![Kent Overstreet](/assets/img/avatar_default.png)
Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1393 lines
41 KiB
C
1393 lines
41 KiB
C
/*
|
|
* linux/fs/ext4/indirect.c
|
|
*
|
|
* from
|
|
*
|
|
* linux/fs/ext4/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@redhat.com), 1993, 1998
|
|
*/
|
|
|
|
#include <linux/aio.h>
|
|
#include "ext4_jbd2.h"
|
|
#include "truncate.h"
|
|
#include "ext4_extents.h" /* Needed for EXT_MAX_BLOCKS */
|
|
|
|
#include <trace/events/ext4.h>
|
|
|
|
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;
|
|
}
|
|
|
|
/**
|
|
* ext4_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 ext4 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 ext4_block_to_path(struct inode *inode,
|
|
ext4_lblk_t i_block,
|
|
ext4_lblk_t offsets[4], int *boundary)
|
|
{
|
|
int ptrs = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
|
int ptrs_bits = EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb);
|
|
const long direct_blocks = EXT4_NDIR_BLOCKS,
|
|
indirect_blocks = ptrs,
|
|
double_blocks = (1 << (ptrs_bits * 2));
|
|
int n = 0;
|
|
int final = 0;
|
|
|
|
if (i_block < direct_blocks) {
|
|
offsets[n++] = i_block;
|
|
final = direct_blocks;
|
|
} else if ((i_block -= direct_blocks) < indirect_blocks) {
|
|
offsets[n++] = EXT4_IND_BLOCK;
|
|
offsets[n++] = i_block;
|
|
final = ptrs;
|
|
} else if ((i_block -= indirect_blocks) < double_blocks) {
|
|
offsets[n++] = EXT4_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++] = EXT4_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 {
|
|
ext4_warning(inode->i_sb, "block %lu > max in inode %lu",
|
|
i_block + direct_blocks +
|
|
indirect_blocks + double_blocks, inode->i_ino);
|
|
}
|
|
if (boundary)
|
|
*boundary = final - 1 - (i_block & (ptrs - 1));
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* ext4_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 reads all @depth-1 indirect blocks successfully and finds
|
|
* the whole chain, all way to the data (returns %NULL, *err == 0).
|
|
*
|
|
* Need to be called with
|
|
* down_read(&EXT4_I(inode)->i_data_sem)
|
|
*/
|
|
static Indirect *ext4_get_branch(struct inode *inode, int depth,
|
|
ext4_lblk_t *offsets,
|
|
Indirect chain[4], int *err)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
Indirect *p = chain;
|
|
struct buffer_head *bh;
|
|
int ret = -EIO;
|
|
|
|
*err = 0;
|
|
/* i_data is not going away, no lock needed */
|
|
add_chain(chain, NULL, EXT4_I(inode)->i_data + *offsets);
|
|
if (!p->key)
|
|
goto no_block;
|
|
while (--depth) {
|
|
bh = sb_getblk(sb, le32_to_cpu(p->key));
|
|
if (unlikely(!bh)) {
|
|
ret = -ENOMEM;
|
|
goto failure;
|
|
}
|
|
|
|
if (!bh_uptodate_or_lock(bh)) {
|
|
if (bh_submit_read(bh) < 0) {
|
|
put_bh(bh);
|
|
goto failure;
|
|
}
|
|
/* validate block references */
|
|
if (ext4_check_indirect_blockref(inode, bh)) {
|
|
put_bh(bh);
|
|
goto failure;
|
|
}
|
|
}
|
|
|
|
add_chain(++p, bh, (__le32 *)bh->b_data + *++offsets);
|
|
/* Reader: end */
|
|
if (!p->key)
|
|
goto no_block;
|
|
}
|
|
return NULL;
|
|
|
|
failure:
|
|
*err = ret;
|
|
no_block:
|
|
return p;
|
|
}
|
|
|
|
/**
|
|
* ext4_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 ext4_fsblk_t ext4_find_near(struct inode *inode, Indirect *ind)
|
|
{
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
|
|
__le32 *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 referred to from the inode itself? OK, just put it
|
|
* into the same cylinder group then.
|
|
*/
|
|
return ext4_inode_to_goal_block(inode);
|
|
}
|
|
|
|
/**
|
|
* ext4_find_goal - find a preferred place for allocation.
|
|
* @inode: owner
|
|
* @block: block we want
|
|
* @partial: pointer to the last triple within a chain
|
|
*
|
|
* Normally this function find the preferred place for block allocation,
|
|
* returns it.
|
|
* Because this is only used for non-extent files, we limit the block nr
|
|
* to 32 bits.
|
|
*/
|
|
static ext4_fsblk_t ext4_find_goal(struct inode *inode, ext4_lblk_t block,
|
|
Indirect *partial)
|
|
{
|
|
ext4_fsblk_t goal;
|
|
|
|
/*
|
|
* XXX need to get goal block from mballoc's data structures
|
|
*/
|
|
|
|
goal = ext4_find_near(inode, partial);
|
|
goal = goal & EXT4_MAX_BLOCK_FILE_PHYS;
|
|
return goal;
|
|
}
|
|
|
|
/**
|
|
* ext4_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 total number of blocks to be allocate, including the
|
|
* direct and indirect blocks.
