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git.proxmox.com Git - mirror_ubuntu-bionic-kernel.git/blob - fs/gfs2/bmap.c
2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved.
5 * This copyrighted material is made available to anyone wishing to use,
6 * modify, copy, or redistribute it subject to the terms and conditions
7 * of the GNU General Public License version 2.
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/gfs2_ondisk.h>
16 #include <linux/crc32.h>
19 #include "lm_interface.h"
30 #include "ops_address.h"
32 /* This doesn't need to be that large as max 64 bit pointers in a 4k
33 * block is 512, so __u16 is fine for that. It saves stack space to
37 __u16 mp_list
[GFS2_MAX_META_HEIGHT
];
40 typedef int (*block_call_t
) (struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
41 struct buffer_head
*bh
, uint64_t *top
,
42 uint64_t *bottom
, unsigned int height
,
47 unsigned int sm_height
;
51 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
53 * @dibh: the dinode buffer
54 * @block: the block number that was allocated
55 * @private: any locked page held by the caller process
60 static int gfs2_unstuffer_page(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
61 uint64_t block
, struct page
*page
)
63 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
64 struct inode
*inode
= &ip
->i_inode
;
65 struct buffer_head
*bh
;
68 if (!page
|| page
->index
) {
69 page
= grab_cache_page(inode
->i_mapping
, 0);
75 if (!PageUptodate(page
)) {
76 void *kaddr
= kmap(page
);
78 memcpy(kaddr
, dibh
->b_data
+ sizeof(struct gfs2_dinode
),
80 memset(kaddr
+ ip
->i_di
.di_size
, 0,
81 PAGE_CACHE_SIZE
- ip
->i_di
.di_size
);
84 SetPageUptodate(page
);
87 if (!page_has_buffers(page
))
88 create_empty_buffers(page
, 1 << inode
->i_blkbits
,
91 bh
= page_buffers(page
);
93 if (!buffer_mapped(bh
))
94 map_bh(bh
, inode
->i_sb
, block
);
96 set_buffer_uptodate(bh
);
97 if ((sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
) || gfs2_is_jdata(ip
))
98 gfs2_trans_add_bh(ip
->i_gl
, bh
, 0);
99 mark_buffer_dirty(bh
);
103 page_cache_release(page
);
110 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
111 * @ip: The GFS2 inode to unstuff
112 * @unstuffer: the routine that handles unstuffing a non-zero length file
113 * @private: private data for the unstuffer
115 * This routine unstuffs a dinode and returns it to a "normal" state such
116 * that the height can be grown in the traditional way.
121 int gfs2_unstuff_dinode(struct gfs2_inode
*ip
, struct page
*page
)
123 struct buffer_head
*bh
, *dibh
;
125 int isdir
= gfs2_is_dir(ip
);
128 down_write(&ip
->i_rw_mutex
);
130 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
134 if (ip
->i_di
.di_size
) {
135 /* Get a free block, fill it with the stuffed data,
136 and write it out to disk */
139 block
= gfs2_alloc_meta(ip
);
141 error
= gfs2_dir_get_new_buffer(ip
, block
, &bh
);
144 gfs2_buffer_copy_tail(bh
,
145 sizeof(struct gfs2_meta_header
),
146 dibh
, sizeof(struct gfs2_dinode
));
149 block
= gfs2_alloc_data(ip
);
151 error
= gfs2_unstuffer_page(ip
, dibh
, block
, page
);
157 /* Set up the pointer to the new block */
159 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
161 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
163 if (ip
->i_di
.di_size
) {
164 *(uint64_t *)(dibh
->b_data
+ sizeof(struct gfs2_dinode
)) =
166 ip
->i_di
.di_blocks
++;
169 ip
->i_di
.di_height
= 1;
171 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
177 up_write(&ip
->i_rw_mutex
);
183 * calc_tree_height - Calculate the height of a metadata tree
184 * @ip: The GFS2 inode
185 * @size: The proposed size of the file
187 * Work out how tall a metadata tree needs to be in order to accommodate a
188 * file of a particular size. If size is less than the current size of
189 * the inode, then the current size of the inode is used instead of the
192 * Returns: the height the tree should be
195 static unsigned int calc_tree_height(struct gfs2_inode
*ip
, uint64_t size
)
