From 65ed39d6ca78f07d2958814e08440e4264b6b488 Mon Sep 17 00:00:00 2001 From: Mark Fasheh Date: Tue, 28 Aug 2007 17:13:23 -0700 Subject: [PATCH] ocfs2: move nonsparse hole-filling into ocfs2_write_begin() By doing this, we can remove any higher level logic which has to have knowledge of btree functionality - any callers of ocfs2_write_begin() can now expect it to do anything necessary to prepare the inode for new data. Signed-off-by: Mark Fasheh Reviewed-by: Joel Becker --- fs/ocfs2/aops.c | 40 ++++++++- fs/ocfs2/file.c | 219 +++++++++++++++++------------------------------- fs/ocfs2/file.h | 2 + 3 files changed, 116 insertions(+), 145 deletions(-) diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c index f37f25c931f5..fae07672eb18 100644 --- a/fs/ocfs2/aops.c +++ b/fs/ocfs2/aops.c @@ -301,12 +301,8 @@ int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page, { int ret; - down_read(&OCFS2_I(inode)->ip_alloc_sem); - ret = block_prepare_write(page, from, to, ocfs2_get_block); - up_read(&OCFS2_I(inode)->ip_alloc_sem); - return ret; } @@ -1360,6 +1356,36 @@ static int ocfs2_populate_write_desc(struct inode *inode, return ret; } +/* + * This function only does anything for file systems which can't + * handle sparse files. + * + * What we want to do here is fill in any hole between the current end + * of allocation and the end of our write. That way the rest of the + * write path can treat it as an non-allocating write, which has no + * special case code for sparse/nonsparse files. + */ +static int ocfs2_expand_nonsparse_inode(struct inode *inode, loff_t pos, + unsigned len, + struct ocfs2_write_ctxt *wc) +{ + int ret; + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + loff_t newsize = pos + len; + + if (ocfs2_sparse_alloc(osb)) + return 0; + + if (newsize <= i_size_read(inode)) + return 0; + + ret = ocfs2_extend_no_holes(inode, newsize, newsize - len); + if (ret) + mlog_errno(ret); + + return ret; +} + int ocfs2_write_begin_nolock(struct address_space *mapping, loff_t pos, unsigned len, unsigned flags, struct page **pagep, void **fsdata, @@ -1381,6 +1407,12 @@ int ocfs2_write_begin_nolock(struct address_space *mapping, return ret; } + ret = ocfs2_expand_nonsparse_inode(inode, pos, len, wc); + if (ret) { + mlog_errno(ret); + goto out; + } + ret = ocfs2_populate_write_desc(inode, wc, &clusters_to_alloc, &extents_to_split); if (ret) { diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index f3bc3658e7a5..781ba6c4ef85 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -779,25 +779,6 @@ static int __ocfs2_extend_allocation(struct inode *inode, u32 logical_start, return status; } -static int ocfs2_extend_allocation(struct inode *inode, u32 logical_start, - u32 clusters_to_add, int mark_unwritten) -{ - int ret; - - /* - * The alloc sem blocks peope in read/write from reading our - * allocation until we're done changing it. We depend on - * i_mutex to block other extend/truncate calls while we're - * here. - */ - down_write(&OCFS2_I(inode)->ip_alloc_sem); - ret = __ocfs2_extend_allocation(inode, logical_start, clusters_to_add, - mark_unwritten); - up_write(&OCFS2_I(inode)->ip_alloc_sem); - - return ret; -} - /* Some parts of this taken from generic_cont_expand, which turned out * to be too fragile to do exactly what we need without us having to * worry about recursive locking in ->prepare_write() and @@ -889,25 +870,47 @@ static int ocfs2_zero_extend(struct inode *inode, return ret; } -/* - * A tail_to_skip value > 0 indicates that we're being called from - * ocfs2_file_aio_write(). This has the following implications: - * - * - we don't want to update i_size - * - di_bh