|
|
*/
|
|
static int ext4_blks_to_allocate(Indirect *branch, int k, unsigned int blks,
|
|
int blocks_to_boundary)
|
|
{
|
|
unsigned int 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 we don't handle 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;
|
|
}
|
|
|
|
/**
|
|
* ext4_alloc_branch - allocate and set up a chain of blocks.
|
|
* @handle: handle for this transaction
|
|
* @inode: owner
|
|
* @indirect_blks: number of allocated indirect blocks
|
|
* @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 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 ext4_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 ext4_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
|
|
* ext4_alloc_block() (normally -ENOSPC). Otherwise we set the chain
|
|
* as described above and return 0.
|
|
*/
|
|
static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
|
|
ext4_lblk_t iblock, int indirect_blks,
|
|
int *blks, ext4_fsblk_t goal,
|
|
ext4_lblk_t *offsets, Indirect *branch)
|
|
{
|
|
struct ext4_allocation_request ar;
|
|
struct buffer_head * bh;
|
|
ext4_fsblk_t b, new_blocks[4];
|
|
__le32 *p;
|
|
int i, j, err, len = 1;
|
|
|
|
/*
|
|
* Set up for the direct block allocation
|
|
*/
|
|
memset(&ar, 0, sizeof(ar));
|
|
ar.inode = inode;
|
|
ar.len = *blks;
|
|
ar.logical = iblock;
|
|
if (S_ISREG(inode->i_mode))
|
|
ar.flags = EXT4_MB_HINT_DATA;
|
|
|
|
for (i = 0; i <= indirect_blks; i++) {
|
|
if (i == indirect_blks) {
|
|
ar.goal = goal;
|
|
new_blocks[i] = ext4_mb_new_blocks(handle, &ar, &err);
|
|
} else
|
|
goal = new_blocks[i] = ext4_new_meta_blocks(handle, inode,
|
|
goal, 0, NULL, &err);
|
|
if (err) {
|
|
i--;
|
|
goto failed;
|
|
}
|
|
branch[i].key = cpu_to_le32(new_blocks[i]);
|
|
if (i == 0)
|
|
continue;
|
|
|
|
bh = branch[i].bh = sb_getblk(inode->i_sb, new_blocks[i-1]);
|
|
if (unlikely(!bh)) {
|
|
err = -ENOMEM;
|
|
goto failed;
|
|
}
|
|
lock_buffer(bh);
|
|
BUFFER_TRACE(bh, "call get_create_access");
|
|
err = ext4_journal_get_create_access(handle, bh);
|
|
if (err) {
|
|
unlock_buffer(bh);
|
|
goto failed;
|
|
}
|
|
|
|
memset(bh->b_data, 0, bh->b_size);
|
|
p = branch[i].p = (__le32 *) bh->b_data + offsets[i];
|
|
b = new_blocks[i];
|
|
|
|
if (i == indirect_blks)
|
|
len = ar.len;
|
|
for (j = 0; j < len; j++)
|
|
*p++ = cpu_to_le32(b++);
|
|
|
|
BUFFER_TRACE(bh, "marking uptodate");
|
|
set_buffer_uptodate(bh);
|
|
unlock_buffer(bh);
|
|
|
|
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
|
|
err = ext4_handle_dirty_metadata(handle, inode, bh);
|
|
if (err)
|
|
goto failed;
|
|
}
|
|
*blks = ar.len;
|
|
return 0;
|
|
failed:
|
|
for (; i >= 0; i--) {
|
|
if (i != indirect_blks && branch[i].bh)
|
|
ext4_forget(handle, 1, inode, branch[i].bh,
|
|
branch[i].bh->b_blocknr);
|
|
ext4_free_blocks(handle, inode, NULL, new_blocks[i],
|
|
(i == indirect_blks) ? ar.len : 1, 0);
|
|
}
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ext4_splice_branch - splice the allocated branch onto inode.
|
|
* @handle: handle for this transaction
|
|
* @inode: owner
|
|
* @block: (logical) number of block we are adding
|
|
* @chain: chain of indirect blocks (with a missing link - see
|
|
* ext4_alloc_branch)
|
|
* @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 int ext4_splice_branch(handle_t *handle, struct inode *inode,
|
|
ext4_lblk_t block, Indirect *where, int num,
|
|
int blks)
|
|
{
|
|
int i;
|
|
int err = 0;
|
|
ext4_fsblk_t current_block;
|
|
|
|
/*
|
|
* If we're splicing into a [td]indirect block (as opposed to the
|
|
* inode) then we need to get write access to the [td]indirect block
|
|
* before the splice.
|
|
*/
|
|
if (where->bh) {
|
|
BUFFER_TRACE(where->bh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, where->bh);
|
|
if (err)
|
|
goto err_out;
|
|
}
|
|
/* 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++);
|
|
}
|
|
|
|
/* We are done with atomic stuff, now do the rest of housekeeping */
|
|
/* had we spliced it onto indirect block? */
|
|
if (where->bh) {
|
|
/*
|
|
* If we spliced it onto an indirect block, we haven't
|
|
* altered the inode. Note however that if it is being spliced
|
|
* onto an indirect block at the very end of the file (the
|
|
* file is growing) then we *will* alter the inode to reflect
|
|
* the new i_size. But that is not done here - it is done in
|
|
* generic_commit_write->__mark_inode_dirty->ext4_dirty_inode.
