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/*
* 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/fs.h>
#include <linux/ext2_fs.h>
#include <linux/locks.h>
#include <linux/smp_lock.h>
#include <linux/sched.h>
#include <linux/highuid.h>
#include <linux/quotaops.h>
#include <linux/module.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);
/*
* Called at each iput()
*/
void ext2_put_inode (struct inode * inode)
{
ext2_discard_prealloc (inode);
}
/*
* Called at the last iput() if i_nlink is zero.
*/
void ext2_delete_inode (struct inode * inode)
{
lock_kernel();
if (is_bad_inode(inode) ||
inode->i_ino == EXT2_ACL_IDX_INO ||
inode->i_ino == EXT2_ACL_DATA_INO)
goto no_delete;
inode->u.ext2_i.i_dtime = CURRENT_TIME;
mark_inode_dirty(inode);
ext2_update_inode(inode, IS_SYNC(inode));
inode->i_size = 0;
if (inode->i_blocks)
ext2_truncate (inode);
ext2_free_inode (inode);
unlock_kernel();
return;
no_delete:
unlock_kernel();
clear_inode(inode); /* We must guarantee clearing of inode... */
}
void ext2_discard_prealloc (struct inode * inode)
{
#ifdef EXT2_PREALLOCATE
lock_kernel();
/* Writer: ->i_prealloc* */
if (inode->u.ext2_i.i_prealloc_count) {
unsigned short total = inode->u.ext2_i.i_prealloc_count;
unsigned long block = inode->u.ext2_i.i_prealloc_block;
inode->u.ext2_i.i_prealloc_count = 0;
inode->u.ext2_i.i_prealloc_block = 0;
/* Writer: end */
ext2_free_blocks (inode, block, total);
}
unlock_kernel();
#endif
}
static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err)
{
#ifdef EXT2FS_DEBUG
static unsigned long alloc_hits = 0, alloc_attempts = 0;
#endif
unsigned long result;
#ifdef EXT2_PREALLOCATE
/* Writer: ->i_prealloc* */
if (inode->u.ext2_i.i_prealloc_count &&
(goal == inode->u.ext2_i.i_prealloc_block ||
goal + 1 == inode->u.ext2_i.i_prealloc_block))
{
result = inode->u.ext2_i.i_prealloc_block++;
inode->u.ext2_i.i_prealloc_count--;
/* Writer: end */
ext2_debug ("preallocation hit (%lu/%lu).\n",
++alloc_hits, ++alloc_attempts);
} else {
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,
&inode->u.ext2_i.i_prealloc_count,
&inode->u.ext2_i.i_prealloc_block, err);
else
result = ext2_new_block (inode, goal, 0, 0, err);
}
#else
result = ext2_new_block (inode, goal, 0, 0, err);
#endif
return result;
}
typedef struct {
u32 *p;
u32 key;
struct buffer_head *bh;
} Indirect;
static inline void add_chain(Indirect *p, struct buffer_head *bh, u32 *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
*
* 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 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;
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;
} else if ( (i_block -= direct_blocks) < indirect_blocks) {
offsets[n++] = EXT2_IND_BLOCK;
offsets[n++] = i_block;
} 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);
} 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);
} else {
ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
}
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, inode->u.ext2_i.i_data + *offsets);
if (!p->key)
goto no_block;
while (--depth) {
bh = sb_bread(sb, le32_to_cpu(p->key));
if (!bh)
goto failure;
/* Reader: pointers */
if (!verify_chain(chain, p))
goto changed;
add_chain(++p, bh, (u32*)bh->b_data + *++offsets);
/* Reader: end */
if (!p->key)
goto no_block;
}
return NULL;
changed:
*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.
* Caller must make sure that @ind is valid and will stay that way.
*/
static inline unsigned long ext2_find_near(struct inode *inode, Indirect *ind)
{
u32 *start = ind->bh ? (u32*) ind->bh->b_data : inode->u.ext2_i.i_data;
u32 *p;
/* 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.
*/
return (inode->u.ext2_i.i_block_group *
EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
le32_to_cpu(inode->i_sb->u.ext2_sb.s_es->s_first_data_block);
}
/**
* 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)
{
/* Writer: ->i_next_alloc* */
if (block == inode->u.ext2_i.i_next_alloc_block + 1) {
inode->u.ext2_i.i_next_alloc_block++;
inode->u.ext2_i.i_next_alloc_goal++;
}
/* Writer: end */
/* Reader: pointers, ->i_next_alloc* */
if (verify_chain(chain, partial)) {
/*
* try the heuristic for sequential allocation,
* failing that at least try to get decent locality.
