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linux-next/fs/ext2/inode.c
Christian Brauner 549c729771
fs: make helpers idmap mount aware
Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.

As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.

Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24 14:27:20 +01:00

1700 lines
48 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* 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/time.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
#include <linux/dax.h>
#include <linux/blkdev.h>
#include <linux/quotaops.h>
#include <linux/writeback.h>
#include <linux/buffer_head.h>
#include <linux/mpage.h>
#include <linux/fiemap.h>
#include <linux/iomap.h>
#include <linux/namei.h>
#include <linux/uio.h>
#include "ext2.h"
#include "acl.h"
#include "xattr.h"
static int __ext2_write_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);
}
static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
static void ext2_write_failed(struct address_space *mapping, loff_t to)
{
struct inode *inode = mapping->host;
if (to > inode->i_size) {
truncate_pagecache(inode, inode->i_size);
ext2_truncate_blocks(inode, inode->i_size);
}
}
/*
* Called at the last iput() if i_nlink is zero.
*/
void ext2_evict_inode(struct inode * inode)
{
struct ext2_block_alloc_info *rsv;
int want_delete = 0;
if (!inode->i_nlink && !is_bad_inode(inode)) {
want_delete = 1;
dquot_initialize(inode);
} else {
dquot_drop(inode);
}
truncate_inode_pages_final(&inode->i_data);
if (want_delete) {
sb_start_intwrite(inode->i_sb);
/* set dtime */
EXT2_I(inode)->i_dtime = ktime_get_real_seconds();
mark_inode_dirty(inode);
__ext2_write_inode(inode, inode_needs_sync(inode));
/* truncate to 0 */
inode->i_size = 0;
if (inode->i_blocks)
ext2_truncate_blocks(inode, 0);
ext2_xattr_delete_inode(inode);
}
invalidate_inode_buffers(inode);
clear_inode(inode);
ext2_discard_reservation(inode);
rsv = EXT2_I(inode)->i_block_alloc_info;
EXT2_I(inode)->i_block_alloc_info = NULL;
if (unlikely(rsv))
kfree(rsv);
if (want_delete) {
ext2_free_inode(inode);
sb_end_intwrite(inode->i_sb);
}
}
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_msg(inode->i_sb, KERN_WARNING,
"warning: %s: block < 0", __func__);
} 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_msg(inode->i_sb, KERN_WARNING,
"warning: %s: block is too big", __func__);
}
if (boundary)
*boundary = final - 1 - (i_block & (ptrs - 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 preferred 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 ext2_fsblk_t 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;
ext2_fsblk_t bg_start;
ext2_fsblk_t 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 referred from inode itself? OK, just put it into
* the same cylinder group then.
*/
bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
colour = (current->pid % 16) *
(EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
return bg_start + colour;
}
/**
* ext2_find_goal - find a preferred place for allocation.
* @inode: owner
* @block: block we want
* @partial: pointer to the last triple within a chain
*
* Returns preferred place for a block (the goal).
*/
static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
Indirect *partial)
{
struct ext2_block_alloc_info *block_i;
block_i = EXT2_I(inode)->i_block_alloc_info;
/*
* try the heuristic for sequential allocation,
* failing that at least try to get decent locality.
*/
if (block_i && (block == block_i->last_alloc_logical_block + 1)
&& (block_i->last_alloc_physical_block != 0)) {
return block_i->last_alloc_physical_block + 1;
}
return ext2_find_near(inode, partial);
}
/**
* ext2_blks_to_allocate: Look up the block map and count the number
* of direct blocks need to be allocated for the given branch.
*
* @branch: chain of indirect blocks
* @k: number of blocks need for indirect blocks
* @blks: number of data blocks to be mapped.
* @blocks_to_boundary: the offset in the indirect block
*
* return the number of direct blocks to allocate.
*/
static int
ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
int blocks_to_boundary)
{
unsigned long count = 0;
/*
* Simple case, [t,d]Indirect block(s) has not allocated yet
* then it's clear blocks on that path have not allocated
*/
if (k > 0) {
/* right now don't hanel cross boundary allocation */
if (blks < blocks_to_boundary + 1)
count += blks;
else
count += blocks_to_boundary + 1;
return count;
}
count++;
while (count < blks && count <= blocks_to_boundary
&& le32_to_cpu(*(branch[0].p + count)) == 0) {
count++;
}
return count;
}
/**
* ext2_alloc_blocks: multiple allocate blocks needed for a branch
* @indirect_blks: the number of blocks need to allocate for indirect
* blocks
* @blks: the number of blocks need to allocate for direct blocks
* @new_blocks: on return it will store the new block numbers for
* the indirect blocks(if needed) and the first direct block,
*/
static int ext2_alloc_blocks(struct inode *inode,
ext2_fsblk_t goal, int indirect_blks, int blks,
ext2_fsblk_t new_blocks[4], int *err)
{
int target, i;
unsigned long count = 0;
int index = 0;
ext2_fsblk_t current_block = 0;
int ret = 0;
/*
* Here we try to allocate the requested multiple blocks at once,
* on a best-effort basis.