|
|
*/
|
|
jbd_debug(5, "splicing indirect only\n");
|
|
BUFFER_TRACE(where->bh, "call ext4_handle_dirty_metadata");
|
|
err = ext4_handle_dirty_metadata(handle, inode, where->bh);
|
|
if (err)
|
|
goto err_out;
|
|
} else {
|
|
/*
|
|
* OK, we spliced it into the inode itself on a direct block.
|
|
*/
|
|
ext4_mark_inode_dirty(handle, inode);
|
|
jbd_debug(5, "splicing direct\n");
|
|
}
|
|
return err;
|
|
|
|
err_out:
|
|
for (i = 1; i <= num; i++) {
|
|
/*
|
|
* branch[i].bh is newly allocated, so there is no
|
|
* need to revoke the block, which is why we don't
|
|
* need to set EXT4_FREE_BLOCKS_METADATA.
|
|
*/
|
|
ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
|
|
EXT4_FREE_BLOCKS_FORGET);
|
|
}
|
|
ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
|
|
blks, 0);
|
|
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* The ext4_ind_map_blocks() function handles non-extents inodes
|
|
* (i.e., using the traditional indirect/double-indirect i_blocks
|
|
* scheme) for ext4_map_blocks().
|
|
*
|
|
* 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.
|
|
*
|
|
* The ext4_ind_get_blocks() function should be called with
|
|
* down_write(&EXT4_I(inode)->i_data_sem) if allocating filesystem
|
|
* blocks (i.e., flags has EXT4_GET_BLOCKS_CREATE set) or
|
|
* down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system
|
|
* blocks.
|
|
*/
|
|
int ext4_ind_map_blocks(handle_t *handle, struct inode *inode,
|
|
struct ext4_map_blocks *map,
|
|
int flags)
|
|
{
|
|
int err = -EIO;
|
|
ext4_lblk_t offsets[4];
|
|
Indirect chain[4];
|
|
Indirect *partial;
|
|
ext4_fsblk_t goal;
|
|
int indirect_blks;
|
|
int blocks_to_boundary = 0;
|
|
int depth;
|
|
int count = 0;
|
|
ext4_fsblk_t first_block = 0;
|
|
|
|
trace_ext4_ind_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
|
|
J_ASSERT(!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)));
|
|
J_ASSERT(handle != NULL || (flags & EXT4_GET_BLOCKS_CREATE) == 0);
|
|
depth = ext4_block_to_path(inode, map->m_lblk, offsets,
|
|
&blocks_to_boundary);
|
|
|
|
if (depth == 0)
|
|
goto out;
|
|
|
|
partial = ext4_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 < map->m_len && count <= blocks_to_boundary) {
|
|
ext4_fsblk_t blk;
|
|
|
|
blk = le32_to_cpu(*(chain[depth-1].p + count));
|
|
|
|
if (blk == first_block + count)
|
|
count++;
|
|
else
|
|
break;
|
|
}
|
|
goto got_it;
|
|
}
|
|
|
|
/* Next simple case - plain lookup or failed read of indirect block */
|
|
if ((flags & EXT4_GET_BLOCKS_CREATE) == 0 || err == -EIO)
|
|
goto cleanup;
|
|
|
|
/*
|
|
* Okay, we need to do block allocation.
|
|
*/
|
|
if (EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
|
|
EXT4_FEATURE_RO_COMPAT_BIGALLOC)) {
|
|
EXT4_ERROR_INODE(inode, "Can't allocate blocks for "
|
|
"non-extent mapped inodes with bigalloc");
|
|
return -ENOSPC;
|
|
}
|
|
|
|
goal = ext4_find_goal(inode, map->m_lblk, 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 totoal number of
|
|
* direct blocks to allocate for this branch.
|
|
*/
|
|
count = ext4_blks_to_allocate(partial, indirect_blks,
|
|
map->m_len, blocks_to_boundary);
|
|
/*
|
|
* Block out ext4_truncate while we alter the tree
|
|
*/
|
|
err = ext4_alloc_branch(handle, inode, map->m_lblk, indirect_blks,
|
|
&count, goal,
|
|
offsets + (partial - chain), partial);
|
|
|
|
/*
|
|
* The ext4_splice_branch call will free and forget any buffers
|
|
* on the new chain if there is a failure, but that risks using
|
|
* up transaction credits, especially for bitmaps where the
|
|
* credits cannot be returned. Can we handle this somehow? We
|
|
* may need to return -EAGAIN upwards in the worst case. --sct
|
|
*/
|
|
if (!err)
|
|
err = ext4_splice_branch(handle, inode, map->m_lblk,
|
|
partial, indirect_blks, count);
|
|
if (err)
|
|
goto cleanup;
|
|
|
|
map->m_flags |= EXT4_MAP_NEW;
|
|
|
|
ext4_update_inode_fsync_trans(handle, inode, 1);
|
|
got_it:
|
|
map->m_flags |= EXT4_MAP_MAPPED;
|
|
map->m_pblk = le32_to_cpu(chain[depth-1].key);
|
|
map->m_len = count;
|
|
if (count > blocks_to_boundary)
|
|
map->m_flags |= EXT4_MAP_BOUNDARY;
|
|
err = count;
|
|
/* Clean up and exit */
|
|
partial = chain + depth - 1; /* the whole chain */
|
|
cleanup:
|
|
while (partial > chain) {
|
|
BUFFER_TRACE(partial->bh, "call brelse");
|
|
brelse(partial->bh);
|
|
partial--;
|
|
}
|
|
out:
|
|
trace_ext4_ind_map_blocks_exit(inode, map, err);
|
|
return err;
|
|
}
|
|
|
|
/*
|
|
* O_DIRECT for ext3 (or indirect map) based files
|
|
*
|
|
* If the O_DIRECT write will extend the file then add this inode to the
|
|
* orphan list. So recovery will truncate it back to the original size
|
|
* if the machine crashes during the write.
