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author | Steven Whitehouse <swhiteho@redhat.com> | 2010-08-11 08:37:53 (GMT) |
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committer | Steven Whitehouse <swhiteho@redhat.com> | 2010-09-20 10:18:16 (GMT) |
commit | ff8f33c8b30d7b7efdcf2548c7f6e64db6a89b29 (patch) | |
tree | a21bad4d2b48f743dd96277b1c966c35aefe1ce2 /fs/gfs2/bmap.c | |
parent | 2422084a94fcd5038406261b331672a13c92c050 (diff) | |
download | linux-ff8f33c8b30d7b7efdcf2548c7f6e64db6a89b29.tar.xz |
GFS2: New truncate sequence
This updates GFS2's truncate code to use the new truncate
sequence correctly. This is a stepping stone to being
able to remove ip->i_disksize in favour of using i_size
everywhere now that the two sizes are always identical.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'fs/gfs2/bmap.c')
-rw-r--r-- | fs/gfs2/bmap.c | 247 |
1 files changed, 119 insertions, 128 deletions
diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 6f48280..20b971a 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -50,7 +50,7 @@ struct strip_mine { * @ip: the inode * @dibh: the dinode buffer * @block: the block number that was allocated - * @private: any locked page held by the caller process + * @page: The (optional) page. This is looked up if @page is NULL * * Returns: errno */ @@ -109,8 +109,7 @@ static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, /** * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big * @ip: The GFS2 inode to unstuff - * @unstuffer: the routine that handles unstuffing a non-zero length file - * @private: private data for the unstuffer + * @page: The (optional) page. This is looked up if the @page is NULL * * This routine unstuffs a dinode and returns it to a "normal" state such * that the height can be grown in the traditional way. @@ -885,83 +884,14 @@ out: } /** - * do_grow - Make a file look bigger than it is - * @ip: the inode - * @size: the size to set the file to - * - * Called with an exclusive lock on @ip. - * - * Returns: errno - */ - -static int do_grow(struct gfs2_inode *ip, u64 size) -{ - struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); - struct gfs2_alloc *al; - struct buffer_head *dibh; - int error; - - al = gfs2_alloc_get(ip); - if (!al) - return -ENOMEM; - - error = gfs2_quota_lock_check(ip); - if (error) - goto out; - - al->al_requested = sdp->sd_max_height + RES_DATA; - - error = gfs2_inplace_reserve(ip); - if (error) - goto out_gunlock_q; - - error = gfs2_trans_begin(sdp, - sdp->sd_max_height + al->al_rgd->rd_length + - RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0); - if (error) - goto out_ipres; - - error = gfs2_meta_inode_buffer(ip, &dibh); - if (error) - goto out_end_trans; - - if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { - if (gfs2_is_stuffed(ip)) { - error = gfs2_unstuff_dinode(ip, NULL); - if (error) - goto out_brelse; - } - } - - ip->i_disksize = size; - ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; - gfs2_trans_add_bh(ip->i_gl, dibh, 1); - gfs2_dinode_out(ip, dibh->b_data); - -out_brelse: - brelse(dibh); -out_end_trans: - gfs2_trans_end(sdp); -out_ipres: - gfs2_inplace_release(ip); -out_gunlock_q: - gfs2_quota_unlock(ip); -out: - gfs2_alloc_put(ip); - return error; -} - - -/** * gfs2_block_truncate_page - Deal with zeroing out data for truncate * * This is partly borrowed from ext3. */ -static int gfs2_block_truncate_page(struct address_space *mapping) +static int gfs2_block_truncate_page(struct address_space *mapping, loff_t from) { struct inode *inode = mapping->host; struct gfs2_inode *ip = GFS2_I(inode); - loff_t from = inode->i_size; unsigned long index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); unsigned blocksize, iblock, length, pos; @@ -1023,9 +953,11 @@ unlock: return err; } -static int trunc_start(struct gfs2_inode *ip, u64 size) +static int trunc_start(struct inode *inode, u64 oldsize, u64 newsize) { - struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); + struct address_space *mapping = inode->i_mapping; struct buffer_head *dibh; int journaled = gfs2_is_jdata(ip); int error; @@ -1039,31 +971,27 @@ static int trunc_start(struct gfs2_inode *ip, u64 size) if (error) goto out; + gfs2_trans_add_bh(ip->i_gl, dibh, 1); + if (gfs2_is_stuffed(ip)) { - u64 dsize = size + sizeof(struct gfs2_dinode); - ip->i_disksize = size; - ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; - gfs2_trans_add_bh(ip->i_gl, dibh, 1); - gfs2_dinode_out(ip, dibh->b_data); - if (dsize > dibh->b_size) - dsize = dibh->b_size; - gfs2_buffer_clear_tail(dibh, dsize); - error = 1; + gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize); } else { - if (size & (u64)(sdp->sd_sb.sb_bsize - 1)) - error = gfs2_block_truncate_page(ip->i_inode.i_mapping); - - if (!error) { - ip->i_disksize = size; - ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; - ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; - gfs2_trans_add_bh(ip->i_gl, dibh, 1); - gfs2_dinode_out(ip, dibh->b_data); + if (newsize & (u64)(sdp->sd_sb.sb_bsize - 1)) { + error = gfs2_block_truncate_page(mapping, newsize); + if (error) + goto out_brelse; } + ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; } - brelse(dibh); + i_size_write(inode, newsize); + ip->i_disksize = newsize; + ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; + gfs2_dinode_out(ip, dibh->b_data); + truncate_pagecache(inode, oldsize, newsize); +out_brelse: + brelse(dibh); out: gfs2_trans_end(sdp); return error; @@ -1143,86 +1071,149 @@ out: /** * do_shrink - make a file smaller - * @ip: the inode - * @size: the size to make the file - * @truncator: function to truncate the last partial block + * @inode: the inode + * @oldsize: the current inode size + * @newsize: the size to make the file * - * Called with an exclusive lock on @ip. + * Called with an exclusive lock on @inode. The @size must + * be equal to or smaller than the current inode size. * * Returns: errno */ -static int do_shrink(struct gfs2_inode *ip, u64 size) +static int do_shrink(struct inode *inode, u64 oldsize, u64 newsize) { + struct gfs2_inode *ip = GFS2_I(inode); int error; - error = trunc_start(ip, size); + error = trunc_start(inode, oldsize, newsize); if (error < 0) return error; - if (error > 0) + if (gfs2_is_stuffed(ip)) return 0; - error = trunc_dealloc(ip, size); - if (!error) + error = trunc_dealloc(ip, newsize); + if (error == 0) error = trunc_end(ip); return error; } -static int do_touch(struct gfs2_inode *ip, u64 size) +void gfs2_trim_blocks(struct inode *inode) { - struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + u64 size = inode->i_size; + int ret; + + ret = do_shrink(inode, size, size); + WARN_ON(ret != 0); +} + +/** + * do_grow - Touch and update inode size + * @inode: The inode + * @size: The new size + * + * This function updates the timestamps on the inode and + * may also increase the size of the inode. This function + * must not be called with @size any smaller than the current + * inode size. + * + * Although it is not strictly required to unstuff files here, + * earlier versions of GFS2 have a bug in the stuffed file reading + * code which will result in a buffer overrun if the size is larger + * than the max stuffed file size. In order to prevent this from + * occuring, such files are unstuffed, but in other cases we can + * just update the inode size directly. + * + * Returns: 0 on success, or -ve on error + */ + +static int do_grow(struct inode *inode, u64 size) +{ + struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_sbd *sdp = GFS2_SB(inode); struct buffer_head *dibh; + struct gfs2_alloc *al = NULL; int error; - error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (gfs2_is_stuffed(ip) && + (size > (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)))) { + al = gfs2_alloc_get(ip); + if (al == NULL) + return -ENOMEM; + + error = gfs2_quota_lock_check(ip); + if (error) + goto do_grow_alloc_put; + + al->al_requested = 1; + error = gfs2_inplace_reserve(ip); + if (error) + goto do_grow_qunlock; + } + + error = gfs2_trans_begin(sdp, RES_DINODE + 1, 0); if (error) - return error; + goto do_grow_release; - down_write(&ip->i_rw_mutex); + if (al) { + error = gfs2_unstuff_dinode(ip, NULL); + if (error) + goto do_end_trans; + } error = gfs2_meta_inode_buffer(ip, &dibh); if (error) - goto do_touch_out; + goto do_end_trans; + i_size_write(inode, size); + ip->i_disksize = size; ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; gfs2_trans_add_bh(ip->i_gl, dibh, 1); gfs2_dinode_out(ip, dibh->b_data); brelse(dibh); -do_touch_out: - up_write(&ip->i_rw_mutex); +do_end_trans: gfs2_trans_end(sdp); +do_grow_release: + if (al) { + gfs2_inplace_release(ip); +do_grow_qunlock: + gfs2_quota_unlock(ip); +do_grow_alloc_put: + gfs2_alloc_put(ip); + } return error; } /** - * gfs2_truncatei - make a file a given size - * @ip: the inode - * @size: the size to make the file - * @truncator: function to truncate the last partial block + * gfs2_setattr_size - make a file a given size + * @inode: the inode + * @newsize: the size to make the file * - * The file size can grow, shrink, or stay the same size. + * The file size can grow, shrink, or stay the same size. This + * is called holding i_mutex and an exclusive glock on the inode + * in question. * * Returns: errno */ -int gfs2_truncatei(struct gfs2_inode *ip, u64 size) +int gfs2_setattr_size(struct inode *inode, u64 newsize) { - int error; + int ret; + u64 oldsize; - if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), S_ISREG(ip->i_inode.i_mode))) - return -EINVAL; + BUG_ON(!S_ISREG(inode->i_mode)); - if (size > ip->i_disksize) - error = do_grow(ip, size); - else if (size < ip->i_disksize) - error = do_shrink(ip, size); - else - /* update time stamps */ - error = do_touch(ip, size); + ret = inode_newsize_ok(inode, newsize); + if (ret) + return ret; - return error; + oldsize = inode->i_size; + if (newsize >= oldsize) + return do_grow(inode, newsize); + + return do_shrink(inode, oldsize, newsize); } int gfs2_truncatei_resume(struct gfs2_inode *ip) |