* To build a branch, we should allocate blocks for
* the indirect blocks(if not allocated yet), and at least
* the first direct block of this branch. That's the
* minimum number of blocks need to allocate(required)
*/
target = blks + indirect_blks;
while (1) {
count = target;
/* allocating blocks for indirect blocks and direct blocks */
current_block = ext2_new_blocks(inode,goal,&count,err);
if (*err)
goto failed_out;
target -= count;
/* allocate blocks for indirect blocks */
while (index < indirect_blks && count) {
new_blocks[index++] = current_block++;
count--;
}
if (count > 0)
break;
}
/* save the new block number for the first direct block */
new_blocks[index] = current_block;
/* total number of blocks allocated for direct blocks */
ret = count;
*err = 0;
return ret;
failed_out:
for (i = 0; i <index; i++)
ext2_free_blocks(inode, new_blocks[i], 1);
if (index)
mark_inode_dirty(inode);
return ret;
}
/**
* ext2_alloc_branch - allocate and set up a chain of blocks.
* @inode: owner
* @indirect_blks: depth of the chain (number of blocks to allocate)
* @blks: number of allocated direct blocks
* @goal: preferred place for allocation
* @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(), except 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 indirect_blks, int *blks, ext2_fsblk_t goal,
int *offsets, Indirect *branch)
{
int blocksize = inode->i_sb->s_blocksize;
int i, n = 0;
int err = 0;
struct buffer_head *bh;
int num;
ext2_fsblk_t new_blocks[4];
ext2_fsblk_t current_block;
num = ext2_alloc_blocks(inode, goal, indirect_blks,
*blks, new_blocks, &err);
if (err)
return err;
branch[0].key = cpu_to_le32(new_blocks[0]);
/*
* metadata blocks and data blocks are allocated.
*/
for (n = 1; n <= indirect_blks; n++) {
/*
* 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, new_blocks[n-1]);
if (unlikely(!bh)) {
err = -ENOMEM;
goto failed;
}
branch[n].bh = bh;
lock_buffer(bh);
memset(bh->b_data, 0, blocksize);
branch[n].p = (__le32 *) bh->b_data + offsets[n];
branch[n].key = cpu_to_le32(new_blocks[n]);
*branch[n].p = branch[n].key;
if ( n == indirect_blks) {
current_block = new_blocks[n];
/*
* End of chain, update the last new metablock of
* the chain to point to the new allocated
* data blocks numbers
*/
for (i=1; i < num; i++)
*(branch[n].p + i) = cpu_to_le32(++current_block);
}
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_write_sync()
* and b_inode_buffers. But not for directories.
*/
if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
sync_dirty_buffer(bh);
}
*blks = num;
return err;
failed:
for (i = 1; i < n; i++)
bforget(branch[i].bh);
for (i = 0; i < indirect_blks; i++)
ext2_free_blocks(inode, new_blocks[i], 1);
ext2_free_blocks(inode, new_blocks[i], num);
return err;
}
/**
* ext2_splice_branch - splice the allocated branch onto inode.
* @inode: owner
* @block: (logical) number of block we are adding
* @where: location of missing link
* @num: number of indirect blocks we are adding
* @blks: number of direct blocks we are adding
*
* This function 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.
*/
static void ext2_splice_branch(struct inode *inode,
long block, Indirect *where, int num, int blks)
{
int i;
struct ext2_block_alloc_info *block_i;
ext2_fsblk_t current_block;
block_i = EXT2_I(inode)->i_block_alloc_info;
/* XXX LOCKING probably should have i_meta_lock ?*/
/* That's it */
*where->p = where->key;
/*
* Update the host buffer_head or inode to point to more just allocated
* direct blocks blocks
*/
if (num == 0 && blks > 1) {
current_block = le32_to_cpu(where->key) + 1;
for (i = 1; i < blks; i++)
*(where->p + i ) = cpu_to_le32(current_block++);
}
/*
* update the most recently allocated logical & physical block
* in i_block_alloc_info, to assist find the proper goal block for next
* allocation
*/
if (block_i) {
block_i->last_alloc_logical_block = block + blks - 1;
block_i->last_alloc_physical_block =
le32_to_cpu(where[num].key) + blks - 1;
}
/* We are done with atomic stuff, now do the rest of housekeeping */
/* had we spliced it onto indirect block? */
if (where->bh)
mark_buffer_dirty_inode(where->bh, inode);
inode->i_ctime = current_time(inode);
mark_inode_dirty(inode);
}
/*
* 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.