|
|
*
|
|
* If the O_DIRECT write is intantiating holes inside i_size and the machine
|
|
* crashes then stale disk data _may_ be exposed inside the file. But current
|
|
* VFS code falls back into buffered path in that case so we are safe.
|
|
*/
|
|
ssize_t ext4_ind_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;
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
handle_t *handle;
|
|
ssize_t ret;
|
|
int orphan = 0;
|
|
size_t count = iov_length(iov, nr_segs);
|
|
int retries = 0;
|
|
|
|
if (rw == WRITE) {
|
|
loff_t final_size = offset + count;
|
|
|
|
if (final_size > inode->i_size) {
|
|
/* Credits for sb + inode write */
|
|
handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
|
|
if (IS_ERR(handle)) {
|
|
ret = PTR_ERR(handle);
|
|
goto out;
|
|
}
|
|
ret = ext4_orphan_add(handle, inode);
|
|
if (ret) {
|
|
ext4_journal_stop(handle);
|
|
goto out;
|
|
}
|
|
orphan = 1;
|
|
ei->i_disksize = inode->i_size;
|
|
ext4_journal_stop(handle);
|
|
}
|
|
}
|
|
|
|
retry:
|
|
if (rw == READ && ext4_should_dioread_nolock(inode)) {
|
|
if (unlikely(atomic_read(&EXT4_I(inode)->i_unwritten))) {
|
|
mutex_lock(&inode->i_mutex);
|
|
ext4_flush_unwritten_io(inode);
|
|
mutex_unlock(&inode->i_mutex);
|
|
}
|
|
/*
|
|
* Nolock dioread optimization may be dynamically disabled
|
|
* via ext4_inode_block_unlocked_dio(). Check inode's state
|
|
* while holding extra i_dio_count ref.
|
|
*/
|
|
atomic_inc(&inode->i_dio_count);
|
|
smp_mb();
|
|
if (unlikely(ext4_test_inode_state(inode,
|
|
EXT4_STATE_DIOREAD_LOCK))) {
|
|
inode_dio_done(inode);
|
|
goto locked;
|
|
}
|
|
ret = __blockdev_direct_IO(rw, iocb, inode,
|
|
inode->i_sb->s_bdev, iov,
|
|
offset, nr_segs,
|
|
ext4_get_block, NULL, NULL, 0);
|
|
inode_dio_done(inode);
|
|
} else {
|
|
locked:
|
|
ret = blockdev_direct_IO(rw, iocb, inode, iov,
|
|
offset, nr_segs, ext4_get_block);
|
|
|
|
if (unlikely((rw & WRITE) && ret < 0)) {
|
|
loff_t isize = i_size_read(inode);
|
|
loff_t end = offset + iov_length(iov, nr_segs);
|
|
|
|
if (end > isize)
|
|
ext4_truncate_failed_write(inode);
|
|
}
|
|
}
|
|
if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
|
|
goto retry;
|
|
|
|
if (orphan) {
|
|
int err;
|
|
|
|
/* Credits for sb + inode write */
|
|
handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
|
|
if (IS_ERR(handle)) {
|
|
/* This is really bad luck. We've written the data
|
|
* but cannot extend i_size. Bail out and pretend
|
|
* the write failed... */
|
|
ret = PTR_ERR(handle);
|
|
if (inode->i_nlink)
|
|
ext4_orphan_del(NULL, inode);
|
|
|
|
goto out;
|
|
}
|
|
if (inode->i_nlink)
|
|
ext4_orphan_del(handle, inode);
|
|
if (ret > 0) {
|
|
loff_t end = offset + ret;
|
|
if (end > inode->i_size) {
|
|
ei->i_disksize = end;
|
|
i_size_write(inode, end);
|
|
/*
|
|
* We're going to return a positive `ret'
|
|
* here due to non-zero-length I/O, so there's
|
|
* no way of reporting error returns from
|
|
* ext4_mark_inode_dirty() to userspace. So
|
|
* ignore it.
