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git.proxmox.com Git - mirror_ubuntu-jammy-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/slab.h>
11 #include <linux/spinlock.h>
12 #include <linux/completion.h>
13 #include <linux/buffer_head.h>
14 #include <linux/gfs2_ondisk.h>
15 #include <linux/crc32.h>
16 #include <linux/lm_interface.h>
29 #include "ops_address.h"
31 /* This doesn't need to be that large as max 64 bit pointers in a 4k
32 * block is 512, so __u16 is fine for that. It saves stack space to
36 __u16 mp_list
[GFS2_MAX_META_HEIGHT
];
39 typedef int (*block_call_t
) (struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
40 struct buffer_head
*bh
, __be64
*top
,
41 __be64
*bottom
, unsigned int height
,
46 unsigned int sm_height
;
50 * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page
52 * @dibh: the dinode buffer
53 * @block: the block number that was allocated
54 * @private: any locked page held by the caller process
59 static int gfs2_unstuffer_page(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
60 u64 block
, struct page
*page
)
62 struct inode
*inode
= &ip
->i_inode
;
63 struct buffer_head
*bh
;
66 if (!page
|| page
->index
) {
67 page
= grab_cache_page(inode
->i_mapping
, 0);
73 if (!PageUptodate(page
)) {
74 void *kaddr
= kmap(page
);
76 memcpy(kaddr
, dibh
->b_data
+ sizeof(struct gfs2_dinode
),
78 memset(kaddr
+ ip
->i_di
.di_size
, 0,
79 PAGE_CACHE_SIZE
- ip
->i_di
.di_size
);
82 SetPageUptodate(page
);
85 if (!page_has_buffers(page
))
86 create_empty_buffers(page
, 1 << inode
->i_blkbits
,
89 bh
= page_buffers(page
);
91 if (!buffer_mapped(bh
))
92 map_bh(bh
, inode
->i_sb
, block
);
94 set_buffer_uptodate(bh
);
95 if (!gfs2_is_jdata(ip
))
96 mark_buffer_dirty(bh
);
97 if (!gfs2_is_writeback(ip
))
98 gfs2_trans_add_bh(ip
->i_gl
, bh
, 0);
102 page_cache_release(page
);
109 * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big
110 * @ip: The GFS2 inode to unstuff
111 * @unstuffer: the routine that handles unstuffing a non-zero length file
112 * @private: private data for the unstuffer
114 * This routine unstuffs a dinode and returns it to a "normal" state such
115 * that the height can be grown in the traditional way.
120 int gfs2_unstuff_dinode(struct gfs2_inode
*ip
, struct page
*page
)
122 struct buffer_head
*bh
, *dibh
;
123 struct gfs2_dinode
*di
;
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
, sizeof(struct gfs2_meta_header
),
145 dibh
, sizeof(struct gfs2_dinode
));
148 block
= gfs2_alloc_data(ip
);
150 error
= gfs2_unstuffer_page(ip
, dibh
, block
, page
);
156 /* Set up the pointer to the new block */
158 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
159 di
= (struct gfs2_dinode
*)dibh
->b_data
;
160 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
162 if (ip
->i_di
.di_size
) {
163 *(__be64
*)(di
+ 1) = cpu_to_be64(block
);
164 ip
->i_di
.di_blocks
++;
165 gfs2_set_inode_blocks(&ip
->i_inode
);
166 di
->di_blocks
= cpu_to_be64(ip
->i_di
.di_blocks
);
169 ip
->i_di
.di_height
= 1;
170 di
->di_height
= cpu_to_be16(1);
175 up_write(&ip
->i_rw_mutex
);
180 * calc_tree_height - Calculate the height of a metadata tree
181 * @ip: The GFS2 inode
182 * @size: The proposed size of the file
184 * Work out how tall a metadata tree needs to be in order to accommodate a
185 * file of a particular size. If size is less than the current size of