*
* `handle' can be NULL if create == 0.
*
* return > 0, # of blocks mapped or allocated.
* return = 0, if plain lookup failed.
* return < 0, error case.
*/
static int ext2_get_blocks(struct inode *inode,
sector_t iblock, unsigned long maxblocks,
u32 *bno, bool *new, bool *boundary,
int create)
{
int err;
int offsets[4];
Indirect chain[4];
Indirect *partial;
ext2_fsblk_t goal;
int indirect_blks;
int blocks_to_boundary = 0;
int depth;
struct ext2_inode_info *ei = EXT2_I(inode);
int count = 0;
ext2_fsblk_t first_block = 0;
BUG_ON(maxblocks == 0);
depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
if (depth == 0)
return -EIO;
partial = ext2_get_branch(inode, depth, offsets, chain, &err);
/* Simplest case - block found, no allocation needed */
if (!partial) {
first_block = le32_to_cpu(chain[depth - 1].key);
count++;
/*map more blocks*/
while (count < maxblocks && count <= blocks_to_boundary) {
ext2_fsblk_t blk;
if (!verify_chain(chain, chain + depth - 1)) {
/*
* Indirect block might be removed by
* truncate while we were reading it.
* Handling of that case: forget what we've
* got now, go to reread.
*/
err = -EAGAIN;
count = 0;
partial = chain + depth - 1;
break;
}
blk = le32_to_cpu(*(chain[depth-1].p + count));
if (blk == first_block + count)
count++;
else
break;
}
if (err != -EAGAIN)
goto got_it;
}
/* Next simple case - plain lookup or failed read of indirect block */
if (!create || err == -EIO)
goto cleanup;
mutex_lock(&ei->truncate_mutex);
/*
* If the indirect block is missing while we are reading
* the chain(ext2_get_branch() returns -EAGAIN err), or
* if the chain has been changed after we grab the semaphore,
* (either because another process truncated this branch, or
* another get_block allocated this branch) re-grab the chain to see if
* the request block has been allocated or not.
*
* Since we already block the truncate/other get_block
* at this point, we will have the current copy of the chain when we
* splice the branch into the tree.
*/
if (err == -EAGAIN || !verify_chain(chain, partial)) {
while (partial > chain) {
brelse(partial->bh);
partial--;
}
partial = ext2_get_branch(inode, depth, offsets, chain, &err);
if (!partial) {
count++;
mutex_unlock(&ei->truncate_mutex);
goto got_it;
}
if (err) {
mutex_unlock(&ei->truncate_mutex);
goto cleanup;
}
}
/*
* Okay, we need to do block allocation. Lazily initialize the block
* allocation info here if necessary
*/
if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
ext2_init_block_alloc_info(inode);
goal = ext2_find_goal(inode, iblock, partial);
/* the number of blocks need to allocate for [d,t]indirect blocks */
indirect_blks = (chain + depth) - partial - 1;
/*
* Next look up the indirect map to count the total number of
* direct blocks to allocate for this branch.
*/
count = ext2_blks_to_allocate(partial, indirect_blks,
maxblocks, blocks_to_boundary);
/*
* XXX ???? Block out ext2_truncate while we alter the tree
*/
err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
offsets + (partial - chain), partial);
if (err) {
mutex_unlock(&ei->truncate_mutex);
goto cleanup;
}
if (IS_DAX(inode)) {
/*
* We must unmap blocks before zeroing so that writeback cannot
* overwrite zeros with stale data from block device page cache.