|
|
*/
|
|
ext4_mark_inode_dirty(handle, inode);
|
|
}
|
|
}
|
|
err = ext4_journal_stop(handle);
|
|
if (ret == 0)
|
|
ret = err;
|
|
}
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Calculate the number of metadata blocks need to reserve
|
|
* to allocate a new block at @lblocks for non extent file based file
|
|
*/
|
|
int ext4_ind_calc_metadata_amount(struct inode *inode, sector_t lblock)
|
|
{
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
sector_t dind_mask = ~((sector_t)EXT4_ADDR_PER_BLOCK(inode->i_sb) - 1);
|
|
int blk_bits;
|
|
|
|
if (lblock < EXT4_NDIR_BLOCKS)
|
|
return 0;
|
|
|
|
lblock -= EXT4_NDIR_BLOCKS;
|
|
|
|
if (ei->i_da_metadata_calc_len &&
|
|
(lblock & dind_mask) == ei->i_da_metadata_calc_last_lblock) {
|
|
ei->i_da_metadata_calc_len++;
|
|
return 0;
|
|
}
|
|
ei->i_da_metadata_calc_last_lblock = lblock & dind_mask;
|
|
ei->i_da_metadata_calc_len = 1;
|
|
blk_bits = order_base_2(lblock);
|
|
return (blk_bits / EXT4_ADDR_PER_BLOCK_BITS(inode->i_sb)) + 1;
|
|
}
|
|
|
|
int ext4_ind_trans_blocks(struct inode *inode, int nrblocks, int chunk)
|
|
{
|
|
int indirects;
|
|
|
|
/* if nrblocks are contiguous */
|
|
if (chunk) {
|
|
/*
|
|
* With N contiguous data blocks, we need at most
|
|
* N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
|
|
* 2 dindirect blocks, and 1 tindirect block
|
|
*/
|
|
return DIV_ROUND_UP(nrblocks,
|
|
EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
|
|
}
|
|
/*
|
|
* if nrblocks are not contiguous, worse case, each block touch
|
|
* a indirect block, and each indirect block touch a double indirect
|
|
* block, plus a triple indirect block
|
|
*/
|
|
indirects = nrblocks * 2 + 1;
|
|
return indirects;
|
|
}
|
|
|
|
/*
|
|
* Truncate transactions can be complex and absolutely huge. So we need to
|
|
* be able to restart the transaction at a conventient checkpoint to make
|
|
* sure we don't overflow the journal.
|
|
*
|
|
* Try to extend this transaction for the purposes of truncation. If
|
|
* extend fails, we need to propagate the failure up and restart the
|
|
* transaction in the top-level truncate loop. --sct
|
|
*
|
|
* Returns 0 if we managed to create more room. If we can't create more
|
|
* room, and the transaction must be restarted we return 1.
|
|
*/
|
|
static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
|
|
{
|
|
if (!ext4_handle_valid(handle))
|
|
return 0;
|
|
if (ext4_handle_has_enough_credits(handle, EXT4_RESERVE_TRANS_BLOCKS+1))
|
|
return 0;
|
|
if (!ext4_journal_extend(handle, ext4_blocks_for_truncate(inode)))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
}
|
|
|
|
/**
|
|
* ext4_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 ext4_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 ext4_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 ext4_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].
|
|
* (no partially truncated stuff there). */
|
|
|
|
static Indirect *ext4_find_shared(struct inode *inode, int depth,
|
|
ext4_lblk_t offsets[4], Indirect chain[4],
|
|
__le32 *top)
|
|
{
|
|
Indirect *partial, *p;
|
|
int k, err;
|
|
|
|
*top = 0;
|
|
/* Make k index the deepest non-null offset + 1 */
|
|
for (k = depth; k > 1 && !offsets[k-1]; k--)
|
|
;
|
|
partial = ext4_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((__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;
|
|
/* Nope, don't do this in ext4. Must leave the tree intact */
|
|
#if 0
|
|
*p->p = 0;
|
|
#endif
|
|
}
|
|
/* Writer: end */
|
|
|
|
while (partial > p) {
|
|
brelse(partial->bh);
|
|
partial--;
|
|
}
|
|
no_top:
|
|
return partial;
|
|
}
|
|
|
|
/*
|
|
* Zero a number of block pointers in either an inode or an indirect block.
|
|
* If we restart the transaction we must again get write access to the
|
|
* indirect block for further modification.
|
|
*
|
|
* We release `count' blocks on disk, but (last - first) may be greater
|
|
* than `count' because there can be holes in there.
|
|
*
|
|
* Return 0 on success, 1 on invalid block range
|
|
* and < 0 on fatal error.
|
|
*/
|
|
static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *bh,
|
|
ext4_fsblk_t block_to_free,
|
|
unsigned long count, __le32 *first,
|
|
__le32 *last)
|
|
{
|
|
__le32 *p;
|
|
int flags = EXT4_FREE_BLOCKS_FORGET | EXT4_FREE_BLOCKS_VALIDATED;
|
|
int err;
|
|
|
|
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
|
|
flags |= EXT4_FREE_BLOCKS_METADATA;
|
|
|
|
if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), block_to_free,
|
|
count)) {
|
|
EXT4_ERROR_INODE(inode, "attempt to clear invalid "
|
|
"blocks %llu len %lu",
|
|
(unsigned long long) block_to_free, count);
|
|
return 1;
|
|
}
|
|
|
|
if (try_to_extend_transaction(handle, inode)) {
|
|
if (bh) {
|
|
BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
|
|
err = ext4_handle_dirty_metadata(handle, inode, bh);
|
|
if (unlikely(err))
|
|
goto out_err;
|
|
}
|
|
err = ext4_mark_inode_dirty(handle, inode);
|
|
if (unlikely(err))
|
|
goto out_err;
|
|
err = ext4_truncate_restart_trans(handle, inode,
|
|
ext4_blocks_for_truncate(inode));
|
|
if (unlikely(err))
|
|
goto out_err;
|
|
if (bh) {
|
|
BUFFER_TRACE(bh, "retaking write access");
|
|
err = ext4_journal_get_write_access(handle, bh);
|
|
if (unlikely(err))
|
|
goto out_err;
|
|
}
|
|
}
|
|
|
|
for (p = first; p < last; p++)
|
|
*p = 0;
|
|
|
|
ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
|
|
return 0;
|
|
out_err:
|
|
ext4_std_error(inode->i_sb, err);
|
|
return err;
|
|
}
|
|
|
|
/**
|
|
* ext4_free_data - free a list of data blocks
|
|
* @handle: handle for this transaction
|
|
* @inode: inode we are dealing with
|
|
* @this_bh: indirect buffer_head which contains *@first and *@last
|
|
* @first: array of block numbers
|
|
* @last: 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.