*/
if (block == inode->u.ext2_i.i_next_alloc_block)
*goal = inode->u.ext2_i.i_next_alloc_goal;
if (!*goal)
*goal = ext2_find_near(inode, partial);
return 0;
}
/* Reader: end */
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);
lock_buffer(bh);
memset(bh->b_data, 0, blocksize);
branch[n].bh = bh;
branch[n].p = (u32*) bh->b_data + offsets[n];
*branch[n].p = branch[n].key;
mark_buffer_uptodate(bh, 1);
unlock_buffer(bh);
mark_buffer_dirty_inode(bh, inode);
if (IS_SYNC(inode) || inode->u.ext2_i.i_osync) {
ll_rw_block (WRITE, 1, &bh);
wait_on_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)
{
int i;
/* Verify that place we are splicing to is still there and vacant */
/* Writer: pointers, ->i_next_alloc* */
if (!verify_chain(chain, where-1) || *where->p)
/* Writer: end */
goto changed;
/* That's it */
*where->p = where->key;
inode->u.ext2_i.i_next_alloc_block = block;
inode->u.ext2_i.i_next_alloc_goal = le32_to_cpu(where[num-1].key);
/* Writer: end */
/* We are done with atomic stuff, now do the rest of housekeeping */
inode->i_ctime = CURRENT_TIME;
/* had we spliced it onto indirect block? */
if (where->bh) {
mark_buffer_dirty_inode(where->bh, inode);
if (IS_SYNC(inode) || inode->u.ext2_i.i_osync) {
ll_rw_block (WRITE, 1, &where->bh);
wait_on_buffer(where->bh);
}
}
if (IS_SYNC(inode) || inode->u.ext2_i.i_osync)
ext2_sync_inode (inode);
else
mark_inode_dirty(inode);
return 0;
changed:
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.
*/
static int ext2_get_block(struct inode *inode, long 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 depth = ext2_block_to_path(inode, iblock, offsets);
if (depth == 0)
goto out;
lock_kernel();
reread:
partial = ext2_get_branch(inode, depth, offsets, chain, &err);
/* Simplest case - block found, no allocation needed */
if (!partial) {
got_it:
bh_result->b_dev = inode->i_dev;
bh_result->b_blocknr = le32_to_cpu(chain[depth-1].key);
bh_result->b_state |= (1UL << BH_Mapped);
/* 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--;
}
unlock_kernel();
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;
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_splice_branch(inode, iblock, chain, partial, left) < 0)
goto changed;
bh_result->b_state |= (1UL << BH_New);
goto got_it;
changed:
while (partial > chain) {
brelse(partial->bh);
partial--;
}
goto reread;
}
static int ext2_writepage(struct page *page)
{
return block_write_full_page(page,ext2_get_block);
}
static int ext2_readpage(struct file *file, struct page *page)
{
return block_read_full_page(page,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_bmap(struct address_space *mapping, long block)
{
return generic_block_bmap(mapping,block,ext2_get_block);
}
static int ext2_direct_IO(int rw, struct inode * inode, struct kiobuf * iobuf, unsigned long blocknr, int blocksize)
{
return generic_direct_IO(rw, inode, iobuf, blocknr, blocksize, ext2_get_block);
}
struct address_space_operations ext2_aops = {
readpage: ext2_readpage,
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,
};
/*
* 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(u32 *p, u32 *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],
u32 *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);
/* Writer: pointers */
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.