186 * the inode, then the current size of the inode is used instead of the
189 * Returns: the height the tree should be
192 static unsigned int calc_tree_height(struct gfs2_inode
*ip
, u64 size
)
194 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
196 unsigned int max
, height
;
198 if (ip
->i_di
.di_size
> size
)
199 size
= ip
->i_di
.di_size
;
201 if (gfs2_is_dir(ip
)) {
202 arr
= sdp
->sd_jheightsize
;
203 max
= sdp
->sd_max_jheight
;
205 arr
= sdp
->sd_heightsize
;
206 max
= sdp
->sd_max_height
;
209 for (height
= 0; height
< max
; height
++)
210 if (arr
[height
] >= size
)
217 * build_height - Build a metadata tree of the requested height
218 * @ip: The GFS2 inode
219 * @height: The height to build to
225 static int build_height(struct inode
*inode
, unsigned height
)
227 struct gfs2_inode
*ip
= GFS2_I(inode
);
228 unsigned new_height
= height
- ip
->i_di
.di_height
;
229 struct buffer_head
*dibh
;
230 struct buffer_head
*blocks
[GFS2_MAX_META_HEIGHT
];
231 struct gfs2_dinode
*di
;
237 if (height
<= ip
->i_di
.di_height
)
240 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
244 for(n
= 0; n
< new_height
; n
++) {
245 bn
= gfs2_alloc_meta(ip
);
246 blocks
[n
] = gfs2_meta_new(ip
->i_gl
, bn
);
247 gfs2_trans_add_bh(ip
->i_gl
, blocks
[n
], 1);
251 bn
= blocks
[0]->b_blocknr
;
252 if (new_height
> 1) {
253 for(; n
< new_height
-1; n
++) {
254 gfs2_metatype_set(blocks
[n
], GFS2_METATYPE_IN
,
256 gfs2_buffer_clear_tail(blocks
[n
],
257 sizeof(struct gfs2_meta_header
));
258 bp
= (__be64
*)(blocks
[n
]->b_data
+
259 sizeof(struct gfs2_meta_header
));
260 *bp
= cpu_to_be64(blocks
[n
+1]->b_blocknr
);
265 gfs2_metatype_set(blocks
[n
], GFS2_METATYPE_IN
, GFS2_FORMAT_IN
);
266 gfs2_buffer_copy_tail(blocks
[n
], sizeof(struct gfs2_meta_header
),
267 dibh
, sizeof(struct gfs2_dinode
));
269 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
270 di
= (struct gfs2_dinode
*)dibh
->b_data
;
271 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
272 *(__be64
*)(di
+ 1) = cpu_to_be64(bn
);
273 ip
->i_di
.di_height
+= new_height
;
274 ip
->i_di
.di_blocks
+= new_height
;
275 gfs2_set_inode_blocks(&ip
->i_inode
);
276 di
->di_height
= cpu_to_be16(ip
->i_di
.di_height
);
277 di
->di_blocks
= cpu_to_be64(ip
->i_di
.di_blocks
);
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
, u64 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
] = 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 __be64
*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
= ((__be64
*)(bh
->b_data
+ head_size
)) + mp
->mp_list
[height
];
372 if (ptr
+ 1 == (__be64
*)(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, u64
*block
)
398 __be64
*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
++;
419 gfs2_set_inode_blocks(&ip
->i_inode
);
425 static inline void bmap_lock(struct inode
*inode
, int create
)
427 struct gfs2_inode
*ip
= GFS2_I(inode
);
429 down_write(&ip
->i_rw_mutex
);
431 down_read(&ip
->i_rw_mutex
);
434 static inline void bmap_unlock(struct inode
*inode
, int create
)
436 struct gfs2_inode
*ip
= GFS2_I(inode
);
438 up_write(&ip
->i_rw_mutex
);
440 up_read(&ip
->i_rw_mutex
);
444 * gfs2_block_map - Map a block from an inode to a disk block
446 * @lblock: The logical block number
447 * @bh_map: The bh to be mapped
449 * Find the block number on the current device which corresponds to an
450 * inode's block. If the block had to be created, "new" will be set.
