| Message ID | 4D841D34.3020101@linux.vnet.ibm.com |
|---|---|
| State | Superseded, archived |
| Headers | show |
On Fri, 2011-03-18 at 20:04 -0700, Allison Henderson wrote: > This patch modifies the truncate routines to support hole punching > Below is a brief summary of the patches changes: > > - Added end param to ext_ext4_rm_leaf > This function has been modified to accept an end parameter > which enables it to punch holes in leafs instead of just > truncating them. > > - Implemented the "remove head" case in the ext_remove_blocks routine > This routine is used by ext_ext4_rm_leaf to remove the tail > of an extent during a truncate. The new ext_ext4_rm_leaf > routine will now also use it to remove the head of an extent in the > case that the hole covers a region of blocks at the beginning > of an extent. > > - Added "end" param to ext4_ext_remove_space routine > This function has been modified to accept a stop parameter, which > is passed through to ext4_ext_rm_leaf. > > Signed-off-by: Allison Henderson <achender@us.ibm.com> This patch is reusing truncate code to handling free up spaces on disk in a range, not to the end of file. Reviewed-by: Mingming Cao <cmm@us.ibm.com> > --- > :100644 100644 b78b41f... 01a83a1... M fs/ext4/extents.c > fs/ext4/extents.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++------- > 1 files changed, 126 insertions(+), 19 deletions(-) > > diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c > index b78b41f..01a83a1 100644 > --- a/fs/ext4/extents.c > +++ b/fs/ext4/extents.c > @@ -2159,8 +2159,16 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, > ext4_free_blocks(handle, inode, NULL, start, num, flags); > } else if (from == le32_to_cpu(ex->ee_block) > && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { > - printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", > - from, to, le32_to_cpu(ex->ee_block), ee_len); > + /* head removal */ > + ext4_lblk_t num; > + ext4_fsblk_t start; > + > + num = to - from; > + start = ext4_ext_pblock(ex); > + > + ext_debug("free first %u blocks starting %llu\n", num, start); > + ext4_free_blocks(handle, inode, 0, start, num, flags); > + > } else { > printk(KERN_INFO "strange request: removal(2) " > "%u-%u from %u:%u\n", > @@ -2272,9 +2280,22 @@ fix_extent_len: > return err; > } > > + > +/* > + * ext4_ext_rm_leaf() Removes the extents associated with the > + * blocks appearing between "start" and "end", and splits the extents > + * if "start" and "end" appear in the same extent > + * > + * @handle: The journal handle > + * @inode: The files inode > + * @path: The path to the leaf > + * @start: The first block to remove > + * @end: The last block to remove > + */ > static int > ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, > - struct ext4_ext_path *path, ext4_lblk_t start) > + struct ext4_ext_path *path, ext4_lblk_t start, > + ext4_lblk_t end) > { > int err = 0, correct_index = 0; > int depth = ext_depth(inode), credits; > @@ -2314,31 +2335,88 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, > path[depth].p_ext = ex; > > a = ex_ee_block > start ? ex_ee_block : start; > - b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? > - ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; > + b = ex_ee_block+ex_ee_len - 1 < end ? > + ex_ee_block+ex_ee_len - 1 : end; > > ext_debug(" border %u:%u\n", a, b); > > - if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { > - block = 0; > - num = 0; > - BUG(); > + /* If this extent is beyond the end of the hole, skip it */ > + if (end <= ex_ee_block) { > + ex--; > + ex_ee_block = le32_to_cpu(ex->ee_block); > + ex_ee_len = ext4_ext_get_actual_len(ex); > + continue; > + } else if (a != ex_ee_block && > + b != ex_ee_block + ex_ee_len - 1) { > + /* > + * If this is a truncate, then this condition should > + * never happen because at least one of the end points > + * needs to be on the edge of the extent. > + */ > + if (end == EXT_MAX_BLOCK) { > + ext_debug(" bad truncate %u:%u\n", > + start, end); > + block = 0; > + num = 0; > + err = -EIO; > + goto out; > + } > + /* > + * else this is a hole punch, so the extent needs to > + * be split since neither edge of the hole is on the > + * extent edge > + */ > + else{ > + err = ext4_split_extents(handle, inode, > + b, path, 0); > + if (err) > + goto out; > + > + ex_ee_len = ext4_ext_get_actual_len(ex); > + > + b = ex_ee_block+ex_ee_len - 1 < end ? > + ex_ee_block+ex_ee_len - 1 : end; > + > + /* Then remove tail of this extent */ > + block = ex_ee_block; > + num = a - block; > + } > } else if (a != ex_ee_block) { > /* remove tail of the extent */ > block = ex_ee_block; > num = a - block; > } else if (b != ex_ee_block + ex_ee_len - 1) { > /* remove head of the extent */ > - block = a; > - num = b - a; > - /* there is no "make a hole" API yet */ > - BUG(); > + block = b; > + num = ex_ee_block + ex_ee_len - b; > + > + /* > + * If this is a truncate, this condition > + * should never happen > + */ > + if (end == EXT_MAX_BLOCK) { > + ext_debug(" bad truncate %u:%u\n", > + start, end); > + err = -EIO; > + goto out; > + } > } else { > /* remove whole extent: excellent! */ > block = ex_ee_block; > num = 0; > - BUG_ON(a != ex_ee_block); > - BUG_ON(b != ex_ee_block + ex_ee_len - 1); > + if (a != ex_ee_block) { > + ext_debug(" bad truncate %u:%u\n", > + start, end); > + err = -EIO; > + goto out; > + } > + > + if (b != ex_ee_block + ex_ee_len - 1) { > + ext_debug(" bad truncate %u:%u\n", > + start, end); > + err = -EIO; > + goto out; > + } > } > > /* > @@ -2369,7 +2447,13 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, > if (num == 0) { > /* this extent is removed; mark slot entirely unused */ > ext4_ext_store_pblock(ex, 0); > - le16_add_cpu(&eh->eh_entries, -1); > + } else if (block != ex_ee_block) { > + /* > + * If this was a head removal, then we need to update > + * the physical block since it is now at a different > + * location > + */ > + ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a)); > } > > ex->ee_block = cpu_to_le32(block); > @@ -2385,6 +2469,27 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, > if (err) > goto out; > > + /* > + * If the extent was completely released, > + * we need to remove it from the leaf > + */ > + if (num == 0) { > + if (end != EXT_MAX_BLOCK) { > + /* > + * For hole punching, we need to scoot all the > + * extents up when an extent is removed so that > + * we dont have blank extents in the middle > + */ > + memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * > + sizeof(struct ext4_extent)); > + > + /* Now get rid of the one at the end */ > + memset(EXT_LAST_EXTENT(eh), 0, > + sizeof(struct ext4_extent)); > + } > + le16_add_cpu(&eh->eh_entries, -1); > + } > + > ext_debug("new extent: %u:%u:%llu\n", block, num, > ext4_ext_pblock(ex)); > ex--; > @@ -2425,7 +2530,8 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path) > return 1; > } > > -static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) > +static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, > + ext4_lblk_t end) > { > struct super_block *sb = inode->i_sb; > int depth = ext_depth(inode); > @@ -2464,7 +2570,8 @@ again: > while (i >= 0 && err == 0) { > if (i == depth) { > /* this is leaf block */ > - err = ext4_ext_rm_leaf(handle, inode, path, start); > + err = ext4_ext_rm_leaf(handle, inode, path, > + start, end); > /* root level has p_bh == NULL, brelse() eats this */ > brelse(path[i].p_bh); > path[i].p_bh = NULL; > @@ -3676,7 +3783,7 @@ void ext4_ext_truncate(struct inode *inode) > > last_block = (inode->i_size + sb->s_blocksize - 1) > >> EXT4_BLOCK_SIZE_BITS(sb); > - err = ext4_ext_remove_space(inode, last_block); > + err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCK); > > /* In a multi-transaction truncate, we only make the final > * transaction synchronous. -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index b78b41f..01a83a1 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2159,8 +2159,16 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode, ext4_free_blocks(handle, inode, NULL, start, num, flags); } else if (from == le32_to_cpu(ex->ee_block) && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) { - printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n", - from, to, le32_to_cpu(ex->ee_block), ee_len); + /* head removal */ + ext4_lblk_t num; + ext4_fsblk_t start; + + num = to - from; + start = ext4_ext_pblock(ex); + + ext_debug("free first %u blocks starting %llu\n", num, start); + ext4_free_blocks(handle, inode, 0, start, num, flags); + } else { printk(KERN_INFO "strange request: removal(2) " "%u-%u from %u:%u\n", @@ -2272,9 +2280,22 @@ fix_extent_len: return err; } + +/* + * ext4_ext_rm_leaf() Removes the extents associated with the + * blocks appearing between "start" and "end", and splits the extents + * if "start" and "end" appear in the same extent + * + * @handle: The journal handle + * @inode: The files inode + * @path: The path to the leaf + * @start: The first block to remove + * @end: The last block to remove + */ static int ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, - struct ext4_ext_path *path, ext4_lblk_t start) + struct ext4_ext_path *path, ext4_lblk_t start, + ext4_lblk_t end) { int err = 0, correct_index = 0; int depth = ext_depth(inode), credits; @@ -2314,31 +2335,88 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, path[depth].p_ext = ex; a = ex_ee_block > start ? ex_ee_block : start; - b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? - ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; + b = ex_ee_block+ex_ee_len - 1 < end ? + ex_ee_block+ex_ee_len - 1 : end; ext_debug(" border %u:%u\n", a, b); - if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { - block = 0; - num = 0; - BUG(); + /* If this extent is beyond the end of the hole, skip it */ + if (end <= ex_ee_block) { + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = ext4_ext_get_actual_len(ex); + continue; + } else if (a != ex_ee_block && + b != ex_ee_block + ex_ee_len - 1) { + /* + * If this is a truncate, then this condition should + * never happen because at least one of the end points + * needs to be on the edge of the extent. + */ + if (end == EXT_MAX_BLOCK) { + ext_debug(" bad truncate %u:%u\n", + start, end); + block = 0; + num = 0; + err = -EIO; + goto out; + } + /* + * else this is a hole punch, so the extent needs to + * be split since neither edge of the hole is on the + * extent edge + */ + else{ + err = ext4_split_extents(handle, inode, + b, path, 0); + if (err) + goto out; + + ex_ee_len = ext4_ext_get_actual_len(ex); + + b = ex_ee_block+ex_ee_len - 1 < end ? + ex_ee_block+ex_ee_len - 1 : end; + + /* Then remove tail of this extent */ + block = ex_ee_block; + num = a - block; + } } else if (a != ex_ee_block) { /* remove tail of the extent */ block = ex_ee_block; num = a - block; } else if (b != ex_ee_block + ex_ee_len - 1) { /* remove head of the extent */ - block = a; - num = b - a; - /* there is no "make a hole" API yet */ - BUG(); + block = b; + num = ex_ee_block + ex_ee_len - b; + + /* + * If this is a truncate, this condition + * should never happen + */ + if (end == EXT_MAX_BLOCK) { + ext_debug(" bad truncate %u:%u\n", + start, end); + err = -EIO; + goto out; + } } else { /* remove whole extent: excellent! */ block = ex_ee_block; num = 0; - BUG_ON(a != ex_ee_block); - BUG_ON(b != ex_ee_block + ex_ee_len - 1); + if (a != ex_ee_block) { + ext_debug(" bad truncate %u:%u\n", + start, end); + err = -EIO; + goto out; + } + + if (b != ex_ee_block + ex_ee_len - 1) { + ext_debug(" bad truncate %u:%u\n", + start, end); + err = -EIO; + goto out; + } } /* @@ -2369,7 +2447,13 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, if (num == 0) { /* this extent is removed; mark slot entirely unused */ ext4_ext_store_pblock(ex, 0); - le16_add_cpu(&eh->eh_entries, -1); + } else if (block != ex_ee_block) { + /* + * If this was a head removal, then we need to update + * the physical block since it is now at a different + * location + */ + ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a)); } ex->ee_block = cpu_to_le32(block); @@ -2385,6 +2469,27 @@ ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, if (err) goto out; + /* + * If the extent was completely released, + * we need to remove it from the leaf + */ + if (num == 0) { + if (end != EXT_MAX_BLOCK) { + /* + * For hole punching, we need to scoot all the + * extents up when an extent is removed so that + * we dont have blank extents in the middle + */ + memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) * + sizeof(struct ext4_extent)); + + /* Now get rid of the one at the end */ + memset(EXT_LAST_EXTENT(eh), 0, + sizeof(struct ext4_extent)); + } + le16_add_cpu(&eh->eh_entries, -1); + } + ext_debug("new extent: %u:%u:%llu\n", block, num, ext4_ext_pblock(ex)); ex--; @@ -2425,7 +2530,8 @@ ext4_ext_more_to_rm(struct ext4_ext_path *path) return 1; } -static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start) +static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start, + ext4_lblk_t end) { struct super_block *sb = inode->i_sb; int depth = ext_depth(inode); @@ -2464,7 +2570,8 @@ again: while (i >= 0 && err == 0) { if (i == depth) { /* this is leaf block */ - err = ext4_ext_rm_leaf(handle, inode, path, start); + err = ext4_ext_rm_leaf(handle, inode, path, + start, end); /* root level has p_bh == NULL, brelse() eats this */ brelse(path[i].p_bh); path[i].p_bh = NULL; @@ -3676,7 +3783,7 @@ void ext4_ext_truncate(struct inode *inode) last_block = (inode->i_size + sb->s_blocksize - 1) >> EXT4_BLOCK_SIZE_BITS(sb); - err = ext4_ext_remove_space(inode, last_block); + err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCK); /* In a multi-transaction truncate, we only make the final * transaction synchronous.
This patch modifies the truncate routines to support hole punching Below is a brief summary of the patches changes: - Added end param to ext_ext4_rm_leaf This function has been modified to accept an end parameter which enables it to punch holes in leafs instead of just truncating them. - Implemented the "remove head" case in the ext_remove_blocks routine This routine is used by ext_ext4_rm_leaf to remove the tail of an extent during a truncate. The new ext_ext4_rm_leaf routine will now also use it to remove the head of an extent in the case that the hole covers a region of blocks at the beginning of an extent. - Added "end" param to ext4_ext_remove_space routine This function has been modified to accept a stop parameter, which is passed through to ext4_ext_rm_leaf. Signed-off-by: Allison Henderson <achender@us.ibm.com> --- :100644 100644 b78b41f... 01a83a1... M fs/ext4/extents.c fs/ext4/extents.c | 145 ++++++++++++++++++++++++++++++++++++++++++++++------- 1 files changed, 126 insertions(+), 19 deletions(-)