*/
if (!partial->key && *partial->p)
/* Writer: end */
goto no_top;
for (p=partial; p>chain && all_zeroes((u32*)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;
}
/* Writer: end */
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, u32 *p, u32 *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, u32 *p, u32 *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,
(u32*)bh->b_data,
(u32*)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)
{
u32 *i_data = inode->u.ext2_i.i_data;
int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
int offsets[4];
Indirect chain[4];
Indirect *partial;
int 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 (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);
block_truncate_page(inode->i_mapping, inode->i_size, ext2_get_block);
n = ext2_block_to_path(inode, iblock, offsets);
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,
(u32*)partial->bh->b_data + addr_per_block,
(chain+n-1) - partial);
mark_buffer_dirty_inode(partial->bh, inode);
if (IS_SYNC(inode)) {
ll_rw_block (WRITE, 1, &partial->bh);
wait_on_buffer (partial->bh);
}
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;
if (IS_SYNC(inode))
ext2_sync_inode (inode);
else
mark_inode_dirty(inode);
}
void ext2_read_inode (struct inode * inode)
{
struct buffer_head * bh;
struct ext2_inode * raw_inode;
unsigned long block_group;
unsigned long group_desc;
unsigned long desc;
unsigned long block;
unsigned long offset;
struct ext2_group_desc * gdp;
if ((inode->i_ino != EXT2_ROOT_INO && inode->i_ino != EXT2_ACL_IDX_INO &&
inode->i_ino != EXT2_ACL_DATA_INO &&
inode->i_ino < EXT2_FIRST_INO(inode->i_sb)) ||
inode->i_ino > le32_to_cpu(inode->i_sb->u.ext2_sb.s_es->s_inodes_count)) {
ext2_error (inode->i_sb, "ext2_read_inode",
"bad inode number: %lu", inode->i_ino);
goto bad_inode;
}
block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count) {
ext2_error (inode->i_sb, "ext2_read_inode",
"group >= groups count");
goto bad_inode;
}
group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(inode->i_sb);
desc = block_group & (EXT2_DESC_PER_BLOCK(inode->i_sb) - 1);
bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
if (!bh) {
ext2_error (inode->i_sb, "ext2_read_inode",
"Descriptor not loaded");
goto bad_inode;
}
gdp = (struct ext2_group_desc *) bh->b_data;
/*
* Figure out the offset within the block group inode table
*/
offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
EXT2_INODE_SIZE(inode->i_sb);
block = le32_to_cpu(gdp[desc].bg_inode_table) +
(offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
if (!(bh = sb_bread(inode->i_sb, block))) {
ext2_error (inode->i_sb, "ext2_read_inode",
"unable to read inode block - "
"inode=%lu, block=%lu", inode->i_ino, block);
goto bad_inode;
}
offset &= (EXT2_BLOCK_SIZE(inode->i_sb) - 1);
raw_inode = (struct ext2_inode *) (bh->b_data + offset);
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 = le32_to_cpu(raw_inode->i_atime);
inode->i_ctime = le32_to_cpu(raw_inode->i_ctime);
inode->i_mtime = le32_to_cpu(raw_inode->i_mtime);
inode->u.ext2_i.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 || inode->u.ext2_i.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);
inode->i_version = ++event;
inode->u.ext2_i.i_flags = le32_to_cpu(raw_inode->i_flags);
inode->u.ext2_i.i_faddr = le32_to_cpu(raw_inode->i_faddr);
inode->u.ext2_i.i_frag_no = raw_inode->i_frag;
inode->u.ext2_i.i_frag_size = raw_inode->i_fsize;
inode->u.ext2_i.i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
if (S_ISREG(inode->i_mode))
inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
else
inode->u.ext2_i.i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
inode->i_generation = le32_to_cpu(raw_inode->i_generation);
inode->u.ext2_i.i_prealloc_count = 0;
inode->u.ext2_i.i_block_group = block_group;
/*
* 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 (block = 0; block < EXT2_N_BLOCKS; block++)
inode->u.ext2_i.i_data[block] = raw_inode->i_block[block];
if (inode->i_ino == EXT2_ACL_IDX_INO ||
inode->i_ino == EXT2_ACL_DATA_INO)
/* Nothing to do */ ;
else if (S_ISREG(inode->i_mode)) {
inode->i_op = &ext2_file_inode_operations;
inode->i_fop = &ext2_file_operations;
inode->i_mapping->a_ops = &ext2_aops;
} else if (S_ISDIR(inode->i_mode)) {
inode->i_op = &ext2_dir_inode_operations;
inode->i_fop = &ext2_dir_operations;
inode->i_mapping->a_ops = &ext2_aops;
} else if (S_ISLNK(inode->i_mode)) {
if (!inode->i_blocks)
inode->i_op = &ext2_fast_symlink_inode_operations;
else {