*/
clean_bdev_aliases(inode->i_sb->s_bdev,
le32_to_cpu(chain[depth-1].key),
count);
/*
* block must be initialised before we put it in the tree
* so that it's not found by another thread before it's
* initialised
*/
err = sb_issue_zeroout(inode->i_sb,
le32_to_cpu(chain[depth-1].key), count,
GFP_NOFS);
if (err) {
mutex_unlock(&ei->truncate_mutex);
goto cleanup;
}
}
*new = true;
ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
mutex_unlock(&ei->truncate_mutex);
got_it:
if (count > blocks_to_boundary)
*boundary = true;
err = count;
/* Clean up and exit */
partial = chain + depth - 1; /* the whole chain */
cleanup:
while (partial > chain) {
brelse(partial->bh);
partial--;
}
if (err > 0)
*bno = le32_to_cpu(chain[depth-1].key);
return err;
}
int ext2_get_block(struct inode *inode, sector_t iblock,
struct buffer_head *bh_result, int create)
{
unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
bool new = false, boundary = false;
u32 bno;
int ret;
ret = ext2_get_blocks(inode, iblock, max_blocks, &bno, &new, &boundary,
create);
if (ret <= 0)
return ret;
map_bh(bh_result, inode->i_sb, bno);
bh_result->b_size = (ret << inode->i_blkbits);
if (new)
set_buffer_new(bh_result);
if (boundary)
set_buffer_boundary(bh_result);
return 0;
}
#ifdef CONFIG_FS_DAX
static int ext2_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
unsigned flags, struct iomap *iomap, struct iomap *srcmap)
{
unsigned int blkbits = inode->i_blkbits;
unsigned long first_block = offset >> blkbits;
unsigned long max_blocks = (length + (1 << blkbits) - 1) >> blkbits;
struct ext2_sb_info *sbi = EXT2_SB(inode->i_sb);
bool new = false, boundary = false;
u32 bno;
int ret;
ret = ext2_get_blocks(inode, first_block, max_blocks,
&bno, &new, &boundary, flags & IOMAP_WRITE);
if (ret < 0)
return ret;
iomap->flags = 0;
iomap->bdev = inode->i_sb->s_bdev;
iomap->offset = (u64)first_block << blkbits;
iomap->dax_dev = sbi->s_daxdev;
if (ret == 0) {
iomap->type = IOMAP_HOLE;
iomap->addr = IOMAP_NULL_ADDR;
iomap->length = 1 << blkbits;
} else {
iomap->type = IOMAP_MAPPED;
iomap->addr = (u64)bno << blkbits;
iomap->length = (u64)ret << blkbits;
iomap->flags |= IOMAP_F_MERGED;
}
if (new)
iomap->flags |= IOMAP_F_NEW;
return 0;
}
static int
ext2_iomap_end(struct inode *inode, loff_t offset, loff_t length,
ssize_t written, unsigned flags, struct iomap *iomap)
{
if (iomap->type == IOMAP_MAPPED &&
written < length &&
(flags & IOMAP_WRITE))
ext2_write_failed(inode->i_mapping, offset + length);
return 0;
}
const struct iomap_ops ext2_iomap_ops = {
.iomap_begin = ext2_iomap_begin,
.iomap_end = ext2_iomap_end,
};
#else
/* Define empty ops for !CONFIG_FS_DAX case to avoid ugly ifdefs */
const struct iomap_ops ext2_iomap_ops;
#endif /* CONFIG_FS_DAX */
int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
u64 start, u64 len)
{
return generic_block_fiemap(inode, fieinfo, start, len,
ext2_get_block);
}
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 void ext2_readahead(struct readahead_control *rac)
{
mpage_readahead(rac, ext2_get_block);
}
static int
ext2_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
ret = block_write_begin(mapping, pos, len, flags, pagep,
ext2_get_block);
if (ret < 0)
ext2_write_failed(mapping, pos + len);
return ret;
}
static int ext2_write_end(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned copied,
struct page *page, void *fsdata)
{
int ret;
ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
if (ret < len)
ext2_write_failed(mapping, pos + len);
return ret;
}
static int
ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
int ret;
ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
ext2_get_block);
if (ret < 0)
ext2_write_failed(mapping, pos + len);
return ret;
}
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 ssize_t
ext2_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
size_t count = iov_iter_count(iter);
loff_t offset = iocb->ki_pos;
ssize_t ret;
ret = blockdev_direct_IO(iocb, inode, iter, ext2_get_block);
if (ret < 0 && iov_iter_rw(iter) == WRITE)
ext2_write_failed(mapping, offset + count);
return ret;
}
static int
ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
return mpage_writepages(mapping, wbc, ext2_get_block);
}
static int
ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc)
{
struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb);