455 int gfs2_block_map(struct inode
*inode
, u64 lblock
, int create
,
456 struct buffer_head
*bh_map
)
458 struct gfs2_inode
*ip
= GFS2_I(inode
);
459 struct gfs2_sbd
*sdp
= GFS2_SB(inode
);
460 struct buffer_head
*bh
;
463 unsigned int end_of_metadata
;
469 unsigned int maxlen
= bh_map
->b_size
>> inode
->i_blkbits
;
475 if (gfs2_assert_warn(sdp
, !gfs2_is_stuffed(ip
)))
478 bmap_lock(inode
, create
);
479 clear_buffer_mapped(bh_map
);
480 clear_buffer_new(bh_map
);
481 clear_buffer_boundary(bh_map
);
482 bsize
= gfs2_is_dir(ip
) ? sdp
->sd_jbsize
: sdp
->sd_sb
.sb_bsize
;
483 size
= (lblock
+ 1) * bsize
;
485 if (size
> ip
->i_di
.di_size
) {
486 height
= calc_tree_height(ip
, size
);
487 if (ip
->i_di
.di_height
< height
) {
491 error
= build_height(inode
, height
);
497 find_metapath(ip
, lblock
, &mp
);
498 end_of_metadata
= ip
->i_di
.di_height
- 1;
499 error
= gfs2_meta_inode_buffer(ip
, &bh
);
503 for (x
= 0; x
< end_of_metadata
; x
++) {
504 lookup_block(ip
, bh
, x
, &mp
, create
, &new, &dblock
);
509 error
= gfs2_meta_indirect_buffer(ip
, x
+1, dblock
, new, &bh
);
514 boundary
= lookup_block(ip
, bh
, end_of_metadata
, &mp
, create
, &new, &dblock
);
516 map_bh(bh_map
, inode
->i_sb
, dblock
);
518 set_buffer_boundary(bh_map
);
520 struct buffer_head
*dibh
;
521 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
523 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
524 gfs2_dinode_out(ip
, dibh
->b_data
);
527 set_buffer_new(bh_map
);
530 while(--maxlen
&& !buffer_boundary(bh_map
)) {
533 mp
.mp_list
[end_of_metadata
]++;
534 boundary
= lookup_block(ip
, bh
, end_of_metadata
, &mp
, 0, &new, &eblock
);
535 if (eblock
!= ++dblock
)
537 bh_map
->b_size
+= (1 << inode
->i_blkbits
);
539 set_buffer_boundary(bh_map
);
547 bmap_unlock(inode
, create
);
551 int gfs2_extent_map(struct inode
*inode
, u64 lblock
, int *new, u64
*dblock
, unsigned *extlen
)
553 struct buffer_head bh
= { .b_state
= 0, .b_blocknr
= 0 };
561 bh
.b_size
= 1 << (inode
->i_blkbits
+ 5);
562 ret
= gfs2_block_map(inode
, lblock
, create
, &bh
);
563 *extlen
= bh
.b_size
>> inode
->i_blkbits
;
564 *dblock
= bh
.b_blocknr
;
573 * recursive_scan - recursively scan through the end of a file
575 * @dibh: the dinode buffer
576 * @mp: the path through the metadata to the point to start
577 * @height: the height the recursion is at
578 * @block: the indirect block to look at
579 * @first: 1 if this is the first block
580 * @bc: the call to make for each piece of metadata
581 * @data: data opaque to this function to pass to @bc
583 * When this is first called @height and @block should be zero and
584 * @first should be 1.