|
|
*
|
|
* We accumulate contiguous runs of blocks to free. Conveniently, if these
|
|
* blocks are contiguous then releasing them at one time will only affect one
|
|
* or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
|
|
* actually use a lot of journal space.
|
|
*
|
|
* @this_bh will be %NULL if @first and @last point into the inode's direct
|
|
* block pointers.
|
|
*/
|
|
static void ext4_free_data(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *this_bh,
|
|
__le32 *first, __le32 *last)
|
|
{
|
|
ext4_fsblk_t block_to_free = 0; /* Starting block # of a run */
|
|
unsigned long count = 0; /* Number of blocks in the run */
|
|
__le32 *block_to_free_p = NULL; /* Pointer into inode/ind
|
|
corresponding to
|
|
block_to_free */
|
|
ext4_fsblk_t nr; /* Current block # */
|
|
__le32 *p; /* Pointer into inode/ind
|
|
for current block */
|
|
int err = 0;
|
|
|
|
if (this_bh) { /* For indirect block */
|
|
BUFFER_TRACE(this_bh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, this_bh);
|
|
/* Important: if we can't update the indirect pointers
|
|
* to the blocks, we can't free them. */
|
|
if (err)
|
|
return;
|
|
}
|
|
|
|
for (p = first; p < last; p++) {
|
|
nr = le32_to_cpu(*p);
|
|
if (nr) {
|
|
/* accumulate blocks to free if they're contiguous */
|
|
if (count == 0) {
|
|
block_to_free = nr;
|
|
block_to_free_p = p;
|
|
count = 1;
|
|
} else if (nr == block_to_free + count) {
|
|
count++;
|
|
} else {
|
|
err = ext4_clear_blocks(handle, inode, this_bh,
|
|
block_to_free, count,
|
|
block_to_free_p, p);
|
|
if (err)
|
|
break;
|
|
block_to_free = nr;
|
|
block_to_free_p = p;
|
|
count = 1;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!err && count > 0)
|
|
err = ext4_clear_blocks(handle, inode, this_bh, block_to_free,
|
|
count, block_to_free_p, p);
|
|
if (err < 0)
|
|
/* fatal error */
|
|
return;
|
|
|
|
if (this_bh) {
|
|
BUFFER_TRACE(this_bh, "call ext4_handle_dirty_metadata");
|
|
|
|
/*
|
|
* The buffer head should have an attached journal head at this
|
|
* point. However, if the data is corrupted and an indirect
|
|
* block pointed to itself, it would have been detached when
|
|
* the block was cleared. Check for this instead of OOPSing.
|
|
*/
|
|
if ((EXT4_JOURNAL(inode) == NULL) || bh2jh(this_bh))
|
|
ext4_handle_dirty_metadata(handle, inode, this_bh);
|
|
else
|
|
EXT4_ERROR_INODE(inode,
|
|
"circular indirect block detected at "
|
|
"block %llu",
|
|
(unsigned long long) this_bh->b_blocknr);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* ext4_free_branches - free an array of branches
|
|
* @handle: JBD handle for this transaction
|
|
* @inode: inode we are dealing with
|
|
* @parent_bh: the buffer_head which contains *@first and *@last
|
|
* @first: array of block numbers
|
|
* @last: 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 ext4_free_branches(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *parent_bh,
|
|
__le32 *first, __le32 *last, int depth)
|
|
{
|
|
ext4_fsblk_t nr;
|
|
__le32 *p;
|
|
|
|
if (ext4_handle_is_aborted(handle))
|
|
return;
|
|
|
|
if (depth--) {
|
|
struct buffer_head *bh;
|
|
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
|
p = last;
|
|
while (--p >= first) {
|
|
nr = le32_to_cpu(*p);
|
|
if (!nr)
|
|
continue; /* A hole */
|
|
|
|
if (!ext4_data_block_valid(EXT4_SB(inode->i_sb),
|
|
nr, 1)) {
|
|
EXT4_ERROR_INODE(inode,
|
|
"invalid indirect mapped "
|
|
"block %lu (level %d)",
|
|
(unsigned long) nr, depth);
|
|
break;
|
|
}
|
|
|
|
/* Go read the buffer for the next level down */
|
|
bh = sb_bread(inode->i_sb, nr);
|
|
|
|
/*
|
|
* A read failure? Report error and clear slot
|
|
* (should be rare).