197 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
199 unsigned int max
, height
;
201 if (ip
->i_di
.di_size
> size
)
202 size
= ip
->i_di
.di_size
;
204 if (gfs2_is_dir(ip
)) {
205 arr
= sdp
->sd_jheightsize
;
206 max
= sdp
->sd_max_jheight
;
208 arr
= sdp
->sd_heightsize
;
209 max
= sdp
->sd_max_height
;
212 for (height
= 0; height
< max
; height
++)
213 if (arr
[height
] >= size
)
220 * build_height - Build a metadata tree of the requested height
221 * @ip: The GFS2 inode
222 * @height: The height to build to
228 static int build_height(struct inode
*inode
, unsigned height
)
230 struct gfs2_inode
*ip
= GFS2_I(inode
);
231 unsigned new_height
= height
- ip
->i_di
.di_height
;
232 struct buffer_head
*dibh
;
233 struct buffer_head
*blocks
[GFS2_MAX_META_HEIGHT
];
239 if (height
<= ip
->i_di
.di_height
)
242 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
246 for(n
= 0; n
< new_height
; n
++) {
247 bn
= gfs2_alloc_meta(ip
);
248 blocks
[n
] = gfs2_meta_new(ip
->i_gl
, bn
);
249 gfs2_trans_add_bh(ip
->i_gl
, blocks
[n
], 1);
253 bn
= blocks
[0]->b_blocknr
;
254 if (new_height
> 1) {
255 for(; n
< new_height
-1; n
++) {
256 gfs2_metatype_set(blocks
[n
], GFS2_METATYPE_IN
,
258 gfs2_buffer_clear_tail(blocks
[n
],
259 sizeof(struct gfs2_meta_header
));
260 bp
= (u64
*)(blocks
[n
]->b_data
+
261 sizeof(struct gfs2_meta_header
));
262 *bp
= cpu_to_be64(blocks
[n
+1]->b_blocknr
);
267 gfs2_metatype_set(blocks
[n
], GFS2_METATYPE_IN
, GFS2_FORMAT_IN
);
268 gfs2_buffer_copy_tail(blocks
[n
], sizeof(struct gfs2_meta_header
),
269 dibh
, sizeof(struct gfs2_dinode
));
271 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
272 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
273 bp
= (u64
*)(dibh
->b_data
+ sizeof(struct gfs2_dinode
));
274 *bp
= cpu_to_be64(bn
);
275 ip
->i_di
.di_height
+= new_height
;
276 ip
->i_di
.di_blocks
+= new_height
;
277 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
283 * find_metapath - Find path through the metadata tree
284 * @ip: The inode pointer
285 * @mp: The metapath to return the result in
286 * @block: The disk block to look up
288 * This routine returns a struct metapath structure that defines a path
289 * through the metadata of inode "ip" to get to block "block".
292 * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a
293 * filesystem with a blocksize of 4096.
295 * find_metapath() would return a struct metapath structure set to:
296 * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48,
297 * and mp_list[2] = 165.
299 * That means that in order to get to the block containing the byte at
300 * offset 101342453, we would load the indirect block pointed to by pointer
301 * 0 in the dinode. We would then load the indirect block pointed to by
302 * pointer 48 in that indirect block. We would then load the data block
303 * pointed to by pointer 165 in that indirect block.
305 * ----------------------------------------
310 * ----------------------------------------
314 * ----------------------------------------
318 * |0 5 6 7 8 9 0 1 2|
319 * ----------------------------------------
323 * ----------------------------------------
328 * ----------------------------------------
332 * ----------------------------------------
333 * | Data block containing offset |
337 * ----------------------------------------
341 static void find_metapath(struct gfs2_inode
*ip
, uint64_t block
,
344 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
348 for (i
= ip
->i_di
.di_height
; i
--;)
349 mp
->mp_list
[i
] = (__u16
)do_div(b
, sdp
->sd_inptrs
);
354 * metapointer - Return pointer to start of metadata in a buffer
356 * @height: The metadata height (0 = dinode)
359 * Return a pointer to the block number of the next height of the metadata
360 * tree given a buffer containing the pointer to the current height of the
364 static inline u64
*metapointer(struct buffer_head
*bh
, int *boundary
,
365 unsigned int height
, const struct metapath
*mp
)
367 unsigned int head_size
= (height
> 0) ?