589 static int recursive_scan(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
590 struct metapath
*mp
, unsigned int height
,
591 u64 block
, int first
, block_call_t bc
,
594 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
595 struct buffer_head
*bh
= NULL
;
596 __be64
*top
, *bottom
;
599 int mh_size
= sizeof(struct gfs2_meta_header
);
602 error
= gfs2_meta_inode_buffer(ip
, &bh
);
607 top
= (__be64
*)(bh
->b_data
+ sizeof(struct gfs2_dinode
)) + mp
->mp_list
[0];
608 bottom
= (__be64
*)(bh
->b_data
+ sizeof(struct gfs2_dinode
)) + sdp
->sd_diptrs
;
610 error
= gfs2_meta_indirect_buffer(ip
, height
, block
, 0, &bh
);
614 top
= (__be64
*)(bh
->b_data
+ mh_size
) +
615 (first
? mp
->mp_list
[height
] : 0);
617 bottom
= (__be64
*)(bh
->b_data
+ mh_size
) + sdp
->sd_inptrs
;
620 error
= bc(ip
, dibh
, bh
, top
, bottom
, height
, data
);
624 if (height
< ip
->i_di
.di_height
- 1)
625 for (; top
< bottom
; top
++, first
= 0) {
629 bn
= be64_to_cpu(*top
);
631 error
= recursive_scan(ip
, dibh
, mp
, height
+ 1, bn
,
643 * do_strip - Look for a layer a particular layer of the file and strip it off
645 * @dibh: the dinode buffer
646 * @bh: A buffer of pointers
647 * @top: The first pointer in the buffer
648 * @bottom: One more than the last pointer
649 * @height: the height this buffer is at
650 * @data: a pointer to a struct strip_mine
655 static int do_strip(struct gfs2_inode
*ip
, struct buffer_head
*dibh
,
656 struct buffer_head
*bh
, __be64
*top
, __be64
*bottom
,
657 unsigned int height
, void *data
)
659 struct strip_mine
*sm
= data
;
660 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
661 struct gfs2_rgrp_list rlist
;
665 unsigned int rg_blocks
= 0;
667 unsigned int revokes
= 0;
674 if (height
!= sm
->sm_height
)
682 metadata
= (height
!= ip
->i_di
.di_height
- 1);
684 revokes
= (height
) ? sdp
->sd_inptrs
: sdp
->sd_diptrs
;
686 error
= gfs2_rindex_hold(sdp
, &ip
->i_alloc
.al_ri_gh
);
690 memset(&rlist
, 0, sizeof(struct gfs2_rgrp_list
));
694 for (p
= top
; p
< bottom
; p
++) {
698 bn
= be64_to_cpu(*p
);
700 if (bstart
+ blen
== bn
)
704 gfs2_rlist_add(sdp
, &rlist
, bstart
);
712 gfs2_rlist_add(sdp
, &rlist
, bstart
);
714 goto out
; /* Nothing to do */
716 gfs2_rlist_alloc(&rlist
, LM_ST_EXCLUSIVE
, 0);
718 for (x
= 0; x
< rlist
.rl_rgrps
; x
++) {
719 struct gfs2_rgrpd
*rgd
;
720 rgd
= rlist
.rl_ghs
[x
].gh_gl
->gl_object
;
721 rg_blocks
+= rgd
->rd_length
;
724 error
= gfs2_glock_nq_m(rlist
.rl_rgrps
, rlist
.rl_ghs
);
728 error
= gfs2_trans_begin(sdp
, rg_blocks
+ RES_DINODE
+
729 RES_INDIRECT
+ RES_STATFS
+ RES_QUOTA
,
734 down_write(&ip
->i_rw_mutex
);
736 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
737 gfs2_trans_add_bh(ip
->i_gl
, bh
, 1);
742 for (p
= top
; p
< bottom
; p
++) {
746 bn
= be64_to_cpu(*p
);
748 if (bstart
+ blen
== bn
)
753 gfs2_free_meta(ip
, bstart
, blen
);
755 gfs2_free_data(ip
, bstart
, blen
);
763 if (!ip
->i_di
.di_blocks
)
764 gfs2_consist_inode(ip
);
765 ip
->i_di
.di_blocks
--;
766 gfs2_set_inode_blocks(&ip
->i_inode
);
770 gfs2_free_meta(ip
, bstart
, blen
);
772 gfs2_free_data(ip
, bstart
, blen
);
775 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
777 gfs2_dinode_out(ip
, dibh
->b_data
);
779 up_write(&ip
->i_rw_mutex
);
784 gfs2_glock_dq_m(rlist
.rl_rgrps
, rlist
.rl_ghs
);
786 gfs2_rlist_free(&rlist
);
788 gfs2_glock_dq_uninit(&ip
->i_alloc
.al_ri_gh
);
793 * do_grow - Make a file look bigger than it is
795 * @size: the size to set the file to
797 * Called with an exclusive lock on @ip.