return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc);
}
const struct address_space_operations ext2_aops = {
.readpage = ext2_readpage,
.readahead = ext2_readahead,
.writepage = ext2_writepage,
.write_begin = ext2_write_begin,
.write_end = ext2_write_end,
.bmap = ext2_bmap,
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage = buffer_migrate_page,
.is_partially_uptodate = block_is_partially_uptodate,
.error_remove_page = generic_error_remove_page,
};
const struct address_space_operations ext2_nobh_aops = {
.readpage = ext2_readpage,
.readahead = ext2_readahead,
.writepage = ext2_nobh_writepage,
.write_begin = ext2_nobh_write_begin,
.write_end = nobh_write_end,
.bmap = ext2_bmap,
.direct_IO = ext2_direct_IO,
.writepages = ext2_writepages,
.migratepage = buffer_migrate_page,
.error_remove_page = generic_error_remove_page,
};
static const struct address_space_operations ext2_dax_aops = {
.writepages = ext2_dax_writepages,
.direct_IO = noop_direct_IO,
.set_page_dirty = noop_set_page_dirty,
.invalidatepage = noop_invalidatepage,
};
/*
* 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 referred 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 referred 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 {
ext2_free_blocks (inode, block_to_free, count);
mark_inode_dirty(inode);
free_this:
block_to_free = nr;
count = 1;
}
}
}
if (count > 0) {
ext2_free_blocks (inode, block_to_free, count);
mark_inode_dirty(inode);
}
}
/**
* 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 referred 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);
}
/* dax_sem must be held when calling this function */
static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
{
__le32 *i_data = EXT2_I(inode)->i_data;
struct ext2_inode_info *ei = EXT2_I(inode);
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;
blocksize = inode->i_sb->s_blocksize;
iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
#ifdef CONFIG_FS_DAX
WARN_ON(!rwsem_is_locked(&ei->dax_sem));
#endif
n = ext2_block_to_path(inode, iblock, offsets, NULL);
if (n == 0)
return;
/*
* From here we block out all ext2_get_block() callers who want to
* modify the block allocation tree.
*/
mutex_lock(&ei->truncate_mutex);
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);
}
fallthrough;
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);
}
fallthrough;
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);
}
break;
case EXT2_TIND_BLOCK:
;
}
ext2_discard_reservation(inode);
mutex_unlock(&ei->truncate_mutex);
}
static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
{
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;
dax_sem_down_write(EXT2_I(inode));
__ext2_truncate_blocks(inode, offset);
dax_sem_up_write(EXT2_I(inode));
}
static int ext2_setsize(struct inode *inode, loff_t newsize)
{
int error;
if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
S_ISLNK(inode->i_mode)))
return -EINVAL;
if (ext2_inode_is_fast_symlink(inode))
return -EINVAL;
if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
return -EPERM;
inode_dio_wait(inode);
if (IS_DAX(inode)) {
error = iomap_zero_range(inode, newsize,
PAGE_ALIGN(newsize) - newsize, NULL,
&ext2_iomap_ops);
} else if (test_opt(inode->i_sb, NOBH))
error = nobh_truncate_page(inode->i_mapping,
newsize, ext2_get_block);
else
error = block_truncate_page(inode->i_mapping,
newsize, ext2_get_block);
if (error)
return error;
dax_sem_down_write(EXT2_I(inode));
truncate_setsize(inode, newsize);
__ext2_truncate_blocks(inode, newsize);
dax_sem_up_write(EXT2_I(inode));
inode->i_mtime = inode->i_ctime = current_time(inode);
if (inode_needs_sync(inode)) {
sync_mapping_buffers(inode->i_mapping);
sync_inode_metadata(inode, 1);
} else {
mark_inode_dirty(inode);
}
return 0;
}
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, NULL);
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 | S_DAX);
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;
if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode))
inode->i_flags |= S_DAX;
}
void ext2_set_file_ops(struct inode *inode)
{
inode->i_op = &ext2_file_inode_operations;
inode->i_fop = &ext2_file_operations;
if (IS_DAX(inode))
inode->i_mapping->a_ops = &ext2_dax_aops;
else if (test_opt(inode->i_sb, NOBH))
inode->i_mapping->a_ops = &ext2_nobh_aops;
else
inode->i_mapping->a_ops = &ext2_aops;