368 sizeof(struct gfs2_meta_header
) : sizeof(struct gfs2_dinode
);
371 ptr
= ((u64
*)(bh
->b_data
+ head_size
)) + mp
->mp_list
[height
];
372 if (ptr
+ 1 == (u64
*)(bh
->b_data
+ bh
->b_size
))
378 * lookup_block - Get the next metadata block in metadata tree
379 * @ip: The GFS2 inode
380 * @bh: Buffer containing the pointers to metadata blocks
381 * @height: The height of the tree (0 = dinode)
383 * @create: Non-zero if we may create a new meatdata block
384 * @new: Used to indicate if we did create a new metadata block
385 * @block: the returned disk block number
387 * Given a metatree, complete to a particular height, checks to see if the next
388 * height of the tree exists. If not the next height of the tree is created.
389 * The block number of the next height of the metadata tree is returned.
393 static int lookup_block(struct gfs2_inode
*ip
, struct buffer_head
*bh
,
394 unsigned int height
, struct metapath
*mp
, int create
,
395 int *new, uint64_t *block
)
398 uint64_t *ptr
= metapointer(bh
, &boundary
, height
, mp
);
401 *block
= be64_to_cpu(*ptr
);
410 if (height
== ip
->i_di
.di_height
- 1 && !gfs2_is_dir(ip
))
411 *block
= gfs2_alloc_data(ip
);
413 *block
= gfs2_alloc_meta(ip
);
415 gfs2_trans_add_bh(ip
->i_gl
, bh
, 1);
417 *ptr
= cpu_to_be64(*block
);
418 ip
->i_di
.di_blocks
++;
425 * gfs2_block_pointers - Map a block from an inode to a disk block
427 * @lblock: The logical block number
428 * @new: Value/Result argument (1 = may create/did create new blocks)
429 * @boundary: gets set if we've hit a block boundary
430 * @mp: metapath to use
432 * Find the block number on the current device which corresponds to an
433 * inode's block. If the block had to be created, "new" will be set.
438 static struct buffer_head
*gfs2_block_pointers(struct inode
*inode
, u64 lblock
,
439 int *new, u64
*dblock
,
443 struct gfs2_inode
*ip
= GFS2_I(inode
);
444 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
445 struct buffer_head
*bh
;
449 unsigned int end_of_metadata
;
456 if (gfs2_assert_warn(sdp
, !gfs2_is_stuffed(ip
)))
459 bsize
= (gfs2_is_dir(ip
)) ? sdp
->sd_jbsize
: sdp
->sd_sb
.sb_bsize
;
461 height
= calc_tree_height(ip
, (lblock
+ 1) * bsize
);
462 if (ip
->i_di
.di_height
< height
) {
466 error
= build_height(inode
, height
);
471 find_metapath(ip
, lblock
, mp
);
472 end_of_metadata
= ip
->i_di
.di_height
- 1;
474 error
= gfs2_meta_inode_buffer(ip
, &bh
);
478 for (x
= 0; x
< end_of_metadata
; x
++) {
479 lookup_block(ip
, bh
, x
, mp
, create
, new, dblock
);
484 error
= gfs2_meta_indirect_buffer(ip
, x
+1, *dblock
, *new, &bh
);
489 *boundary
= lookup_block(ip
, bh
, end_of_metadata
, mp
, create
, new, dblock
);
491 struct buffer_head
*dibh
;
492 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
494 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
495 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
501 return ERR_PTR(error
);
505 static inline void bmap_lock(struct inode
*inode
, int create
)
507 struct gfs2_inode
*ip
= GFS2_I(inode
);
509 down_write(&ip
->i_rw_mutex
);
511 down_read(&ip
->i_rw_mutex
);
514 static inline void bmap_unlock(struct inode
*inode
, int create
)
516 struct gfs2_inode
*ip
= GFS2_I(inode
);
518 up_write(&ip