802 static int do_grow(struct gfs2_inode
*ip
, u64 size
)
804 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
805 struct gfs2_alloc
*al
;
806 struct buffer_head
*dibh
;
810 al
= gfs2_alloc_get(ip
);
812 error
= gfs2_quota_lock(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
816 error
= gfs2_quota_check(ip
, ip
->i_inode
.i_uid
, ip
->i_inode
.i_gid
);
820 al
->al_requested
= sdp
->sd_max_height
+ RES_DATA
;
822 error
= gfs2_inplace_reserve(ip
);
826 error
= gfs2_trans_begin(sdp
,
827 sdp
->sd_max_height
+ al
->al_rgd
->rd_length
+
828 RES_JDATA
+ RES_DINODE
+ RES_STATFS
+ RES_QUOTA
, 0);
832 if (size
> sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
)) {
833 if (gfs2_is_stuffed(ip
)) {
834 error
= gfs2_unstuff_dinode(ip
, NULL
);
839 h
= calc_tree_height(ip
, size
);
840 if (ip
->i_di
.di_height
< h
) {
841 down_write(&ip
->i_rw_mutex
);
842 error
= build_height(&ip
->i_inode
, h
);
843 up_write(&ip
->i_rw_mutex
);
849 ip
->i_di
.di_size
= size
;
850 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
852 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
856 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
857 gfs2_dinode_out(ip
, dibh
->b_data
);
863 gfs2_inplace_release(ip
);
865 gfs2_quota_unlock(ip
);
873 * gfs2_block_truncate_page - Deal with zeroing out data for truncate
875 * This is partly borrowed from ext3.
877 static int gfs2_block_truncate_page(struct address_space
*mapping
)
879 struct inode
*inode
= mapping
->host
;
880 struct gfs2_inode
*ip
= GFS2_I(inode
);
881 loff_t from
= inode
->i_size
;
882 unsigned long index
= from
>> PAGE_CACHE_SHIFT
;
883 unsigned offset
= from
& (PAGE_CACHE_SIZE
-1);
884 unsigned blocksize
, iblock
, length
, pos
;
885 struct buffer_head
*bh
;
889 page
= grab_cache_page(mapping
, index
);
893 blocksize
= inode
->i_sb
->s_blocksize
;
894 length
= blocksize
- (offset
& (blocksize
- 1));
895 iblock
= index
<< (PAGE_CACHE_SHIFT
- inode
->i_sb
->s_blocksize_bits
);
897 if (!page_has_buffers(page
))
898 create_empty_buffers(page
, blocksize
, 0);
900 /* Find the buffer that contains "offset" */
901 bh
= page_buffers(page
);
903 while (offset
>= pos
) {
904 bh
= bh
->b_this_page
;
911 if (!buffer_mapped(bh
)) {
912 gfs2_get_block(inode
, iblock
, bh
, 0);
913 /* unmapped? It's a hole - nothing to do */
914 if (!buffer_mapped(bh
))
918 /* Ok, it's mapped. Make sure it's up-to-date */
919 if (PageUptodate(page
))
920 set_buffer_uptodate(bh
);
922 if (!buffer_uptodate(bh
)) {
924 ll_rw_block(READ
, 1, &bh
);
926 /* Uhhuh. Read error. Complain and punt. */
927 if (!buffer_uptodate(bh
))
932 if (!gfs2_is_writeback(ip
))
933 gfs2_trans_add_bh(ip
->i_gl
, bh
, 0);
935 zero_user_page(page
, offset
, length
, KM_USER0
);
939 page_cache_release(page
);
943 static int trunc_start(struct gfs2_inode
*ip
, u64 size
)
945 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
946 struct buffer_head
*dibh
;
947 int journaled
= gfs2_is_jdata(ip
);
950 error
= gfs2_trans_begin(sdp
,
951 RES_DINODE
+ (journaled
? RES_JDATA
: 0), 0);