|
|
*/
|
|
if (!bh) {
|
|
EXT4_ERROR_INODE_BLOCK(inode, nr,
|
|
"Read failure");
|
|
continue;
|
|
}
|
|
|
|
/* This zaps the entire block. Bottom up. */
|
|
BUFFER_TRACE(bh, "free child branches");
|
|
ext4_free_branches(handle, inode, bh,
|
|
(__le32 *) bh->b_data,
|
|
(__le32 *) bh->b_data + addr_per_block,
|
|
depth);
|
|
brelse(bh);
|
|
|
|
/*
|
|
* Everything below this this pointer has been
|
|
* released. Now let this top-of-subtree go.
|
|
*
|
|
* We want the freeing of this indirect block to be
|
|
* atomic in the journal with the updating of the
|
|
* bitmap block which owns it. So make some room in
|
|
* the journal.
|
|
*
|
|
* We zero the parent pointer *after* freeing its
|
|
* pointee in the bitmaps, so if extend_transaction()
|
|
* for some reason fails to put the bitmap changes and
|
|
* the release into the same transaction, recovery
|
|
* will merely complain about releasing a free block,
|
|
* rather than leaking blocks.
|
|
*/
|
|
if (ext4_handle_is_aborted(handle))
|
|
return;
|
|
if (try_to_extend_transaction(handle, inode)) {
|
|
ext4_mark_inode_dirty(handle, inode);
|
|
ext4_truncate_restart_trans(handle, inode,
|
|
ext4_blocks_for_truncate(inode));
|
|
}
|
|
|
|
/*
|
|
* The forget flag here is critical because if
|
|
* we are journaling (and not doing data
|
|
* journaling), we have to make sure a revoke
|
|
* record is written to prevent the journal
|
|
* replay from overwriting the (former)
|
|
* indirect block if it gets reallocated as a
|
|
* data block. This must happen in the same
|
|
* transaction where the data blocks are
|
|
* actually freed.
|
|
*/
|
|
ext4_free_blocks(handle, inode, NULL, nr, 1,
|
|
EXT4_FREE_BLOCKS_METADATA|
|
|
EXT4_FREE_BLOCKS_FORGET);
|
|
|
|
if (parent_bh) {
|
|
/*
|
|
* The block which we have just freed is
|
|
* pointed to by an indirect block: journal it
|
|
*/
|
|
BUFFER_TRACE(parent_bh, "get_write_access");
|
|
if (!ext4_journal_get_write_access(handle,
|
|
parent_bh)){
|
|
*p = 0;
|
|
BUFFER_TRACE(parent_bh,
|
|
"call ext4_handle_dirty_metadata");
|
|
ext4_handle_dirty_metadata(handle,
|
|
inode,
|
|
parent_bh);
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
/* We have reached the bottom of the tree. */
|
|
BUFFER_TRACE(parent_bh, "free data blocks");
|
|
ext4_free_data(handle, inode, parent_bh, first, last);
|
|
}
|
|
}
|
|
|
|
void ext4_ind_truncate(handle_t *handle, struct inode *inode)
|
|
{
|
|
struct ext4_inode_info *ei = EXT4_I(inode);
|
|
__le32 *i_data = ei->i_data;
|
|
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
|
ext4_lblk_t offsets[4];
|
|
Indirect chain[4];
|
|
Indirect *partial;
|
|
__le32 nr = 0;
|
|
int n = 0;
|
|
ext4_lblk_t last_block, max_block;
|
|
unsigned blocksize = inode->i_sb->s_blocksize;
|
|
|
|
last_block = (inode->i_size + blocksize-1)
|
|
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
|
|
max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
|
|
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
|
|
|
|
if (last_block != max_block) {
|
|
n = ext4_block_to_path(inode, last_block, offsets, NULL);
|
|
if (n == 0)
|
|
return;
|
|
}
|
|
|
|
ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
|
|
|
|
/*
|
|
* The orphan list entry will now protect us from any crash which
|
|
* occurs before the truncate completes, so it is now safe to propagate
|
|
* the new, shorter inode size (held for now in i_size) into the
|
|
* on-disk inode. We do this via i_disksize, which is the value which
|
|
* ext4 *really* writes onto the disk inode.
|
|
*/
|
|
ei->i_disksize = inode->i_size;
|
|
|
|
if (last_block == max_block) {
|
|
/*
|
|
* It is unnecessary to free any data blocks if last_block is
|
|
* equal to the indirect block limit.
|
|
*/
|
|
return;
|
|
} else if (n == 1) { /* direct blocks */
|
|
ext4_free_data(handle, inode, NULL, i_data+offsets[0],
|
|
i_data + EXT4_NDIR_BLOCKS);
|
|
goto do_indirects;
|
|
}
|
|
|
|
partial = ext4_find_shared(inode, n, offsets, chain, &nr);
|
|
/* Kill the top of shared branch (not detached) */
|
|
if (nr) {
|
|
if (partial == chain) {
|
|
/* Shared branch grows from the inode */
|
|
ext4_free_branches(handle, inode, NULL,
|
|
&nr, &nr+1, (chain+n-1) - partial);
|
|
*partial->p = 0;
|
|
/*
|
|
* We mark the inode dirty prior to restart,
|
|
* and prior to stop. No need for it here.
