Don't use inode->i_size directly, since we're not holding i_mutex.
This also fixes another bug, that i_size can change after it's checked
against 0 and then (i_size - 1) can be negative.
Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
---
fs/btrfs/ioctl.c | 7 ++++---
1 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 31fe6d4..6f2b257 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -972,6 +972,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
struct btrfs_super_block *disk_super;
struct file_ra_state *ra = NULL;
unsigned long last_index;
+ u64 isize = i_size_read(inode);
u64 features;
u64 last_len = 0;
u64 skip = 0;
@@ -997,7 +998,7 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
compress_type = range->compress_type;
}
- if (inode->i_size == 0)
+ if (isize == 0)
return 0;
/*
@@ -1022,10 +1023,10 @@ int btrfs_defrag_file(struct inode *inode, struct file *file,
/* find the last page to defrag */
if (range->start + range->len > range->start) {
- last_index = min_t(u64, inode->i_size - 1,
+ last_index = min_t(u64, isize - 1,
range->start + range->len - 1) >> PAGE_CACHE_SHIFT;
} else {
- last_index = (inode->i_size - 1) >> PAGE_CACHE_SHIFT;
+ last_index = (isize - 1) >> PAGE_CACHE_SHIFT;
}
if (newer_than) {
--
1.7.3.1
--
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