inode->i_op = &page_symlink_inode_operations;
inode->i_mapping->a_ops = &ext2_aops;
}
} else
init_special_inode(inode, inode->i_mode,
le32_to_cpu(raw_inode->i_block[0]));
brelse (bh);
inode->i_attr_flags = 0;
if (inode->u.ext2_i.i_flags & EXT2_SYNC_FL) {
inode->i_attr_flags |= ATTR_FLAG_SYNCRONOUS;
inode->i_flags |= S_SYNC;
}
if (inode->u.ext2_i.i_flags & EXT2_APPEND_FL) {
inode->i_attr_flags |= ATTR_FLAG_APPEND;
inode->i_flags |= S_APPEND;
}
if (inode->u.ext2_i.i_flags & EXT2_IMMUTABLE_FL) {
inode->i_attr_flags |= ATTR_FLAG_IMMUTABLE;
inode->i_flags |= S_IMMUTABLE;
}
if (inode->u.ext2_i.i_flags & EXT2_NOATIME_FL) {
inode->i_attr_flags |= ATTR_FLAG_NOATIME;
inode->i_flags |= S_NOATIME;
}
return;
bad_inode:
make_bad_inode(inode);
return;
}
static int ext2_update_inode(struct inode * inode, int do_sync)
{
struct buffer_head * bh;
struct ext2_inode * raw_inode;
unsigned long block_group;
unsigned long group_desc;
unsigned long desc;
unsigned long block;
unsigned long offset;
int err = 0;
struct ext2_group_desc * gdp;
if ((inode->i_ino != EXT2_ROOT_INO &&
inode->i_ino < EXT2_FIRST_INO(inode->i_sb)) ||
inode->i_ino > le32_to_cpu(inode->i_sb->u.ext2_sb.s_es->s_inodes_count)) {
ext2_error (inode->i_sb, "ext2_write_inode",
"bad inode number: %lu", inode->i_ino);
return -EIO;
}
block_group = (inode->i_ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
if (block_group >= inode->i_sb->u.ext2_sb.s_groups_count) {
ext2_error (inode->i_sb, "ext2_write_inode",
"group >= groups count");
return -EIO;
}
group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(inode->i_sb);
desc = block_group & (EXT2_DESC_PER_BLOCK(inode->i_sb) - 1);
bh = inode->i_sb->u.ext2_sb.s_group_desc[group_desc];
if (!bh) {
ext2_error (inode->i_sb, "ext2_write_inode",
"Descriptor not loaded");
return -EIO;
}
gdp = (struct ext2_group_desc *) bh->b_data;
/*
* Figure out the offset within the block group inode table
*/
offset = ((inode->i_ino - 1) % EXT2_INODES_PER_GROUP(inode->i_sb)) *
EXT2_INODE_SIZE(inode->i_sb);
block = le32_to_cpu(gdp[desc].bg_inode_table) +
(offset >> EXT2_BLOCK_SIZE_BITS(inode->i_sb));
if (!(bh = sb_bread(inode->i_sb, block))) {
ext2_error (inode->i_sb, "ext2_write_inode",
"unable to read inode block - "
"inode=%lu, block=%lu", inode->i_ino, block);
return -EIO;
}
offset &= EXT2_BLOCK_SIZE(inode->i_sb) - 1;
raw_inode = (struct ext2_inode *) (bh->b_data + offset);
raw_inode->i_mode = cpu_to_le16(inode->i_mode);
if(!(test_opt(inode->i_sb, NO_UID32))) {
raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
/*
* Fix up interoperability with old kernels. Otherwise, old inodes get
* re-used with the upper 16 bits of the uid/gid intact
*/
if(!inode->u.ext2_i.i_dtime) {
raw_inode->i_uid_high = cpu_to_le16(high_16_bits(inode->i_uid));
raw_inode->i_gid_high = cpu_to_le16(high_16_bits(inode->i_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(inode->i_uid));
raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(inode->i_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);
raw_inode->i_ctime = cpu_to_le32(inode->i_ctime);
raw_inode->i_mtime = cpu_to_le32(inode->i_mtime);
raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
raw_inode->i_dtime = cpu_to_le32(inode->u.ext2_i.i_dtime);
raw_inode->i_flags = cpu_to_le32(inode->u.ext2_i.i_flags);
raw_inode->i_faddr = cpu_to_le32(inode->u.ext2_i.i_faddr);
raw_inode->i_frag = inode->u.ext2_i.i_frag_no;
raw_inode->i_fsize = inode->u.ext2_i.i_frag_size;
raw_inode->i_file_acl = cpu_to_le32(inode->u.ext2_i.i_file_acl);
if (S_ISDIR(inode->i_mode))
raw_inode->i_dir_acl = cpu_to_le32(inode->u.ext2_i.i_dir_acl);
else {
raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
if (inode->i_size > 0x7fffffffULL) {
struct super_block *sb = inode->i_sb;
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))
raw_inode->i_block[0] = cpu_to_le32(kdev_t_to_nr(inode->i_rdev));
else for (block = 0; block < EXT2_N_BLOCKS; block++)
raw_inode->i_block[block] = inode->u.ext2_i.i_data[block];
mark_buffer_dirty(bh);
if (do_sync) {
ll_rw_block (WRITE, 1, &bh);
wait_on_buffer (bh);
if (buffer_req(bh) && !buffer_uptodate(bh)) {
printk ("IO error syncing ext2 inode ["
"%s:%08lx]\n",
bdevname(inode->i_dev), inode->i_ino);
err = -EIO;
}
}
brelse (bh);
return err;
}
void ext2_write_inode (struct inode * inode, int wait)
{
lock_kernel();
ext2_update_inode (inode, wait);
unlock_kernel();
}
int ext2_sync_inode (struct inode *inode)
{
return ext2_update_inode (inode, 1);
}
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