->i_rw_mutex
);
520 up_read(&ip
->i_rw_mutex
);
523 int gfs2_block_map(struct inode
*inode
, u64 lblock
, int *new, u64
*dblock
, int *boundary
)
526 struct buffer_head
*bh
;
529 bmap_lock(inode
, create
);
530 bh
= gfs2_block_pointers(inode
, lblock
, new, dblock
, boundary
, &mp
);
531 bmap_unlock(inode
, create
);
540 int gfs2_extent_map(struct inode
*inode
, u64 lblock
, int *new, u64
*dblock
, unsigned *extlen
)
542 struct gfs2_inode
*ip
= GFS2_I(inode
);
543 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
545 struct buffer_head
*bh
;
553 bmap_lock(inode
, create
);
554 bh
= gfs2_block_pointers(inode
, lblock
, new, dblock
, &boundary
, &mp
);
557 if (bh
&& !IS_ERR(bh
) && *dblock
&& !*new) {
561 unsigned end_of_metadata
= ip
->i_di
.di_height
- 1;
563 nptrs
= (end_of_metadata
) ? sdp
->sd_inptrs
: sdp
->sd_diptrs
;
564 while (++mp
.mp_list
[end_of_metadata
] < nptrs
) {
565 lookup_block(ip
, bh
, end_of_metadata
, &mp
, 0, &tmp_new
, &tmp_dblock
);
566 if (*dblock
+ *extlen
!= tmp_dblock
)
571 bmap_unlock(inode
, create
);
581 * recursive_scan - recursively scan through the end of a file
583 * @dibh: the dinode buffer
584 * @mp: the path through the metadata to the point to start
585 * @height: the height the recursion is at
586 * @block: the indirect block to look at
587 * @first: 1 if this is the first block
588 * @bc: the call to make for each piece of metadata
589 * @data: data opaque to this function to pass to @bc
591 * When this is first called @height and @block should be zero and
592 * @first should be 1.
597 static int recursive_scan(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
598 struct metapath
*mp
, unsigned int height
,
599 uint64_t block
, int first
, block_call_t bc
,
602 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
603 struct buffer_head
*bh
= NULL
;
604 uint64_t *top
, *bottom
;
607 int mh_size
= sizeof(struct gfs2_meta_header
);
610 error
= gfs2_meta_inode_buffer(ip
, &bh
);
615 top
= (uint64_t *)(bh
->b_data
+ sizeof(struct gfs2_dinode
)) +
617 bottom
= (uint64_t *)(bh
->b_data
+ sizeof(struct gfs2_dinode
)) +
620 error
= gfs2_meta_indirect_buffer(ip
, height
, block
, 0, &bh
);
624 top
= (uint64_t *)(bh
->b_data
+ mh_size
) +
625 ((first
) ? mp
->mp_list
[height
] : 0);
627 bottom
= (uint64_t *)(bh
->b_data
+ mh_size
) + sdp
->sd_inptrs
;
630 error
= bc(ip
, dibh
, bh
, top
, bottom
, height
, data
);
634 if (height
< ip
->i_di
.di_height
- 1)
635 for (; top
< bottom
; top
++, first
= 0) {
639 bn
= be64_to_cpu(*top
);
641 error
= recursive_scan(ip
, dibh
, mp
, height
+ 1, bn
,
654 * do_strip - Look for a layer a particular layer of the file and strip it off
656 * @dibh: the dinode buffer
657 * @bh: A buffer of pointers
658 * @top: The first pointer in the buffer
659 * @bottom: One more than the last pointer
660 * @height: the height this buffer is at
661 * @data: a pointer to a struct strip_mine
666 static int do_strip(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
667 struct buffer_head
*bh
, uint64_t *top
, uint64_t *bottom
,
668 unsigned int height
, void *data
)
670 struct strip_mine
*sm
= data
;
671 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
672 struct gfs2_rgrp_list rlist
;
676 unsigned int rg_blocks