will be NULL, which is fine because it's only used in the - * case where we want to update i_size. - * - ocfs2_zero_extend() will then only be filling the hole created - * between i_size and the start of the write. - */ +int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size, u64 zero_to) +{ + int ret; + u32 clusters_to_add; + struct ocfs2_inode_info *oi = OCFS2_I(inode); + + clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size); + if (clusters_to_add < oi->ip_clusters) + clusters_to_add = 0; + else + clusters_to_add -= oi->ip_clusters; + + if (clusters_to_add) { + ret = __ocfs2_extend_allocation(inode, oi->ip_clusters, + clusters_to_add, 0); + if (ret) { + mlog_errno(ret); + goto out; + } + } + + /* + * Call this even if we don't add any clusters to the tree. We + * still need to zero the area between the old i_size and the + * new i_size. + */ + ret = ocfs2_zero_extend(inode, zero_to); + if (ret < 0) + mlog_errno(ret); + +out: + return ret; +} + static int ocfs2_extend_file(struct inode *inode, struct buffer_head *di_bh, - u64 new_i_size, - size_t tail_to_skip) + u64 new_i_size) { int ret = 0; - u32 clusters_to_add = 0; - BUG_ON(!tail_to_skip && !di_bh); + BUG_ON(!di_bh); /* setattr sometimes calls us like this. */ if (new_i_size == 0) @@ -917,13 +920,8 @@ static int ocfs2_extend_file(struct inode *inode, goto out; BUG_ON(new_i_size < i_size_read(inode)); - if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) { - BUG_ON(tail_to_skip != 0); + if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) goto out_update_size; - } - - clusters_to_add = ocfs2_clusters_for_bytes(inode->i_sb, new_i_size) - - OCFS2_I(inode)->ip_clusters; /* * protect the pages that ocfs2_zero_extend is going to be @@ -938,35 +936,25 @@ static int ocfs2_extend_file(struct inode *inode, goto out; } - if (clusters_to_add) { - ret = ocfs2_extend_allocation(inode, - OCFS2_I(inode)->ip_clusters, - clusters_to_add, 0); - if (ret < 0) { - mlog_errno(ret); - goto out_unlock; - } - } - /* - * Call this even if we don't add any clusters to the tree. We - * still need to zero the area between the old i_size and the - * new i_size. + * The alloc sem blocks people in read/write from reading our + * allocation until we're done changing it. We depend on + * i_mutex to block other extend/truncate calls while we're + * here. */ - ret = ocfs2_zero_extend(inode, (u64)new_i_size - tail_to_skip); + down_write(&OCFS2_I(inode)->ip_alloc_sem); + ret = ocfs2_extend_no_holes(inode, new_i_size, new_i_size); + up_write(&OCFS2_I(inode)->ip_alloc_sem); + if (ret < 0) { mlog_errno(ret); goto out_unlock; } out_update_size: - if (!tail_to_skip) { - /* We're being called from ocfs2_setattr() which wants - * us to update i_size */ - ret = ocfs2_simple_size_update(inode, di_bh, new_i_size); - if (ret < 0) - mlog_errno(ret); - } + ret = ocfs2_simple_size_update(inode, di_bh, new_i_size); + if (ret < 0) + mlog_errno(ret); out_unlock: if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) @@ -1035,7 +1023,7 @@ int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) if (i_size_read(inode) > attr->ia_size) status = ocfs2_truncate_file(inode, bh, attr->ia_size); else - status = ocfs2_extend_file(inode, bh, attr->ia_size, 0); + status = ocfs2_extend_file(inode, bh, attr->ia_size); if (status < 0) { if (status != -ENOSPC) mlog_errno(status); @@ -1713,15 +1701,13 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, int appending, int *direct_io) { - int ret = 0, meta_level = appending; + int ret = 0, meta_level = 0; struct inode *inode = dentry->d_inode; - u32 clusters; - loff_t newsize, saved_pos; + loff_t