mode = cpu_to_le16(inode->i_mode); if (!(test_opt(sb, NO_UID32))) { raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); /* * Fix up interoperability with old kernels. Otherwise, old inodes get * re-used with the upper 16 bits of the uid/gid intact */ if (!ei->i_dtime) { raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); } else { raw_inode->i_uid_high = 0; raw_inode->i_gid_high = 0; } } else { raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); raw_inode->i_uid_high = 0; raw_inode->i_gid_high = 0; } raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); raw_inode->i_size = cpu_to_le32(inode->i_size); raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); raw_inode->i_flags = cpu_to_le32(ei->i_flags); raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); raw_inode->i_frag = ei->i_frag_no; raw_inode->i_fsize = ei->i_frag_size; raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); if (!S_ISREG(inode->i_mode)) raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); else { raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); if (inode->i_size > 0x7fffffffULL) { if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || EXT2_SB(sb)->s_es->s_rev_level == cpu_to_le32(EXT2_GOOD_OLD_REV)) { /* If this is the first large file * created, add a flag to the superblock. */ lock_kernel(); ext2_update_dynamic_rev(sb); EXT2_SET_RO_COMPAT_FEATURE(sb, EXT2_FEATURE_RO_COMPAT_LARGE_FILE); unlock_kernel(); ext2_write_super(sb); } } } raw_inode->i_generation = cpu_to_le32(inode->i_generation); if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { if (old_valid_dev(inode->i_rdev)) { raw_inode->i_block[0] = cpu_to_le32(old_encode_dev(inode->i_rdev)); raw_inode->i_block[1] = 0; } else { raw_inode->i_block[0] = 0; raw_inode->i_block[1] = cpu_to_le32(new_encode_dev(inode->i_rdev)); raw_inode->i_block[2] = 0; } } else for (n = 0; n < EXT2_N_BLOCKS; n++) raw_inode->i_block[n] = ei->i_data[n]; mark_buffer_dirty(bh); if (do_sync) { sync_dirty_buffer(bh); if (buffer_req(bh) && !buffer_uptodate(bh)) { printk ("IO error syncing ext2 inode [%s:%08lx]\n", sb->s_id, (unsigned long) ino); err = -EIO; } } ei->i_state &= ~EXT2_STATE_NEW; brelse (bh); return err; } int ext2_write_inode(struct inode *inode, int wait) { return ext2_update_inode(inode, wait); } int ext2_sync_inode(struct inode *inode) { struct writeback_control wbc = { .sync_mode = WB_SYNC_ALL, .nr_to_write = 0, /* sys_fsync did this */ }; return sync_inode(inode, &wbc); } int ext2_setattr(struct dentry *dentry, struct iattr *iattr) { struct inode *inode = dentry->d_inode; int error; error = inode_change_ok(inode, iattr); if (error) return error; if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; if (error) return error; } error = inode_setattr(inode, iattr); if (!error && (iattr->ia_valid & ATTR_MODE)) error = ext2_acl_chmod(inode); return error; }