= 0;
678 unsigned int revokes
= 0;
685 if (height
!= sm
->sm_height
)
693 metadata
= (height
!= ip
->i_di
.di_height
- 1);
695 revokes
= (height
) ? sdp
->sd_inptrs
: sdp
->sd_diptrs
;
697 error
= gfs2_rindex_hold(sdp
, &ip
->i_alloc
.al_ri_gh
);
701 memset(&rlist
, 0, sizeof(struct gfs2_rgrp_list
));
705 for (p
= top
; p
< bottom
; p
++) {
709 bn
= be64_to_cpu(*p
);
711 if (bstart
+ blen
== bn
)
715 gfs2_rlist_add(sdp
, &rlist
, bstart
);
723 gfs2_rlist_add(sdp
, &rlist
, bstart
);
725 goto out
; /* Nothing to do */
727 gfs2_rlist_alloc(&rlist
, LM_ST_EXCLUSIVE
, 0);
729 for (x
= 0; x
< rlist
.rl_rgrps
; x
++) {
730 struct gfs2_rgrpd
*rgd
;
731 rgd
= rlist
.rl_ghs
[x
].gh_gl
->gl_object
;
732 rg_blocks
+= rgd
->rd_ri
.ri_length
;
735 error
= gfs2_glock_nq_m(rlist
.rl_rgrps
, rlist
.rl_ghs
);
739 error
= gfs2_trans_begin(sdp
, rg_blocks
+ RES_DINODE
+
740 RES_INDIRECT
+ RES_STATFS
+ RES_QUOTA
,
745 down_write(&ip
->i_rw_mutex
);
747 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
748 gfs2_trans_add_bh(ip
->i_gl
, bh
, 1);
753 for (p
= top
; p
< bottom
; p
++) {
757 bn
= be64_to_cpu(*p
);
759 if (bstart
+ blen
== bn
)
764 gfs2_free_meta(ip
, bstart
, blen
);
766 gfs2_free_data(ip
, bstart
, blen
);
774 if (!ip
->i_di
.di_blocks
)
775 gfs2_consist_inode(ip
);
776 ip
->i_di
.di_blocks
--;
780 gfs2_free_meta(ip
, bstart
, blen
);
782 gfs2_free_data(ip
, bstart
, blen
);
785 ip
->i_di
.di_mtime
= ip
->i_di
.di_ctime
= get_seconds();
787 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
789 up_write(&ip
->i_rw_mutex
);
794 gfs2_glock_dq_m(rlist
.rl_rgrps
, rlist
.rl_ghs
);
797 gfs2_rlist_free(&rlist
);
800 gfs2_glock_dq_uninit(&ip
->i_alloc
.al_ri_gh
);
806 * do_grow - Make a file look bigger than it is
808 * @size: the size to set the file to
810 * Called with an exclusive lock on @ip.
815 static int do_grow(struct gfs2_inode
*ip
, uint64_t size
)
817 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
818 struct gfs2_alloc
*al
;
819 struct buffer_head
*dibh
;
823 al
= gfs2_alloc_get(ip
);
825 error
= gfs2_quota_lock(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
829 error
= gfs2_quota_check(ip
, ip
->i_di
.di_uid
, ip
->i_di
.di_gid
);
833 al
->al_requested
= sdp
->sd_max_height
+ RES_DATA
;
835 error
= gfs2_inplace_reserve(ip
);
839 error
= gfs2_trans_begin(sdp
,
840 sdp
->sd_max_height
+ al
->al_rgd
->rd_ri
.ri_length
+
841 RES_JDATA
+ RES_DINODE
+ RES_STATFS
+ RES_QUOTA
, 0);
845 if (size
> sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
)) {
846 if (gfs2_is_stuffed(ip
)) {
847 error
= gfs2_unstuff_dinode(ip
, NULL
);
852 h
= calc_tree_height(ip
, size
);
853 if (ip
->i_di
.di_height
< h
) {
854 down_write(&ip
->i_rw_mutex
);
855 error
= build_height(&ip
->i_inode
, h
);
856 up_write(&ip
->i_rw_mutex
);
862 ip
->i_di
.di_size
= size
;
863 ip
->i_di
.di_mtime
= ip
->i_di
.di_ctime
= get_seconds();
865 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
869 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
870 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
877 gfs2_inplace_release(ip
);
880 gfs2_quota_unlock(ip
);
890 * gfs2_block_truncate_page - Deal with zeroing out data for truncate
892 * This is partly borrowed from ext3.