|
|
*/
|
|
} else {
|
|
/* Shared branch grows from an indirect block */
|
|
BUFFER_TRACE(partial->bh, "get_write_access");
|
|
ext4_free_branches(handle, inode, partial->bh,
|
|
partial->p,
|
|
partial->p+1, (chain+n-1) - partial);
|
|
}
|
|
}
|
|
/* Clear the ends of indirect blocks on the shared branch */
|
|
while (partial > chain) {
|
|
ext4_free_branches(handle, inode, partial->bh, partial->p + 1,
|
|
(__le32*)partial->bh->b_data+addr_per_block,
|
|
(chain+n-1) - partial);
|
|
BUFFER_TRACE(partial->bh, "call brelse");
|
|
brelse(partial->bh);
|
|
partial--;
|
|
}
|
|
do_indirects:
|
|
/* Kill the remaining (whole) subtrees */
|
|
switch (offsets[0]) {
|
|
default:
|
|
nr = i_data[EXT4_IND_BLOCK];
|
|
if (nr) {
|
|
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
|
|
i_data[EXT4_IND_BLOCK] = 0;
|
|
}
|
|
case EXT4_IND_BLOCK:
|
|
nr = i_data[EXT4_DIND_BLOCK];
|
|
if (nr) {
|
|
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
|
|
i_data[EXT4_DIND_BLOCK] = 0;
|
|
}
|
|
case EXT4_DIND_BLOCK:
|
|
nr = i_data[EXT4_TIND_BLOCK];
|
|
if (nr) {
|
|
ext4_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
|
|
i_data[EXT4_TIND_BLOCK] = 0;
|
|
}
|
|
case EXT4_TIND_BLOCK:
|
|
;
|
|
}
|
|
}
|
|
|
|
static int free_hole_blocks(handle_t *handle, struct inode *inode,
|
|
struct buffer_head *parent_bh, __le32 *i_data,
|
|
int level, ext4_lblk_t first,
|
|
ext4_lblk_t count, int max)
|
|
{
|
|
struct buffer_head *bh = NULL;
|
|
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
|
int ret = 0;
|
|
int i, inc;
|
|
ext4_lblk_t offset;
|
|
__le32 blk;
|
|
|
|
inc = 1 << ((EXT4_BLOCK_SIZE_BITS(inode->i_sb) - 2) * level);
|
|
for (i = 0, offset = 0; i < max; i++, i_data++, offset += inc) {
|
|
if (offset >= count + first)
|
|
break;
|
|
if (*i_data == 0 || (offset + inc) <= first)
|
|
continue;
|
|
blk = *i_data;
|
|
if (level > 0) {
|
|
ext4_lblk_t first2;
|
|
bh = sb_bread(inode->i_sb, le32_to_cpu(blk));
|
|
if (!bh) {
|
|
EXT4_ERROR_INODE_BLOCK(inode, le32_to_cpu(blk),
|
|
"Read failure");
|
|
return -EIO;
|
|
}
|
|
first2 = (first > offset) ? first - offset : 0;
|
|
ret = free_hole_blocks(handle, inode, bh,
|
|
(__le32 *)bh->b_data, level - 1,
|
|
first2, count - offset,
|
|
inode->i_sb->s_blocksize >> 2);
|
|
if (ret) {
|
|
brelse(bh);
|
|
goto err;
|
|
}
|
|
}
|
|
if (level == 0 ||
|
|
(bh && all_zeroes((__le32 *)bh->b_data,
|
|
(__le32 *)bh->b_data + addr_per_block))) {
|
|
ext4_free_data(handle, inode, parent_bh, &blk, &blk+1);
|
|
*i_data = 0;
|
|
}
|
|
brelse(bh);
|
|
bh = NULL;
|
|
}
|
|
|
|
err:
|
|
return ret;
|
|
}
|
|
|
|
int ext4_free_hole_blocks(handle_t *handle, struct inode *inode,
|
|
ext4_lblk_t first, ext4_lblk_t stop)
|
|
{
|
|
int addr_per_block = EXT4_ADDR_PER_BLOCK(inode->i_sb);
|
|
int level, ret = 0;
|
|
int num = EXT4_NDIR_BLOCKS;
|
|
ext4_lblk_t count, max = EXT4_NDIR_BLOCKS;
|
|
__le32 *i_data = EXT4_I(inode)->i_data;
|
|
|
|
count = stop - first;
|
|
for (level = 0; level < 4; level++, max *= addr_per_block) {
|
|
if (first < max) {
|
|
ret = free_hole_blocks(handle, inode, NULL, i_data,
|
|
level, first, count, num);
|
|
if (ret)
|
|
goto err;
|
|
if (count > max - first)
|
|
count -= max - first;
|
|
else
|
|
break;
|
|
first = 0;
|
|
} else {
|
|
first -= max;
|
|
}
|
|
i_data += num;
|
|
if (level == 0) {
|
|
num = 1;
|
|
max = 1;
|
|
}
|
|
}
|
|
|
|
err:
|
|
return ret;
|
|
}
|
|
|