955 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
959 if (gfs2_is_stuffed(ip
)) {
960 ip
->i_di
.di_size
= size
;
961 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
962 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
963 gfs2_dinode_out(ip
, dibh
->b_data
);
964 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
) + size
);
968 if (size
& (u64
)(sdp
->sd_sb
.sb_bsize
- 1))
969 error
= gfs2_block_truncate_page(ip
->i_inode
.i_mapping
);
972 ip
->i_di
.di_size
= size
;
973 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
974 ip
->i_di
.di_flags
|= GFS2_DIF_TRUNC_IN_PROG
;
975 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
976 gfs2_dinode_out(ip
, dibh
->b_data
);
987 static int trunc_dealloc(struct gfs2_inode
*ip
, u64 size
)
989 unsigned int height
= ip
->i_di
.di_height
;
997 lblock
= (size
- 1) >> GFS2_SB(&ip
->i_inode
)->sd_sb
.sb_bsize_shift
;
999 find_metapath(ip
, lblock
, &mp
);
1002 error
= gfs2_quota_hold(ip
, NO_QUOTA_CHANGE
, NO_QUOTA_CHANGE
);
1007 struct strip_mine sm
;
1008 sm
.sm_first
= !!size
;
1009 sm
.sm_height
= height
;
1011 error
= recursive_scan(ip
, NULL
, &mp
, 0, 0, 1, do_strip
, &sm
);
1016 gfs2_quota_unhold(ip
);
1023 static int trunc_end(struct gfs2_inode
*ip
)
1025 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1026 struct buffer_head
*dibh
;
1029 error
= gfs2_trans_begin(sdp
, RES_DINODE
, 0);
1033 down_write(&ip
->i_rw_mutex
);
1035 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
1039 if (!ip
->i_di
.di_size
) {
1040 ip
->i_di
.di_height
= 0;
1041 ip
->i_di
.di_goal_meta
=
1042 ip
->i_di
.di_goal_data
=
1044 gfs2_buffer_clear_tail(dibh
, sizeof(struct gfs2_dinode
));
1046 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
1047 ip
->i_di
.di_flags
&= ~GFS2_DIF_TRUNC_IN_PROG
;
1049 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
1050 gfs2_dinode_out(ip
, dibh
->b_data
);
1054 up_write(&ip
->i_rw_mutex
);
1055 gfs2_trans_end(sdp
);
1060 * do_shrink - make a file smaller
1062 * @size: the size to make the file
1063 * @truncator: function to truncate the last partial block
1065 * Called with an exclusive lock on @ip.
1070 static int do_shrink(struct gfs2_inode
*ip
, u64 size
)
1074 error
= trunc_start(ip
, size
);
1080 error
= trunc_dealloc(ip
, size
);
1082 error
= trunc_end(ip
);
1087 static int do_touch(struct gfs2_inode
*ip
, u64 size
)
1089 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1090 struct buffer_head
*dibh
;
1093 error
= gfs2_trans_begin(sdp
, RES_DINODE
, 0);
1097 down_write(&ip
->i_rw_mutex
);
1099 error
= gfs2_meta_inode_buffer(ip
, &dibh
);
1103 ip
->i_inode
.i_mtime
= ip
->i_inode
.i_ctime
= CURRENT_TIME
;
1104 gfs2_trans_add_bh(ip
->i_gl
, dibh
, 1);
1105 gfs2_dinode_out(ip
, dibh
->b_data
);
1109 up_write(&ip
->i_rw_mutex
);
1110 gfs2_trans_end(sdp
);
1115 * gfs2_truncatei - make a file a given size
1117 * @size: the size to make the file
1118 * @truncator: function to truncate the last partial block
1120 * The file size can grow, shrink, or stay the same size.