894 static int gfs2_block_truncate_page(struct address_space
*mapping
)
896 struct inode
*inode
= mapping
->host
;
897 struct gfs2_inode
*ip
= GFS2_I(inode
);
898 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
899 loff_t from
= inode
->i_size
;
900 unsigned long index
= from
>> PAGE_CACHE_SHIFT
;
901 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
902 unsigned blocksize
, iblock
, length
, pos
;
903 struct buffer_head
*bh
;
908 page
= grab_cache_page(mapping
, index
);
912 blocksize
= inode
->i_sb
->s_blocksize
;
913 length
= blocksize
- (offset
& (blocksize
- 1));
914 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
916 if (!page_has_buffers(page
))
917 create_empty_buffers(page
, blocksize
, 0);
919 /* Find the buffer that contains "offset" */
920 bh
= page_buffers(page
);
922 while (offset
>= pos
) {
923 bh
= bh
->b_this_page
;
930 if (!buffer_mapped(bh
)) {
931 gfs2_get_block(inode
, iblock
, bh
, 0);
932 /* unmapped? It's a hole - nothing to do */
933 if (!buffer_mapped(bh
))
937 /* Ok, it's mapped. Make sure it's up-to-date */
938 if (PageUptodate(page
))
939 set_buffer_uptodate(bh
);
941 if (!buffer_uptodate(bh
)) {
943 ll_rw_block(READ
, 1, &bh
);
945 /* Uhhuh. Read error. Complain and punt. */
946 if (!buffer_uptodate(bh
))
950 if (sdp
->sd_args
.ar_data
== GFS2_DATA_ORDERED
|| gfs2_is_jdata(ip
))
951 gfs2_trans_add_bh(ip
->i_gl
, bh
, 0);
953 kaddr
= kmap_atomic(page
, KM_USER0
);
954 memset(kaddr
+ offset
, 0, length
);
955 flush_dcache_page(page
);
956 kunmap_atomic(kaddr
, KM_USER0
);
960 page_cache_release(page
);
964 static int trunc_start(struct gfs2_inode
*ip
, uint64_t size
)
966 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
967 struct buffer_head
*dibh
;
968 int journaled
= gfs2_is_jdata(ip
);
971 error
= gfs2_trans_begin(sdp
,
972 RES_DINODE
+ ((journaled
) ? RES_JDATA
: 0), 0);
976 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
980 if (gfs2_is_stuffed(ip
)) {
981 ip
->i_di
.di_size
= size
;
982 ip
->i_di
.di_mtime
= ip
->i_di
.di_ctime
= get_seconds();
983 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
984 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
985 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
) + size
);
989 if (size
& (uint64_t)(sdp
->sd_sb
.sb_bsize
- 1))
990 error
= gfs2_block_truncate_page(ip
->i_inode
.i_mapping
);
993 ip
->i_di
.di_size
= size
;
994 ip
->i_di
.di_mtime
= ip
->i_di
.di_ctime
= get_seconds();
995 ip
->i_di
.di_flags
|= GFS2_DIF_TRUNC_IN_PROG
;
996 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
997 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
1004 gfs2_trans_end(sdp
);
1009 static int trunc_dealloc(struct gfs2_inode
*ip
, uint64_t size
)
1011 unsigned int height
= ip
->i_di
.di_height
;
1019 lblock
= (size
- 1) >> GFS2_SB(&ip
->i_inode
)->sd_sb
.sb_bsize_shift
;
1021 find_metapath(ip
, lblock
, &mp
);
1024 error
= gfs2_quota_hold(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
1029 struct strip_mine sm
;
1030 sm
.sm_first
= !!size
;
1031 sm
.sm_height
= height
;
1033 error
= recursive_scan(ip
, NULL
, &mp
, 0, 0, 1, do_strip
, &sm
);
1038 gfs2_quota_unhold(ip
);
1045 static int trunc_end(struct gfs2_inode
*ip
)
1047 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1048 struct buffer_head
*dibh
;
1051 error
= gfs2_trans_begin(sdp
, RES_DINODE
, 0);
1055 down_write(&ip
->i_rw_mutex
);
1057 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
1061 if (!ip
->i_di
.di_size
) {
1062 ip
->i_di
.di_height
= 0;
1063 ip
->i_di
.di_goal_meta
=
1064 ip
->i_di
.di_goal_data
=
1066 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
1068 ip
->i_di
.di_mtime
= ip
->i_di
.di_ctime
= get_seconds();
1069 ip
->i_di
.di_flags
&= ~GFS2_DIF_TRUNC_IN_PROG
;
1071 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
1072 gfs2_dinode_out(&ip
->i_di
, dibh
->b_data
);
1076 up_write(&ip
->i_rw_mutex
);
1078 gfs2_trans_end(sdp
);
1084 * do_shrink - make a file smaller
1086 * @size: the size to make the file
1087 * @truncator: function to truncate the last partial block
1089 * Called with an exclusive lock on @ip.