saved_pos, end; /* - * We sample i_size under a read level meta lock to see if our write - * is extending the file, if it is we back off and get a write level - * meta lock. + * We start with a read level meta lock and only jump to an ex + * if we need to make modifications here. */ for(;;) { ret = ocfs2_meta_lock(inode, NULL, meta_level); @@ -1763,87 +1749,38 @@ static int ocfs2_prepare_inode_for_write(struct dentry *dentry, saved_pos = *ppos; } - if (ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) { - loff_t end = saved_pos + count; + end = saved_pos + count; - /* - * Skip the O_DIRECT checks if we don't need - * them. - */ - if (!direct_io || !(*direct_io)) - break; + /* + * Skip the O_DIRECT checks if we don't need + * them. + */ + if (!direct_io || !(*direct_io)) + break; - /* - * Allowing concurrent direct writes means - * i_size changes wouldn't be synchronized, so - * one node could wind up truncating another - * nodes writes. - */ - if (end > i_size_read(inode)) { - *direct_io = 0; - break; - } - - /* - * We don't fill holes during direct io, so - * check for them here. If any are found, the - * caller will have to retake some cluster - * locks and initiate the io as buffered. - */ - ret = ocfs2_check_range_for_holes(inode, saved_pos, - count); - if (ret == 1) { - *direct_io = 0; - ret = 0; - } else if (ret < 0) - mlog_errno(ret); + /* + * Allowing concurrent direct writes means + * i_size changes wouldn't be synchronized, so + * one node could wind up truncating another + * nodes writes. + */ + if (end > i_size_read(inode)) { + *direct_io = 0; break; } /* - * The rest of this loop is concerned with legacy file - * systems which don't support sparse files. + * We don't fill holes during direct io, so + * check for them here. If any are found, the + * caller will have to retake some cluster + * locks and initiate the io as buffered. */ - - newsize = count + saved_pos; - - mlog(0, "pos=%lld newsize=%lld cursize=%lld\n", - (long long) saved_pos, (long long) newsize, - (long long) i_size_read(inode)); - - /* No need for a higher level metadata lock if we're - * never going past i_size. */ - if (newsize <= i_size_read(inode)) - break; - - if (meta_level == 0) { - ocfs2_meta_unlock(inode, meta_level); - meta_level = 1; - continue; - } - - spin_lock(&OCFS2_I(inode)->ip_lock); - clusters = ocfs2_clusters_for_bytes(inode->i_sb, newsize) - - OCFS2_I(inode)->ip_clusters; - spin_unlock(&OCFS2_I(inode)->ip_lock); - - mlog(0, "Writing at EOF, may need more allocation: " - "i_size = %lld, newsize = %lld, need %u clusters\n", - (long long) i_size_read(inode), (long long) newsize, - clusters); - - /* We only want to continue the rest of this loop if - * our extend will actually require more - * allocation. */ - if (!clusters) - break; - - ret = ocfs2_extend_file(inode, NULL, newsize, count); - if (ret < 0) { - if (ret != -ENOSPC) - mlog_errno(ret); - goto out_unlock; - } + ret = ocfs2_check_range_for_holes(inode, saved_pos, count); + if (ret == 1) { + *direct_io = 0; + ret = 0; + } else if (ret < 0) + mlog_errno(ret); break; } diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h index 36fe27f268ee..066f14add3a8 100644 --- a/fs/ocfs2/file.h +++ b/fs/ocfs2/file.h @@ -47,6 +47,8 @@ int ocfs2_do_extend_allocation(struct ocfs2_super *osb, struct ocfs2_alloc_context *data_ac, struct ocfs2_alloc_context *meta_ac, enum ocfs2_alloc_restarted *reason_ret); +int ocfs2_extend_no_holes(struct inode *inode, u64 new_i_size, + u64 zero_to); int ocfs2_lock_allocators(struct inode *inode, struct ocfs2_dinode *di, u32 clusters_to_add, u32 extents_to_split, struct ocfs2_alloc_context **data_ac,