1125 int gfs2_truncatei(struct gfs2_inode
*ip
, u64 size
)
1129 if (gfs2_assert_warn(GFS2_SB(&ip
->i_inode
), S_ISREG(ip
->i_inode
.i_mode
)))
1132 if (size
> ip
->i_di
.di_size
)
1133 error
= do_grow(ip
, size
);
1134 else if (size
< ip
->i_di
.di_size
)
1135 error
= do_shrink(ip
, size
);
1137 /* update time stamps */
1138 error
= do_touch(ip
, size
);
1143 int gfs2_truncatei_resume(struct gfs2_inode
*ip
)
1146 error
= trunc_dealloc(ip
, ip
->i_di
.di_size
);
1148 error
= trunc_end(ip
);
1152 int gfs2_file_dealloc(struct gfs2_inode
*ip
)
1154 return trunc_dealloc(ip
, 0);
1158 * gfs2_write_calc_reserv - calculate number of blocks needed to write to a file
1160 * @len: the number of bytes to be written to the file
1161 * @data_blocks: returns the number of data blocks required
1162 * @ind_blocks: returns the number of indirect blocks required
1166 void gfs2_write_calc_reserv(struct gfs2_inode
*ip
, unsigned int len
,
1167 unsigned int *data_blocks
, unsigned int *ind_blocks
)
1169 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1172 if (gfs2_is_dir(ip
)) {
1173 *data_blocks
= DIV_ROUND_UP(len
, sdp
->sd_jbsize
) + 2;
1174 *ind_blocks
= 3 * (sdp
->sd_max_jheight
- 1);
1176 *data_blocks
= (len
>> sdp
->sd_sb
.sb_bsize_shift
) + 3;
1177 *ind_blocks
= 3 * (sdp
->sd_max_height
- 1);
1180 for (tmp
= *data_blocks
; tmp
> sdp
->sd_diptrs
;) {
1181 tmp
= DIV_ROUND_UP(tmp
, sdp
->sd_inptrs
);
1187 * gfs2_write_alloc_required - figure out if a write will require an allocation
1188 * @ip: the file being written to
1189 * @offset: the offset to write to
1190 * @len: the number of bytes being written
1191 * @alloc_required: set to 1 if an alloc is required, 0 otherwise
1196 int gfs2_write_alloc_required(struct gfs2_inode
*ip
, u64 offset
,
1197 unsigned int len
, int *alloc_required
)
1199 struct gfs2_sbd
*sdp
= GFS2_SB(&ip
->i_inode
);
1200 u64 lblock
, lblock_stop
, dblock
;
1205 *alloc_required
= 0;
1210 if (gfs2_is_stuffed(ip
)) {
1212 sdp
->sd_sb
.sb_bsize
- sizeof(struct gfs2_dinode
))
1213 *alloc_required
= 1;
1217 if (gfs2_is_dir(ip
)) {
1218 unsigned int bsize
= sdp
->sd_jbsize
;
1220 do_div(lblock
, bsize
);
1221 lblock_stop
= offset
+ len
+ bsize
- 1;
1222 do_div(lblock_stop
, bsize
);
1224 unsigned int shift
= sdp
->sd_sb
.sb_bsize_shift
;
1225 lblock
= offset
>> shift
;
1226 lblock_stop
= (offset
+ len
+ sdp
->sd_sb
.sb_bsize
- 1) >> shift
;
1229 for (; lblock
< lblock_stop
; lblock
+= extlen
) {
1230 error
= gfs2_extent_map(&ip
->i_inode
, lblock
, &new, &dblock
, &extlen
);
1235 *alloc_required
= 1;