1094 static int do_shrink(struct gfs2_inode
*ip
, uint64_t size
)
1098 error
= trunc_start(ip
, size
);
1104 error
= trunc_dealloc(ip
, size
);
1106 error
= trunc_end(ip
);
1112 * gfs2_truncatei - make a file a given size
1114 * @size: the size to make the file
1115 * @truncator: function to truncate the last partial block
1117 * The file size can grow, shrink, or stay the same size.
1122 int gfs2_truncatei(struct gfs2_inode
*ip
, uint64_t size
)
1126 if (gfs2_assert_warn(GFS2_SB(&ip
->i_inode
), S_ISREG(ip
->i_di
.di_mode
)))
1129 if (size
> ip
->i_di
.di_size
)
1130 error
= do_grow(ip
, size
);
1132 error
= do_shrink(ip
, size
);
1137 int gfs2_truncatei_resume(struct gfs2_inode
*ip
)
1140 error
= trunc_dealloc(ip
, ip
->i_di
.di_size
);
1142 error
= trunc_end(ip
);
1146 int gfs2_file_dealloc(struct gfs2_inode
*ip
)
1148 return trunc_dealloc(ip
, 0);
1152 * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
1154 * @len: the number of bytes to be written to the file
1155 * @data_blocks: returns the number of data blocks required
1156 * @ind_blocks: returns the number of indirect blocks required
1160 void gfs2_write_calc_reserv(struct gfs2_inode
*ip
, unsigned int len
,
1161 unsigned int *data_blocks
, unsigned int *ind_blocks
)
1163 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1166 if (gfs2_is_dir(ip
)) {
1167 *data_blocks
= DIV_ROUND_UP(len
, sdp
->sd_jbsize
) + 2;
1168 *ind_blocks
= 3 * (sdp
->sd_max_jheight
- 1);
1170 *data_blocks
= (len
>> sdp
->sd_sb
.sb_bsize_shift
) + 3;
1171 *ind_blocks
= 3 * (sdp
->sd_max_height
- 1);
1174 for (tmp
= *data_blocks
; tmp
> sdp
->sd_diptrs
;) {
1175 tmp
= DIV_ROUND_UP(tmp
, sdp
->sd_inptrs
);
1181 * gfs2_write_alloc_required - figure out if a write will require an allocation
1182 * @ip: the file being written to
1183 * @offset: the offset to write to
1184 * @len: the number of bytes being written
1185 * @alloc_required: set to 1 if an alloc is required, 0 otherwise
1190 int gfs2_write_alloc_required(struct gfs2_inode
*ip
, uint64_t offset
,
1191 unsigned int len
, int *alloc_required
)
1193 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1194 uint64_t lblock
, lblock_stop
, dblock
;
1199 *alloc_required
= 0;
1204 if (gfs2_is_stuffed(ip
)) {
1206 sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
))
1207 *alloc_required
= 1;
1211 if (gfs2_is_dir(ip
)) {
1212 unsigned int bsize
= sdp
->sd_jbsize
;
1214 do_div(lblock
, bsize
);
1215 lblock_stop
= offset
+ len
+ bsize
- 1;
1216 do_div(lblock_stop
, bsize
);
1218 unsigned int shift
= sdp
->sd_sb
.sb_bsize_shift
;
1219 lblock
= offset
>> shift
;
1220 lblock_stop
= (offset
+ len
+ sdp
->sd_sb
.sb_bsize
- 1) >> shift
;
1223 for (; lblock
< lblock_stop
; lblock
+= extlen
) {
1224 error
= gfs2_extent_map(&ip
->i_inode
, lblock
, &new, &dblock
, &extlen
);
1229 *alloc_required
= 1;