}
struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
{
struct ext2_inode_info *ei;
struct buffer_head * bh = NULL;
struct ext2_inode *raw_inode;
struct inode *inode;
long ret = -EIO;
int n;
uid_t i_uid;
gid_t i_gid;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
ei = EXT2_I(inode);
ei->i_block_alloc_info = NULL;
raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
if (IS_ERR(raw_inode)) {
ret = PTR_ERR(raw_inode);
goto bad_inode;
}
inode->i_mode = le16_to_cpu(raw_inode->i_mode);
i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
if (!(test_opt (inode->i_sb, NO_UID32))) {
i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
}
i_uid_write(inode, i_uid);
i_gid_write(inode, i_gid);
set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
inode->i_size = le32_to_cpu(raw_inode->i_size);
inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
inode->i_mtime.tv_sec = (signed)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 */
ret = -ESTALE;
goto bad_inode;
}
inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
ei->i_flags = le32_to_cpu(raw_inode->i_flags);
ext2_set_inode_flags(inode);
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 (ei->i_file_acl &&
!ext2_data_block_valid(EXT2_SB(sb), ei->i_file_acl, 1)) {
ext2_error(sb, "ext2_iget", "bad extended attribute block %u",
ei->i_file_acl);
ret = -EFSCORRUPTED;
goto bad_inode;
}
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);
if (i_size_read(inode) < 0) {
ret = -EFSCORRUPTED;
goto bad_inode;
}
ei->i_dtime = 0;
inode->i_generation = le32_to_cpu(raw_inode->i_generation);
ei->i_state = 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)) {
ext2_set_file_ops(inode);
} 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_link = (char *)ei->i_data;
inode->i_op = &ext2_fast_symlink_inode_operations;
nd_terminate_link(ei->i_data, inode->i_size,
sizeof(ei->i_data) - 1);
} else {
inode->i_op = &ext2_symlink_inode_operations;
inode_nohighmem(inode);
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);
unlock_new_inode(inode);
return inode;
bad_inode:
brelse(bh);
iget_failed(inode);
return ERR_PTR(ret);
}
static int __ext2_write_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 = i_uid_read(inode);
gid_t gid = i_gid_read(inode);
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.
*/
spin_lock(&EXT2_SB(sb)->s_lock);
ext2_update_dynamic_rev(sb);
EXT2_SET_RO_COMPAT_FEATURE(sb,
EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
spin_unlock(&EXT2_SB(sb)->s_lock);
ext2_sync_super(sb, EXT2_SB(sb)->s_es, 1);
}
}
}
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, struct writeback_control *wbc)
{
return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
}
int ext2_getattr(struct user_namespace *mnt_userns, const struct path *path,
struct kstat *stat, u32 request_mask, unsigned int query_flags)
{
struct inode *inode = d_inode(path->dentry);
struct ext2_inode_info *ei = EXT2_I(inode);
unsigned int flags;
flags = ei->i_flags & EXT2_FL_USER_VISIBLE;
if (flags & EXT2_APPEND_FL)
stat->attributes |= STATX_ATTR_APPEND;
if (flags & EXT2_COMPR_FL)
stat->attributes |= STATX_ATTR_COMPRESSED;
if (flags & EXT2_IMMUTABLE_FL)
stat->attributes |= STATX_ATTR_IMMUTABLE;
if (flags & EXT2_NODUMP_FL)
stat->attributes |= STATX_ATTR_NODUMP;
stat->attributes_mask |= (STATX_ATTR_APPEND |
STATX_ATTR_COMPRESSED |
STATX_ATTR_ENCRYPTED |
STATX_ATTR_IMMUTABLE |
STATX_ATTR_NODUMP);
generic_fillattr(&init_user_ns, inode, stat);
return 0;
}
int ext2_setattr(struct user_namespace *mnt_userns, struct dentry *dentry,
struct iattr *iattr)
{
struct inode *inode = d_inode(dentry);
int error;
error = setattr_prepare(&init_user_ns, dentry, iattr);
if (error)
return error;
if (is_quota_modification(inode, iattr)) {
error = dquot_initialize(inode);
if (error)
return error;
}
if ((iattr->ia_valid & ATTR_UID && !uid_eq(iattr->ia_uid, inode->i_uid)) ||
(iattr->ia_valid & ATTR_GID && !gid_eq(iattr->ia_gid, inode->i_gid))) {
error = dquot_transfer(inode, iattr);
if (error)
return error;
}
if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
error = ext2_setsize(inode, iattr->ia_size);
if (error)
return error;
}
setattr_copy(&init_user_ns, inode, iattr);
if (iattr->ia_valid & ATTR_MODE)
error = posix_acl_chmod(&init_user_ns, inode, inode->i_mode);
mark_inode_dirty(inode);
return error;
}